FInal Flashcards
What are the functions of the kidneys?
Regulate water volume in body
Filter blood
Produce epo and renin
Regulate ion concentration
What layer of the kidney are the renal pyramids located?
Renal medulla
What veins and arteries are in the renal cortex?
Cortical radiate
Arcuate
What is the order of structures in which waste is removed? Starting from the collecting duct
Collecting duct Minor calyx Major calyx Renal pelvis Ureter Bladder
What is the structural and functional unit of the kidney?
Nephron
What are the two parts of a nephron?
Renal corpuscle
Renal tubule
What are the two parts of the renal corpuscle?
Glomerulus
Bowman’s capsule
What is the importance of the parietal layer of the bowman’s capsule?
Comprised of simple squamous epithelium
Contributes to capsule structure
Plays no part in forming filtrate
What is the importance of the visceral later of the bowman’s capsule?
Comprised of podocytes
Allows filtrate to enter the capsular space
What is the order in which blood flows through the gomerulus?
Cortical radiate artery Afferent arteriole Glomerular capillaries Efferent arteriole Vasa recta Cortical radiate vein
What are the three major parts of the renal tubule?
Proximal convoluted tubule
Nephron loop
Distal convoluted tubule
What is the importance of the PCT?
Comprised of cuboidal epithelial cells with dense microvilli
Important in reabsorbing water and solutes from filtrate
What are the two divisions of the loop of henle?
Descending limb
Ascending limb
What is the ascending limb divided into?
Thin part - allows for water reabsorption
Thick part - Has tight-tight junctions, nothing passes
What are the two divisions of the DCT?
Diluting segment
Late segment
What is the importance of the diluting segment?
Few microvilli
Functions more in secretion than reabsorption
What is the importance of the late segment?
Connects the DCT to the collecting duct
What are the functions of collecting ducts?
Maintain water and sodium balance
Maintain acid-base balance in blood
What are the three types of nephrons?
Cortical nephrons - 30%
Midcortical nephrons - 55%
Juxtamedullary - 15% - important in concentrated urine formation
How much fluid does the kidney process daily?
180 L
What is filtration and where does it occur?
Takes solutes and water out of blood
Happens in glomerulus
Filtrate collected in bowman’s capsule
What is reabsorption and where does it occur?
Some of filtrate reenters the capillaries
Happens in renal tubules and collecting ducts
What is secretion and where does it occur?
Moving substances from the blood into the filtrate
Occurs in the tubule and collecting duct
What are the three nephron capillary beds?
Glomerulus - filtarion
Peritubular Capillaries - reabsorption
Vasa recta - juxtamedullary
What are the three layers of the filtration membrane?
Capillary endothelium
Basement membrane
Foot processes of podocytes of glomerular capsule
What are the three cell populations that help regulate filtrate formation and systemic blood pressure for the JGC?
Macula densa
Granular cells
Extraglomerular mesangial cells
What is the function of macula densa cells?
Chemoreceptors that monitor the NaCl concentration in filtrate
Found in ascending limb
What is the function of granular cells?
Mechanoreceptors that sense blood pressure in afferent arteriole
Contain renin
Cells of arteriole
What is the function of extragomerular mesangial cells?
Send signals between granular cells and macula densa
What is the net filtration pressure?
Net pressure in the gomerulus
Is equal to 10 mm Hg
What are the pressures that account for NFP?
Hydrostatic pressure of glomerular capillaries (55)
Osmotic pressure of glomerular capillaries (30)
Hydrostatic pressure of capsular space (15)
What is glomerular filtration rate?
Volume of filtrate formed by all the glomeruli in the body in one minute
Average is 125ml/min
What are the two types of intrinsic control for GFR regulation?
Myogenic mechanism
Tubuloglomerular feedback mechanism
What is myogenic mechanism?
Increased BP Afferent arteriole muscle stretches Afferent arterioles contract Bloodflow restricted into glomerulus Opposite occurs if BP is low
What is the process of tubuloglomerular feedback mechanism?
GFR increases
Macula densa detects high NaCl concentration
Macula densa releases vasoconstrictor chemicals
Afferent arteriole constricts
Blood flow into glomerulus decreases
Opposite occurs if GFR is low
What is the primary goal of the extrinsic control system?
Regulation of systemic blood pressure
How does the extrinsic control system regulate fluid volume?
Norepinephrine and epinephrine cause vasocontriction if bp is low
What are the two major routes for tubular reabsorption?
Transcellular
Paracellular
What is transcellular reabsorption?
Solute or water passes through the cell, then across the interstitial fluid and into the capillary
What is paracellular absorption?
Solute or water passes between cells, then across interstitial fluid and into the capillary
What is transport maximum?
There is a limit of carriers that the body has, so you can max out at being able to be reabsorbed
What is the countercurrent multiplier?
Interaction between the blow of filtrate through the ascending and descending limbs of juxtamedullary nephrons
What is the countercurrecnt exchanger?
Flow of blood through the ascending and descending portions of vasa recta
What are the three steps of urination?
Contraction of detrusor by ANS
Opening of internal urethral sphincter by ANS
Volunterilly open external urethral sphincter
What is the process by which a fetus becomes male?
SRY gene Mullerian inhibiting substance prevents mullerian duct Wolfinian duct formed Leydig cells form Testosterone produced Fetus forms male organs
What is the function of leydig cells?
Aid in the production of testosterone
What is the function of sertoli cells?
Aid in the maturation of sperm
What does the hypothalamus release during puberty?
GnRH
Gonadotropic releasing hormone
What are the two gonadotropins and where are they released from?
Luetenizing hormone
Follicle stimulating hormone
Released from the anterior pituitary
What is the function of FSH and LH in males?
FSH - Sperm production
LH - Testosterone production
Where do sperm cells mature?
Epididymus
What is decapacitation?
Process of adding proteins to sperm
Decreases mobility
Protects sperm
Happens in epididymus
What is aerosome?
Covering on head of sperm that allows it to penetrate the egg
What is the process of spermatogenesis?
Type b daughter cell Primary spermatocycte Secondary spermatocytes Spermatids Spermatozoon
What is semenogelin?
Causes sperm to clot once it enters female reproductive tract so it stays inside
What is PSA?
Causes liquification of sperm after it clotted
Allows sperm to swim in uterus
Created by prostate
What is the function of the corpus spongiosa?
Prevents urthra collapse
What is the function of corpus cavernosa?
Main tissue for erection
What vasodialator is released to cause an erection?
Nitrousoxide
What is the function of seminal fluid?
Consists of fructose - energy for sperm
Acts as a buffer
Meets with sperm at ejaculatory duct
What is the function of pre-jac?
Acts as a buffer
Cleans out the urethra
Secreted by the bulbo-urethral gland
What are the functions of LH and FSH in females?
LH - theca cells - estrogen
FSH - granulosa cells - estrodial and forms follicle
What are the layers of the uterine wall?
Endometrium
Myometrium
Perimetrium
What are the layers of the endometrium?
Stratum functionalis - comes off during menstration
Stratum basalis - generates new cells
What is oogenesis?
Production of female gametes
What is the function of leptin in female maturation?
Causes the hypothalamus to be less sensitive to estrogen so GnRH can be activated
What are the stages of menstration?
Follicular phase - (1-14) development of follicle
Ovulation - day 14
Luteal phase - (15-28) degeneration of the corpus luteum
What are the phases of the uterine cycle?
Menstrual - day 1-5
Proliferative phase - day 6-14
Secretory phase - day 15-28
Where do primary oocytes develop?
Primoridal follicles
What is the function of gastrin?
Stimulates stomach gland secretion
Increases contractile force of stomach
Stimulates pyloric sphincter contraction
What kind of chyme moves quickly through the duodenum?
Carbohydrate rich
How is chyme released into the duodenum?
Delivered in 3 mL spurts
Retropulsion pushes the rest back
What is the function of GIP?
Prevents stomach contractions
What are the three enterogastrones?
Secretin
CCK
VIP
What are the three ways that the duodenum can regulate gastric emptying?
Enterogastric reflex
Amount of fat in the duodenum
INS detects food via stretch and chemoreceptors
How does the enterogastric reflex regulate gastric emptying?
Slows stomach contraction
Causes liver and pancreas to release secretions
CCK and secretin release
How does the amount of fat in the duodenum regulate gastric emptying?
High fat concentrations cause the release of CCK, secretin, GIP and gastrin - all slow stomach down
What do the receptors in the duodenum detect?
Acidity
Stretch
Peptides
Osmolaity
What is the function of CCK?
Stimulates bile and pancreatic juice release
Inhibits gastric secretion
What is the function of motilin?
Stimulates intestinal movement
What is the function of VIP?
Increases pancreatic and gastric secretions
Relaxes intestine
What is the function of secretin?
Inhibits gastric secretion
Increases bile and pancreatic juice output
Where does feces get its color?
Bilirubin from bile
What specializations does the small intestine have for increased absorption?
Circular folds
Villi
Microvilli
What is the function of bile?
Break down fats
What is the function of pancreatic juices?
Buffer the acidity of the chyme that is leaving the stomach
What are the three reflexes that occur for movement of food in the small intestine?
Intestinal-intestinal
Gastroileal reflex
Iliogastric reflex
What happens in the gastroileal reflex?
Stomach fills
Iliocecal valve relaxes
Ileum contracts
What happens in the iliogastric reflex?
Ilieum fills
Tells stomach to relax
What causes the release of bile and pancreatic juices?
Chyme enters duodenum
CCK and secretin are released
CCk and secretin cause release of bile and pancreatic juice
What is the purpose of the gastrocolic reflex?
Contractions move masses through colon
Initiated by food in the stomach
What is the defecation reflex?
Rectum fills and causes contraction of the sigmoid colo and rectum
Internal anal sphincter relaxes and opens
External anal sphincter is under voluntary control