HUBS192 Lecture 28 - Urinary System I, An Overview & Gross Structure of the Kidney Flashcards
what is urine?
waste product excreted to maintain balance within the body
what 4 things are expelled in urine?
1) excess water
2) excess salts
3) wastes of metabolism
4) many toxins and drugs
what 6 things does a normal urine sample contain?
1) water
2) salts
3) urea
4) metabolites
5) hormones
6) small proteins
what determines the filtering system of the kidneys?
size of waste products
what is the pH of urine and what is it influenced by?
urine pH is not tightly regulated (between 4.6-8) and is influenced by what is secreted
what 3 things may be present in abnormal urine?
1) large proteins that are too large to filtered
2) RBC’s that are too big to be filtered
3) Glucose that is filtered but is completely reabsorbed
what 7 things are required for the urinary system to be effective?
1) delivery system for blood
2) selective filtration system
3) filtrate recovery mechanism
4) system to return recovered, filtered fluid to the body
5) protection
6) ability to communicate with relevant parts of the body
7) adaptable to meet the body’s changing needs
what are the main components of the renal urinary system?
- 2 kidneys
- 2 ureters
- urinary bladder
- urethra
what 4 things does the structure of the kidneys allow?
1) blood to be brought into close proximity with the nephron, for filtering
2) blood that has been filtered to leave the kidney
3) a pathway for urine to be removed from the kidney, stored and then excreted
4) protection
what is the shape of the kidneys?
- convex sides that face laterally
- medial surface has a concave notch called the hilum
what is the location of the kidneys?
at the 11th and 12th ribs between the 12th thoracic vertebrae and 3rd lumbar vertebrae
are the kidneys located symmetrically?
no the left kidney is slightly higher than the right kidney because the location of the liver pushes the right kidney downwards
what gland sits on top of the kidney?
adrenal gland
where is the kidneys located in terms of the peritoneum?
located retroperitoneal
-posterior to the abdominal, covered on the anterior side by peritoneum
what are the kidneys surrounded, supported and protected by?
surrounded, supported and protected by fat
what are the 3 regions of the kidney from superficial to deep?
1) cortex
2) medulla
3) pelvis
what is the fibrous capsule?
thick protective adventitia layer that is the most superficial
what is a medullary pyramid?
the medulla is divided up into triangle regions called medullary triangles
what is the inner medulla divided into?
- divided into pyramids
- each medullary pyramid ends in a papilla
what is a papilla?
apex of a medullary triangle
what is the function of renal columns?
cortical tissue that divide medullary triangles
is the inner medulla segmented or continuous?
segmented
what is the outer cortex?
a continuous layer
what is a lobe?
a single medially pyramid and the wall of the cortex that surrounds it - renal columns
what are the cortex and the medulla divided into?
multiple functional lobes
how many lobes are there per kidney?
5-11 lobes per kidney
what is a kidney lobe largely made up of?
nephrons
-tiny tubes that filter from blood and create urine
what are nephrons?
tiny tubes that filter from blood and create urine
what is a calyx?
something that receives fluid
what is the plural for calyx?
calyces
what is the function of a calyx?
where urine collects that has drained from each papilla
what forms the renal pelvis?
calyces join to form the renal pelvis
when does the pelvis narrow?
narrows as it exits the hilum to become the ureter
what is the travel pathway of urine in the kidneys?
travels into the papilla –> minor calyx –> major calyx –> renal pelvis –> ureter
what are the 3 structures that provide external protection for the kidneys?
1) 11th and 12th ribs
2) renal fat pad
3) fibrous capsule
are the blood vessels in the kidneys small or large?
the blood vessels are small because the nephrons are small
where does filtration occur?
occurs in the cortex of the kidney
what artery arises from the abdominal aorta?
the renal artery
what is the relationship between branching arteries and the cortex of the kidney?
branching arteries get smaller and smaller till they reach the cortex
what is the function of veins in filtering blood from the kidneys?
veins return filtered blood from the cortex to the renal vein, then to the inferior vena cava
what is the function of the afferent arteriole?
delivers blood from the arteries to the glomerulus
what is the glomerulus made up of and what occurs at the glomerulus?
made up of glomerular capillaries and is where filtration occurs
where does filtration occur when blood is in the cortex?
in the glomerular capillaries
where does the filtered blood from the afferent arteriole go?
goes to the efferent arteriole
what is the function of peritubular capillaries?
reabsorb anything that is required back into the bloodstream
what is the function of the efferent arteriole?
carries blood from the glomerulus to the peritubular capillaries
what is the flow of blood through the kidneys in simple terms?
arteriole –> capillary –> arteriole —> capillary
what is the flow of blood through the kidney for blood supply INTO the cortex to be filtered?
from the abdominal aorta –> renal artery –> series of arteries –> afferent arteriole
–> glomerular capillary
what is the flow of blood through the kidney for blood supply AWAY from the cortex after being filtered?
from the glomerular capillary –> efferent arteriole –> peritubular capillaries –> series of veins –> renal vein –> inferior vena cava
what is the kidney innervated by?
innervation is from a network of autonomic nerves and ganglia = renal plexus
what is the renal plexus?
network of autonomic nerves and ganglia
what is the function of sympathetic nerves?
act to adjust the diameter of renal arteries therefore regulating blood flow
what is the nephron?
microscopic functional unit of the kidney
what are the 3 functions of the nephron?
1) filters blood
2) selectively reabsorbs or secretes
3) produces urine
what is the bulk of the kidney made up of?
nephrons
what are the 5 parts of a nephron?
1) renal corpuscule
2) proximal convoluted tubule
3) nephron loop
4) distal convoluted tubule
5) collecting duct
what 4 structures pass through the hilum of the kidney?
- renal vein
- lymphatics
- renal nerves
- renal artery
which kidney is the most inferior and why?
the right kidney because of the location of the liver
what structures comprise a kidney lobe?
a medullary pyramid and the cortex that surrounds it
