Urinary system Flashcards
Dorsal boundary: bladder?
Sacrum/ sacral vertebrae
Ventral boundary: bladder?
Bones of the pelvis
Cranial boundary: bladder?
Pelvic inlet
Caudal boundary: bladder?
Pelvic outlet
Lateral boundary of bladder? Left and right
Bones of the pelvis
Bladder location/ empty
Ventral
Pelvic cavity
Bladder location/ full
Only neck of bladder remaines in pelvic cavity
Body of bladder moves ventrally and cranially into abdominal cavity
Where are the structures of the urinary system found?
Caudal abdomen
X kidneys = cranio-dorsally in abdomen
What are the components of the urinary system?
2 kidneys
2 ureters
urinary bladder
urethra
5 functions of the kidneys?
Maintain blood volume
Maintain blood pressure
Maintain electrolyte balance
Maintain acid-base balance
Control red blood cell production
3 parts of the kidney?
Cortex
Medulla
Renal pelvis
What happens to blood when it arrives at the kidney?
filtration process
Location: filtration process
Nephrons
During the filtration process, what is blood filtered of? (7)
Water
Electrolytes
Small proteins
Amino acids
Fatty acids
Glucose
Urea
Why is blood pressure important when blood arrives at the kidneys?
Too high - nephrons will B damaged
Too low - efficiency cld drop
The amount of blood flow to the kidneys is known as…
Renal perfusion
What controls renal perfusion?
Renin-Angiotensin-Aldosterone-System
Why is the blood pressure in the glomerulus increased?
Lumen of the efferent arteriole is narrower than lumen of the afferent arteriole
What is the glomerulus?
Bundle of capillaries
Permeable walls
Fluid is forced out of capillary walls
High pressure
What is ultrafiltration?
Most plasma of blood filtered out
Leaving behind larger molecules and blood cells.
Where is filtrate first collected?
In the glomerular/ Bowman’s capsule.
What process(es) takes place in the PCT?
Concentration of urea by removing water
Sodium and chloride reabsorption
Reabsorption of ALL glucose
Secretion of toxins and certain drugs
In the loop of Henle: the descending limb is…
permeable to water
In the loop of Henle: the ascending limb is…
permeable to salts
If an animal is dehydrated…
more water is reabsorbed in the loop of Henle, reducing urine output
If an animal is over-hydrated..
less water is reabsorbed in the loop of Henle and will be passed out into the urine
What is released if electrolytes are scarce?
Aldosterone
What produces/releases aldosterone?
Adrenal gland
Where does electrolyte reabsorption take place?
In the Distal Convoluted Tubules and Collecting Ducts
What increases salt reabsorption from the DCT to the bloodstream?
Aldosterone
Aldosterone increases ……………………………………..from the DCT to the bloodstream?
salt reabsorption
By what process does water follow salts being reabsorbed?
Osmosis
What do the kidneys excrete in to the distal convoluted tubule which raises the pH?
Hydrogen ions
What happens when the kidneys excrete hydrogen ions into the DCT?
It raises the pH
What is formed by the materials not reabsorbed?
Wastes aka urine
Where does urine go after it’s been emptied into the collecting ducts?
Away to the renal pelvis
Where does urine come from before it goes to the renal pelvis?
Collecting ducts
What is released in times of fluid shortage?
Anti-Diuretic Hormone (ADH)
What releases Anti-Diuretic Hormone?
Posterior Pituitary gland
What stimulates reabsorption of more water within the collecting ducts?
Release of Anti-Diuretic Hormone
Function of - Bowman’s/ Glomerular capsule
Collects the filtrate
Function of - Distal Convoluted Tubule
Reabsords electrolytes, salts and water (aldosterone)
Function of - Collecting ducts
Reabsorbs water (ADH)
Function of the ureters
Transport urine from kidneys to bladder
Where are the ureters located? (3)
Attached to kidneys at renal pelvis
In abdomen: Dorsal & bi-lateral
In pelvic cavity: turn medially to dorsal surface of bladder
Ureters pass obliquely through bladder wall - Why?
Stop backflow of urine from bladder (when high pressure)
Backwards flow is known as …
Reflux
Even during periods of high pressure within the bladder, urine passes down the ureters by ..
peristalsis
What controls peristalsis?
Smooth muscles of the walls
What allows the ureters to expand for passage of urine?
Transitional epithelium
What allows for the wall of ureter to contract allowing peristalsis for movement of urine?
Smooth muscle
3 openings in the bladder?
Trigone
What picks up the urge to urinate in the bladder?
Stretch receptors when the bladder wall stretches
What prevents the urine escaping?
2 set of spincter muscles
What are the 2 different sphincter muscles in the bladder?
Internal urethral sphincter (at the neck of bladder)
External urethral sphincter (urethra)
What needs to happen for urine to leave the body?
Sphincter muscles need to relax
What are internal urethral sphincter made of?
Smooth muscle (involuntary)
What are external urethral urethral sphincter made of?
Skeletal muscle (voluntary)
What is the name of the muscle of the bladder?
Detrusor
Features of detrusor muscles?
3 different layers which lie in different directions - so bladder can contract uniformly.
Muscle used for expansion of bladder?
Transitional epithelium
Which muscle allowes for the bladder to expand and return to its former size?
Elastic tissue
What type of muscle allows the bladder to contract and empty?
Smooth muscle
What 2 systems (nerves) control the bladder?
Sympathetic and parasympathetic nerves
Function of sympathetic nerves
Prevent urination
- Inhibit bladder contraction
- Cause sphincters to constrict
Function of parasympathetic nerves?
Cause urination
- Inhibit the constriction of sphincters
- Cause bladder to contract
What does the urethra do?
Transport urine from bladder to outside the body
What nervous systems can urethra use?
Somatic (voluntary) and autonomic (involuntary) to allow control of urination
What action does the urethra use to pass urine?
Peristalsis
Difference between the male and female urethras?
Female’s: short and wide
Male: longer and narrower
Function of the peri-renal fat
Protect kidneys
Energy reserve
What is the primary function of the loop of Henle
Concentrates urine depending on the hydration status of the plasma
What is the primary function of the loop of Henle
Regulates the concentration and volume of urine according to status of ECF
Where is the exterior opening of the urethra in the female?
Vaginal wall
Where is the exterior opening of the urethra in the male?
Distal penis
Why does the urethra contain smooth muscle?
To allow peristalsis for movement of urine
Location and function of urethra?
Convey urine caudally from neck of bladder to the outside (in males: also conveys sperm)
2 muscles involved in process of urination + location
Detrusor muscles in bladder wall
Urethral sphincter in bladder neck
Renal vain drains blood from …
kidney to vena cava
Renal artery supplies blood from…
aorta to kidney
Function of microvili in PCT?
Increase SA to reabsorbe water + electrolytes
What happens to muscles when an animal urinates?
Detrusor muscle contracts
Sphincter muscle relaxes
Location of female exterior opening of urethra?
Vaginal wall
Location of male exterior opening of urethra?
Distal penis
