CH 26: The Urinary System Flashcards
What does the urinary system do?
It is a filtering system that:
1.Regulates plasma ion concentration
2.Regulate blood volume and blood pressure
3.Helps to stabilize blood pH
4.Prevent the loss of valuable nutrients
5.Prevent dehydration (fluid balance)
What does the urinary system consist of?
Kidneys
Ureters
Urinary bladder
Urethra
What are the three layers of connective tissue that serve to protect the kidneys?
1.Fibrous capsule— dense irregular connective tissue
(Directly around the kidney to protect)
2.Perinephric fat— adipose tissue
3.Renal fascia— loose connective tissue
Sectional View : Frontal view
Where do renal arteries enter the kidney?
Where do renal veins and ureters exit the kidney?
The Hilum
Sectional Anatomy: Frontal or Coronal Cut
This sectional anatomy consist of ?
1.Renal cortex
2.Renal medulla
— Renal pyramids
— Renal Papillae
— Renal columns
3.Renal pelvis
— minor calyx
— major calyx
What is the blood supply to the kidneys?
Renal artery➡️ Segmental artery ➡️ Arcuate arteries ➡️ Cortical radiate arteries➡️ Afferent arterioles➡️ Glomerular capillaries
Waste (glomerular filtrate) material leaves the glomerular capillaries and enters
Glomerular capsule ➡️ proximal convoluted tubule (PCT)➡️nephron loop
➡️distal convoluted tubule (DCT)
What are the two main types of nephrons?
1.Cortical nephrons (85% of the nephrons)
Has a short nephron loop (loop of Henle)
2.Juxtamedullary nephrons (15%)
Has a long nephron loop
(Produces dark urine)
What does the Renal Corpuscle consist of?
Glomerular capsule
Glomerulus
What are podocytes?
Podocytes are specialized epithelial cells that cover the outer surfaces of glomerular capillaries.
Podocytes have long cellular extensions that wrap around the basal lamina
What are filtration slits?
The spaces between the pedicels on the glomerular basement membrane through which water, glucose, amino acids, and other chemicals pass as they become renal filtrate.
What are the two hormones produced by the juxtaglomerular?
1.Renin - regulates blood pressure
2.Erythropoietin -involved in erythrocyte production
Juxta— “right next to”
What does the collecting duct do?
It drains the urine away and makes final adjustments to urine volume
“ this is where the antidiuretic hormone works“
Know the Ureteral opening and Trigone on the Anatomy of the urinary bladder
What kind of epithelium lines the ureter?
Transitional epithelium
What are the three layers of the ureter?
Inner mucosa-
Middle muscular layer- smooth muscle
Adventitia -dense irregular connective tissue
Where is the base of the urinary bladder for Males?
Between the rectum and the pubic symphysis
Where is the base of the urinary bladder for Females?
Inferior to the uterus and anterior to the vagina
What is the muscular layer of the urinary bladder called and what does it do?
Detrusor muscle
It squeezes and contract when we are ready to urinate
What is the smooth muscle at the exit of the urinary bladder and entrance to the urethra?
Internal urethral sphincter
— when we feel the urgency to pee it’s this sphincter opening under the pressure of the bladder being full
(Involuntary control)
What is the length of the female urethra?
3 to 5 cm
What is the length of the male urethra?
18 to 20 cm
What is the Urethra?
A tube located at the bottom of the bladder that allows urine to exit the body during urination.
What is the external opening of the urethra for females?
External urethral orifice— it is near the interior wall of the vagina
What is the three subdivision of the urethra for males?
Prostatic urethra - comes out of a gland and goes to the prostate
Membranous urethra - goes out of the pelvis
Spongy urethra - goes out and through the penis
What is the skeletal muscle that is voluntary and permits us to relax and allow urine to pass?
External urethral sphincter
Why are females prone to bladder infections than males?
This is because the urethra is very short
What is Micturition?
The process of urination
How many ML has the bladder filled up when we first get the urge to urinate?
200 ML
How many ML of urine still remains in the bladder after “complete void”?
10 ML
