Chapter 10B Flashcards
Glomerular filtration depends on three main pressures. One pressure promotes
filtration and two pressures oppose filtration:
- Glomerular blood hydrostatic pressure (GBHP) is the blood pressure in
glomerular capillaries. It promotes/opposes filtration
promotes: filtration by forcing water and solutes in blood plasma through the filtration
membrane
Capsular hydrostatic pressure (CHP) is the hydrostatic pressure which promotes/opposes the filtration
opposes:
by fluid already in the capsular space and renal tubule. (back pressure)
Blood colloid osmotic pressure (BCOP), which is due to the presence of proteins
such as albumin, globulins, and fibrinogen in blood plasma, promotes/opposes filtration?
also opposes filtration.
Net filtration pressure (NFP) is the total pressure that opposes/promotes filtration.
promotes
The amount of filtrate formed in both/one kidney(s) each minute is
the glomerular filtration rate (GFR).
both
In adults, the GFR averages 125 mL/min in males and 105 mL/min in females.
ok
The mechanisms that regulate glomerular filtration rate operate in two main ways:
- Adjusting blood flow into and out of the glomerulus: GFR increases when blood
flow into the glomerular capillaries increases. - Altering the glomerular capillary X available for filtration.
surface area
Three mechanisms control GFR:
- Renal autoregulation.
- X regulation.
- Hormonal regulation.
Neural
Renal autoregulation: consists of two mechanisms:
- Myogenic mechanism: X receptors in the walls of the afferent arterioles monitor
blood pressure (faster mechanism). - Tubuloglomerular feedback: Xreceptors in the macula densa detect the increased
delivery of Na+, Cl−, and water (slower mechanism).
stretch
chemo
Neural Regulation of GFR:
Like most blood vessels of the body, those of the kidneys are supplied by
parasympathetic/sympathetic ANS fibers that release norepinephrine: causes vasodilation/constriction
through the activation of α1 receptors, which are particularly plentiful in the
smooth muscle fibers of afferent arterioles
sympathetic
constriction
With moderate sympathetic stimulation, both afferent and efferent arterioles
constrict to the same degree. Blood flow into and out of the glomerulus is
restricted to the same extent, which decreases GFR only slightly.
- With greater sympathetic stimulation, however, as occurs during exercise or
hemorrhage, vasoconstriction of the afferent arterioles predominates. As a
result, blood flow into glomerular capillaries is greatly decreased, and GFR
drops.
This lowering of renal blood flow has two consequences:
- It reduces urine output, which helps conserve blood volume.
- It permits X
greater blood flow to other body tissues.
Hormonal regulation:
AngioX 2 (a very potent vasoconstrictor) is released only when necessary and vasoconstrict
efferent arteriole, increasing GFR.
tensin
ANP , atrial natriuretic peptide, is the only regulation of GFR that in/decreases GFR
increases
The functions of the tubule are:
- Recovering everything you do not want to lose (reabsorption).
- Segregating to the lumen what you want to eliminate and it has not been
filtered (X). - Adjust urinary volume and composition based on intake.
secretion
Excretion = filtration + secretion - reabsorption
ok
Solutes that are reabsorbed by both active and passive processes include:
- glucose,
- amino acids,
- X, and
- ions: Na+, K+, Ca2+, Cl−, HCO3− (bicarbonate), and HPO42− (phosphate).
urea
Most small proteins and peptides that pass through the filter also are
reabsorbed, usually via pinocytosis
true/false
true
Epithelial cells all along the renal tubule and duct carry out reabsorption, but
proximal X tubule cells make the largest contribution.
convoluted
a substance being reabsorbed can take two routes before entering a peritubular capillary:
- Paracellular reabsorption: water and solutes in tubular fluid return to the
bloodstream by moving between/passing through tubule cells - Transcellular reabsorption: water and solutes in tubular fluid return to the bloodstream by moving between/passing through tubule cell.
between
passing through
- Occurs along with the reabsorption of solutes such as Na+
, Cl−, and glucose. - Occurs in the proximal convoluted tubule and the descending limb of the
nephron loop because these segments of the nephron are always permeable to
water.
obligatory or facultative?
obligatory
- Represents 10% of the reabsorption of the water.
- Is regulated by antidiuretic hormone.
- Occurs mainly in the collecting ducts.
obligatory or facultative?
facultative
These transporters in the kidney can reabsorb up to 240 mg / min of glucose ..
ezelsbruggetje?
24/08 is siph dr verjaardag
What will happen if the glucose kidney transporters limit is exceeded?
glycosuria
P.61 for overview of kidney and absorpion/excretion
ok
Three coats make up the wall of the urinary bladder. Put in right order from superficial layer to deep layer.
- Muscularis
- Mucosa
- Adventitia & serosa
- adv (epithelium, lamina)
- muscularis (internal / external urethral sphincter)
- mucosa (epithelial + lamina)
Micturition = ?
urinating
