Exam 4 study guide Flashcards
What is the flow of filtrate in the kidneys?
Bowman’s capsule–>proximal tubule–>loop of henle
–>back to renal medulla—>renal cortex
What layer of the filtration membrane has three layers and facilitates the flow of plasma water and small solutes while restricts the flow of large plasma proteins such as albumin?
Capillary endothelium
What layer of the filtration membrane provides a scaffold that supports the physiological function of the glomerular endothelium and podocytes?
Basement membrane
What layer of the filtration membrane is composed of the podocytes that have a more cuboidal shape and play a role in filtration of blood?
Visceral layer of glomerular capsule
What layer of the filtration membrane is composed of the podocytes that have a more cuboidal shape and play a role in filtration of blood?
Visceral layer of glomerular capsule
What layer of the filtration membrane consists of mesangial cells, modified pericytes that in other parts of the body separate capillaries from each other?
Basement membrane
What layer lines the capillaries?
Capillary endothelium
What are the pressures that affect glomerular filtration?
hydrostatic pressure and colloid osmotic pressure
Under normal circumstances ______ pressure is typically greater and filtration occurs.
hydrostatic pressure
What is NFP?
The total pressure that promotes filtration
What is the blood pressure in glomerular capillaries, which is about 55mm Hg?
Hydrostatic pressure
What is the 2nd force opposing filtration. It is mainly due to the presence of proteins?
Colloid osmotic pressure
Renal Autoregulation, Myogenic, Tubulogloerular Feedback Mechanism are examples of ________ control.
Intrinsic
Neural control, Renin-Angiotensin Mechanism are examples of _______ control.
Extrinsic
_________ a vital homeostatic mechanism that protects the kidney from elevations in arterial pressure that would be transmitted to the glomerular capillaries and cause injury.
Renal autoregulation
_______ mechanism is how arteries and arterioles react to an increase or decrease of blood pressure to keep the blood flow constant within the blood vessel.
myogenic
_________ is an adaptive mechanism that links the rate of glomerular filtration to the concentration of salt in the tubule fluid at the macula densa..
Tubulogloerular feedback mechanism
_______ increased efferent renal sympathetic nerve activity decreases renal blood flow and glomerular filtration rate, increases renal tubular sodium and water reabsorption, and increases renin release. Decreased efferent renal sympathetic nerve activity produces opposite functional responses.
Neural control mechanism
What mechanism In instances of blood loss or dehydration, it reduces both GFR and renal blood flow, thereby limiting fluid loss and preserving blood volume..
Renin-angiotensin mechanism
What is the transport maximum?
the point at which increase in concentration of a substance does not result in an increase in movement of a substance across a cell membrane.
Where does H20 reabsorption occur and what causes it?
Reabsorption is the movement of water and solutes from the tubule back into the plasma. Reabsorption of water and specific solutes occurs to varying degrees over the entire length of the renal tubule. Bulk reabsorption, which is not under hormonal control, occurs largely in the proximal tubule.
What causes H2O reabsorption?
ADH causes the insertion of water channels into the membranes of cells lining the collecting ducts, allowing water reabsorption to occur.
How is dilute urine formed?
by pumping salts out of the lumen of tubule segments that are impermeable to water. What is left behind is tubule fluid that is hypo-osmotic (dilute) with respect to the blood.
How is concentrated urine formed?
In the presence of ADH, the medullary collecting ducts become freely permeable to solute and water. As a consequence, the fluid entering the ducts (en route to the renal pelvis and subsequent elimination) acquires the concentration of the interstitial fluid of the medulla; i.e., the urine becomes concentrated.
What controls Na+ reabsorption?
aldosterone
What is the importance of tubular secretion?
it helps in the maintenance of ionic and acid base balance of body fluids.
What are the layers of the wall that forms the ureters, urinary bladder, and urethra?
fibrous coat, muscle coat, and the mucosa
What is the function of the fibrous coat?
To support structure
What is the function of the muscle coat?
peristalsis
What is the function of the mucosa?
secretes mucus, which coats and protects the surface of the cells.
How does micturition occur?
The brain signals the bladder muscles to tighten, which squeezes urine out of the bladder. At the same time, the brain signals the sphincter muscles to relax to let urine exit the bladder through the urethra. When all the signals occur in the correct order, normal urination occurs.
What is storage reflex?
activated during bladder filling and are organized primarily in the spinal cord, whereas voiding is mediated by reflex mechanisms that are organized in the brain
What is micturition reflex?
When the bladder is full of urine, stretch receptors in the bladder wall trigger the micturition reflex. The detrusor muscle that surrounds the bladder contracts. The internal urethral sphincter relaxes, allowing for urine to pass out of the bladder into the urethra. Both of these reactions are involuntary.
What are the stages of spermatogenesis?
(1) proliferation and differentiation of spermatogonia, (2) meiosis, and (3) spermiogenesis
Where does spermatogenesis take place?
inside the seminiferous tubules
What is the function of sustentacular cells?
Provide growth factors to germ cells, promote germ cell development, protect germ cells, and to provide nutrients to germ cells.
Sustentacular cells are also known as ______ cells.
sertoli
How is testicular function regulated?
Control of both functions is guided by the central nervous system in a classic endocrine feedback loop with follicle stimulating hormone (FSH) and luteinizing hormone (LH) as the key hormonal signals.
What are the stages of oogenesis?
proliferation, growth, and maturation,
How does ejaculation occur?
friction and other stimuli send signals through the nervous system, the walls of the epididymis contract (squeeze) to create peristaltic waves that push sperm into the vas deferens.
Where does oogenesis take place?
in the ovary
When does oogenesis begin?
Around 7 weeks
What are the effects of menopause?
hot flashes, night sweats, vaginal dryness, and a reduced sex drive. It can also lead to anxiety, changes in mood, and a reduced sex drive.
