Urinary system Flashcards
Intro
Bladder can hold 2 cups of urine comfortable and 1L when full
- during 24 hours, kidneys process 150-180L of water and solutes
- avg adult voids 1-2 L a day
- regulates content of blood plasma to maintain homeostasis of internal fluid environment
- not related to waste elimination are
1. Maintaining blood volume
2. Maintiaing normal blood pressure
3. Maintaining normal blood composition
4. Maintaining normal body and blood pH
Anatomy of urinary system
Kidneys, ureters, urniary bladder, urethra
Kidneys
Size of soap with medial indentation (hilum)
- left kidney is larger than right
- right kidney lies lower
- sandwich ther vertebral column between T12 and L3 (posterior aspect of abdomen = retroperitoneal
- fat surrounds each kidney
External anatomy of kidney
Renal hilum: Blood vessels and other structures enter or leave the kidney
- surroundig kidney:
1. Superficial = renal fascia
2. Middle = adipose capsule
3. Deep = renal capsule
Internal structures
- renal cortex
- renal medulla
- renal pyramids
- renal columns
- calyx
- renal pelvis
Renal cortex
Outer region
- superficial light red region
- smooth-textured area
- extends from the renal capsule to the bases of the renal pyramids and into the spaces between them
- the portions that extend between the renal pyramids are called renal columns
- divided into the outer cortical zone and the inner juxtamedullary zone
- together with renal pyramids constitute the parenchyma
Renal medulla
Inner region
- renal pyramids: several cone shaped structure of the renal medulla
- base = wide, apex = renal papilla which points to hilum
- contains nephrons
- each renal papilla ends in a cup like structure called a calyx
Nephron
Functional unit of the kidney (filters)
- filtrate drains into papillary ducts, which extend through renal papillar of the pyramids. Ducts drain into cuplike structures called minor and majorly calyces
Renal pelvis
Received urine from the major calyces
- narrows as it exits a kidney to become a ureter
Blood vessels of kidneys
Highly vascularized
- 1200mL/min of blood flows through them
- receive 20-25% of resting cardiac output via right and left renal arteries
Renal corpuscle
First part of the nephron
- glomerus (capillaries): capillary network
- bowman capsule: (glomerular) double walled epitheial cup that surrounds the globular capillaries
- fluid from the blood filters out of the glomerus and into the glomerular capsule
Renal tubule
In nephron
- Proximal convoluted tube
- henle loop (nephron loop)
- distal convoluted tubule
Glomerular (bowman’s) capsule
- cup shaped mouth of nephron
- formed by tow layers of epithelial cells with a space between them
- plasma (fluids, waste products, an delectrolyes) passes through the glomerular capillaries and enters this space to be processed into urine
Glomerulus
A network of fine capillaries in bowman’s Caplsule
- glomerular capillaries have thin, membranous walls
- the endothelium has many pores present which are important for filtration
Renal tubule
- collecting duct: joining the renal tubules of several nephrons. All collectiong ducts of one renal pyramid converge at a renal papilla. Openings at the renal papilla release urine into one of the minor calyces
1. Proximal convoluted tubule (PCT): first part of the renal tubule, attached to glomerular capsule
2. Nephron loos (loop of henle): segment of renal tubule beyond the PCT. important in the production of highly concentrated or very dilute urine
3. Distal convoluted tubule (DCT): convoluted tubule beyond the nephron loop. Extends into th renal medulla