urinary tract Flashcards
(22 cards)
organs of the urinary tract
kidneys
urinary tract: ureters, urinary bladder and urethra
urination or micronutrition
kidney function
- excretion: removal of metabolic wastes form body fluids
- elimination: discharge of these wastes fomr body
- homeostatic regulation: of volume and soluate concentration of blood
homeostatic functions of the urinary system
- regulating blood volume and blood pressure
- regulating plasma in ion concentrations
- healping to stabilise blood pH
- conserving valuable nutrients
- assisting liver
about the kidneys
- bean shaped
- retroperitoneal
- protected by lower part of rib cage and three layers of supportive tissue
what are the three layers of support tissue in the kidneys?
- Renal fascia: dense connective tissue – anchor kidneys to surrounding structures
- Perinephric fat capsule: fatty mass protects kidneys from trauma
- Fibrous capsule: transparent layer; protection from infection
aobut the adrenal glands
- two triangle shaped endocrine glads
- make hormones: adrenaline, nonadrenaline, cortisol and aldosterone
internal anatomy of kidneys
renal cortex: outer region, contains nephrons
renal medulla: middle region, channels urine to renal pelvis
renal pelvis: inner region, drains urine into ureters
the nephron - functional unit of the kidney
- Structural and functional unit of kidney
- ~1 million per kidney
- Perform the processes to filter blood plasma and form urine
- Consist of:
Renal corpuscle and,
Renal tubule
renal corpuscle
consists of 2 parts
1. Bowmans capsule
2. glomerulus
function: to produce the filtrate, a protein free solution
renal tubule
has 3 main parts
1. Proximal convoluted tubule (PCT)
2. Nephron loop (Loop of Henle)
3. Distal convoluted tubule (DCT)
processes of urine fomraiton
- Glomerular filtration
- Makes a protein-free filtrate that contains water, ions, nutrients and waste products - Tubular reabsorption
- Selective movement of valuable wanted substance from filtrate back into blood
- Glucose, amino acids, 99% of water, salt - Tubular secretion
- Selective movement of some unwanted substances from blood back into filtrate
what is the pyelogram
x-ray image of the urinary system
what is the glomerular filtration rate (GFR)
= total amount of filtrate that both kidneys produce each minute.
regulation of glomerular filtration rate (GFR)
Regulated by 2 mechanisms
Ensures…
- adequate blood flow to kidneys
- normal filtration pressures:
- Intrinsic (autoregulation)- acting locally at kidney and involves the nephrons and,
- Extrinsic- acting from a distance e.g. autonomic regulation by sympathetic nerves and hormonal regulation initiated by kidneys
what is filtrate
= blood plasma minus blood proteins and blood cells
what is urine
filtrate minus water, nutrientes, essentail ions plus added wastes
renal maintenance of blood pH
if pH drops - kidneys will secrere more H+ and retain more HCO3, to bring bakc blood pH to homeostasis
if pH increases - kidneys will retain more H+ and secrete HCO3- to bring blood pH back to homeostasis
what is erythropoiesis
production of red blood cells (RBC)
renal control of erythropoiesis
Erythropoiesis – production of red blood cells
Stimulated by the hormone erythropoietin (EPO)
Released by kidneys in response to hypoxia
what is hypoxia?
decreased oxygen levels in the blood
causes of hypoxia:
- Decreased RBC numbers due to haemorrhage or increased destruction
- Insufficient haemoglobin per RBC
- Reduced availability of O2
the production of erythropoeisis (RBC)
its controlled by a negative feedbakc mechanism
1. decreases oxygen levels in blood (hypoxia)
2. kindey “senses” hypoxia and releases an enzyme: renal erythropoietin factor (REF)
3. REF converts a plasma protein to hormone - erythropoietin
4. EPO stimulates red bone marrow to produce more RBCs to carry more oxygen
5. oxygen levels in blood return to normal
