Exam 4 Flashcards
What are the kidney functions?
-regulate total water volume & solute concentration
-regulate ion concentrations
-removal of metabolic wastes
ensure long-term acid base balance
Endocrine functions
-renin
-erythropoietin
-activation of vitamin D
-glucogenesis during prolonged fasting
Renin regulates
blood pressure
Erythropoietin regulates
RBC production
What do the ureters do?
transport urine from kidneys to urinary bladder
What is the purpose of the urinary bladder?
temporarily transports reservoir for urine
What is the purpose of the urethra?
transports urine out of body
Layers of surrounding supportive tissue consist of:
-renal fascia
-perirenal fat capsule
-fibrous capsule
The renal cortex is the
granular appearing superficial region
The renal medulla is
-composed of cone shaped medullary pyramids
-pyramids are separated by renal columns
The papilla is the
tip of pyramid, which released urine into minor calyx
The lobe is the
medullary pyramid and its surrounding tissue
The renal pelvis is the
funnel shaped tube continuous with ureter
The function of the minor calyx is to
drain pyramids at papillae
The function of the major calyx is to
-collect urine from minor calyxes
-empty urine into renal pelvis
What is the order of urine flow?
renal pyramid-minor calyx-major calyx- renal pelvis-ureter
Pyelitis is the
infection of renal pelvis and calyxes
Pyelonephritis is the
infection/inflammation of entire kidney
Nerve supply via sympathetic fibers from
renal plexus
The two main parts of the nephron are
-renal corpuscle
-renal tubule
The two parts that compose the renal corpuscle are
-glomerulus
-glomerular capsule
Describe the glomerulus
little tuft of capillaries
Describe the glomerular capsule(aka Bowman’s capsule)
cup shaped, hollow structure around the glomerulus
What are the three parts of the renal tubule?
-proximal convoluted tubule(PCT)
-nephron look(aka loop of Henle)
-distal convoluted tubule(DCT)
What are the two types of cells within the collecting ducts?
- principal cells
- intercalated cells
Describe the principal cells
-sparse, short microvilli
-maintain water and Na balance
Describe the intercalated cells
-abundant microvilli
-type A and B: both help maintain acid base balance of blood
Describe the collecting duct
-receives filtrate from many nephrons
-run through medullary pyramid
-fuse together in minor calyx to deliver urine through papillae
What are the two classes of nephrons
-cortical nephrons
-juxtamedullary nephrons
Describe the cortical nephrons
85% of nephrons; almost entirely in cortex
Describe the juxtamedullary nephrons
-long nephron loops that deeply invade medulla
-important in production of concentrated urine
The glomerulus is specialized for
filtration
Why is the blood pressure in glomerulus high?
-afferent arterioles larger in diameter than efferent arterioles
-arterioles are high resistance vessels
Describe the peritubular capillaries
-low pressure, porous capillaries adapted for absorption of water and solutes
-arise from efferent arterioles
-empty into venules
Describe the vasa recta
-long, thin walled vessels parallel to long nephron loops of juxtamedullary nephrons
What is the function of the vasa recta?
function in formation of concentrated urine
Describe the juxtaglomerular complex(JGC)
-one per nephron
-important for rate of filtrate formation and blood pressure
Describe the macula densa
-tall, closely packed cells of ascending limb
-chemoreceptors: sense NaCl content of filtrate
What are the three cell populations of the juxtaglomerular complex?
macula densa, granular cells, extraglomerular mesangial cells
Describe the granular cells
-enlarged, smooth muscle cells of arteriole
-secretory granules contain enzyme renin
-mechanoreceptors: sense bp in afferent arteriole
Describe extraglomerular mesangial cells
-between arteriole and tubule cells
-interconnected w gap junctions
-may pass signals between macula densa and granular cells
How much urine is produced per day?
1.5 L
What are the three processes in urine formation?
- glomerular filtration
- tubular reabsorption
- tubular secretion
Describe glomerular filtration
PASSIVE process
produces cell and protein free filtrate
no metabolic energy required
hydrostatic pressure forces fluids and solutes through filtration membrane
Describe tubular reabsorption
SELECTIVELY returns 99% of substances from filtrate to blood in renal tubules and collecting ducts
Describe tubular secretion
SELECTIVELY moves substances from blood to filtrate in renal tubules and collecting ducts
Filtrate is produced by
glomerular filtration
Urine is
<1% of original filtrate
contains metabolic wastes & unneeded substances
Glomerular capsule consists of what two layers>
-parietal layer
-visceral layer
What are podocytes?
specialized epithelial cells that cover the outer surfaces of glomerular capillaries
What is the filtration membrane?
porous membrane between blood and interior of glomerular capsule
What are the three layers of the filtration membrane
- fenestrated endothelium
- basement membrane
- foot process of podocytes
the glomerular blood pressure =
the hydrostatic pressure pressure in the glomerular capillaries
What are the two routes of tubular respiration?
transcellular and paracellular
Paracellular route
between tubule cells
Transcellular route
-apical membrane of tubule cells
-cytosol of tubule cells
Aquaporins are inserted into collecting ducts only if
ADH present(ie: dehydrated)
Aquaporins are always present in
PCT
Where is the site of most reabsorption?
PCT
In the descending limb, ____ can leave, _____ cannot
water; solutes
In the ascending limb, _____ can leave, _____ cannot
solutes; water
Reabsorption is _______ regulated
hormonally
Antidiuretic hormone controls
water
Aldosterone controls
sodium
Atrial natriuretic peptide controls
sodium
PTH controls
calcium
ADH is released by
posterior pituitary gland
ADH causes
principal cells of collecting ducts to insert aquaporins in apical membranes for water reabsorption
ADH increase causes
increased water reabsorption
Osmolality is
the number of solute particles in 1 kg of H2O
Osmolality is expressed in
milliosmols(mOsm)
Kidneys regulate with
countercurrent mechanism
Countercurrent multiplier
interaction of filtrate flow in ascending/descending limbs of nephron loops of justamedullary nephrons
Countercurrent exchanger
blood flow in ascending/descending limbs of vasa recta
Describe the descending limb
-freely permeable to H2O(aquaporins)
-H2O goes out of filtrate into medullary interstitial fluid
-interstitial osmolality increases to ~1200 mOsm
Describe the ascending limb
-impermeable to H2O
-selectively permeable to solutes
-filtrate osmolality decreases to 100mOsm
____________________ create the gradient
Long nephron loops of juxtamedullary nephrons
The descending limb pumps out ______, but keeps ______.
water; salt
The ascending limb pumps out ____, but not _____.
salt; water
Dehydration =
small volume of concentrated urine
Overhydration =
large volume of dilute urine
Osmotic gradient is used to
raise urine concentration
300 mOsm is used to
conserve water
Uremia
raised level of blood & other nitrogenous waste in the urea
The chemical composition of urine is
95% water & 5% solutes
Nitrogenous wastes in urine include
-urea(most)
-uric acid
-creatinine
What are the three layers of the ureter wall from inside out
- mucosa
- muscularis
- adventitia
Renal calculi are
kidney stones in renal pelvis
Trigone is
smooth triangular area in bladder outlined by opening for ureters and urethra
What are the layers of the bladder wall
- mucosa
- thick destrusor muscle
- fibrous adventitia
A full bladder holds
500 ml (can hold twice that if necessary)
The two urethral sphincters are
-internal urethral sphincter(involuntary)
-external urethral sphincter(voluntary)
Incontinence is defined as
loss of bladder control
Meiosis is
cell division producing gametes(sex cells)
Mitosis produces
clones
Functions of meiosis include
genetic diversity
Primary sex organs include
testes and ovaries
The primary sex organs produce ______ and secrete _______.
sperm and ova; sex hormones
Accessory reproductive organs consist of
ducts, glands, & external genitalia
Sperm is produced by the
seminiferous tubules in testes
The site of sperm production is
seminiferous tubules
Prostatitis is
inflammatory disorder caused by bacterial infection
Benign prostatic hyperplasia
distorts urethra
Most body cells have __ chromosomes
46
The diploid chromosomal number is (2n)
46
The haploid chromosomal number is (n)
23
In meiosis I, the primary spermatocyte becomes
two secondary spermatocytes (n)
In meiosis II, each secondary spermatocyte becomes
two spermatids
How does testosterone affect the male reproductive function
-promotes spermatogenesis
-targets all accessory organs
When do the spikes in testosterone/estrogen occur?
in utero, birth, and puberty
What is the most common cause for cervical cancers?
Human Papillomavirus (HPV)
What vaccine protects against HPV?
gardasil; three dose vaccine
When does oogonia begin?
begins in fetal period
Oogonia multiplies by _____ and _____ _______.
mitosis; stores nutrients
Primary oocytes develop in _______ _______.
primordial follicles
Primary oocytes begin _______
meiosis
Spermatogenesis creates:
4 viable sperm
Oogenesis creates:
1 viable gamete & 3 polar bodies
Antidiuretic hormone(ADH) is produced by
posterior pituitary gland
Follicle stimulating and luteinizing hormones are produced by
anterior pituitary gland
The ovarian cycle(28 days) consists of
follicular phase(1-14 days)
ovulation(midcycle)
luteal phase(14-28 days)
The uterine(menstrual) cycle consists of
Menstrual phase(days 1-5)
Proliferative phase(days 6-14)
Secretory phase(days 15-28)
When does luteinizing hormone spike during the ovarian cycle?
midcycle
What purpose does LH have in the ovarian cycle?
-transforms the ruptured follicle into the corpus luteum
-from there, progesterone and some estrogen occur
Progesterone helps maintain
functionalis OR maintains pregnancy if occurs
If no pregnancy…
-corpus luteum degenerates when LH levels fall
-cycle starts again
Fertilization occurs when
sperm’s chromosomes combine with secondary oocyte to form zygote
A blastocyst is
a rapidly dividing ball of cells
Blastocyst floats for about _______ days
2-3 days
Implantation begins _______ after ovulation.
6-7 days
Blastocyst adheres to uterine wall using
trophoblasts
human chorionic gonadotropin (hCG)
secreted by trophoblast
Germ layer formation consists of
ectoderm, mesoderm, endoderm
Ectoderm becomes
the nervous system and skin epidermis
Endoderm becomes
epithelial linings of digestive, respiratory, and urogenital systems
Mesoderm becomes
everything else
Initiation of labor is caused by
increase of CRH levels
The stages of labor include
- dilation stage
- expulsion stage
- Placental stage
Karyotype is
diploid chromosomal complement displayed in homologous pairs; aka an individual’s complete set of chromosomes
What is a chromosome?
really long piece of DNA wrapped up with proteins
Alleles are
genes that occur at the same location on homologous chromosomes
hCG is produced by
the placenta
