ALL THE THINGS! Flashcards
What are the 3 functions of the lymphatic system?
return fluid/plasma proteins to blood
return lymphocytes to recirculating pool
add antibodies formed in lymph nodes
What is lymph?
ultrafiltrate of plasma
What are the 3 types of lymphatic vessels?
Capillaries, vessels, ducts
What are the characteristics of lymphatic capillaries?
thin walled, incomplete basement membrane, anchoring filaments, end in extracellular spaces
What are the characteristics of lymphatic vessels?
larger lumen than blood vessels, thick walls, flow depends on pressure
What are the characteristics of lymphatic ducts?
main ducts are right lymphatic and thoracic
empty in R/L venous angles
What is diffuse lymphoid tissue?
not delineated from connective tissue, made up reticular fibers, found in lymph nodes, spleen, tonsils, MALT in GI
What are lymphoid nodules?
dense lymphoid tissue found in the cortex of lymph nodes, splenic white pulp, tonsils, and MALT
What are primary lymphoid nodules?
rounded, tightly packed with small lymphocytes.
Primary lymphoid nodules house B or T cells?
T cells
What are secondary lymphoid nodules?
spherical cluster of larger pale stained cells surrounded by a small lymphocyte cap. Have germinal centers.
Secondary lymphoid nodules house B or T cells? Where?
B cells in the germinal centers
What is the function of lymph nodes?
filter lymph and lymphocyte production (immune response)
Where are lymph nodes found?
found in mesentery, axilla, groin
The cortex of a lymph node has what characteristics?
an outer portion filled with lymphoid nodules and a deep portion of diffuse lymphoid tissue known as the Thymus dependent are filled with T-lymphocytes
The medulla of a lymph node has what characteristics?
consists of lymphoid tissue with irregular anastomosing medullary cords, which form spaces called medullary sinuses. Mainly have B-cells
What is the pathway taken by lymph as it passes on its way through a lymph node?
Affertent lymphatic vessel to subscapular sinus to peritrabechular sinus to medullary sinus to efferent lymphatic vessel
WHat are the characteristics of a lymphatic sinus in a lymph node?
lined with dendritic cells and macrophages, with a permeable wall. Facilitate the macrophages.
What forms the reticular meshwork in lymphatic sinuses in lymph nodes?
dendritic cells and macrophages
What are medullary cords?
aggregations of diffuse lymphoid tissue, B-lymphocytes, and macrophages.
What are medullary sinuses?
large, tortuous, channels that anastomose. They are between trabeculae and cords
What are postcapillary venules?
they are traversed by small lymphocytes from the blood and they represent the entry way from blood to lymph
What is another name for postcapillary venules?
high endothelial venule (HEV)
What are some characteristics of the spleen>
complex blood filtration system made up of large amounts of lymphoid tissue. Made up of white and red pulp
What are the functions of the spleen?
storage and destruction of blood cells and platelets
production of lymphocytes
iron metabolism
immune response
Describe splenic white pulp
lymphoid tissue nodules that form peri-arterial lymphoid sheath (PALS) around central arteries, which pass inti pukp from trabeculae
Describe splenic red pulp
rich in blood and contains splenic sinusoids and splenic cords, which are supported by a reticular meshwork
What are the splenic marginal zones?
area between the two pulps. Harbors blood-borne antigens
Through which structures does blood flow on its way through the spleen?
Splenic artery to trabecular arteries to central arteries to penicillar arterioles to splenic sinus to pulp vein to trabecular vein to splenic vein
What is a splenic sinusoid?
they possess lingitudinal slits that resemble a leaky barrel for blood elements to pass through
What is a splenic cord?
found in the red pulp of the spleen between the sinusoids, consisting of fibrils and connective tissue cells with a large population of monocytes and macrophages.
What is another name for splenic cords?
Cords of Billroth
What are the functions of the Thymus?
T-cell maturation and immunologic response
Describe how the Thymus is organized into lobes and lobules
thymus has two lobes, which extend into lobules, which then have a cortex and medulla
What are the characteristics of the thymic cortex?
has an outer cortex with lymphoblasts
cortex is smaller in the middle and houses small lymphocytes near the medulla.
lower mitotic rate in inner cortex.
Has naive T-cells
What are some characteristics of the thymic medulla?
continuous between lobules, less dense than cortex, and contains Hassal’s corpuscles. Has selected immunocompetent T-Cells
Describe how blood vessels are arranged in the thymus
arteries form arterioles which follow the corticomedullary junction
capillaries go up and down into cortex and medulla, and the cortical capillaries drain into corticomedullary postcapillary venules
What are the components of the blood-thymus barrier?
made up of a continuous endothelium with a basement membrane, a perivascular space (macrophages present), and a reticular epithelium with a basement membrane
What is the blood-thymus barrier?
it regulates entrance into the blood from the thymus to create the needed environment for T-cell development
How many types of thymic reticular cells are there and what are their general functions?
6 types that secrete cytokines for thymocyte migration and they also produce hormonal factors for T-cell maturation (Thymosin)
Which thymic reticular cells are found in the cortex?
Types I, II, III
Which thymic reticular cells are found in the medulla?
Types IV, V, VI
What is the function of Type I cells?
barrier to isolate developing T_cells
What is the function of Type II cells?
compartmentilization of the cortex, and positive selection
What is the function of Type III cells?
barrier between cortex and medulla (cortical side)
What is the function of Type IV cells?
barrier between cortex and medulla (medullary side)
What is the function of Type V cells?
framework of the medulla and negative selection
What is the function of Type VI cells?
These are Hassal’s Corpuscles: concentric lamellae that may produce cytokines to program thymocytes
What are the two main divisions of the pituitary gland?
adenohypophysis (ant)
neurohypophysis (post)
What are the parts of the ant. pituitary?
pars disatlis, tuberalis, and intermedia
What are the parts of the post. pituitary?
pars nervosa, median eminence, and infundibular stalk
How is the pituitary gland developed?
infundibulum invaginates from the floor of the brain and forms the infundibular stalk and the pars nervosa
What role does Rathke’s pouch play in development of the pituitary?
it forms the oral ectoderm; forms the adenohypophysis
Describe the blood supply of the pituitary gland
inferior hypophyseal arteries supply the neurohypophysis
superior hypophyseal arteries supply the capillary plexus in the pars tuberalis
How does blood flow from the superior hypophyseal arteries?
sup hypo a. to 1st plexus to hypophyseal vein to 2nd plexus
capillaries reach from the plexus to the median eminence and infundibular stalk
primary plexus drains to the hypophyseal veins, then into sinusoidal capillaries in the pars distalis (2nd plexus)
What are the 3 main cell types of the pars distalis and what percentage does each make up?
A - acidophils 40%
B - basophils 10%
C - chromophobes 50%
Describe chromophobes
degranulated, supporting cells
What do acidophils secrete?
prolactin and GH
What do basophils secrete?
TSH, FSH, LH, ACTH
What are the hormones of the ant pituitary?
The Pirate FLAG
TSH Prolactin FSH LH ACTH GH
What does prolactin do?
causes progesterone secretion by corpus luteum, mammary gland development, and milk formation
What does Growth Hormone do?
body growth, stimulates insulin like GF1 (IGF - 1) for muscle growth
What does TSH do?
thyroid hormone production/secretion
What does FSH do?
ovarian follicle stimulation, estrogen secretion, sertoli cell stimulation (sperm)
What does LH do?
corpus luteum formation, ovulation, progesterone secretion, leydig cell stimulation (testosterone secretion)
What does ACTH do?
gluco and gonadocorticoid secretion from the adrenal cortex
What are the releasing and inhibiting hormones produced in the hypothalamus and what are their functions?
TRH - stimulates prolactin/TSH (antagonist is dopamine)
GHRH - stimulates GH (antagonist is somatostatin)
GRH - at low frequency stimulates FSH and at high frequency stimulates LH
Describe the pars intermedia
poorly developed, produces MSH (melanocyte production)
Describe the pars tuberalis
forms the collar around the infundibular stalk, produces gonadotropin
Name the components of the neurohypophysis
made up of pituicytes and cell axons from the hypothalamus
hypothalamo-hypophyseal tract arises from the supraoptic and paraventricular nuclei. contains Herring bodies which are hormone accumulations in the axons
What are the hormones in the pars nervosa? Name the specific locations
Oxytocin from paraventricular nucleus
Vasopressin from supraoptic
Neurophysin is a carrier protein for oxytocin and ADH
What does oxytocin do?
uterine contraction, milk ejection reflex
What does vasopressin do?
produces ADH which allows for water reabsorption in the kidney; raises BP
What does neurophysin do?
is a carrying protein for oxytocin and ADH; prevents diffusion out of axons
What are endocrine glands? Examples?
ductless and secrete product into bloodstream
adrenal, thyroid, parathyroid, pituitary, and pineal
What are exocrine glands? Examples?
attached by duct to surface where it is emptied
sweat, salivary, sebaceous, and mammary glands
What glands have both Endo and Exo functions?
gonads and pancreas
What is a hormone?
chemical transported by blood or body fluid that has specific regulatory effect on cells away from its origin
What are the two cell types of the pineal gland?
Pinealocytes
Glial cells
What do pinealocytes do?
main cell type in pineal gland arranged in clusters; release melatonin
What do pineal glial cells do?
they are interstitial cells, scattered between pinealocytes, that resemble astrocytes (support)
How does melatonin help control the circadian clock?
during darkness, it is released, and it acts on the hypothalamus and pituitary to induce sleepiness. also inhibits GnRH, which reduces FSH/LH and in turn decreases gonadal steroid production
What blocks melatonin?
light and sympathetic blocking agents inhibit melatonin
What is brain sand?
aka corpora arenacea; calcium/magnesium phosphates and carbonates that illustrate the midline of the brain radiographically (look like clumps)
secreted by pinealocytes
Describe the location and organization of the adrenal gland
located at the sup pole of each kidney
triangular bodies are covered by a capsule and CT trabeculae that projects into each gland.
Has a large cortex and a small medulla
What are the 3 layers of the adrenal cortex? (In order)
Zona glomerulosa
Zona fasciculata
Zona reticularis
Describe the arrangement of the zona glomerulosa
small, ovoid cell groups surrounded by fenestrated sinusoids
Describe the arrangement of the zona fasciculata
thickets layer of large, parallel cords of cells that are separated by fenestrated sinusoids
Describe the arrangement of the zona reticularis
small cells anastomosing cells separated by fenestrated sinusoids
What is the main hormone produced by the adrenal cortex?
corticosteroids (gluco and mineralocorticoids)
also produces androgens
Zona glomerulosa produces
mineralocorticoids (aldosterone) which increases BP
stimulated by angiotensin II
Zona fasciculata produces
glucocorticoids (cortisol), for carb metabolims, protein metab, lipid metablolism, and inflammation
stimulated by ACTH
Zona reticularis produces
androgens (DHEA), e.g. testosterone precursor
stimulated by ACTH
The adrenal medula produces what?
catecholamines epinephrine and norepinephrine
Describe the blood supply of the adrenal gland
supplied by suprarenal arteries that enter at the hilum and branch into capsular plexus
medulla also supplied by medullary artery
After entering the hilum and branching into the capsular plexus, how is blood supplied by the suprarenal arteries?
capsular capillaries supply the capsule
fenerstrated cortical capillaries go through the glomerulosa and form a network in the reticularis; these capillaries drain into medullary venous sinusoids in the medulla
The adrenal medulla receives dual blood supply how?
medulla gets dual blood supply; venous from medullary sinusoids and arterial from medullary arteries
What is the origin and function of chromaffin cells>
arranged around blood vessels and are modified postsynaptic sympathetic neurons without axons
secrete catecholamines in the adrenal medulla
Describe the location and organization of the thyroid gland?
two lobes on each side of trachea connected by an isthmus
has a thin fibro-elastic capsule that forms trabeculae that divide the gland into lobules
each functional unit of the gland is called a follicle and they are surrounded by fenestrted capillaries
Describe the thyroid follicle
an epithelial sac lined by a single layer of follicular epithelium
consists of colloid, gel like material thats main part is thyroglobulin (inactive thyroid hormone storage)
follicular cells produce TH, also contact the colloid and contain lysosomes
parafollicular cells also present that dont reach the lumen and produce calcitonin ( C-Cells)
What are the steps involved in the synthesis, storage, uptake and secretion of thyroid hormone (TH)
- synthesis of thyroglobulin
- uptake of Iodide
- oxidation of Iodide
- T3/T4 liberation
What does thyroid hormone do?
regulates cell metabolism (growth and development)
What are symptoms of HYPOthyroidism?
cretinism in children and myxedema in adults (T3/T4 can’t stimulate HGH)
What are the symptoms of HYPERthyroidism?
stimulates more T3/T4 production, metabolism and weight down
Describe the location of the parathyroid glands
two glands on each side behind the thyroid lobes
small oval glands with thin capsule
cells appear as a dense mass in anastomosing cords, and many fenestrated capillaries between the cords
What cell type is responsible for producing parathyroid hormone?
chief cells: principal cells that produce PTH (increase blood Ca level)
What is the function of parathyroid hormone?
antagonist to calcitonin
PTH regulates calcium concentration in blood and bone
In the endocrine pancreas, what are islets of Langerhans?
large, pale staining areas supported by reticular tissue
have irregular anastomosing cords and cell clumps separated by capillaries
What are the 3 cell types found in the islets of Langerhans?
Alpha
Beta
Delta
What do Alpha cells do?
secrete glucagon
insulin antagonist, stimulates glucose release into bloodstream; increase blood glucose
What do Beta cells do?
Secrete insulin
stimulates glucose uptake
What do Delta cells do?
secrete somatostatin
inhibits Alpha and Beta cells
How does the liver receive venous blood?
from the intestines via the portal vein
How does the liver receive arterial blood?
from circulation via the hepatic artery
Where do the hepatic veins drain>
directly into the IVC
What are the main functions of the liver?
metabolizes digestion products from the intestine
detoxification of toxins
bile production/release
amino acid/protein production (plasma proteins)
carb storage and glucose release
lipid metabolism
vitamins/iron storage and conversion (Vit A,D,K)
hormone synthesis
Describe the classical liver lobule
hexagonal with central vein in center and portal triad at each corner
List the structures within the portal triad/area
portal vein, hepatic artery, and bile duct
sometimes contains a lymphatic vessel
Where does the portal triad enter the liver?
enters the porta hepatis on the inferior surface of the liver
What is the sequence of blood vessels in the liver?
Blood enters sinusoids from terminal branches of the hepatic artery and portal vein (More portal blood). Blood then reaches the central vein (arterial and venous) from the sinusoids
After entering the central vein, how does blood flow through the liver?
drains into sublobular vein then to hepatic vein and finally to IVC
What are the two cell types that line the hepatic sinusoids?
Endothelial cells
Kupffer cells
Describe the endothelial cells of the hepatic sinusoids
have large fenestrations and a discontinuous basement membrane (no filtration barrier)
Describe Kupffer cells of the hepatic sinusoids
derived from monocytes (phagocytic) are between the endothelial cells and destroy bacteria
What is the Space of Disse? (Not the function)
the perisinusoidal space between endothelial cells and hepatocytes
numerous microvilli on hepatocytes increase SA for absorption
What is the function of the Space of Disse?
is an area for proteins to be absorbed from the sinusoids into the hepatocytes
Hepatic stellate cells in the Space of Disse help store what?
Vitamin A
In the Space of Disse, what can the Hepatic stellate cells differentiate into? What will they produce?
into myofibroblasts and produce collagen (fibrosis and cirrhosis)
Describe the structure of the bile canaliculus
little canals between hepatocytes
tight junctions seal these canaliculi
What is the function of the bile canaliculus?
bile is actively secreted into these canaliculi from hepatocytes
In the liver, canaliculi join to form what that drain where?
form intrahepatic ductules (canals of Hering) that drain into interlobular ducts in the portal areas
How is the hepatic duct formed?
interlobular ducts join main ducts to form the hepatic duct.
When the cystic duct joins the hepatic duct, what is formed? Where does this carry bile to?
common bile duct is formed which carries bile to the duodenum
The gallbladder is attached to the liver. What kind of bile does it receive and through which duct?
diluted bile from the hepatic duct
What kind of epithelium makes up the walls of the gallbladder?
simple columnar epithelium with microvilli (has many folds)
The lamina propria of the gallbladder is full of what kinds of capillaries?
fenestrated capillaries
The fibromuscular layer of the gallbladder discharges what?
bile
What does the gallbladder even do?
concentrate and store bile
Which cells secrete cholecystokinin (CCK)?
enteroendocrine cells of the small intestine
What happens when CCK is released by the enteroendocrine cells of the small intestine?
the muscular layer of the gallbladder contracts and releases bile into the duodenum
What is the composition and function of saliva?
colorless liquid containing water, mucin, carbs, protein and inorganic compounds. Also contains enzymes amylase, maltase, and lipase to digest carbs and lipids
Which glands produce saliva?
salivary glands that include the parotid, submandibular and sublingual
Describe the serous secretory unit within the salivary glands
has round nuclei, intercellular canaliculi, zymogen granules in apical cytoplasm, product is watery with enzymes
Describe the mucous secretory unit within the salivary glands
has flat nuclei, no intercellular canaliculi, larger lumen than serous, mucinogen granules in cell apex and lumen
Describe the structure, function, and location of salivary gland myoepithelial cells
present in both secretory units
lie between glandular cells and the basement membrane
contain myofilaments that allow contraction to facilitate secretion into ducts
What are the 3 types of ducts in salivary glands?
intercalated ducts
striated ducts
excretory ducts
What are the intercalated ducts of the salivary glands?
intralobular, small ducts that secrete bicarbonate and absorb chloride; many in serous glands
What are the striated ducts of the salivary glands?
intraloblar, columnar cells that secrete potassium and bicarbonate and absorb sodium
What are the excretory ducts of the salivary glands?
INTERlobular, and epithelium goes from columnar to pseudostratified to stratified
Describe the parotid gland
largest, paired, anterior to ear, and are purely serous with numerous intercalated and striated ducts
Describe the submandibular gland
paired, in floor of mouth and side of neck, with both types of secretions (serous/mucous)
Describe the sublingual gland
collection of glands in floor of mouth (each with own duct) and the majority of alveoli are mucous
State the function of the exocrine pancreas
produces/secretes digestive enzymes
Describe the structure of the pancreatic acinus
are compound serous and have secretory capillaries between them with a central lumen.
base of each cell is basophilic and the apex is acidophilic
List the types of ducts in the pancreas beginning at the acinus
Intercalated ducts empty into INTERlobular ducts which converge on main ducts (no striated ducts)
Main pancreatic duct of Wirsung and the accessory pancreatic duct of Santorini make up the two large ducts
Where does the main pancreatic duct of Wirsung empty into the duodenum?
in the hepatopancreatic ampulla of Vater
List the digestive enzymes produced by the pancreas
Zymogen granules contain protease precursors
nucleases
amylase
lipases
What two duodenal hormones control pancreatic activity?
Secretin
CCK
What does Secretin do?
induces release of bicarbonate fluid to neutralize intestinal acid, provides optimal pH for pancreatic enzyme activity
How does CCK effect the pancreas?
causes pancreatic secretion of digestive enzymes as well stimulate gallbladder contraction
Describe the outer surface of the lip
covered with thin hairy skin
red area is the transition from skin to mucous membrane (highly vascular, not heavily keratinized, with no sweat glands, hair follicles, or sebaceous glands)
Describe the inner surface of the lip
covered with stratified non-keratinized epithelium and small clusters of mucous glands in the lamina propria
Describe the mucous membrane typical of the oral cavity
stratified, non-keratinized epithelium with high papillae in the lamina propria
What is and where is the Sulcus terminalis located?
V-shaped groove on the dorsal surface of the tongue
The sulcus terminalis divides the tongue into what divisions?
anterior 2/3 (oral)
posterior 1/3 (pharyngeal)
What are the kinds of papillae on the dorsal surface of the tongue?
Filiform
Fungiform
Foliate
Circumvallate
What is the filiform papillae?
parallel to sulcus terminalis, arranged in rows, and are high/narrow conical structures
NO TASTE BUDS
What is the fungiform papillae?
scattered among filiform papillae and numerous at tip of tongue; look like fungus and have taste buds on upper surface
What is the foliate papillae?
leaf shaped, non keratinized, with taste buds
What is the circumvallate papillae?
about a dozen near the sulcus terminalis with many taste buds, and glands of von Ebner (serous) empty into the middle of them
Describe the lingual tonsil
root of tongue with epithelium extending into lymphatic tissue to form crypts, and they have mucous glands to wash out the crypts
Describe the palatine tonsil
between the glossopalatine and pharyngopalatine arches and have a CT capsule with septa passing inward; have primary and secondary crypts
their ducts open on surface and not in crypts (prone to infection)
List the layers of the GI tract in order
Mucosa
Submucosa
Muscularis externa
Serosa/Adventitia
Describe the mucosal layer of the GI tract
epithelium with lamina propria (loose CT) and muscularis mucosae (2 layers of smooth muscle)
Describe the submucosal layer of the GI tract
dense irregular CT with elastic fibers and Meissner’s nerve plexus
Describe the muscularis externa layer of the GI tract
2 layers of smooth muscle (inner circular, outer longitudinal), with Auerbach’s nerve plexus
Describe the serosa/adventitia layer of the GI tract
mesothelium of simple squamous epithelium (serosa) or it blends with CT of surrounding organs (adventitia)
Where are glands associated with the GI located?
in the lamina propria and submucosa
Name the 3 parts of the pharynx and give the type of epithelium lining each type
Nasopharynx - respiratory epithelium (pseudostratified ciliated w/ goblet cells)
Oropharynx - stratified, non-keratinized epithelium
Laryngopharynx - stratified, non-keratinized epithelium
Describe the muscularis mucosa of the esophagus at upper, middle, and lower levels
Upper 1/3 - skeletal muscle
Middle 1/3 - skeletal/smooth muscle
Lower 1/3 - smooth muscle
Describe the rugae and gastric pits of the stomach
Rugae - irregular folds in submucosa for increased SA for absorption
Gastric pits - invaginations of mucosal surface that descend into the lamina propria that are the home of gastric glands
What type of epithelium lines the stomach?
simple columnar with surface mucous cells
What cells line the stomach?
No goblet cells
has mucinogen granules in the apical portion of the surface cells
How are gastric glands and gastric pits related?
Gastric glands are present throughout the gastric mucosa and are branched; they empty into gastric pits that have surface mucous cells
What are the 4 cell types in gastric glands?
Chief (zymogenic) cells
Parietal cells
Mucous neck cells
Enteroendocrine cells
Undifferentiated cells
What is the function of the chief cells?
secrete pepsinogen and lipase
What is the function of the parietal cells?
secrete HCl and intrinsic factor (Vitamin B12 absorption for RBC maturation)
What is the function of the mucous neck cells?
secrete mucin
What is the function of the enteroendocrine cells of the gastric glands?
secrete gastrin, serotinin, histamine
What is the function of the undifferentiated cells?
replace pit/surface epithelium upward and glandular epithelial cells downward
What are the 4 ways the surface area of the small intestine can be increased for absorption?
long distance of the intestine
Plicae circulares - semicircular folds
Intestinal villi - finger-like projections
Microvilli - increase SA of epithelial cells
What 2 cell types are found in the surface epithelium of the small intestine?
Enterocytes - columnar absorptive cells
goblet cells
What is the function of the enterocytes in the small intestine?
housed in the simple columnar epithelium, help in absorptions and digestions
What is the function of the goblet cells in the small intestine?
discharge mucin
Where are the crypts of Lieberkuhn located?
in the lamina propria of the small intestine and invaginate from surface
Which cells are contained in the upper half of the crypts of Lieberkuhn?
absorptive goblet and enteroendocrine cells (CCK secretion)
Which cells are contained in the lower half of the crypts of Lieberkuhn?
Paneth cells - large eosinophilic cells that secrete antimicrobial lysozymes and defensins
Where can you find Brunner’s glands?
in the submucosa of the duodenum
What is the function of Brunner’s glands?
are compound tubular glands that produce bicarbonate filled mucus
ducts penetrate the muscularis mucosae and empty into the crypts
What are Peyer’s Patches?
lymphatic nodules in the lamina propria and submucosa of the ileum (contains antigen presenting cells called M-Cells)
What is the role of the undifferentiated columnar cells in the crypts?
Stem cells in the crypts migrate from the base to the tip of the villi in 3 days, and millions of them are shed everyday and replaced by upward migration
Describe the structure of the large intestine (compared to the small intestine)
No villi
long and straight crypts
No Paneth cells
Outer longitudinal layer of muscularis externa is divided into 3 longitudinal bands called taeniae coli
What does the taeniae coli of the large intestine form?
form saccules in the large intestine called haustrae
What are the principal features of the vermiform appendix?
No villi
lymphoid tissue in lamina propria
less crypts
poorly developed muscularis mucosae
the submucosa has blood vessels
No taeniae coli
Where does the kidney lie i the body? What space?
retroperitoneal space
What is the kidney surrounded by and what is it divided into?
surrounded by capsule and divided into cortex and medulla
The Hilum of the kidney has what that travels all the way to the bladder?
ureter
In the hemisected view, what all would you see in the kidney?
medullary pyramids (8-12) renal colums medullary rays lobes lobules pelvis papilla collecting ducts
List the segments of a nephron
renal corpuscle
proximal convoluted tubule
Loop of Henle (thick/thin; descending/ascending)
distal convoluted tubule which joins a collecting duct
What are the primary processes of podocytes?
foot like processes that extend from the nuclear region
Describe the secondary processes of the podocytes and how they are associated with glomerular capillaries
arise from primary processes
have thin gaps (filtration slits) to allow filtration barrier between the blood in the glomerular capillaries and Bowman’s capsule
List the components of the filtration barrier established by podocytes
fenestrated endothelium of glomerular capillaries, capillary basement membrane, and the slit membrane in filtration slits
What factors contribute to ultrafiltration?
occurs due to efferent arterioles being smaller than afferent ones (increased BP in glomerular capillaries)
slowed blood flow over the glomerular capillaries
thin nature of filtration barrier
Where is the mesangium located?
in the renal corpuscle between glomerular capillaries
What functions do the mesangial cells carry out?
function in phagocytosis in the glomerulrar basement membrane
contraction for blood flow regulation
structural support and secretion (cytokines and growth factors)
Where is the juxtaglomerular apparatus located?
at the vascular pole formed from the terminal portion of the distal straight tubule and an afferent arteriole
What are the 2 components of the juxtaglomerular apparatus?
Macula densa
Juxtaglomerular cells
What is the Macula densa?
region in the distal tubule where cells are narrow and packed to help with sampling sodium concentration and pressure of the ultrafiltrate
What do the juxtaglomerular cells do?
modified smooth muscle cells in the tunica media of the afferent arteriole with renin granules that lead to an increase in BP through the renin-angiotensin-aldosterone system
Compare the epithelial lining of the proximal tubule, thin segment of the loop of henle, and distal tubule
Proximal tubule - simple cuboidal cells with microvilli brush border
Thin segment - simple squamous
Distal straight tubule (thick segment) - simple cuboidal
Several collecting tubules empty into what?
a collecting duct which then descends into medullar ray
Several of the collecting ducts join to form what that open into what?
form papillary ducts of Bellini that open into minor calyx
Describe the epithelium of collecting ducts
has light cells with aquaporins and dark cells (secrete H+ or bicarbonate, depending)
What is the composition of the interstitial tissue?
little interstitial tissue in the cortex, but abundant in the medulla
has fibrolasts that produce the ECM and macrophages
What are the endocrine functions of the kidneys?
renin produced by the juxtaglomerular cell increases blood volume and BP
erythropoietin (EPO) produced by fibrolasts increases RBC formation
calcitriol produced by cells lining the PCT increase Ca2+ to increase blood Ca
The abdominal aorta gives off what to supply the kidneys?
renal arteries
The renal arteries divide into how many branches?
3 main branches
The 3 main branches of the renal arteries divide into how many pyramid branches?
3-4
In the hilum, the pyramid branches divide into what?
INTERlobar arteries which ascend between pyramids
At the corticomedullary junction, the interlobar arteries form what?
arcuate arteries that run parallel to the kidney surface
The arcuate arteries give rise to what?
INTERlobular arteries that ascend into the cortex
The interlobular arteries branch to form what?
afferent arterioles
The afferent arterioles form what?
glomerular capillaries
Unfiltered blood is collected by what in the kidneys?
efferent arterioles
When the efferent arterioles leave the glomeruli, they break up into what?
peritubular capillary network in the cortical nephrons
vasa recta in juxtamedullary nephrons
In what order does blood flow through the kidney?
- renal arteries
- pyramidal arteries
- interlobar arteries
- arcuate arteries
- interlobular arteries
- afferent arterioles
- glomerular capillaries
- efferent arterioles
- peritubular capillary/vasa recta
In cross section, where is the ureter located?
is continuous with the renal pelvis
Describe the ureter in cross section (epithelium, etc.)
lined with 4-5 layers of transitional epithelium, with a thick muscularis (inner longitudinal, outer circular), and it is surrounded by adventitia
The urinary bladder is similar to the ureter, except why?
except that the transitional epithelium is thicker with binucleate cells
The plasma membrane of the lumen of the urinary bladder is what? (thick or thin)
thick
How many layers of muscularis are there in the urinary bladder? What is the region also called?
3 layers
prominent middle layer
What are the divisions of the male urethra? (2 divisions)
prostatic urethra
penile urethra
What epithelium is found in the prostatic urethra?
transitional epithelium
What epithelium is found in the penile urethra?
pseudostratified epithelium
What are the 3 parts of the male urethra? (You already said two of them on previous cards :] )
prostatic, membranous, penile
Describe the female urethra
short with transitional epithelium
List the main features of the cortex of the ovary
CT stroma containing follicles
simple cuboidal epithelium
tunica albuginea
List the main features of the medulla of the ovary
loose CT
elastic and smooth muscle fibers
blood vessels
lymphatics
nerves
Before birth, the mesoderm at the surface of the ovaries forms what kind of epithelium?
germinal epithelium
Where do the oogonia develop and where do they migrate before birth?
develop in the yolk sac
migrate to the ovary
Once in the ovary, what happens to the oogonia? What forms? (still before birth)
the oogonia divide many times and enlarge to form primary oocytes
The primary oocytes become enclosed by what kind of epithelium? What do they then form? (still before birth)
become enclosed by simple squamous epithelium to form primordial follicles
The primordial follicles enter which meiosis? Which stage? How many oocytes remain at birth?
enter meiosis 1 and rest in prophase until puberty
1 million oocytes remain at birth
List the order of maturation of an ovarian follicle
- primordial follicle (squamous)
- primary follicle (cuboidal)
- secondary follicle
- Graafian follicle
During the maturation of an ovarian follicle in the follicular phase, what stimulates the primary oocyte growth in the primordial follicle? (What hormone)
FSH - follicle stimulating hormone
During the follicular phase, the follicular cells form several layers that form what?
Zona granulosa
During the follicular phase, the granulosa cells formm what?
the zona pellucid which provides nutrients
After the zona pellucida forms, what else forms in the granulosa?
an antrum forms in the granulosa
Following the formation of an antrum, what else forms?
theca folliculi
What are the divisions of the theca folliculi?
theca interna
theca externa
What is the function of the theca interna?
secretory function - secretes estrogen
What is the theca externa? Describe it.
it is connective tissue
After how many days is the ovarian follicle fully mature?
10-14 days
Which cells in produce estrogen during this maturation?
granulosa cells (secreted by theca interna)
What is the first step in the process of ovulation?
Graafian (mature) follicle bulges on the ovary surface
After the Graafian follicle bulges on the ovary surface, what is the second step of ovulation?
the surface layers rupture
After the surface layer ruptures, what is the final stage of ovulation?
the ovum is released and drawn into the oviduct by its fimbriae
What is fertilization?
the sperm fertilizes the egg once it is in the ampulla
What is the corpus luteum?
is the collapsed follicle after ovulation
What is the function of the corpus luteum?
secretes mostly progesterone and some estrogen
If fertilization occurs, how many months does the corpus luteum last?
6 months
6 months after fertilization, what happens to the corpus luteum?
declines gradually to a corpus albicans
If fertilization doesn’t occur, how many days before the corpus luteum generates the corpus albicans?
14 days
What is an atretic follicle?
the follicles that do not mature become a CT scar
What is the corpus albicans?
after birth, the corpus luteum becomes a CT scar
What transports the ovum from the ovary to the uterus?
the oviduct
What epithelium does the oviduct have?
simple columnar epithelium with some ciliated cells and others for nutrient secretion
The muscularis layer of the oviduct is divided into what layers? What are the divisions for?
inner circular and outer longitudinal layer to move the fertilized ovum to the uterus
The oviduct has how many segments?
4
What are the segments of the oviduct? Give a unique feature for each
Infundibulum - has fimbriae
Ampulla - longest part, where fertilization occurs
Isthmus - medial narrow third
Intramural part - crosses the uterine wall to open into the uterine cavity
Describe the perimetrium of the uterus
typical serosa that’s continuous with the broad ligament
Describe the myometrium
3 smooth muscle layers with a thick circular middle layer that aids in fetal expulsion at birth (oxytocin acts on this layer for contraction)
Describe the endometrium
simple columnar w/ two types of cells - ciliated and secretory
What kinds of glands are present in the endometrium? What do they secrete?
tubular glands that secrete glycogen
Which layer changes during the menstrual cycle?
endometrium
What layer of the endometrium remains after menstruation?
stratum basale (basal layer)
Which layer of the endometrium is lost after menstruation?
stratum functionale (functional layer)
What is used to regenerate the stratum functionale?
the stratum basale
Which artery is destroyed during menstruation?
spiral artery
What is the spiral artery branching off of?
Straight artery that comes from the stratum basale
The proliferative phase goes from which day to which day?
day 4-14
What happens during the proliferative phase?
endometrium thickens; glands are straight/narrow
In the proliferative phase, how are the coiled arteries positioned?
do not extend beyond the lower half of the functional layer
The secretory phase lasts how many days?
12-14 days
In the secretory phase, what happens to the glands? What about secretions?
become tortuous with accumulating secretions
In the secretory phase, how are the coiled arteries positioned?
extend into the superficial endometrium
In the last 2-3 days of the secretory phase, what happens to the arteries?
arteries become constricted due to a decrease in estrogen and progesterone
What accumulates, specifically, in the epithelium during the secretory phase?
glycogen
How many days does the menstrual phase last?
4 days
What structures are lost in the menstrual phase?
stratum functionale along with its part of the spiral arteries are lost
What is supplying the stratum basale after the stratum functionale and it’s associated arteries are lost?
now the spiral arteries only supply the basal layer of the endometrium, specifically the straight artery
What is the initial trigger for the onset of the menstrual phase?
ischemia during the end of the secretory phase due to a decrease in estrogen and progesterone
What happens following the initiation step of the menstrual phase?
blanching of the superficial zone of the endometrium occurs
progesterone and estrogen increase and the constricted arteries dilate causing blood and tissue fluid to lift the endometrium
What are the two main divisions of the cervix?
Endo and exocervix
What makes up the lower segment of the endocervix?
a fibromuscular wall with dense CT and smooth muscle
What kind of epithelium lines the endocervix?
simple columnar epithelium with cilia
What kind of glands are present in the endocervix?
tubular branched glands
What kind of cysts are present on the uterine surface?
mucus-filled cysts called Nabothian cysts
What kind of epithelium lines the exocervic? Does it share this epithelium with another structure?
stratified non-keratinized epithelium
Yes, it’s epithelium is like the Vagina
Does the vagina have any glands?
No
If it doesn’t have glands, then how is the vagina lubricated?
by cervical secretions
These are found on each side of the vaginal orifice (outside) and they secrete mucous
Bartholin’s glans
What kind of epithelium lines the vagina? What is found in the superficial layer in large amounts?
stratified non-keratinized epithelium with large amounts of glycogen in the superficial layers
In the vagina, how does Estrogen form lactic acid? What aids it?
forms lactic acid from glycogen and is aided by Lactobacillus bacteria
The lamina propria of the vagina has what in it?
lymphocytes and lymph nodules
What are the 3 layers of the testis?
tunica vaginalis
tunica albuginea
tunica vasculosa
What is the tunica vaginalis?
cells of peritoneal origin
What is the tunica albuginea?
dense CT and smooth muscle region to help move sperm
Invaginatons in the tunica albuginea form what?
form the mediastinum that split the testis into lobules
What is the tunica vasculosa?
blood vessel network that helps maintain temperature
The radial septa of the tunica albuginea forms roughly how many lobules in the testis?
250 lobules
What is contained in each lobule in the testis?
1-4 seminiferous tubules
Within the lobules of the testis, describe the seminiferous tubules and what kind of epithelium lines them
are highly convoluted and lined by germinal epithelium
Do the seminiferous tubules anastomose with each other?
YES
Each seminiferous tubule is surrounded by what?
by CT and contractile myoid cells to help move the spermatozoa because they are not motile yet
In spermatogenesis, spermatogonia are adjacent to what?
the basement membrane
What are the different types of spermatogonia?
Type A Dark
Type A Pale
Type B
What do the Type A dark spermatogonia serve as?
serve as stem cells
When dividing by mitosis, what can the Type A dark spermatogonia form?
2 Type A Dark
or
2 Type A Pale
Are the Type A Pale spermatogonia committed to differentiating into other cell types?
YES
After undergoing several mitotic divisions, what type do Type A Pale spermatogonia become?
Type B
What Type represents the last stage of the spermatogonia?
Type B
What are primary spermatocytes? Where are they found? Which meiotic division do they undergo?
large, spherical cells, in the middle zone of epithelium
undergo first meiotic division
What are the secondary spermatocytes? Where are they located and what meiotic division do they undergo?
smaller and closer to the lumen
undergo second meiotic division
What is a spermatid?
even smaller than a secondary spermatocyte, and is next to the lumen
It is spherical with round nuclei
List the order of spermatogenesis from start to finish
- spermatogonia
- primary spermatocyte
- secondary spermatocyte
- spermatid
- immature spermatozoa
- mature spermatozoa
What is the structure of the Sertoli cells?
tall and irregular cells with a central pale nucleus
The Sertoli cells give nutrition to what cells?
germ cells
What barrier do Sertoli cells form?
blood-testis barrier
Sertoli cells aid in the release of what?
spermatozoa
Sertoli cells produce what protein that maintains testosterone concentration in tubules?
androgen binding protein
How many phases/steps are there in spermiogenesis?
4
What are the 4 steps/phases of spermiogenesis?
- Golgi Phase
- Cap Phase
- Acrosomal Phase
- Maturation Phase
What is happening in the Golgi phase of spermiogenesis?
proacrosomal vesicles are produced by the Golgi
centrioles move to opposite poles of cell and a flagellum forms
What is happening in the Cap phase of spermiogenesis?
an acrosome forms (head-cap) over the nucleus
What is happening in the Acrosomal phase of spermiogenesis?
reorientation of spermatid, so that the flagella faces the lumen
production of flagella
What is happening in the Maturation phase of spermiogenesis?
mitochondria regroup around the flagellum
surplus cytoplasm is cast off as residual body and phagocytized by the Sertoli cell
What are three divisions that make up the structure of the mature sperm?
Head
Neck
Tail
Describe the Head of the mature sperm
condensed to reduce size, acrosome contains hyalurodinase (released at ovum) that helps sperm pass through corona radiata prior to fertilization
Describe the Neck of the mature sperm
contains 2 centrioles
What are the divisions of the tail of the sperm?
Mid piece
Principal piece
End piece
Describe the Mid-piece of the tail of the sperm
contains axoneme of 9 x 2 microtubules and 9 outer dense fibers
Describe the Principal piece of the tail of the sperm
absent mitochondria, outer dense fibers continue to fibrous sheath
Describe the End piece of the tail of the sperm
microtubule continuation, no fibrous sheath
Where are the Leydig cells found and what do they do?
are interstitial cells between the seminiferous tubules
produce testosterone
Which ducts do sperm pass through?
Tubuli recti Rete testis Ductuli efferentes Ductus epididymis Ductus deferens
What is the Tubuli recti?
merging of the seminiferous tubules at the apex of each lobule, has Sertoli cells
What is the Rete testis?
combines spermatozoa from different tubules; anastomoses the channels
What is the Ductuli efferentes?
spiral ducts emerge on the testis surface; with ciliated columnar epithelium with smooth muscle
What is the Ductus epididymis?
single coiled tube, site of sperm storage and maturation; “swimming lessons”; has smooth muscle
What is the Ductus deferens?
from epididymis to seminal vesicle, has pseudostratified epithelium with stereocilia; also has 3 layers of muscle
What is the function of the seminal vesicle? What epithelium is it lined with?
produce fructose to provide energy for the sperm
has pseudostratified epithelium with secretion granules
What is the function of the prostate gland?
has secretions that help transport sperm and neutralize lactic acid in vagina (calcification of prostatic secretions can occur)
What is another name for the Bulbourethral glands?
Cowper’s glands
What are the Bulbourethral (Cowper’s) glands?
lie lateral to the base of the penis, produce a clear viscous secretion (pre-ejaculate) to lubricate the urethra and neutralize acidic urine
When viewed in cross section, what two structures are visible in the penis?
two corpora cavernosa with a deep artery in the center of each
The two corpora cavernosa of the penis are enclosed by what?
tunica albuginea
When viewed in cross section, what single structure that has the urethra at its center can be seen in the penis?
one corpus spongiosum
What encloses the corpus spongiosum?
tunica albuginea
When viewed in cross section, what 3 blood vessels are visible in the penis?
at the top, there are 2 dorsal arteries and 1 dorsal vein
The erectile tissue has many what that fill with blood during a(an)?
has many vascular spaces that fill with blood during an erection
In the penis, which arteries give rise to the deep and dorsal arteries?
internal pudendal arteries
What arteries arise from the deep and dorsal arteries in the penis?
helicine arteries
In the penis, where do the helicine arteries go?
go to cavernous spaces (blood sinuses)
In the penis, where do the helicine arteries drain into?
the deep dorsal vein
To become erect, what impulses are activated and by which division of the nervous system?
vasodilator impulses activated by the parasympathetic nervous system
During an erection, blood flow in which arteries increases in the penis?
in the deep artery and the helicine arteries
Which muscle relaxes during an erection and what spaces fill in the penis?
the cavernous smooth muscle relaxes; the cavernous spaces fill
To become flaccid, what impulses are activated and by which division of the nervous system?
vasoconstrictor impulses are activated by the sympathetic nervous system
When becoming flaccid, blood flow in which arteries decreases in the penis?
in the deep artery and helicine arteries
When becoming flaccid, which muscle contracts and which spaces empty?
the cavernous smooth muscle contracts and the cavernous spaces empty
