Urinary System Flashcards
1
Q
Location and position of the kidneys
A
- sits on the posterior wall of abdomen
- sit laterally to vertebrae T12-L3
- adrenal glands sit on top of the kidneys
2
Q
External Anatomy of Kidney: Renal Capsule
A
- thin membranous sheath that covers the outer surface of each kidney
3
Q
External Anatomy of Kidney: Hilum
A
- location of the renal artery and vein
4
Q
Internal Anatomy: Cortex
A
- most superficial layer
5
Q
Internal Anatomy: Medulla
A
- Deeper Layer
> renal column: cortical tissue extends into medulla
> renal pyramid: medullary tissue
6
Q
Internal Anatomy: Renal Papilla
A
- is the apex of the pyramids and opens to minor calyx
7
Q
Internal Anatomy: Minor calyx (calyces)
A
- receives urine from the papillae (5-15 per kidney)
8
Q
Internal Anatomy: major calyx
A
- formed from multiple minor calyces (2-3 per kidney)
9
Q
Internal Anatomy: Renal Pelvis
A
- formed by the major calyces
10
Q
The nephron is the what?
A
- basic functional unit of kidney
- 1 million per kidney
- where urine will be formed before draining thru the other structures
11
Q
Parts of the nephron
A
- Renal corpuscle
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting duct
12
Q
Renal Corpuscle
A
- = glomerulus + glomerular capsule
- glomerulus: network of specialized capillaries; site of blood filtration
- glomerular filtrate: fluid and dissolved solutes filtered from blood into glomerular capsule
- filtrate contains metabolic wastes, but also useful materials that need to be reabsorbed
13
Q
Proximal convoluted tubule
A
- first section of renal tubule
- reabsorbs organic nutrients, proteins, ions, and water from filtrate
- most reabsorption happens in this segment
14
Q
Nephron Loop (Loop of Henle)
A
- second section of renal tubule
- travels through medulla
- descending limb: reabsorption of water (water stays in body)
- ascending limb: reabsorption of ions; impermeable to water
15
Q
Distal convoluted tubule
A
- third section of renal tubule; end of nephron
- active transport of ions, acids, toxins
16
Q
Collecting duct
A
- receives fluid from several distal convoluted tubules
- antidiuretic hormone (ADH): regulates permeability of collecting ducts to water —> controls concentration of urine
17
Q
Juxtaglomerular apparatus
A
- clusters of cells next to glomerulus
- manipulates blood volume/pressure
- —> autoregulates rate of glomerular filtration
18
Q
Parts of the juxtaglomerular apparatus: macula densa
A
- detects ion levels in bloodstream
> controls dilation of afferent arteriole
> signals for release of renin
19
Q
Parts of the juxtaglomerular apparatus: juxtaglomerular cells
A
- secrete renin (increases blood pressure) and erythropoietin (stimulates red blood cell production)
20
Q
Blood Supply: Renal arteries
A
- branches from the abdominal aorta
- right renal artery = longer bc it passes behind inferior vena cava
21
Q
Renal artery branches: segmental arteries
A
- initial branches from renal artery in (or before) renal sinus
22
Q
Blood Supply: afferent and efferent arterioles and peritubular capillaries
A
- afferent arterioles: supply nephrons at glomerulus
- efferent arterioles: drain blood from glomerulus; feed into capillaries
- peritubular capillaries: surround renal tubule and involved in reabsorption
23
Q
Renal nerve plexus
A
- postganglionic sympathetic fibers
- alters artery smooth muscle tone: regulates rate of urine formation
- releases renin: regulates composition of urine
- no parasympathetic fxn for kidneys
24
Q
Ureters
A
- smooth muscle tubules
- extend from renal pelvis to bladder
- peristaltic contractions propel urine
- run from kidneys to the bladder
25
Kidney stones
- crystalline formations in urinary tract
- caused by lack of hydration, abundance of stone-forming chemicals (e.g. calcium, phosphate, oxalate from high-fructose corn syrup)
26
The bladder
- most anterior organ in the pelvis
- lies behind pubic symphysis/pubic bones
- receives urine from kidneys via ureters
- urine leaves via urethra
27
Trigone
- an area with no rugae, in btw openings for ureters and internal urethral orifice
28
Rugae
- mucosa forms rugae when empty
29
Smooth muscle
- walls consists of smooth muscles
30
Neck of the bladder
31
The Bladder — Females
- anterior to vagina
- inferior to uterus (sits on top of bladder)
32
The Bladder — Males
- neck of the bladder is superior to prostate
33
Detrusor muscle
- smooth muscle in walls of bladder
- expels urine upon contraction
34
The urethra
- extends from internal urethral orifice to external urethral orifice
- shorter length in females than in males
35
Male urethral segments
- prostatic: from bladder thru center of prostate (extends from bladder to pelvic floor)
- membranous: passes through muscular pelvic floor
- spongy (aka penile): passes through penis to external orifice
36
Urethral sphincters
- internal: smooth muscle; involuntary control; btw bladder and urethra
- external: skeletal muscle; voluntary control via resting muscle tone and relaxation
37
Urination — Storage Reflex of Micturition
- initiated by low stretch
- increased sympathetic activity
> inhibits detrusor contraction
> internal sphincter contracts
- stimulation of somatic motor neurons
> external sphincter contracts (via pudendal nerve)
38
Urination — Voiding reflex of micturition
- initiated by high stretch
- increased parasympathetic activity (and reduced sympathetic activity)
> detrusor contracts
> internal sphincter relaxes
- reduced stimulation of somatic motor neurons
> external sphincter relaxes
