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322 Cards in this Set
- Front
- Back
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cartilage
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connective tissue that is soft and elastic, hardens and calcifies to bone, chondrin matrix secreted by chondrocytes, avascular and devoid of nerves, nourishment from capillaries in nearby connective tissue/bone by diffusion through surronding fluid
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compact vs. spongy bone
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compact: dense, no caivites
spongy: less dense, interconnecting lattice of bony spicules (trabeculae) |
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yellow vs. red marrow
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both: fill spongy cavities
yellow: inactive, filled with adipose red: blood cell formation function |
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long bone structure/function
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diaphysis: shaft of compact bone surrounding marrow cavity and surrounded by periosteum (muscle attachment)
epiphysis: spongy, thick ends around shaft with marrow epiphyseal plate: disk of cartilaginous cells that separate diaphysis from epiphysis and allow bone elongation |
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bone matrix components
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organic: proteins, mainly collagen fibers and glycoproteins
inorganic: calcium, phosphate, hydroxide (form into hydroxyapatite crystals which strengthen collagen), sodium, potassium, magnesium ions |
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osteons
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structural units of bony matrix
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Haversian canal
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canal filled with blood vessels, nerve, and lymph and surrounded by circles of bony matrix (lamellae)
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lacunae
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spaces interspersed within matrix that house mature bone cells (osteocytes-bone maintenance), canalicule radiate from each lacuna and these interconnect with each other and Haversian canals to allow nutrient and waste exchange from bone to blood
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osteoblasts vs. osteoclasts
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osteoblasts build up bone by organic secretion and osteoclasts are large, multinucleate cells that cause bone break down
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endochondral ossification
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existing cartilage is replaced by bone (long bone)
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intramembranous ossification
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mesenchymal (embryonic, undifferentiated) connective tissue is transformed into/replaced by bone
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immovable joints
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joints that don't move relative to each other
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movable joints
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move relative to each other and additionally supported/strengthened by ligaments, have synovial capsule that encloses joint cavity with synovial fluid with facilitates movement (articular cartilage against each surface also reduces friction)
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skeletal muscle
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voluntary movements by somatic nervous system, pundle of parallel fibers of multinucleate cells (fusion of several embryonic cells)
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myofibrils
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embedded in muscle fibers which contain the sarcomere units, have a surrounding sarcoplasmic reticulum that stores calcium ions, membrane of myofibril is sarcolemma and is capable of propagating action potential
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transverse tubules
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oriented perpendicular to myofibrils, channels for ion flow throughout the nuscle fibers (everything can get innervated, helps propagate action potential)
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red vs. white fibers
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red: slow-twitch, high myoglobin, many mitochondria, energy dervied from aerobic respiration, capable of sustained/vigorous activity
white: fast-twitch, anaerobic, less myoglobin and fewer mitochondria, greater rate of contraction but fatigue more easily |
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sarcomere bands
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Z line: define sarcomere boundaries, where actin is connected
M line: center line, only myosin I band: only actin between two sarcomeres H zone: thick filaments only in center around M line A band: spans entire thick filament range (includes overlap with actin) |
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action potential in muscle cell
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SR releases calcium, binds to troponin, twists tropomyosin to reveal myosin binding sites, myosin heads binds and pull actin together and shorten sarcomere, ATP hydrolysis powers contraction, bound ATP causes dissociation of actin and myosin, relaxation when calcium pumped back into SR
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stimulus intentsity
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individual muscle fibers are all-or-nothing, but whole muscles can have contraction strenght increased by activation of more individual fibers (threshold), maximal when all fibers reach threshold; tonus is the fact that muscles are always in a continual low-grade state of contraction
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simple twitch
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response of single muscle fiber to brief stimulus at or above threshold; latent period is time between stimulation and onset of contraction, contraction period is the contraction that reaches maximal force, relaxation period is when muscle becomes unresposnive to stimulus (absolute refractory)-after this there is a relative refractory period that can be stimulated with an extra strong stimulus
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summation and tetanus
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when fibers of a muscle are exposed to very frequent stimuli the contractions can combine and become stronger and more prolonged (frequency summation), muscle can't relax between, tetanus is when they add together to give an overly strong contraction which fatigues muscles
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smooth muscle
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involuntary actions by autonomic nervous system, only one centrally located nucleus, lack sarcomere organization (have actin/myosin still), contractions are slower and capably of longer sustainment
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cardiac muscle
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cardiace muscle fibers possess skeletal and smooth muscle fiber characteristics, sarcomeres (striated)
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creatine phosphate
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during rest it is produced in a reaction (make creatine phosphate), during exercise ATP is resynthesized from creatine phosphate
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connective tissue
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bind and support other tissue, includes sparsely populated cells in a ground substance
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loose connective tissue
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binds epithelium to underlying tissues, holds organs in place, cells are mainly fibroblasts which secrete the matrix and macrophages which engulf bacteria and dead cells by phagocytosis
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loose connective tissue fibers
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collagenous fibers (collagen, tensile strength), elastic fibers (elastin, resilience), reticular fibers (branched, tightly woven, join connective tissue to adjoining tissue)
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dense connective tissue
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high proportion of collagenous fibers organized in parallel bundles for great strength; form tendons (attach muscle to bone) and ligaments (hold bones together at joints)
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origin/insertion (bone)
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the end of the muscle attached to the stationary bone (proximal bone), insertion is the end of the muscle contacting the moving bone (distal)
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flexor vs. extensor muscle
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flexor works to decrease the angle of a joint while extensor increases angle (straighten joint)-antagonistic pair
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abductor vs. adductor
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abductor moves part away from midline while adductor moves it toward the midline
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human digestive tract
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oral cavity, pharynx, esophagus, stomach, small intestine, large intestine (accessory organs: salivary glands, pnacreas, liver)
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epithelium
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free surface exposed to air or liquid (may be ciliated) and other side connective to basement membrane; protect/line organs, absorb/secrete solutions
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simple epithelium
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single layer of cells
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stratified epithelium
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multiple layers of cells
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pseudostratified epithelium
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single-layered but appears stratified because cells vary in height
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epithelial cell shapes
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cuboidal, columnar, squamous
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mucous membrane
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specialized epitheliam that lines most body cavities
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mechanical digestion
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breakdown of large food particles into smaller ones, increases surface area for more efficient enzymatic breakdown
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chemical digestion in mouth
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enzymatic breakdown of macromolecules into smaller molecules when salivary glands secrete saliva as a nervous reflex response; saliva lubricates the food for easier swallowing and provides a solvent for food particles
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salivary amylase
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hydrolyzes starch into simple sugars in the mouth, since the time in the mouth is short only some hydrolysis takes place
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tongue
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taste buds, manipulates food during chewing, rolls it into a bolus (ball), pushes it into the pharynx
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pharynx
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common pathway for breathing and swallowing, epiglottis covers trachea during swallowing
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esophagus
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muscular tube that moves food down by rhythmic waves of involuntary muscular contractions (peristalis), lower esophageal sphincter is a muscular ring at the bottom that opens for food and closes after it goes into stomach to prevent regurgitation
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stomach
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stores and partially digests food, walls are comprised of thick gastric mucosa (includes the gastric and pyloric glands)
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gastric glands
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stimulated by nervous impulses from brain (response of sight, taste, smell of food); include mucous cells, chief cells, and parietal cells
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mucous cells
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secrete mucous to protect stomach lining from acidic environment (gastric juice)
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gastric juice
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made up of secretions from chief cells (pepsinogen-zymogen of pepsin a protein-hydrolyzing enzyme) and parietal cells (secrete HCl which kills bacteria, dissolves intercellular material holding food together and facilitates conversion to pepsin)
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pepsin
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hydrolyzes specific peptide bonds to form fragments of protein
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gastrin
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secreted by pyloric glands in response to food substances, it stimulates gastric glands to secrete more HCl, stimulates stomach muscle contractions to churn food (produces acidic/semi-fluid chyme mixture)
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pyloric sphincter
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regulates passage of chyme from stomach to small intestine by alternating contractions and relaxations, most mutrients are absorbed in small intestine although alcohol and certain drugs can be absorbed through stomach wall
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small intestine
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duodenum, jejunum, ileum; villi extend out of the intestinal submucosa and microvilli extend off of those (increase SA)
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intestinal mucose and carbohydrates
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secretes maltase, lactase, sucrase (sugar breakdown to monosaccharides) and peptidase (protein hydrolysis)
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secretin
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released by duodenum in response to acidic chyme, stimulates pancreas to secrete pancreatic juice
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pancreatic juice
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alkaline fluid (bicarbonate) that helps maintain pH high enough so small intestine enzymes can function (neutralizes acid), secretes proteases and other enzymes that digest lipids and carbohydrates
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trypsinogen
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secrete by pancreas, converted to trypsin by intestinal gland secreted enterokinase
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chymotrypsinogen
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pancreatic zymogen that is converted to chymotrypsin by trypsin cleavage
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carboxypeptidase
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zymogen secreted by pancreas that is activated by trypsin cleavage along with aminopeptidase from the intestinal glands digests polypeptides into amino acids
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cholecystokinin
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secreted into bloodstream by duodenum inresponse to chyme, stimulates pancreatic enzyme secretion and bile release
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bile
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alkaline fluid, made in liver/stored in gall bladder, released into duodenum, made up of bile salts, bile pigments, and cholesterol; bile salts help to solubilze fat by emulsifying fat globules by forming micelles, amount of bile released proportional to amount of fat ingested
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lipases
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hydrolyze fat into glycerol and fatty acids, facilitated by micelle formation (more surface area)
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enterogastrone
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hormone secreted by duodenum when chyme is very fatty and inhibits stomach peristalis so chyme is released from stomach into duodenum more slowly (fat is the longest to digest)
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nervous system regulation of digestion
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parasympathetic stimulates, sympathetic inhibits
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small macromolecule absorption by jejunum/ileum
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monosaccharides absorbed via active transport/facilitated diffusion, amino acids by active transport into epithelial cells and diffuse directly into intestinal capillaries and into hepatic portal vein
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larger molecule intestinal absorption
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larger fatty acids, glycerol, and cholesterol diffuse into mucosal cells
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chylomicrons
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FAs recombine with glycerol to form TAGs and are packaged with phosphoglycerides and cholesterol into these protein-coated droplets, secreted into tiny lymph vessels in villi (lacteals), converges with venous blood in thoracic duct in neck
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chylomicron processing
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contents are sent into the blood stream and delivered to liver for repackaging as LDLs, VLDLs, or HDLs (lipoproteins)
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fat-soluble vitamins
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A, D, E, K absorbed with fats
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water-soluble vitamins
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B complexes, C absorbed by simple diffusion into circulatory system (dissolved in intestinal aqueous fluid)
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large intestine
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cecum, colon, rectum (anus)
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cecum
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outshoot from small intestine, connected to appendix (lymphoid tissue)
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colon
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functions in absorption of salts and any left over water from small intestine (diarrhea occurs if matter moves too quickly through colon, constipation when material moves too slow as too much water is reabsorbed)
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rectum
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stores feces (bacteria, water, undigested food, unabsorbed digestive secretions like enzymes and bile); anus is the opening where wastes are eliminated (separated from rectum by 2 sphincters
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pancreatic amylase
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produced in small intestine, secreted into small intestine to hydrolyze starch to maltose
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dipeptidases
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made in intestinal glands and secreted into small intestine to hydrolyze pairs of amino acids
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anatomy of breathing
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external nares, nasal cavities (filtered by mucous and nasal hairs), pharynx, larynx (glottis is larynx opening), trachea, bronchi, bronchioles, alveoli (surfactant to lower surface tension and facilitate gas exchange)
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ventilation
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pressure changes in thoracic cavity (heart and lungs)
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diaphragm
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separates abdomen from thoracic cavity
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visceral and parietal pleura
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visceral pleura surroung lungs first then parietal pleura second, intrapleural space in the middle that contains thing layer of fluid, pressure in this space keeps lungs from collapsing
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inhalation
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diaphragm contracts and flattens, external intercostal muscles contract (push rib cage and chest wall up and out), volume in cavity increases and intrapleural pressure reduces and lungs fill with air
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exhalation
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lungs and chest wall elastically recoil as the diaphragm and external intercostal muscles relax and the chest wall moves inward, air pressure in intrapleural space increases and lungs deflate, force exhalation contracts internal intercostal muscles and pulls rib cage down, surfactant prevents alveolar collapse
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medulla oblongata and breathing
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ventilation is regulated by neurons in this part of the brain (rhythmic signals), modified by chemoreceptors (aorta) that respond to pH and CO2 in blood to increase or decrease breathing rate
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conscious breathing
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cerebrum can control breathing at times, but medulla oblongata can override this attempt when CO2 levels get too high (hold breath)
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hyperventilation
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lowers pCO2 too much, chemoreceptors sense this and send signals to respiratory center to temporarily inhibit breathing
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vital capacity
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maximum amount of air that can be forcibly inhaled and exhaled from lungs
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tidal volume
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amount of air normally inhaled and exhaled with each breath
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residual volume
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air that always remains in lungs to prevent alveolar collapse
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expiratory reserve volume
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the amount of air that can still be forcibly exhaled after normal exhalation
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total lung capacity
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vital capacity plus residual volume
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gas exchange
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pulmonary capillaries gain O2 from alveoli (bind with Hb) and lose CO2 (down concentration gradient)
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high altitudes compensation
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more difficult to get sufficient oxygen (lower pO2), hyperventilation, increase in red blood cells (polycythemia), decreased Hb affinity for release in tissues, or greater vascularization of peripheral tissues
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cardiovascular system
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consists of strong 4-chambered heart, blood vessels, and blood itself
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blood pumping pathway
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right atrium, right ventricle, pulmonary artery, lungs, pulmunary vein, left atrium, left ventricle, aorta (coronary arteries and veins), arteries, arterioles, capillaries, venules, veins (inferior vena cava or jugular then superior vena cava)
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portal systems
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blood travels through 2 capillary beds before returning to heart: liver (hepatic portal circulartion), kidneys, brain (hypophyseal portal circulation)
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heart compartments
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right and left side act as separate pumps, atria are thin-walled and ventricles are strong and muscular, the left ventrical is more muscular than the right as it must pump at a greater force (higher resistance circuit)
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atrioventricular valves
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located between atria and ventricles, prevent backflow to atria; tricuspid is on right (3 cusps) mitral on left (2 cusps)
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semilunar valves
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three cusps, between left ventricle and aorta and right ventrical and pulmonary artery
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systole-diastole cycle
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systole is when ventricles contract and diastole is when the muscle relaxes and blood refills heart
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cardiac output
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total volume of blood pumped by left ventricle per minute (cardiac output = heart rate (# beats/min) x stroke volume (volume pumped by left ventricle each contraction)
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contraction control
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no stimulation from nervous system, origination in sinoatrial node (wall of right atrium), impulse goes through both atria so they contract simultaneously, the impulse arrives at the antrioventricular node which conducts slowly so atrial contraction can occur and ventricles can fill with blood, impulse is carried through bundle of His (branches into right and left bundles throughPurkinje fibers in the walls of the ventricles to generate a strong contraction)
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EKG
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P wave occurs right before atrial contraction, QRS right before ventricles contract, T represents ventricle repolarization after contraction
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autonomic nervous system
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modifies heart contraction rate, parasympathetic system innervates heart via vagus nerve (decrease rate), sympathetic innervates through cervical and upper thoracic ganglia (increase, adrenal medulla can secrete epinephrine to increase heart rate
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blood vessels
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arteries: thick-walled, muscular, elastic vessels
veins: thin-walled, inelastic, dependent on skeletal muscle compression (not heart pumping), have valves to prevent backflow (gravity, especially in legs) capillaries: single layer endothelial cells, exchange of gases, nutrients, enzymes, hormones, wastes; smallest diameter (red blood cells often travel through single-file |
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blood pressure
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measured by sphygmomanometer, gradually drops from arteries to capillaries to veins because of greater friction between blood and walls of vessels and increase in cross-sectional area from many capillaries in beds
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blood composition
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55% plasma aqueous mixture of nutrients, salts, respiratory gases, wastes, hormones, and blood proteins (immunoglobulins, albumin, fibrinogen...), 45% cellular erythrocytes, leukocytes, platelets
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erythrocytes
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stem cells made in bone marrow, lose nuclei, mitochondria, and organelles (anaerobic, get ATP from glycolysis), 120 days in circulation then phagocytized by cells in liver and spleen
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leukocytes
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produced in marrow of long bones, increase in number when body battles infection, made up of granular leukocytes, lymphocytes, and monocytes
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granular leukocytes
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neutrophils, basophiles, eosinophils, role in inflammation, allergic reactions, pus formation, and destruction of invading bacteria and parasites
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lymphocytes
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role in immune response, produced in lymph nodes, tonsils, spleen, appendix, thymus, and bone marrow; B and T lymphocytes
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monocytes
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migrate from blood to tissue where they differentiate into macrophages that phagocytize foreign matter/organisms (monocytes have less ability to phagocytize material)
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platelets
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cell fragments formed in bone marrow, lack nuclei, function in clot formation, many per blood volume
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erythroblastosis fetalis
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rh- woman has an rh+ baby, makes antibodies to the antigen and then the next baby will be exposed to antibodies if it is rh+
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Bohr effect
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hemoglobin binds to CO2 generated from tissues (only small amount, most is bicarbonate ion in plasma) and protons (help to release O2 from Hb), so high concentrations of bicarbonate and H+ decreases Hb affinity, in lungs bicarbonate and proton reassociate to form CO2 and H2O for exhalation
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nutrient transport
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amino acids and sugars are absorbed in blood stream through intestinal capillaries, transported to liver for processing by hepatic portal vein, transported throughout the body; fats enter the lymphatic system and drain into the bloodstream at the neck (no liver), metabolic waste diffuses into capillaries for removal
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hydrostatic vs. osmotic pressure
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hydrostatic pressure is greater on the arteriole side of a capilary bed than in the surrounding tissue fluids (moves out), osmotic pressure is greater in the tissue fluid as blood has higher solute concentration (causes fluid movement into the venule side of the capillaries because the venule side has lower hydrostatic pressure); most fluid that is forced out is reabsorbed and what is left is brought back to the blood by the lymphatic system
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clotting
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exposed collagen causes platelets to be attracted and activate other platelets by growth factors to form a paltelet plus, platelets and the damaged tissue release thromboplastin which along with calcium and vitamin K convert prothrombin to thrombin, thrombin converts fibrinogen to fibrin to coat damaged area (red blood cells become trapped to form a clot)
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antibody function
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either attract other cells like leukocytes to phagocytize antigen or cause agglutination of antigens into large, insoluble complexes (facilitates removal by phagocytic cells)
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antibody structure
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two heavy chains with two light chains, a variable region that recognizes one antigen, a constant region important for the process of destroying antigens (five classes are IgM, IgA, IgD, IgG, and IgE)
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humoral response
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production of antibodies by B cells that originate in bone marrow and differentiate in spleen, lymph nodes, and other lymphatic organs
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primary response
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exposure to an antigen causes specific B cells to proliferate and some of the daughter cells become memory cells and other become plasma (effector) cells
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plasma cells
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produce and release antibodies against the antigen 7-10 days after exposure
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memory cells
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long lived cells in the bloodstream (possibly permenant), elicit a more immediate response upon subsequent exposure (secondary response)
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active immunity
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production of one's own antibodies (possibly after vaccination, the introduction of a weakened, inactive, or related form of a particular antigen)
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passive immunity
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transfer of antibodies from one organism to another (passively or by inject), very short-lived and only remains for the time the antibodies circulate in the blood (occurs across the palcenta)
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cell-mediated immunity
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combat fungal and viral infection are T cells which develop in bone marrow and mature/proliferate in thymus, act mainly against body's own cells infected by fungus or virus
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cytotoxic T cells
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destroy antigens directly
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helper T cells
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activate other B and T cells and nonlymphocyte cells (macrophages) by secreting lymphokines (interleukins)
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suppressor T cells
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regulate other B and T cells to decrease their activity against antigens
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T cell secondary response
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some T cells initially differentiate into memory cells, so during another exposure the memory cells proliferate greatly and make many cytotoxic T cells
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T cells and allergic reactions/organ transplant rejection
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pollens/certain foods can elicit response, tissue from a donor may not be recognized and cytotoxic T cells destroy the foreign cells (autoimmune is when body destroys its own cells)
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nonspecific defense mechanisms
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1. skin as a physical barrier against bacterial invasion, sweat contains enzyme that attacks bacterial cell walls
2. passages are lined with ciliated mucous-coated epithelia to filter/trap foreign particles 3. macrophages engulf/destroy foreign particles |
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inflammatory response
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response to physical damage, injured cells release histamine, blood vessels dilate to increase blood flow to damaged region, granulocytes are attracted to injury site and phagocytize antigenic material (usually get a fever)
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interferons
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produced by cells under viral attack, diffuse to other cells to help prevent viral spread
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lymphatic system
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secondary circulatory system that transports excess interstitial fluid (lymph) to keep fluid levels constant (also chylomicrons in small intestine), capillaries are closed at one end and lead into other lymph vessels that have valves to prevent lymph backflow, movement by skeletal muscle contraction and lymph vessel rhythmic contraction
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lymph nodes
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swellings along lymph vessels containing phagocytic leukocytes that filter lymph by removing and destroying foreign particles
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kidney vasculature
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renal artery carries blood to afferent arteriole to glomerulus (capillary bed) to efferent arteriole to the vasa recta capillary bed that enmeshes the nephron, finally converges into the renal vein
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nephron structure
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Bowman's capsule is where glomerulus is drained, the filtrate goes into proximal convoluted tubule, then descending limb to loop of Henle, then ascending limb to distal convoluted tubule and finally to collecting duct (Bowman's capsule and convoluted tubules are in cortex while loop of Henle is in medulla and end of collecting duct is in pelvis region)
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kidney filtration
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blood pressure forces 20% of blood plasma into Bowman's capsule, fluids and small solutes enter and large molecules remain in blood
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nephron secretion
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secretes acids, bases, ions from interstitial fluid into filtrate (passive and active to maintain blood pH, potassium concentration in blood, and nitrogenous waste concentration in filtrate
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proximal convoluted tubule
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virtually all glucose, amino acids, and other organics are reabsorbed by active transport, 60-70% sodium is reabsorbed (Cl- and water passively follow), protons are actively pumped into the nephron tubule
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descending limb of Henle
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the solute concentration increases towards the outer and inner medulla (salts and urea) which causes more water to diffuse out (no salts can get out)
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ascending limb of Henle
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not permeable to water, at the bottom sodium passively diffuses out and Cl- follows, and towards the top sodium is actively pumped out of tube and Cl- follows, some urea leaking out of collecting duct is absorbed at the bottom
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distal convoluted tubule
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sodium is still actively pumped out, nitrogen and potassium can be actively pumped in to filtrate, later more sodium is pumped out actively and protons and potassium can be pumped in
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collecting duct
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mainly water reabsorption under control of ADH, some urea leaks out
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aldosterone
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produced by adrenal cortex, stimulates reabsorption of Na+ from collecting duct (increases water reabsorption) and potassium secretion, higher water reabsorption causes increase in blood volume and pressure
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Addison's disease
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aldosterone is produced insufficiently or not at all, overexcretion of urine with high sodium, leads to drop in blood pressure
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ADH
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made in hypothalamus and stored in posterior pituitary, induces water reabsorption in collecting duct by increasing its permeability to water, high solute concentration in blood increases ADH secretion and low solute reduces its secretion; alcohol and caffeine inhibit secretion (excess excretion of dilute urine and dehydration)
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excretion
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after collecting duct urine is composed of urea, uric acid, and other wastes, goes into ureter to bladder and out through urethra
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liver and glucose levels
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high glucose in blood, liver converts it to storage as glycogen; low glucose in blood, liver breaks down glycogen to glucose or creates glucose from non-carbohydrate precursors (gluconeogenesis)
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liver and nitrogenous wastes
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excess amino acids from small intestine are bnrought to liver where the amino group is removed by deamination to give ammonia, the urea cycle combines the ammonia with CO2 to make urea (excreted by kidneys)
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other liver functions
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detoxification of toxins, storage of iron and vitamin B12, destruction of old erythrocytes, synthesis of bile, synthesis of various blood proteins, defense against various antigens, beta-oxidation of fatty acids to ketones, interconversion of carbohydrates, fats, and amino acids
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large intestine and salts
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absorbs water and sodium not previously absorbed in small intestine, excess calcium, iron, and other salts are excreted into colon and eliminated with feces
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skin layers
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epidermis, dermis, subcutaneous layer (hypodermis)
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epidermis
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epidermis have five cellular layers, deepest layer continually proliferates and pushes older cells upward, as older cells reach the outermost layer they die, lose their nuclei, and transform into squames of keratin (tightly packed cells, protective barrier against microbial attack), hair projects above surface of epithelium and sweat pores open to surface
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dermis
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loose connective tissue (papillary layer) and dense connective tissue (reticular layer), has the sweat glands, the sense organs, blood vessels, and bulbs of hair follicles
|
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|
hypodermis
|
loose connective tissue, many fat cells, binds outer skin layers to body, fat insulates body
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|
skin functions
|
protection from microbial invasion, environmental stress, melanocytes protect from UV, receives stimuli like pressure and temperature, excretes excess salts, and water from body, helps control conservation/release of heat
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|
sweat
|
water, dissolved salts, urea through sweat pores, as sweat evaporates skin is cooled (under nervous control)
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skin hair (fur)
|
entraps and retains warm air at skin's surface
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epinephrine and heat
|
increase metabolic rate, thus more heat produced
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muscles and heat
|
contraction (shivering) produces heat
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blood vessels and heat
|
constriction in dermis retains heat and dilation dissipates heat
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hibernation
|
type of torpor where animal remains dormant, lowering metabolic rate and allowing body temperature to fall below normal
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endocrine glands
|
pituitary, hypothalamus, thyroid, parathyroids, adrenal, pancreas, testes, ovaries, pineal, kidneys, gastrointestinal glands, heart, thymus
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growth hormone
|
secreted by anterior pituitary to promote bone/muscle growth, inhibit glucose uptake by certain cells, stimulates breakdown of fatty acids to conserve glucose, stimulated by the hypothalamic releasing hormone GHRH, inhibited by somatostatin, secretion under neural/metabolic control, deficiency of GH leads to dwarfism (overproduction leads to gigantism)
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acromegaly
|
disorder caused by overproduction of GH where there is a disproportionate growth of bone in certain areas
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prolactin
|
stimulates milke production and secretion in female mammary glands
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adrenocorticotropic hormone (ACTH)
|
stimulates adrenal cortex to synthesize/secrete glucocorticoids, regulated corticotropin releasing factor, anterior pituitary
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thyroid-stimulating hormone (TSH)
|
stimulates thyroid gland to absorb iodine then synthesize/release thyroid hormone, regulated by TRH, anterior pituitary
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luteinizing hormone (LH)
|
females: stimulates ovulation/formation of corpeus luteum
males: stimulates interstital cells to make testosterone regulated by estrogen, progesterone, gonadotropin releasing hormone, anterior pituitary |
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follicle-stimulating hormone (FSH)
|
females: maturation of ovarian follicles
males: maturation of seminiferous tubules and sperm production regulated by estrogen and GnRH, anterior pituitary |
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oxytocin
|
hypothalamus (stored in posterior pituitary), secreted during childbirth to increase strength/frequency of uterine contractions, also induced by sucking to stimulate milk secretion in mammary glands
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antidiuretic hormone (ADH)
|
posterior pituitary stored, increase collecting duct permeability to increase blood volume or to lower plasma osmolarity
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hypothalamic-hypophyseal portal system
|
blood from hypothalamus flows through portal vein into a second capillary network so that hypothalamus hormones can be released and then absorbed by anterior pituitary
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pathway for cortical hormone activation
|
hypothalamus secretes CRF to allow anterior pituitary to secrete ACTH which stimulates the adrenal cortex to make cortical hormones (negative feedback on hypothalamus and anterior pituitary if overproduced)
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hypothalamys interactions with posterior pituitary
|
neurosecretory cells in hypothalamus synthesize oxytocin and ADH (transport to posterior pituitary via axons)
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thryoid hormones
|
thyroxine and triiodothyronine, derived from iodination of tyrosine, necessaru for growth/neurological development of children, increased rate of cellular respiration/rate of protein and fatty acid synthesis/degradation in many tissues, high plasma levels inhibit TRH and TSH in negative feedback
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hypothyroidism
|
caused by inflammation of the thyroid or iodine deficiency, thyroid hormones undersecreted, slowed heart and respiratory rate, fatigue, cold intolerance, weight gain (young infants are mentally retarded)
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hyperthyroidism
|
thyroid is overstimulated, increased metabolic rate, feelings of excessive warmth, profuse sweating, palpitations, weight loss, goiter
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calcitonin
|
thyroid, decreases plasma Ca2+ concentration (inhibits calcium release from bone), secretion regulated by plasma calcium levels
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parathyroid hormone (PTH)
|
parathyroid, stimulates calcium release from bone to deposit in plasma and decreases calcium excretion in kidneys, converts vitamin D into active form (stimulates intestinal calcium absorption), regulated by amount of calcium in plasma (negative feedback)
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corticosteroids
|
synthesized by the adrenal cortex in repsonse to stress signaled by ACTH, these a deribed from cholesterol and include glucocorticoids, mineralocorticoids, and cortical sex hormones
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glucocorticoids
|
examples are cortisol and cortisone, raise blood glucose levels (promote gluconeogenesis) and decrease protein synthesis, reduce body's immunological and inflammatory responses
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mineralocorticoids
|
aldosterone is an example that causes active reabsorption of sodium (passive water) in the nephron, causes rise in blood volume/pressure, aldosterone stimulates secretion of potassium/hydrogen ion (excreted)
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renin-angiotensin system
|
if blood volume falls the juxtaglomerular cells of the kidney produce renin (enzyme that converts the plasma protein angiotensinogen to angiotensin I), angiotensin I is converted to angiotensin II, stimulates adrenal cortex to secrete aldosterone (revival of blood volume removes initial stimulus for renin production
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cortical sex hormones
|
adrenal cortex secretes small amounts of androgens (male sex hormones) in both sexes, small effect in male (testes are more significant), can lead to female masculinization if overproduced
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adrenal medulla
|
secretory cells are specialized sympathetic nerve cells that secrete epinephrine and norepinephrine (catecholamines)
|
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|
epinephrine
|
increases conversion of glycogen to glucose (rise in blood glucose and increase in basal metabolic rate), along with norepinephrin increase rate/strength of heartbeat, dilate and constrict blood vessels to increase blood supply to skeletal muscle, the heart, the brain (decreases blood supply to kidneys, skin, digestive tract)
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glucagon
|
pancrease endocrine, stimulates protein/fat degradation, conversion of glycogen to glucose, and gluconeogenesis (all increase blood glucose), stimulated by decrease in blood glucose and gastrointestinal hormones like CCK and gastrin, inhibited by high plasma glucose
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insulin
|
protein hormone, stimulated by high glucose, stimulates uptake of glucose by muscle and adipose cells and storage of glucose as glycogen in muscle and liver cells (lower blood glucose), stimulates the synthesis of fats from glucose and uptake of amino acids
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hypoglycemia vs. hyperglycemia
|
low blood glucose levels, high blood glucose levels
|
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ketoacidosis
|
lowering of blood pH due to excess keto acids and fatty acids in plasma
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somatostatin
|
pancreas, secretion increased by high blood glucose or high amino acid levels, regulated by CCK and GH levels
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testosterone secretion
|
controlled by negative feedback mechanism involving FSH and LH, insensitivity to the hormone causes genetic males to have female secondary sexual characteristics
|
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secretion of estrogen/progesterone
|
regulated by LH/FSH (which are regulated by GnRH)
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estrogens
|
steroid hormone, normal female maturation, stimulate development of female reproductive tract and secondary sexual characteristics/sex drive, thickening of endometrium, secreted by ovarian follicles and corpus luteum
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progesterone
|
steroid hormone secreted by corpus luteum during luteal phase of mentrual cycle, stimulates/maintains endometrial wall in preparation for implantation
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mentrual cycle phases
|
follicular phase, ovulation, the luteal phase, and menstruation
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follicular phase
|
begins by stopping menstrual flow, FSH and LH together promote development of several ovarian follicles, follicles grow and secrete estrogen, rising estrogen stimulates GnRH secretion which further stimulates LH secretion
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ovulation
|
midway through cycle, mature ovarian follicle bursts to release ovum, peak in estrogen causes peak in LH (FSH peaks too) which causes ovulation
|
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luteal phase
|
LH induces ruptured follicle to become corpus luteum, secretes estrogen/progesterone, progesterone causes endometrial glands to mature/produce secretions in preparation for embryonic implantation, together estrogen and progesterone inhibit GnRH secretion (so inhibit LH and FSH too)-prevents maturation of additional follicles
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menstruation
|
if ovum is not fertilized the corpus luteum atrophies, drop in estrogen/progesterone causes endometrium to slough off (superficial blood vessels) and flow occurs, GnRH is not inhibited anymore so LH and FSH are secreted and the cycle restarts (if ovum is fertilized then menstruation ceases for pregnancy)
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human chorionic gonadotropin (HCG) and pregnancy
|
preserves the corpus luteum during the first trimester of pregnancy, produced by blastocyst and developing placenta, causes estrogen/progesterone secretion to be maintained, HCG decline by second trimester but estrogen/progesterone are still secreted by placenta, which inhibited GnRH and thus FSH and LH (no new menstrual cycle)
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menopause
|
ovary function declines, follicles fail to rupture, no ovulation, less estrogen produced by the ovaries
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melatonin
|
secreted by pineal gland, role unclear (possibly related to circadian rhythms, 24 horu cycles), secretion regulated by light and dark cycles in environment
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renin
|
enzyme secreted by kidney involved in regulation of aldosterone
|
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erythropoietin
|
secreted by kidney in response to decreased renal oxygen levels and stimulates bone marrow to produce red blood cells
|
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atrial natriuretic hormone
|
released by heart, involved in regulation of salt and water balance
|
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thymosin
|
secreted by thymus during childhood, stimulates T lymphocyte development/differentiation, thymus atrophies once immune system is developed
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peptide hormones
|
protein synthesized and secreted by exocytosis, bind to surface receptors to induce intracellular cascades (second messengers)
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steroid hormones
|
lipid-derived molecules with ring structure, produced by testes, ovaries, placenta, and adrenal cortex, precursors present in the cell undergo enzymatic reactions to become steroid hormones (cholesterol), pass through membrane, not stored in cells (secreted at a rate determined by rate of synthesis), enter target cells directly and bind to cytoplasmic receptors, the compelx then enters the nucleus to affect gene expression
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amino acid derivative hormones
|
hormones composed of one or two modified amino acids, synthesized in cytoplasm of glandular cells, some may be further modified and stored in granules until cell is stimulated to release them and others may be made as parts of larger molecules and stored; some bind to receptors on the outside and others enter cell and affect gene expression directly
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myelin production
|
glial cells produce (oligodendrocytes in CNS and Schwann cells in PNS)
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axon hillock
|
where action potential is first initiated (decision point on whether potential will be fired)
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direction and speeds of synapse
|
operate only in one direction due to refractory period in the most recently opened sodium channels, the speed will be greater with greater axon diameter and more myelin insulation
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ways neurotransmitter is removed from synapse
|
taken back into presynaptic nerve terminal (uptake carrier protein) to be reused or discarded, it may be degraded by enzymes in the synapse, it may diffuse out of the synapse
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nerves
|
bundles of axons covered with connective tissue
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neuronal cell bodies
|
cluster together to form ganglia in PNS and nuclei in CNS
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brain functions
|
interpreting sensory information, forming motor plans, cognitive function (gray matter is cell bodies, white matter is myelinated axons)
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telencephalon
|
left and right hemispheres of forebrain divided into four lobes (frontal, parietal, temporal, occipital), cerebral cortex is the gray matter on the surface of the brain
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cerebral cortex function
|
processes/integrates sensory input and motor responses, important for memory and creative thought
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corpus callosum
|
allows right and left cerebral cortices to communicate
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diencephalon
|
part of forebrain with thalamus and hypothalamus
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thalamus
|
relay and integration center for spinal cord and cerebral cortex
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hypothalamus
|
controls visceral functions like hunger, thirst, sex drive, water balance, blood pressure, temperature regulation, and endocrine functions
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midbrain
|
relay center for visual and auditory impulses, role in motor control
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hindbrain
|
cerebellum, pons, medulla (oblongata)
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cerebellum
|
modulate motor impulses initiated by motor cortex, important for balance, hand-eye coordination, timing of rapid movements
|
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pons
|
relay center between cortex and cerebellum
|
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medulla
|
controls functions like breathing, heart rate, and gastrointestinal activity
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brainstem
|
midbrain, pons, medulla (not cerebellum)
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spinal cord neuron locations
|
sensory neurons enters dorsally with cell bodies located in dorsal root ganglia, motor information exits spinal cord ventrally and cords leaving are called roots
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spinal cord divisions
|
head to tail: cervical, thoracic, lumbar, sacral
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somatic nervous system
|
innervates skeletal muscles, responsible for voluntary movement, important for reflex action
|
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monosynaptic reflexes
|
only one synapse between sensory neuron which synapses with motor neuron in spinal cord
|
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polysynaptic reflexes
|
sensory neurons synapse with mroe than one neuron (withdrawal reflex)
|
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|
autonomic nervous system functions
|
involuntary system as it does not involve conscious control, innervation of cardiac and smooth muscle
|
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smooth muscle
|
blood vessels, digestive tract, bladder, bronchi (ANS is important in blood pressure control, gastrointestinal motility, excretory processes, respiration, and reproductivee processes)
|
|
|
sympathetic nervous system
|
readies body for action, increases blood pressure/heart rate/blood flow to skeletal muscles, decreases gut motility, preganglionic neurons emerge from thoracic and lumbar regions of spine and use acetylcholine as the neurotransmitter, post-ganglionic sympathetic neurons release norepinephrine, epinephrine is also released from preganglionic neural stimulation of adrenal medulla
|
|
|
parasympathetic nervous system
|
conserve energy and restore body to resting activity levels, lowers heart rate and increases gut motility, neurons original in brainstem (cranial nerves) and the sacral part of the spinal cord, both pre- and post- ganglionic neurons use acetylcholine
|
|
|
vagus nerve
|
parasympathetic nerve that innervates many of the of the thoracic and abdominal viscera
|
|
|
interoceptors
|
monitor aspects of internal environment like blood pressure, CO2 partial pressure in blood, blood pH
|
|
|
proprioceptors
|
transmit information regard body's position in space (located in muscles/tendons to tell brain where limbs are in space, located in inner ear to tell brain where head is in space
|
|
|
exteroceptors
|
sense things in external environment like light, sound, taste, pain, touch, and temperature
|
|
|
eye function
|
detect light energy and transmit information about intensity, color, and shape to brain
|
|
|
sclera
|
thick opaque layer that covers eyeball (eye white)
|
|
|
choroid layer
|
beneath sclera, helps to provide retina with blood
|
|
|
retina
|
innermost layer of eye with photoreceptors that sense light
|
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|
cornea
|
transparent tissue at front of eye that bends and focuses light rays
|
|
|
pupil
|
place where light rays enter
|
|
|
iris
|
controls diameter of pupil, muscular, responds to intensity of light (higher, more constriction)
|
|
|
eye lens
|
light goes through lens which is right behind pupil, focuses image onto retina (shape controlled by ciliary muscles)
|
|
|
retinal photoreceptors
|
transduce light into action potentials, cones and rods
|
|
|
cones
|
respond to high-intensity illumination with color sensitivity
|
|
|
rods
|
detect low-intensity illumination, important in night vision
|
|
|
pigments and light absorption
|
cones contain pigments that absorb red, green, and blue wavelengths; rods contain rhodopsin and absorbs one wavelength
|
|
|
bipolar cells
|
cells that receive synapse from photoreceptor cells that in turn synapse onto ganglion cells
|
|
|
ganglion cell axons
|
bundle to form right and left optic nerves, conduct visual information to brain
|
|
|
blind spot
|
point at which optic nerve exits eye (no photoreceptors)
|
|
|
fovea
|
small area of retina densely packed with cones, important for high acuity vision
|
|
|
the ear
|
transduces sound energy (pressure waves into impulses perceived by brain as sound
|
|
|
sound wave pathway
|
enter outer ear, reach middle ear where vibration equals frequency of incoming sound, sound is then amplified by ossicle bones into fluid-filled inner ear, vibration of ossicles exerts pressure on the fluid causing action potential transduction, travel through auditory nerve to brain
|
|
|
interpretation of position of head by brain
|
caused when rotation of head dispalces endolymph fluid in ear canals (pressure on hair cells in canal)
|
|
|
taste sense
|
taste buds are located on tongue, soft palate, and epiglottis, receptor surfaces for taste are on taste hairs interwoven with nerves that are stimulated by taste buds and use cranial nerves to transmit information to the brain (sour, salty, sweet, bitter)
|
|
|
smell sense
|
olfactory receptors found in olfactory membrane in upper part of nostrils, cilia in neuron receptors bind substances and axons join to form olfactory nerve which projects directly to olfactory bulb in the base of brain
|
|
|
Klinefelter's syndrome
|
XXY individuals, sterile males with abnormally small testes
|
|
|
Turner's syndrome
|
XO females who fail to develope secondary sexual characteristics, are sterile, and of short stature
|
|
|
metafemales
|
XXX females, usually mentally retarded, sometimes infertile
|
|
|
XYY
|
normal males that tend to be taller than average (possibly more violent)
|
|
|
DNA gyrase
|
type of topoisomerase that enhances action of helicase (relieves strain) by introducing negative supercoils
|
|
|
tRNA
|
recognizes both amino acid and mRNA codon, each amino acid has its own aminoacyl-tRNA synthetase to form an aminoacyl-tRNA complex
|
|
|
post-translational additions
|
a protein might be cleaved or addended at one of its ends, amino acid residues can be phosphorylated, carboxylated, methylated, or glycosylated
|
|
|
viral infection of host cell
|
can only infect cell with surface receptor for virus' protein capsid, some viruses only inject nucleic acid while others enter entirely (release nucleic acid inside cell)
|
|
|
RNA replicase
|
transcribes new RNA from RNA template (viruses either bring in the enzyme already translated or have mRNA coded for the enzyme)
|
|
|
retroviruses
|
use reverse transcriptase to make DNA from RNA template, integrates into host chromosome as prophage, later transcribed back into mRNA needed for prophage assembly
|
|
|
viral progeny release
|
after assembly (spontaneous or with aid of enzymes) viral progeny may be released by host lysis or extrusion (budding)
|
|
|
lytic vs. lysogenic
|
lytic is when phage DNA takes control of the bacterium's genetic machinery and manufactures numerous progeny, lysogenic is when it becomes intergrated into the bacterial genome in a harmless form (spontaneous or induced entry back into lytic cycle)
|
|
|
permeabiltiy of plasma membrane
|
permeable to small, nonpolar molecules and small polar molecules like water, larger nonpolar molecules can get in sometimes, larger charged molecules need carrier proteins
|
|
|
connective tissue
|
body support (bone, cartilage, tendons, ligaments, adipose, blood)
|
|
|
epithelial tissue
|
covers surfaces of body and lines cavities to protect them against injury, invasion, and dessication (important for absorption, secretion, sensation)
|
|
|
ontogeny recapitulates phylogeny
|
embryonic development of certain species is comparable to the evolution of that species (at different stages, different organs or functions show up and then change into more developed ones)
|
|
|
enzyme kinetics
|
E+S<->ES->E+P
Km=(k2+k3)/k1, Km=[S] at 1/2Vmax (half the sites are filled), Vmax occurs when all sites are filled/saturated |
|
|
enzyme reaction rates
|
double for every 10 degrees C added until optimal temperature is reached (denatured after), there is an optimal pH where key groups are protonated or deprotonated
|
|
|
allosteric enzyme
|
2 or more active sites, regulators stabilize a conformation to prevent or promote substrate binding
|
|
|
noncompetitive inhibition
|
reduces the Vmax of an enzyme without affecting binding ability of substrate
|
|
|
uncompetitive inhibition
|
inhibitor binds well to ES complex to decrease turnover rate (stabilize the complex), it decreases Km and Vmax
|
|
|
competitive inhibition
|
binds to active site to increase Km so substrate can't bind as well (Vmax unchanged), can be relieved by higher substrate
|
|
|
allosteric inhibtion
|
binding of inhibitor to another site than active to change shape of active site so substrate can't bind as well (cannot be relieved by higher substrate)
|
|
|
feedback inhibition
|
last product of biosynthetic pathway blocks earlier enzyme when it reaches critical value
|
|
|
irreversible/reversible inhibition
|
irreversible occurs when inhibitor binds covalently or enzyme damage occurs and reversible is usually due to weak noncovalet binding
|
|
|
net glycolysis reaction
|
glucose+2ADP+2Pi+2NAD+-->2 pyruvate+2ATP+2NADH+2H++2H2O
|
|
|
alcohol fermentation
|
yeast and some bacteria, pyruvate is decarboxylated to acetaldehyde and then reduced to ethanol by NADH
|
|
|
lactic acid fermentation
|
some fungi and bacteria, muscles (oxygen debt, O2 supply lags behind glycolysis rate), pyruvate reduced to lactic acid
|
|
|
net pyruvate decarboxylation reaction
|
pyruvate+CoA+NAD+-->NADH+H++CO2+acetyl Coa
(note: 2 pyruvates) |
|
|
net citric acid cycle reaction
|
2 acetyl CoA+6NAD++2FAD+2ADP+2Pi+4H2O-->4CO2+6NADH+2FADH2+2ATP+4H++2CoA
|
|
|
respiratory poisons
|
cyanide blocks electron transfer from cytochrome a3 to O2, dinitrophenol uncouples the ETC from the proton gradient
|
|
|
asexual reproduction methods
|
binary fission (replication then invagination, prokaryotes); budding (hydra/yeast), regeneration (hydra/starfish/tissue healing), parthenogenesis (all cells haploid, unfertilized egg)
|
|
|
interkinesis
|
occurs before meioisis II begins and some uncoiling of chromosomes may take place
|
|
|
spermatid
|
haploid cells that are formed after meiosis two in spermatogenesis from secondary spermatocytes and mature in the epididymis to spermatozoa (gain motility)
|
|
|
fallopian tube cilia
|
line wall of fallopian tube to project egg forward towards uterus
|
|
|
sperm penetration
|
can occur 12-24 hours after ovulation, sperm secretes enzymes to break through corona radiata and acrosome secretes enzymes to break through zona pellucida
|
|
|
formation of MZ twins
|
single zygote splits into 2 embryo at the 2 cell stage (separate chorions/placenta), the blastula stage (same chorionic sac and placenta)
|
|
|
cleavage
|
rapid mitotic divisions (8 cell stage before reaching uterus), increases SA:V and nuclear:cytoplasmic ratios
|
|
|
embryo implantation
|
progesterone causes glandular proliferation of endometrium (mucosal lining of uterus, embryonic cells secrete proteolytic enzymes to break into wall
|
|
|
archenteron
|
forms blastopore (future anus in deuterostomes and future mouth in protostomes)
|
|
|
ectoderm development
|
integument (epidermis, hair, nails, nose epithelium, mouth, anal canal), lens of eye, nervous system
|
|
|
endoderm development
|
epithelial linings of digestive and respiratory tracts (lungs), parts of liver, pancreasn thyroid, bladder (endocrine)
|
|
|
mesoderm development
|
musculoskeletal system, circulatory system, excretory system, gonads, connective tissue throughout body, portions of digestive and respiratory organs (mostly endoderm)
|
|
|
amnion
|
strong, thin shock absorber with amniotic fluid (absorbs labor pressures during uterine contractions)
|
|
|
fetal respiration
|
after 8 weeks oxygen/nutrients/loss of CO2 and wastes occurs via formed placenta (chorionic villi project into endometrium), alantois develops outpocketing of gut and enlarges to become umbillical vessels (nourished by yolk sac) after amnion envelopes the cord
|
|
|
fetal circulation
|
water, glucose, amino acids, vitamins, salts diffuse through placenta (maternal and fetal blood don't mix), prevention of foreign material diffusion
|
|
|
umbilical vein
|
carries oxygenated blood from placenta to fetus, which mixes with deoxygenated blood of vena cavea in right atrium (partially oxygenated)
|
|
|
ductus venosus
|
blood bypasses fetal liver before coverging with inferior vena cava
|
|
|
formamen ovale
|
fetal shunt from right to left atrium
|
|
|
ductus arteriosus
|
shunt from pulmonary artery to aorta to bypass fetal lungs
|
|
|
umbilical arteries
|
deoxygenated blood is returned to placenta
|
|
|
circulation after birth
|
less resistance in pulmonary vessels, decreased inferior vena cava pressure (no umbilical flow), hemaglobin converts to less oxygen-affinity one, right atrial pressure decreases, left atrial pressure increases with lung blood (these atrial changes causes formamen ovale to close), ductus arteriosus and venosus close
|
|
|
gestation-1st trimester
|
major organs form, skeleton turns from cartilege to bone, brain starts to develop
|
|
|
gestation-2nd trimester
|
lots of growing/moving in amniotic fluid
|
|
|
gestation-3rd trimester
|
rapid growth/more brain development/antibodies sent to fetus from mother by active transport (eventually growth rate slows and less activity as room decreases)
|
|
|
childbirth
|
cervis thins out/dilates and aminiotic sac ruptures, rapid contractions, birth of baby, loss of umbilical cord, uterus contracts as it expels placenta and umbilical cord
|
