The Urinary System Flashcards
What do the Kidneys excrete?
Urine
Describe shape and location of kidneys?
Paired - bean shaped located in posterior abdoment
Describe the surface of the kidney?
Lateral is convex
Medial is concave - contains hilum
What are the kidneys capped by?
Adrenal glands
What are the 3 organs that eliminate urine in the urinary tract?
Ureters
Urinary bladder
Urethra
What is urination/micturation?
Process of eliminating urine through urethra and out of body
What is a hilum?
A depression through which ducts nerves or blood vessels enter and leave the organ
What are the 3 key functional roles of the urinary system?
Excretion
Elimination
Homeostatic regulation
Where does Excretion take place?
Occurs in kidneys - the nephron removes waste from bodily fluids
What does it Eliminate?
Storage of urine in the bladder, discharges waste products through urine
How does it maintain homeostatic regulation?
Blood plasma volume and PH
Plasma ion concentrations
Conservation of nutrients
Eliminates toxins
How does the Renal capsule orientate the Kidney?
Fibrous capsule that encases the kidney and prevents infection
How does the adipose capsule orientate the Kidney?
Perinephric fatty mass cushions kidney and aids attachment
How does the Renal Fascia orientate the Kidney?
Outer layer of dense fibrous connective tissue that anchors the kidney
How does the Perirenal fat orientate the kidney?
External to renal fascia and provides protection to kidneys
What is the renal Hilum?
Indented part of kidney on medial surface
Where is the point of entry for the renal hilum?
Renal artery and nerves
Where is the point of exit for the renal hilum?
Renal vein and ureter
What is the Kidney cortex?
Granular superficial region that extends into medulla as renal columns
What is the Kidney medulla?
Subcortex composed of 6-18 triangular renal pyramids seperated by renal columns
Where is the renal papillae?
At the base of the renal pyramids - opens into minor calynx that channel urine towards renal pelvis
What are the 2 types of nephron?
Cortical - only just penetrates medulla
Juxtamedullary - reaches deep into the medulla
What does the Renal Corpuscle of the Nephron consist of?
Glomerulal capsule - cup shaped
Glomerulus - network of capillaries
What is the Renal Tubule of the Nephron?
Long tubular passage, 50mm long begins at renal corpuscle
What type of cells are inside the Renal Corpuscle?
Outer - simple squamous epithelium
Inner - specialised podocytes
What are Podocytes?
Cells with processes adhering to basal lamina over fenestrated capillary endothelium
describe renal blood flow?
25% of cardiac output flows through here, arterial flow into kidney and venous flow out
What is the cells in the Renal tubule?
The Proximal convoluted tubule is the first segment of tubule containing simple cuboidal cells with microvilli on luminal surface
The nephron loop of henle is a descending limb which is squamous passes into medulla ascending limb in cuboidal
What does the Distal convoluted tube of the renal tubule do?
Empties urine into common collecting duct leading to the papillary duct and renal papillae at the top of the renal pyramid
What does Ureter do?
Urine flows from renal pelvis through the ureter to the urinary bladder, the entrance to bladder is oblique the ureters actively proper urine to bladder via peristalsis in response to smooth muscle stretch
Describe ureters?
Have tri-layered wall which has internal mucosa with transitional epithelium (urothelium) a medial muscularis layer and fibrous external connective tissue adventitia
What is the bladder?
Smooth muscle sac that stores urine, rests on pelvic floor bladder expands as urine accumulates without rise of internal pressure
What are the 3 bladder layers?
Transitional epithelium layer, muscle detrusor muscle and adventitia
What is the Trigone of the Bladder?
Triangular area outlined by openings for ureters and the urethra - infections persist here
What is the Urethra?
A muscular tube that drains urine from bladder and out body f=4cm male is 5x more
What is contained in the Internal urethra sphincter?
Involuntary control
located at bladder urethra junction
What is contained in the External urethral sphincter?
Voluntary control, passes through urogenital diaphragm controlled by levator ani muscle on side of pelvis
