Chapter 14 Urinary system Flashcards
Large, bean shaped organs in the abdominal cavity that function to remove wastes and excess solutes from the ECF in the form of urine.
Kidney
What are the 10 main functions of the kidneys?
1) maintaining H2O balance in the body
2) Maintaining proper osmolarity of body fluids
3) Regulating concentration of ECF ions: Na+, Cl−, K+, Ca2+, H+, HCO3−, PO43−, SO42−, Mg2+
4) Maintaining proper plasma volume—important for blood pressure
5) Maintaining proper acid-base balance of the body—by adjusting urinary output of H+ and HCO3−
6) Eliminating the wastes of metabolism—including urea (from proteins), uric acid (from nucleic acids), creatinine (from muscle creatine), bilirubin (from hemoglobin), and hormone metabolites
7) Excreting foreign compounds—drugs, food additives, pesticides, etc.
8) Producing renin—hormone that triggers salt conservation
9) Producing erythropoietin—hormone that stimulates red blood cell production
10) Converting vitamin D into its active form
Pathway of urine
renal pelvis -> ureter -> urinary bladder -> urethra
Is the blood flow to the kidneys just enough to oxygenate the kidneys, or more?
20-25% of cardiac output flows through the kidneys
The smallest unit of the kidney that performs all of the kidney’s function
Nephron
5 parts of a nephron
Glomerulus, Afferent arteriole, Efferent Arteriole, Peritubular capillaries, Bowman’s capsule
What are the 2 types of nephrons? (based on length of loop of henle)
-Cortical nephron (80% of nephrons) short loop
-Juxtomedullary nephron (20% of nephrons) long loop
What are the two regions of the kidney?
Renal cortex and renal medulla
ball like tuft of capillaries where some water and solutes are filtered from blood passing through
Glomerulus
blood vessel entering glomerulus
afferent arteriole
blood vessel exiting the glomerulus
efferent arteriole
supply renal tissue and aid in reabsorption and secretion to form urine
peritubular capillaries
hollow tube surrounding glomerulus (filtered plasma flows into)
Bowmans capsule
filtering of plasma thru the glomerulus
Glomerular filtration
What the three basic renal processes?
Glomerular filtration, Tubular reabsorption, and Tubular secretion
reabsorption of substances of value from the filtrate in the tubules back into the blood vessels
Tubular reabsorption
selective transfer of substances from the peritubular capillary blood into the tubule
Tubular secretion
What are the three layers of the glomerular membrane?
Glomerular capillary wall, Basement membrane, and Inner layer of Bowman’s capsule
What does the glomerular capillary wall do?
It’s a layer of endothelial cells, however they have large pores between and in the middle of the cells. They are very permeable to H2O and solutes
What is the basement membrane?
-It is acellular, and helps block large plasma proteins from getting into the glomerular capillary wall.
-They are negatively charged and repel small plasma proteins that are also negatively charged
What is the inner layer of Bowmans capsule?
They consist of podocytes that give off interdigitating foot process, which form filtration slits that filtrate can pass through
What forces cause plasma to leave the glomerular capillaries and enter Bowman’s capsule?
Glomerular capillary pressure, plasma-colloid osmotic pressure, and Bowmans capsule hydrostatic pressure
glomerular capillary pressure
- blood pressure within the glomerular capillaries (pushing in)
plasma colloid pressure
- plasma proteins stuck in glomerular capillaries displacing water (pushing out)
