Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/322

Click to flip

322 Cards in this Set

  • Front
  • Back
cartilage
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
compact vs. spongy bone
compact: dense, no caivites
spongy: less dense, interconnecting lattice of bony spicules (trabeculae)
yellow vs. red marrow
both: fill spongy cavities
yellow: inactive, filled with adipose
red: blood cell formation function
long bone structure/function
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
bone matrix components
organic: proteins, mainly collagen fibers and glycoproteins
inorganic: calcium, phosphate, hydroxide (form into hydroxyapatite crystals which strengthen collagen), sodium, potassium, magnesium ions
osteons
structural units of bony matrix
Haversian canal
canal filled with blood vessels, nerve, and lymph and surrounded by circles of bony matrix (lamellae)
lacunae
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
osteoblasts vs. osteoclasts
osteoblasts build up bone by organic secretion and osteoclasts are large, multinucleate cells that cause bone break down
endochondral ossification
existing cartilage is replaced by bone (long bone)
intramembranous ossification
mesenchymal (embryonic, undifferentiated) connective tissue is transformed into/replaced by bone
immovable joints
joints that don't move relative to each other
movable joints
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)
skeletal muscle
voluntary movements by somatic nervous system, pundle of parallel fibers of multinucleate cells (fusion of several embryonic cells)
myofibrils
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
transverse tubules
oriented perpendicular to myofibrils, channels for ion flow throughout the nuscle fibers (everything can get innervated, helps propagate action potential)
red vs. white fibers
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
sarcomere bands
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)
action potential in muscle cell
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
stimulus intentsity
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
simple twitch
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
summation and tetanus
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
smooth muscle
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
cardiac muscle
cardiace muscle fibers possess skeletal and smooth muscle fiber characteristics, sarcomeres (striated)
creatine phosphate
during rest it is produced in a reaction (make creatine phosphate), during exercise ATP is resynthesized from creatine phosphate
connective tissue
bind and support other tissue, includes sparsely populated cells in a ground substance
loose connective tissue
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
loose connective tissue fibers
collagenous fibers (collagen, tensile strength), elastic fibers (elastin, resilience), reticular fibers (branched, tightly woven, join connective tissue to adjoining tissue)
dense connective tissue
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)
origin/insertion (bone)
the end of the muscle attached to the stationary bone (proximal bone), insertion is the end of the muscle contacting the moving bone (distal)
flexor vs. extensor muscle
flexor works to decrease the angle of a joint while extensor increases angle (straighten joint)-antagonistic pair
abductor vs. adductor
abductor moves part away from midline while adductor moves it toward the midline
human digestive tract
oral cavity, pharynx, esophagus, stomach, small intestine, large intestine (accessory organs: salivary glands, pnacreas, liver)
epithelium
free surface exposed to air or liquid (may be ciliated) and other side connective to basement membrane; protect/line organs, absorb/secrete solutions
simple epithelium
single layer of cells
stratified epithelium
multiple layers of cells
pseudostratified epithelium
single-layered but appears stratified because cells vary in height
epithelial cell shapes
cuboidal, columnar, squamous
mucous membrane
specialized epitheliam that lines most body cavities
mechanical digestion
breakdown of large food particles into smaller ones, increases surface area for more efficient enzymatic breakdown
chemical digestion in mouth
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
salivary amylase
hydrolyzes starch into simple sugars in the mouth, since the time in the mouth is short only some hydrolysis takes place
tongue
taste buds, manipulates food during chewing, rolls it into a bolus (ball), pushes it into the pharynx
pharynx
common pathway for breathing and swallowing, epiglottis covers trachea during swallowing
esophagus
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
stomach
stores and partially digests food, walls are comprised of thick gastric mucosa (includes the gastric and pyloric glands)
gastric glands
stimulated by nervous impulses from brain (response of sight, taste, smell of food); include mucous cells, chief cells, and parietal cells
mucous cells
secrete mucous to protect stomach lining from acidic environment (gastric juice)
gastric juice
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)
pepsin
hydrolyzes specific peptide bonds to form fragments of protein
gastrin
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)
pyloric sphincter
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
small intestine
duodenum, jejunum, ileum; villi extend out of the intestinal submucosa and microvilli extend off of those (increase SA)
intestinal mucose and carbohydrates
secretes maltase, lactase, sucrase (sugar breakdown to monosaccharides) and peptidase (protein hydrolysis)
secretin
released by duodenum in response to acidic chyme, stimulates pancreas to secrete pancreatic juice
pancreatic juice
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
trypsinogen
secrete by pancreas, converted to trypsin by intestinal gland secreted enterokinase
chymotrypsinogen
pancreatic zymogen that is converted to chymotrypsin by trypsin cleavage
carboxypeptidase
zymogen secreted by pancreas that is activated by trypsin cleavage along with aminopeptidase from the intestinal glands digests polypeptides into amino acids
cholecystokinin
secreted into bloodstream by duodenum inresponse to chyme, stimulates pancreatic enzyme secretion and bile release
bile
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
lipases
hydrolyze fat into glycerol and fatty acids, facilitated by micelle formation (more surface area)
enterogastrone
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)
nervous system regulation of digestion
parasympathetic stimulates, sympathetic inhibits
small macromolecule absorption by jejunum/ileum
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
larger molecule intestinal absorption
larger fatty acids, glycerol, and cholesterol diffuse into mucosal cells
chylomicrons
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
chylomicron processing
contents are sent into the blood stream and delivered to liver for repackaging as LDLs, VLDLs, or HDLs (lipoproteins)
fat-soluble vitamins
A, D, E, K absorbed with fats
water-soluble vitamins
B complexes, C absorbed by simple diffusion into circulatory system (dissolved in intestinal aqueous fluid)
large intestine
cecum, colon, rectum (anus)
cecum
outshoot from small intestine, connected to appendix (lymphoid tissue)
colon
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)
rectum
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
pancreatic amylase
produced in small intestine, secreted into small intestine to hydrolyze starch to maltose
dipeptidases
made in intestinal glands and secreted into small intestine to hydrolyze pairs of amino acids
anatomy of breathing
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)
ventilation
pressure changes in thoracic cavity (heart and lungs)
diaphragm
separates abdomen from thoracic cavity
visceral and parietal pleura
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
inhalation
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
exhalation
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
medulla oblongata and breathing
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
conscious breathing
cerebrum can control breathing at times, but medulla oblongata can override this attempt when CO2 levels get too high (hold breath)
hyperventilation
lowers pCO2 too much, chemoreceptors sense this and send signals to respiratory center to temporarily inhibit breathing
vital capacity
maximum amount of air that can be forcibly inhaled and exhaled from lungs
tidal volume
amount of air normally inhaled and exhaled with each breath
residual volume
air that always remains in lungs to prevent alveolar collapse
expiratory reserve volume
the amount of air that can still be forcibly exhaled after normal exhalation
total lung capacity
vital capacity plus residual volume
gas exchange
pulmonary capillaries gain O2 from alveoli (bind with Hb) and lose CO2 (down concentration gradient)
high altitudes compensation
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
cardiovascular system
consists of strong 4-chambered heart, blood vessels, and blood itself
blood pumping pathway
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)
portal systems
blood travels through 2 capillary beds before returning to heart: liver (hepatic portal circulartion), kidneys, brain (hypophyseal portal circulation)
heart compartments
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)
atrioventricular valves
located between atria and ventricles, prevent backflow to atria; tricuspid is on right (3 cusps) mitral on left (2 cusps)
semilunar valves
three cusps, between left ventricle and aorta and right ventrical and pulmonary artery
systole-diastole cycle
systole is when ventricles contract and diastole is when the muscle relaxes and blood refills heart
cardiac output
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)
contraction control
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)
EKG
P wave occurs right before atrial contraction, QRS right before ventricles contract, T represents ventricle repolarization after contraction
autonomic nervous system
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
blood vessels
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
blood pressure
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
blood composition
55% plasma aqueous mixture of nutrients, salts, respiratory gases, wastes, hormones, and blood proteins (immunoglobulins, albumin, fibrinogen...), 45% cellular erythrocytes, leukocytes, platelets
erythrocytes
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
leukocytes
produced in marrow of long bones, increase in number when body battles infection, made up of granular leukocytes, lymphocytes, and monocytes
granular leukocytes
neutrophils, basophiles, eosinophils, role in inflammation, allergic reactions, pus formation, and destruction of invading bacteria and parasites
lymphocytes
role in immune response, produced in lymph nodes, tonsils, spleen, appendix, thymus, and bone marrow; B and T lymphocytes
monocytes
migrate from blood to tissue where they differentiate into macrophages that phagocytize foreign matter/organisms (monocytes have less ability to phagocytize material)
platelets
cell fragments formed in bone marrow, lack nuclei, function in clot formation, many per blood volume
erythroblastosis fetalis
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+
Bohr effect
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
nutrient transport
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
hydrostatic vs. osmotic pressure
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
clotting
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)
antibody function
either attract other cells like leukocytes to phagocytize antigen or cause agglutination of antigens into large, insoluble complexes (facilitates removal by phagocytic cells)
antibody structure
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)
humoral response
production of antibodies by B cells that originate in bone marrow and differentiate in spleen, lymph nodes, and other lymphatic organs
primary response
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
plasma cells
produce and release antibodies against the antigen 7-10 days after exposure
memory cells
long lived cells in the bloodstream (possibly permenant), elicit a more immediate response upon subsequent exposure (secondary response)
active immunity
production of one's own antibodies (possibly after vaccination, the introduction of a weakened, inactive, or related form of a particular antigen)
passive immunity
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)
cell-mediated immunity
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
cytotoxic T cells
destroy antigens directly
helper T cells
activate other B and T cells and nonlymphocyte cells (macrophages) by secreting lymphokines (interleukins)
suppressor T cells
regulate other B and T cells to decrease their activity against antigens
T cell secondary response
some T cells initially differentiate into memory cells, so during another exposure the memory cells proliferate greatly and make many cytotoxic T cells
T cells and allergic reactions/organ transplant rejection
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)
nonspecific defense mechanisms
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
inflammatory response
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)
interferons
produced by cells under viral attack, diffuse to other cells to help prevent viral spread
lymphatic system
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
lymph nodes
swellings along lymph vessels containing phagocytic leukocytes that filter lymph by removing and destroying foreign particles
kidney vasculature
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
nephron structure
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)
kidney filtration
blood pressure forces 20% of blood plasma into Bowman's capsule, fluids and small solutes enter and large molecules remain in blood
nephron secretion
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
proximal convoluted tubule
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
descending limb of Henle
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)
ascending limb of Henle
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
distal convoluted tubule
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
collecting duct
mainly water reabsorption under control of ADH, some urea leaks out
aldosterone
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
Addison's disease
aldosterone is produced insufficiently or not at all, overexcretion of urine with high sodium, leads to drop in blood pressure
ADH
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)
excretion
after collecting duct urine is composed of urea, uric acid, and other wastes, goes into ureter to bladder and out through urethra
liver and glucose levels
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)
liver and nitrogenous wastes
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)
other liver functions
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
large intestine and salts
absorbs water and sodium not previously absorbed in small intestine, excess calcium, iron, and other salts are excreted into colon and eliminated with feces
skin layers
epidermis, dermis, subcutaneous layer (hypodermis)
epidermis
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
dermis
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
hypodermis
loose connective tissue, many fat cells, binds outer skin layers to body, fat insulates body
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
sweat
water, dissolved salts, urea through sweat pores, as sweat evaporates skin is cooled (under nervous control)
skin hair (fur)
entraps and retains warm air at skin's surface
epinephrine and heat
increase metabolic rate, thus more heat produced
muscles and heat
contraction (shivering) produces heat
blood vessels and heat
constriction in dermis retains heat and dilation dissipates heat
hibernation
type of torpor where animal remains dormant, lowering metabolic rate and allowing body temperature to fall below normal
endocrine glands
pituitary, hypothalamus, thyroid, parathyroids, adrenal, pancreas, testes, ovaries, pineal, kidneys, gastrointestinal glands, heart, thymus
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)
acromegaly
disorder caused by overproduction of GH where there is a disproportionate growth of bone in certain areas
prolactin
stimulates milke production and secretion in female mammary glands
adrenocorticotropic hormone (ACTH)
stimulates adrenal cortex to synthesize/secrete glucocorticoids, regulated corticotropin releasing factor, anterior pituitary
thyroid-stimulating hormone (TSH)
stimulates thyroid gland to absorb iodine then synthesize/release thyroid hormone, regulated by TRH, anterior pituitary
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
follicle-stimulating hormone (FSH)
females: maturation of ovarian follicles
males: maturation of seminiferous tubules and sperm production
regulated by estrogen and GnRH, anterior pituitary
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
antidiuretic hormone (ADH)
posterior pituitary stored, increase collecting duct permeability to increase blood volume or to lower plasma osmolarity
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
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)
hypothalamys interactions with posterior pituitary
neurosecretory cells in hypothalamus synthesize oxytocin and ADH (transport to posterior pituitary via axons)
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
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)
hyperthyroidism
thyroid is overstimulated, increased metabolic rate, feelings of excessive warmth, profuse sweating, palpitations, weight loss, goiter
calcitonin
thyroid, decreases plasma Ca2+ concentration (inhibits calcium release from bone), secretion regulated by plasma calcium levels
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)
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
glucocorticoids
examples are cortisol and cortisone, raise blood glucose levels (promote gluconeogenesis) and decrease protein synthesis, reduce body's immunological and inflammatory responses
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)
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
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
adrenal medulla
secretory cells are specialized sympathetic nerve cells that secrete epinephrine and norepinephrine (catecholamines)
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)
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
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
hypoglycemia vs. hyperglycemia
low blood glucose levels, high blood glucose levels
ketoacidosis
lowering of blood pH due to excess keto acids and fatty acids in plasma
somatostatin
pancreas, secretion increased by high blood glucose or high amino acid levels, regulated by CCK and GH levels
testosterone secretion
controlled by negative feedback mechanism involving FSH and LH, insensitivity to the hormone causes genetic males to have female secondary sexual characteristics
secretion of estrogen/progesterone
regulated by LH/FSH (which are regulated by GnRH)
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
progesterone
steroid hormone secreted by corpus luteum during luteal phase of mentrual cycle, stimulates/maintains endometrial wall in preparation for implantation
mentrual cycle phases
follicular phase, ovulation, the luteal phase, and menstruation
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
ovulation
midway through cycle, mature ovarian follicle bursts to release ovum, peak in estrogen causes peak in LH (FSH peaks too) which causes ovulation
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
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)
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)
menopause
ovary function declines, follicles fail to rupture, no ovulation, less estrogen produced by the ovaries
melatonin
secreted by pineal gland, role unclear (possibly related to circadian rhythms, 24 horu cycles), secretion regulated by light and dark cycles in environment
renin
enzyme secreted by kidney involved in regulation of aldosterone
erythropoietin
secreted by kidney in response to decreased renal oxygen levels and stimulates bone marrow to produce red blood cells
atrial natriuretic hormone
released by heart, involved in regulation of salt and water balance
thymosin
secreted by thymus during childhood, stimulates T lymphocyte development/differentiation, thymus atrophies once immune system is developed
peptide hormones
protein synthesized and secreted by exocytosis, bind to surface receptors to induce intracellular cascades (second messengers)
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
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
myelin production
glial cells produce (oligodendrocytes in CNS and Schwann cells in PNS)
axon hillock
where action potential is first initiated (decision point on whether potential will be fired)
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
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
nerves
bundles of axons covered with connective tissue
neuronal cell bodies
cluster together to form ganglia in PNS and nuclei in CNS
brain functions
interpreting sensory information, forming motor plans, cognitive function (gray matter is cell bodies, white matter is myelinated axons)
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
cerebral cortex function
processes/integrates sensory input and motor responses, important for memory and creative thought
corpus callosum
allows right and left cerebral cortices to communicate
diencephalon
part of forebrain with thalamus and hypothalamus
thalamus
relay and integration center for spinal cord and cerebral cortex
hypothalamus
controls visceral functions like hunger, thirst, sex drive, water balance, blood pressure, temperature regulation, and endocrine functions
midbrain
relay center for visual and auditory impulses, role in motor control
hindbrain
cerebellum, pons, medulla (oblongata)
cerebellum
modulate motor impulses initiated by motor cortex, important for balance, hand-eye coordination, timing of rapid movements
pons
relay center between cortex and cerebellum
medulla
controls functions like breathing, heart rate, and gastrointestinal activity
brainstem
midbrain, pons, medulla (not cerebellum)
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
spinal cord divisions
head to tail: cervical, thoracic, lumbar, sacral
somatic nervous system
innervates skeletal muscles, responsible for voluntary movement, important for reflex action
monosynaptic reflexes
only one synapse between sensory neuron which synapses with motor neuron in spinal cord
polysynaptic reflexes
sensory neurons synapse with mroe than one neuron (withdrawal reflex)
autonomic nervous system functions
involuntary system as it does not involve conscious control, innervation of cardiac and smooth muscle
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
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