Urinary System (Q4, P3) Flashcards
Main Functions of the Urinary System
- Maintain the chemical consistency of the blood
- Filter many liters of fluid from blood
- Send toxins, metabolic wastes, and excess water out of the body
Secondary Functions of the Urinary System
- Regulates blood volume and blood pressure
- Regulates pH
- Eliminates urea
- Controls electrolytes and metabolites
Organs of the Urinary System
- 2 Kidneys
- 2 Ureters
- 1 Urinary Bladder
- 1 Urethra
Location of Kidneys
- Located retroperitoneally: behind the peritoneum
- Lateral to T12-L3 vertebrae
Size of the Average Kidney
- 12 cm tall (4.7 in)
- 6 cm wide (2.4 in)
- 3 cm thick (1.2 in)
Hilus of the Kidneys (Hilum of 1 Kidney)
- an indentation in the surface of a kidney where blood vessels, ducts, nerve fibers, etc. enter or leave it.
- found on the concave surface of the kidney
Renal Capsule
The fibrous connective tissue that surrounds each kidney.
Renal Cortex
the outer layer of the kidney
Renal Pyramids
- kidney tissues that are shaped like cones
- found in the medulla
Renal Pelvis
- The area at the center of the kidney.
- Urine collects here and is funneled into the ureter, the tube that connects the kidney to the bladder.
Renal Plexus
complex network of nerves in the kidneys
Nephron
- the functional units of the kidney.
- composed of the renal corpuscle and renal tubules
- Each kidney has millions of nephrons
Renal Corpuscle
- the blood-filtering component of the nephron of the kidney.
- Composed of a Glomerulus
and Glomerular/Bowman’s Capsule
Glomerulus
- network of small capillaries known as a tuft, located at the beginning of a nephron in the kidney
- where waste products are filtered from the blood.
- Capillaries are fenestrated-little openings that increase permeability
Bowman’s Capsule
- a cup-like sac at the beginning of the tubular component of a nephron in the kidney that performs the first step in the filtration of blood to form urine.
- A glomerulus is enclosed in the sac.
- Fluids from blood in the glomerulus are collected in the Bowman’s capsule.
Renal Tubules
- long pipe like structure containing the tubular fluid filtered through the glomerulus.
- After passing through the renal tubule, the filtrate continues to the collecting duct system
- Composed of the proximal convoluted tubule, Loop of Henle, and the distal convoluted tubule
Proximal Convoluted Tubule
- the segment of the nephron in kidneys which begins from the renal pole of the Bowman’s capsule to the beginning of loop of Henle. (in the renal cortex)
- lined by simple cuboidal epithelium with brush borders which help to increase the area of absorption
- responsible for the reabsorption and secretion of some water and some salts.
Loop of Henle
- Long U-shaped portion of the renal tubule that conducts urine within each nephron of the kidney
- helps concentrate filtrate
Distal Convoluted Tubule
- portion of kidney nephron between the loop of Henle and the collecting tubule.
- reabsorbs some water and some salts
Collecting Ducts/Tubules
The last part of a long, twisting tube that receives urine from the distal convoluted tubules
Ureters
- Carry urine from the kidneys into the urinary bladder
- oblique entry into bladder prevents backflow of urine
External Urethral Sphincter
- voluntarily inhibits urination
- provides voluntary control of urine flow from the bladder to the urethra
Prostatic urethra
- Passes through the prostate gland
- first portion of the male urethra
Membranous Urethra
Through the urogenital diaphram
Spongy/Penile Urethra
Passes through the length of the penis
