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44 Cards in this Set
- Front
- Back
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Need to know about the relationship between the cytoskeleton and the plasma membrane
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o Plasma membrane and cytoskeleton associate through integrins
• Extracellular domain of integrins binds to ECM components and intracellular domain binds to cytoskeletal components • Integrins stabilize plasma membrane and determine/maintain cell shape • Spectrin – composed of alpha and beta chains, provides a scaffold for structural reinforcement • Actin – attaches to binding sites on spectrin tetramers and holds them together |
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Role of intermediate filaments
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o Tissue-specific
• Used in cancer diagnosis o Provide mechanical strength to cells o Do not require GTP or ATP for assembly o Keratin – structural support and tension-bearing role • Enables cells to withstand stress caused by stretching • Serves as immunological marker for tumors arising from epithelium o Vimentin-containing filaments – structural support for cell • Serves as immunological marker for tumors arising from connective tissue o Desmin + Vimentin – links myofibrils and myofilaments • Serves as immunological marker for tumors arising from muscle o GFAP + Vimentin – structural support • Serves as immunological marker for tumors arising from glia o Neurofilaments – support for axons and dendrites • Serves as immunological marker for tumors arising from neuronal origin o Lamina A, B, and C – organize peripheral nuclear chromatin |
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Phases of the cell cycle
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o Interphase – where cells spend most of their time
• Period during which cell doubles in size and DNA content • G1 phase – cell grows and proteins are synthesized • Cells that fail to reach restriction point become resting cells and enter G0 phase • Cyclins D and E bind to CDK that enable the cell to enter and advance through S phase • S phase- DNA replicated and proteins are synthesized → duplication of chromosomes • Cyclin A binds to CDK and enables cell to leave S phase and enter G2 phase and make cyclin B • G2 phase – cell prepares to divide – centrioles mature, energy for mitosis stored, RNA and proteins for mitosis synthesized • Cyclin B binds to CDK and induces the cell to leave G2 phase and enter M phase o M phase – mitosis • Completes cell cycle • Division of nucleus and cytoplasm → two identical daughter cells • Prophase – chromosomes condense, nuclear envelope start to disappear, centrosomes start to move, spindle fibers form • Metaphase – duplicated condensed chromosomes line up along metaphase plate and attach to spindle microtubules at kinetochore • Anaphase – chromatids start to split at centromere and move toward opposite poles • Telophase – chromosomes reach each side of pole and cleavage furrow occurs • Nuclear envelope reestablished |
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Protein synthesis
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o Transcription of DNA to mRNA that is complementary to the template strand of DNA via RNA polymerase I
o Movement of mRNA to cytoplasm where it will bind to ribosome o Translation of protein on ribosomes by reading sequential mRNA codons and assembly of corresponding amino acids by tRNA starting with AUG (start codon) o Movement of peptide chain into ER for further processing (post-translational modification) o Transport of processed protein to Golgi for complete assembly and packaging into vesicles to be used in cell or transported out of cell |
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Structure of the extracellular matrix. What if it were broken?
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o Organized meshwork of marcomolecules surrounding and underlying cells
o Functions – alter cells and influence their shape, migration, division, and differentiation o Ground substance • GAGs = glycosaminoglycans • Repeating disaccharide units • Generally linked to core protein • Heavily hydrated to lubricate joints and make them easier to move around (resists compression) • Proteoglycans – has core protein • Act as binding site for growth factors and other signaling molecules • Glycoproteins – promote adhesion between cell and matrix via receptors on cell surface • Fibronectin – has domains for binding collagen, heparin, surface-cell receptors, and CAMs o Mediates cell adhesion to ECM by binding to fibronectin receptors on cell surface o Manufactured by connective tissue cells • Laminin – mediates interaction between epithelial cells and ECM by anchoring cell surface to basal lamina • Fibronectin Receptors – transmembrane proteins that enable cells to adhere to the ECM (= CAMs) • Links fibronectin outside the cell to cytoskeletal components inside the cell • May activate cell signaling pathways o Fibers • Collagen – most abundant structural protein of ECM • Synthesis can be inhibited by lack of Vitamin C • Elastic – made of elastin • Will return to original shape after being stretched • Allows tissues and ECM to be elastic o If broken, cells wouldn’t be held down – constantly moving • Integrity of tissue would be compromised |
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Clinical Considerations Chapter 1
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o Cystinuria – abnormal carrier proteins can’t remove cysteine from urine → kidney stones
o Cholera toxin – altered G2 protein can’t hydrolyze GTP and increases cAMP levels in absorptive cells in small intestine → excessive loss of electrolytes, water, and severe diarrhea o Pertussis toxin – causes whooping cough o Venoms – inactivate acetylcholine receptors of skeletal muscle sarcolemma at neuromuscular junctions o Autoimmune disorders – leads to the production of antibodies that bind to and activate certain plasma receptors • Ex. Graves disease o Genetic defects – • Defective G proteins → mental retardation, diminished growth and sexual development, decreased responses to certain hormones • Hereditary spherocyosis ← defective spectrin that has a decreased ability to bind to band 4.1 protein → fragile RBCs & anemia |
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Clinical Considerations Chapter 2
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o Aneuploidy – abnormal number of chromosomes
• Down syndrome (Trisomy 21) → mental retardation, short stature, stubby appendages, congenital heart malformations • Klinefelter syndrome (XXY) – nondisjunction of sex chromosomes → infertility and small testes • Turner syndrome (X_) – monosomy of sex chromosomes → shortness, sterility o Transformed cells – lose their ability to respond to signals that control the cell cycle → may undergo cell division continuously → cancer o Oncogenes ← mutations of proto-oncogenes that can stimulate/inhibit proliferation and development |
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Clinical Considerations Chapter 3
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o Lysosomal storage diseases – caused by deficiency in specific lysosomal acid hydrolases → lysosomes are unable to degrade certain compounds
• Tay-Sachs – glycolipids accumulate in lysosomes of neurons • Hurler syndrome – GAGs accumulate in heart, brain, liver, and other organs → skeletal deformities, enlarged organs, mental deterioration, deafness, and death before age 10 • Glycogen storage diseases – glycogen accumulates in liver, skeletal muscle, and heart o Familial hypercholesterolemia – decreased ability of cells to take in cholesterol, inability to synthesize LDL receptors or receptors are unable to bind to clathrin-coated pits → increase cholesterol in bloodstream → atherosclerosis o Peroxisomal diseases – • Zellweger syndrome – peroxisomes are absent → neurological, liver, and kidney problems • Adrenoleukodystrophy – inability of peroxisomes to metabolize fatty acids → lipids accumulate in nervous system and adrenal glands, impairing their functions |
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Examples of various tissue types in the body
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o Epithelial tissue – avascular and receive nourishment via diffusion of molecules through basal lamina
• Function – Transcellular transport, absorption, secretion, selective permeability, protection o Connective tissue – supports organs and cells, acts as a medium for exchange of nutrients and wastes between blood and tissues, protects against microorganisms, repairs damaged tissues, stores fat • Firbroblasts, Pericytes, Adipose cells, Mast cells, Macrophages, Lymphoid cells, Plasma cells, Granulocytes, Basophils • Loose connective tissue, Dense (regular or irregular), Elastic tissue, Reticular tissue, Adipose tissue (white or brown) • Specialized – Cartilage, Bone • Cartilage – supports soft tissues and aids in development and growth of long bones o Hyaline – lubricates joints and helps in movement due to loaded with water • Forms ends of long bones that connect joints o Elastic – found in ears, nose, etc. where flexible support is required o Fibrocartilage – located in areas where support and tensile strength are required • Bone – protects vital organs, supports fleshy structures, provides a calcium reserve o Dynamic tissue – constantly being reshaped |
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Connective tissue pathologies
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o Edema – increased volume of tissue fluid
• May be caused by venous obstruction or decreased venous blood flow, increased capillary permeability, starvation, excessive release of histamine, obstruction of lymphatic vessels o Hay fever – nasal congestion caused by localized edema in nasal mucosa • Results from increased permeability of small blood vessels due to excessive release of histamine from mast cells in nasal mucosa o Asthma – difficulty breathing due to bronchospasms resulting from leukotrines released in the lungs o Anaphylactic shock – from effects of powerful mediators released during an immediate hypersensitivity reaction following an exposure to an antigen • Signs/symptoms – shortness of breath, decreased blood pressure o Obesity – • Hypertrophic obesity – increase in adipose cell size from increased fat storage • Hypercellular obesity – increase in adipose cells • Leptin – enzyme secreted by fat that suppresses appetite |
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Bone formation
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o Intramembranous – flat bones are formed; starts 2-3 weeks old ends when you’re 2-3 years old
• Soft spots on head = no ossification occurred yet • Periosteum and endosteum don’t have cells in surrounding areas so they don’t undergo ossification • Mesenchymal cells → 1˚ ossification centers → osteoblasts → osteoblasts become trapped in own lacunae → gives rise to osteocytes → rise of spongy bone → blood vessles invade spongy bone → rise of bone marrow → development of bone → osteoprogenitor cells starts process over by making more osteoblasts o Endochondral – long bones are formed; Stops when you’re about 18-20 years • Starts in hyaline cartilage • 1˚ - vascularization of perichondrium → transformation of chondrogenic cells to osteoprogenitor cells → osteoblasts → osteoblasts goes into periosteum and starts to form bone collar → osteoclasts form perforations in bone collar → caclification of new spaces → calcified cartilage-calcified bone complex resorbed by osteoblasts → chondrocytes regenerate → forms large cavities • 2˚ - similar to primary without the production of bone collar – osteoprogenitor cells invade epiphysis → osteoblasts → osteoblasts elaborate bone matrix to replace disintergrating cells |
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Muscle anatomy
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o Epimysium – surrounds entire muscle
o Perimysium – surrounds small bundles of muscle cells o Endomysium – surrounds individual muscle cells |
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Events in skeletal muscle contraction
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o Involves binding, hydrolysis, and release of ATP
o Thick and thin filaments don’t shorten, but increase in overlap • Thin filaments slide past thick filaments • A band remains constant in length • I bands and H bands shorten as Z bands are drawn closer together o Depolarization → release of Ca++ → binding of actin and myosin → contraction |
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The neuromuscular junction
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o Synapse between a motor nerve and a skeletal muscle cell
o Axon terminal lacks myelin but has Schwann cells • Presynaptic membrane – on synaptic surface of axon terminal o Synaptic cleft – space between presynaptic membrane and postsynaptic membrane of muscle cell |
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Smooth muscle is different
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o Non-striated
o Uni-nucleated o Contractions occur more slowly and lasts longer than skeletal muscle because rate of ATP hydrolysis is slower o Has tone – factors which stimulate smooth muscle can cause contraction or relaxation |
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Pathology of Musculoskeletal system/Joints
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o Hamstring injuries – pulled/torn hamstring caused by muscular exertion that might tear off part of proximal tendonous attachments of hamstring to ischial tuberosity
o Torticollis – abnormal tonicity of cervical muscles that causes sustained turning, tilting, flexing, or extending of the neck o Bursitis – inflammation of bursa (synovial fluid in elbow, shoulder, hip, and knee) o Arthritis – inflammation of joints caused by erosion of structure inside synovial cavity o ACL – tear in anterior cruciate ligament – anterior drawer sign |
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Examples of specific joints
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o Fibrous joints – bones joined by fibrous tissue
• Sutures – immovable, of the skull • Syndesmoses – between ulna and radius, allows little movement • Gomphoses – teeth to gums o Cartilaginous joints – bones bound by cartilage tissue • Symphyses – fibrocartilage uniting 2 bones • Synchondroses – formed by hyaline cartilage’ o Synovial joints – covered entirely by joint cavity and allows a lot of movement • Plane/gliding – between vertebrae, carpals • Pivot – between atlax and axis • Saddle – thumb • Hinge – knee, elbow • Ellipsoid – atlanto-occipital joint • Ball-and-socket – shoulder/arm, leg/hip |
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Muscles involved in specific movements
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o Shaking head, turning/extending neck = sternocleidomastoid muscle (SCM)
o Flex/turn forearm, resists shoulder dislocation = biceps brachii o Extends, adducts, medially rotates humerus, push-ups = Latissimus dorsi muscle o Extends thigh, assists in rotation, steadies thigh, assists in rising from sitting position = gluteus maximus o Flex thigh/vertebral column, balance trunk, flex trunk when sitting = Psoas muscle o Flexes thigh, stabilize hip joint = Iliacus muscle o Flex hip, extends knee = Quadricep muscles o Extends thigh, flexes leg, rotates leg when knee is flexed = Hamstring muscles o Plantar foot, flex knee = Gastrocnemius muscle |
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Nerve anatomy
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o Epineurium – forms the external coat of nerves
o Perineurium – surrounds each bundle of nerve fibers • Consists of tight junctions that prohibit passage of most macromolecules o Endoneurium – thin layer of reticular fibers that surround individual nerve fibers o Sensory nerves – contain afferent fibers and carry signals from internal and external environment TO the CNS o Motor nerves – contain efferent fibers and carry signals from CNS to effector organs o Mixed nerves – contain both efferent and afferent fibers and carry both motor and sensory signals |
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Nomenclature in the CNS, PNS
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o Tracts – bundles of axons in CNS
o Neurons – clusters of cell bodies in CNS o Nerves – bundles of axons in PNS o Ganglia – clusters of cell bodies in PNS |
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Motor neuron pathways
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o 1. Action potential fires in 1˚ motor cortex to produce axons that go from motor cortex → brain → spinal cord where they become tracts
o 2. Synapses with lower motor neuron at the ventral horn creates the action potential that produces axons where they will travel to muscles to form neuromuscular junction by spinal nerves o 3. Action potential causes Ca++ channels to open and flow into pre-synaptic terminal which clump neurotransmitters into synaptic cleft o 4. Neurotransmitters bind to receptors in muscle tissue • Acetylcholine binds with ligand-gated Na+ channels on muscle membrane → Na+ enters cell → depolarization at T tubules → Ca++ release at sarcoplasmic reticulum → Ca++ binds with tryponin → Sarcomere shortens |
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Organization of the ANS
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o Sympathetic system – effects vasoconstriction; prepares body for flight-or-fight responses by increasing heart rate, respiration, BP, and blood flow to skeletal muscles; dilates pupils; decrease visceral function
o Parasympathetic system – stimulates secretion; prepares body for rest-or-digest functions by decrease HR, respiration, and BP; constricts pupils; increases visceral function |
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Arterial baroreflex
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o Regulates BP in body
o Sensory nerve receptors located near the heart will detect changes in BP → info goes to brain via vagus nerve and glossopharyngeal nerve → brainstem gets info and modifies sympathetic and parasympathetic nerve activity to bring BP back to normal o Increase BP → increase parasympathetic activity/decrease sympathetic activity → decrease BP o Decrease BP → decrease parasympathetic activity/increase sympathetic activity → increase BP |
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Structure of the eye
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o Three layers:
• Sclera = outer layer that is opaque (white part of eye) and made up of fibrous connective tissue • Contains cornea – transparent • Choroid = middle vascular layer • Contains blood vessels to absorb light • Light enters thru pupil (opening of iris) and iris regulates amount of light entering eye • Ciliary body – secretes aqueous humor • Retina = innermost layer of eye • Responsible for photoreception • Fovea – contains only cones and has the most visual acuity • Lens of inner neural layer where images are focused |
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Sensory mechanisms for hearing, balance, taste and smell
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o Hearing – External hear receives sound waves → middle ear transmits sound waves → internal ear where sound waves are transduced into nerve impulses by causing the hair cells in the cochlea to vibrate
o Balance – proprioceptive receptors = “body sense” • Enables us to unconsciously control the position of our body • Depends on receptors in muscles, tendons, and joints • Golgi tendon organs – sensitive to stretch and tension in tendons • Muscle spindle receptors – sense differences in muscle length and tension o Taste – chemoreceptors on tongue • Taste hair – part of taste neuron that comes into contact with food to stimulate taste • “unami” = taste o Smell – nerves for smell located at the top of the nose • Nerve endings stick into mucosa so that sinus can warm the air and moisten the chemicals to prevent it from drying out/damaging |
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Hemopoiesis
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o = Formation of all blood cells
o Starts with “mother” stem cell that gives rise to other primary stem cells o Stem cells – capable of self-renewal and undergoes proliferation • Differentiate into multiple cell lineages and present in circulation and bone marrow o Progenitor cells – proliferate and differentiate into precursor cells o Precursor cells – displays distinct morphological characteristics o CFU-GEMM and CFU-Ly divide and differentiate in bone marrow to form progenitor cells • CFU-GEMM gives rise to RBCs, granulocytes, monocytes, and platelets • CFU-Ly gives rise to T and B lymphocytes, and NK cells o Modulated by growth factors and cytokines • Circulate in bloodstream or act as local factors in bone marrow to facilitate/stimulate formation of blood cells in vicinity • Bind to specific membrane receptors on single target cells • Controls mitotic rate, enhancement of cell survival, number of times cells divide before they differentiate, promotion of cell differentiation |
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Why does blood flow in only one direction through the heart?
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o Vavles prevent regurgitation of ventricular blood into atria and regurgitation of pulmonary and aortic blood flow into the respective ventricles
o Blood flow: RA → tricuspid valve → RV → pulmonary valve → pulmonary artery → lungs → pulmonary veins → LA → mitral valve → LV → aortic valve → aorta → arteries → arterioles → capillaries → venules → veins → heart |
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Electrical conduction system of the heart
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o Starts in RA – SA node begins to depolarize cardiac tissue; atrial cells depolarize and spread to LA so that LA and RA contract at the same time
o Small delay at AV node in depolarization so that atria can finish contracting before ventricles contract – prevents heart from contracting all at once o Bundle of His separate and move to spaces between LV and RV o Ventricles contract together |
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Regulation of blood flow through vessels
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o Arteries → arterioles → capillaries → venules → veins
o Blood flow increases when parasympathetic activity increases o Decreased blood flow when sympathetic activity increases o Vasoconstriction involes arterioles because arterioles regulate blood pressure |
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Vasoconstriction/vasodilation
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o Vasoconstriction – reduces diameter of vessels, reduces blood flow to local region, stimulated by sympathetic nerve fibers, discharging norepinephrine induces contraction of cells
• Ex. Epinephrine/norepinephrine, vasopression (ADH), endothelin I, angiotension II o Vasodilation – increase diameter of vessels, blocks sympathetic receptors, reduction of sympathetic activity, acetylcholine is released from nerve terminals that stimulate endothelium to release NO, NO diffuses to smooth muscle cells and activates a system that leads to the relaxation that dilates lumen |
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Blood-testis barrier
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o Protects developing sperm cells from autoimmune reactions
o Formed by tight junctions with Sertoli cells near the bases and divides the lumen of seminiferous tubules into 2 compartments |
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Structure and functional significance of the respiratory zone
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o 3 structures in respiratory zone are the only ones involved in gas transport
o Respiratory bronchioles – where respiratory zone starts • Simple cuboidal epithelium with Clara cells, ciliated cells o Alveolar ducts – linear passageways continuous with respiratory bronchioles • Contains smooth muscle cells, lined by type II pneumocytes o Alveoli – have thin walls so O2 and CO2 can diffuse between air and blood • Lined by simple squamous epithelium |
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Prominent pathology of Respiratory system
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o Asthma – widespread constriction of smooth muscle in bronchioles → decrease diameter of bronchioles
• Extremely difficult to expire air • Mucus accumulates in passageways • Infiltration of inflammatory cells • Treated with drugs that act to relax bronchiolar smooth muscle cells and dilate passageways and/or with corticosteroids |
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Structure of the nephron – including histology
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o Renal corpuscle – where blood filtration occurs
• Bowman capsule – simple squamous epithelium • Vascular pole – afferent glomerular arteriole enters, and efferent glomerular arteriole leaves • Glomerulus – lots of capillaries that extends into Bowman capsule o Proximal convoluted tubule – simple cuboidal or columnar epithelial cells that have microvilli (brush border) • Drains Bowman capsule at urinary pole • Resorbs from glomerular filtrate all glucose, amino acids, and small proteins, and at least 80% of NaCl and H2O • Exchanges H+ in filtrate • Secretes organic acids and bases and certain foreign substances into filtrate o Loop of Henle • Descending thick – simple cuboidal and brush border • Resorbs, exchanges, and secretes in a manner similar to proximal convoluted tubule • Thin parts – simple squamous with few short microvilli • Ascending thick – cuboidal with few microbilli • Establishes a gradient of osmolarity in medulla o Juxtaglomerular apparatus – smooth muscle cells, closely packed epithelial cells • Maintains blood pressure by decreasing extracellular fluid volume that stimulates the secretion of rennin into bloodstream → rennin covers angiotension I to angiotension II via ACE → angiotension II stimulates release of aldosterone → aldosterone stimulates distal convoluted tubule to remove Na+ and Cl-, followed by water → increases fluid volume and increases BP o Distal Covoluted tubule – simple cuboidal or columnar epithelium without brush border • Resorbs Na+ from filtrate and actively transports it to renal interstitium stimulated by aldosterone |
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Structure / function Digestive System
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o Consists of a hollow tube
• Mucosa – superficial layer of epithelium (stratified squamous → simple columnar → stratified squamous), lamina propria (basement membrane made of connective tissue), muscularis mucosae (smooth muscle cells – inner circular and outer longitudinal) • Submucosa – dense, irregular connective tissue that contains blood vessels and nerves • Muscularis externa – inner circular layer and outer longitudinal layer of smooth muscle • Serosa/Adventitia o Function – secretes enzymes and hormones that function in ingestion, digestion, and absorption of nutrients in elimination of indigestible materials |
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Process of digestion and absorption
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o Esophagus – conveys bolus from pharynx into stomach via peristalsis
o Stomach – acidifies and converts bolus into chyme, produces digestive enzymes and hormones • Parietal cells – secretes HCl and gastric intrinsic factor • Chief cells – secretes pepsinogen, and precursors of rennin and lipase • DNES cells – releases gastrin that stimulates HCl secretion and gastric motility, somatostatin which inhibits release of gastrin, urogastrone which inhibits HCl secretion o Small intestine – secretes hormones, completes digestion, absorbs resulting metabolites • Carbs/Proteins breakdown via amylase and protease → surface absorptive cells → lamina propria → circulation • Fats are degraded by lipase and do not enter circulation o Large intestine – absorbs electrolytes, fluids, and gases |
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Pathology of Endocrine
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o Pituitary adenomas – common tumors of anterior pituitary which enlarge and suppress secretions, and destroys surrounding bone and neural tissues
• Treated by surgical removal o Graves disease – enlargement of thyroid gland and protrusion of eyeball • Excessive production of thyroid hormone and creased amounts of follicular colloid • Caused by the binding of IgG antibodies to TSH receptors that stimulate thyroid follicular cells o Simple goiter – enlargement of thyroid gland caused by insufficient iodine in diet • Treated by dietary iodine o Hyperparathyroidism – excessive secretion of PTH and bone resorption • Associated with high blood calcium levels → deposition of Ca salts in kidneys and walls of blood vessels o Addison disease – secretion of inadequate amounts of adrenocortical hormones due to destruction of adrenal cortex |
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Anatomy of Liver
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o Composed of hepatocytes
o Surrounded by dense, irregular, collagenous connective tissue o Liver lobule – hexagonal mass of tissue composed mostly of plates of hepatocytes that radiate from central vein • Portal triad – portal vein, hepatic artery, and bile duct – present at each corner of a lobule |
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Liver disease
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o Hepatitis – inflammation of liver due to viral/toxic infections
• A – infectious – transmitted by fecal-oral route and may cause jaundice • B – serum – transmitted via blood • C – responsible for most transfusion-related causes of hepatitis |
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Changes in the uterus across the menstrual cycle
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o Primordial follicle – composed of 1˚ oocyte enveloped by a single layer of flat, follicular cells
• 1˚ oocyte is arrested in prophase I o 1˚ follicle – independent of FSH for development • Has zona pellucida that surrounding • Produced by 1˚ oocyte • Unilaminar – develop from primordial cells – single layer of cuboidal follicular cells surrounding 1˚ oocyte • Multilaminar – develop from unilaminar follicles via proliferation of follicular cells via activin • Consists of granulosa cells and has 2 layers (theca interna and theca externa) o 2˚ follicle = antral follicles • Established when fluid accumulates in space between granulosa cells to produce antrum • Dependent on FSH that stimulates granulosa cells to convert androgens to estrogen and receptors for LH • Has gap junctions o Mature follicle – only follicle that will ovulate and is released during ovulation • Corona radiata will contract zona pellucida, Theca interna cells move androgens so they can convert to estrogen, Theca externa provides nourishment for theca interna |
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Effect of age on the ovary
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o As you age, you lose eggs
o Menopause – ovaries stop releasing eggs and periods stop • Hormonal changes – ovary gets desensitized to certain hormones • Decrease in estrogen and progesterone |
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The Viagra story
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o Nobel prize in 1998 to Furchgott, Ignarro, and Murad
o Sildenafil = phosphodieserase inhibitor • Competes with cGMP • Parasympathetic – vasodilator occurs in pulmonary arteries and blood vessels in penis → erection • Sympathetic → erection, emission, and ejaculation |
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Structure and function in the epididymis
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o Efferent ductules reabsorb seminal fluid
o Circular layer of smooth muscle moves sperm toward vas deferens o Has coiled ducts that store sperm o Tall pseudostratified columnar with stereocilia |
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Formation of the placenta
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o 1. Implantation of blastocyst with synctiotrophoblast begins to invade the uterine wall
o 2. Maternal blood vessels encountered by syncytiotrophoblast, lacunae are formed and filled with maternal blood o 3. Cytotrophoblast cord surrounds the syncytiotrophoblast and lacunae and embryonic mesoderm enters cord |
