Reproductive Physiology Flashcards
What is the most obvious function of the kidney?
Regulate composition and function of plasma
What are some of the other renal functions?
Regulate blood pressure and volume (water concentration and fluid volume ; inorganic ion composition), acid-base balance ; excretion (urea, uric acid, creatinine [muscle breakdown], bilirubin [hemoglobin breakdown]) ; remove foreign chemicals (drugs, food additives, pesticides) ; synthesis of glucose (glucoseneogenesis) ; secretion (hormone/enzyme [erythropoietin, 1,25-dihygroxy Vitamin D, renin]
Which ions are higher in extracellular fluid? Which ions are higher in the intracellular fluid?
Extra: Na+, Cl-, HCO3-
Intra: K+, Mg2+, Pi, Protein
What dictates the rate of diffusion?
Chemical properties
What’s the difference between polar and non-polar compounds during diffusion?
Polar molecules generally are unable to diffuse across membrane bilayer (amino acids, glucose, water) whereas non-polar molecules diffuse rapidly (CO2, fatty acids, steroids)
What are aquaporins?
Water channels that regulate the diffusion of water through cell membranes
What is water concentration measured in?
Osmoles: 1 osmoles (osm) is equal to 1 mole of solute particles
What is osmolarity?
Number of solutes per unit volume of solution expressed in moles per liter
What is osmosis?
Net diffusion of water across a selectively permeable membrane from a region of high water concentration to one with a lower water concentration
What is osmotic pressure?
The pressure necessary to prevent solvent movement
What is tonicity determined by?
The concentration of non-penetrating solutes (NPS) [sodium and chloride ions] of an extracellular solution relative to the intracellular environment of a cell.
What is isotonic?
Same concentration of NPS outside and inside the cell; cell volume do not change
What is hypertonic?
Higher concentration of NPS outside than inside of the cell; cells shrink
What is hypotonic?
Lower concentration of NPS outside than inside of the cell; cells swell
What are the factors determining fluid movement along capillaries?
Capillary hydrostatic pressure (Pc), interstitial fluid hydrostatic pressure (Pif), osmotic force due to plasma protein concentration (PIc), osmotic force due to interstitial fluid protein concentration (PIif)
What does the starling law measure?
The net filtration pressure
What are the organs that are part of the urinary system?
Kidney, ureter, bladder and urethra
What is micturition?
The process by which urine is voided out of the body
What is the anatomy of the kidney?
Capsule, outer cortex, inner medulla, nephron (renal corpuscle, renal tubule)
What is the renal corpuscle made up of?
Glomerulus, bowman’s capsule
What does the renal tubule comprised of?
Proximal convoluted tubule, loop of henle, distal convoluted tubule (lined with epithelial but vay in each structure and function in each tubule)
What kind of blood goes through the glomerulus?
Protein-free blood
Explain the 3 stages of the development of renal corpuscle.
Stage 1: Nephrons develop as blind-ended tubules composed of single layer of simple epithelium
Stage 2: Growing tuft of capillaries penetrate the expanded end of tubules
a. Basal lamina is trapped in between endothelial cells of capillaries and epithelial layer
b. Epithelial cell layer differentiates into parietal (outer) and visceral (inner) layer
Stage 3: parietal layer flattened to become wall of Bowman’s capsule Visceral layer becomes podocyte cell layer
What are the layers of the glomerular capillary?
- Fenestrated endothelial layer
- Basement membrane (made up of proteins)
- Podocytes with filtration slits
What are the two types of nephron in the kidney?
- Cortical
- Juxtamedullary (close to the medulla area)
What is the difference between the corticol and juxtamedullary?
The portions of the loop of the corticol nephrone dip slightly into the medulla whereas the loop of henle and ascending limb of the juxtamedullary are found in the renal medula
What are the basic functions of neprhons?
Filtration, reabsorption and secretion
What are the 3 types of capillaries in kidneys?
- Glomerular
- Peritubular
- Vasa recta
What is the function of the afferent arteriole in the kidney?
Branches off from the renal artery and diverges into the capillaries of the glomerulus. The arteriole that brings blood into the glomerular capillary network.
What is the function of the efferent arteriole?
Blood exits the glomerulus through the efferent arteriole. The arteriole branches around to form a set of capillaries called the peritubular capillary network. The peritubular capillaries fuse together to form the renal vein.
What is the function of vasa recta?
Capillaries that are found mostly associated with justamedullary nephrons in the medullary portion of the kidney
Why are the large proteins or albumins are held back?
Because the pore size are not large enough to allow passage;
Pores and BM have negative charges and repels negatively charged proteins;
Podocytes have slits that remain covered with fine semiporous membranes
What is the fine semiporous membranes made up of?
Nephrins and Podocins
What is the function of Nephrins and Podocins?
Cover the slits of the podocytes ; Prevent the passage of substance through the barrier
What is filtered through the glomerulus?
Water, electrolytes, glucose, amino acids, fatty acid, vitamins, and waste products such as urea, uric acid, and creatinine
What is non-filtered?
Plasma protein and blood cells, large anions, anything bound to plasma proteins (ie calcium)
What is Ultrafiltrate?
The concentration of a substance filtered through the filtration layers is the same in the plasma and in the filtrate
What is proteinuria?
A condition where some of the proteins that are not suppose to pass through the filtration barrier show up in the filtrate and ultimately in the urine
What are the forces involved in Glomerular Filtration?
Glomerular capillary hydrostatic pressure (Pgc), Bowman’s space hydrostatic pressure (Pbs), Osmotic force due to proteins in the plasma (Pigc), Starling forces
What is Glomerular capillary hydrostatic pressure (Pgc)?
Hydrostatic pressure of the blood that is found in the glomerular capillaries; this pressure pushes fluid outward into the Bowman’s space, or from the capillary side into Bowman’s space; favours filtration
What is the Bowman’s space hydrostatic pressure (Pbs)?
Fluid pressure in Bowman’s space; opposes filtration
What is the osmotic force due to proteins in the plasma (Pigc)?
Due to proteins that are present in the plasma; the positive pressure which pushes fluid or water containing the substances that are filtered into Bowman’s space
What fraction of the volume entering the glomerular capillaries is filtered?
20%
What is the final volume of fluid is excreted?
1%
What is Glomerular Filtration Rate (GFR)?
The volume of fluid filtered frm the glomerulus into the Bowman’s space per unit time