Lecture 8: Urinary System Flashcards
What are the 3 main roles/ functions of the urinary system
- Excretion / elimination of waste
- Maintain water, solute, etc.. Homeostasis
- Production of various molecules - enzymes, hormones & conversion of vitamins
How does the hormone Renin work in the urinary system
-Kidneys detect a fall in BP
-renin
-angiotensinogen
-angiotensin I
(there is an angiotensin converting enzyme)
-angiotensin II
-vasoconstriction
How does erythropoietin work in urinary system
-Hypoxia from decreased RBC count, decreased amount of Hb, or decreased availability of O2
-Kidney (and liver) release erythropoietin
-erythropoietin stimulates red bone marrow
-enhanced erythropoiesis increases RBC count
O2 carrying ability of blood rises
How does vitamin D work in urinary system
- Hypocalcemia
- increase release of parathyroid hormone
- increased osteoclast activity = release Ca+ into blood OR increased Ca+ reabsorption in kidney tubule OR increased activity of vitamin D by kidney = increased Ca+ absorption from food in small intestine
- all = incressed Ca+ in blood
What are the 4 main organs that make up the urinary system
- kidney
- ureter
- urinary bladder
- urethra
What is the location of the kidneys
- superior region (12th thoracic vertebra, 3r lumbar vert.)
- R kidney is LOWER than L kidney bcs of presence of liver
What are landmarks of the kidneys
Renal hilus
-region where blood and lymphatic vessels, ureters & nerves enter & exit
What are the 3 structures on the exterior of the kidneys
- Fibrous capsule (protects kidney from surrounding infection)
- Renal Fasciae (anchors kidneys to surrounding structures
- Renal fat pad (heavy cushion of fat around each kidney)
What are 6 main layers inside of the kidneys
- renal cortex
- renal medulla
- renal pelvis
- renal pyramid in renal medulla
- fibrous capsule
Describe the renal cortex
- frm external edge of kidney to top of renal pyramid (Malpighi)
- the part that lies btw the renal pyramids is called renal columns
- ramification of renal veins and arteries
Describe the renal medulla
-region including renal pyramids (have stripped appearance as tubules cross them)
–base of pyramid is oriented twrd cortex
-apex has the renal papilla
(converge at minor calyx, release urine)
What is the renal pelvis
a funnel shaped tube that communicates with the ureters
what are the branching extensions of the renal pelvis
Major Calyx
Minor Calyx
(pleural is calyces)
What does the renal pelvis do
conducts filtrate (urine) away from the kidney (collecting duct and hose)
Where is smooth muscle present in the urinary system
- pelvis
- major and minor calyces
- ureters (assists with urine propulsion
Where does blood enter the kidneys
through renal arteries
how much blood from heart enters the kidneys
1/5th
what % of blood enters and supplies (irrigates) the CORTEX
90% - most of the filtration (nephrons)
what are the 2 capillary beds of the kidneys
- Glomerulus
- Peritubular / vasa rectus
What does the Glomerulus capillary bed do
filtration from high pressure to produce filtrate
what do the Peritubular and Vasa Rectus capillary beds do
- absorption from low pressure
- recuperate majority of fluid (water retention)
What is flow of blood circulation through kidney
IN: 1. Renal artery 2. Segmental arteries 3. Interlobar artery 4. Arcuate artery 5. Cortical radiate artery OUT: 1. Cortical radiate vein 2. Arcuate vein 3. Interlobar vein 4. Renal vein
What is structure of the ureter
2 tubes that transport urine from the kidneys (extension of the pelvis) to the bladder
What are the 3 layers that make up the walls of the ureters
- Mucosa
- Muscularis
- Adventicia
