Ch. 24 & 25 Urinary System Flashcards
What is the primary function of the kidneys?
To produce urine and help regulate blood volume and blood composition
Calyx
Collects urine before it passes further into the urinary tract
Renal artery
Branch of the abdominal aorta that brings freshly oxygenated blood into the kidneys. For kidneys to produce urine, they need plenty of blood flow
Renal vein
Blood is drained after bringing oxygen to the kidneys by the veins into the inferior vena cava.
What is the nephron?
Where the urine is produced and blood volume and composition are regulated in the kidneys. Made of the glomerulus and renal tubule. There are about 3 million nephrons in both kidneys.
What is the Glomerulus?
A porus capillary bed that acts like a strainer, part of the nephron.
What is the Renal Tubule?
A yellow tubular structure surrounds the glomerulus.
What are the components of the Urinary System and what do they do?
2 kidneys- regulates BV and blood composition, produces urine
2 ureters- drains urine from the kidneys to the urinary bladder
1 urinary bladder- collects the drained urine
1 urethra- drains urine from the urinary bladder
What does the Renal Tubule do?
Collects material that goes through the glomeruli, getting filtered out of the blood. It collects this filtrate and transports it.
What are the components of the Renal tubule, listed proximal (surrounding glomerulus) to distal (into collecting dump)?
- Bowman’s capsule that envelops the glomerulus and initially collects filtrate.
- Proximal tubule
- Nephron loop/loop of Henle
- Distal tubule
Where does the filtrate go after the distal tubule (7 things)?
Goes to the collecting duct, papillary duct, urine, renal pelvis, ureter, bladder, and out of the body
What is filtration?
A process in the glomerulus that pushes things out of the bloodstream.
What does our body do with filtrate?
Either let what is in the filtrate stay until it is excreted as urine or get back something that we might have filtered out that we don’t want to pee off.
What do our kidneys allow us to do?
Keep what we need to keep and get rid of what we need to get rid of in specific quantities to maintain homeostasis.
What is the process-free filtration?
It does not matter the quantity, if it is present in the bloodstream and it fits through the pores, it gets filtered.
If someone’s kidneys aren’t working, could they develop anemia?
Yes, this is because there wouldn’t be enough RBC production. The kidneys produce a hormone called erythropoietin that tells bone marrow to produce and release more RBC into the circulation.
What are the 3 steps in urine formation by the kidneys?
- Filtration at Glomerulus- depends on renal blood flow, kidneys need plenty of blood flow
- Tubular Reabsorption
- Tubular Secretion
How much blood flow do the kidneys get?
They have a bunch of blood vessels and blood flow. They get about 25% of all our cardiac output.
What doesn’t normally get filtered?
WBC, RBC, platelets, and any significant amount of proteins don’t because they are too big to fit through the pours.
What are two factors that determine renal blood flow (Q)?
How the heart is working and the BV
How much volume we have circulating dictates what?
How much flow gets to a particular area
How much blood flow to the kidneys drives what?
Drives filtration and we need the heart and blood vessels to be working properly for this to happen.
What is the Glomerular Filtration Rate?
How much filtrate is produced by both kidneys per minute.