Week 3 Flashcards
(31 cards)
What are the functions of the urinary system
HOMEOSTASIS
Maintain the stability of the extracellular fluid volume,
electrolyte composition and osmolarity (solute concentration)
1) H 2 O balance to prevent osmotic fluxes IN/OUT of cells
cells swell/shrink
2) Plasma volumes regulates arterial blood pressure
3) Acid-base balance via H + and HCO3- urinary output
4) Ion concentrations and balance
Excretion of waste products of metabolism
(Urea from proteins, bilirubin from haemoglobin)
6) Endocrine functions
Erythropoietin production stimulates erythrocyte production
Renin production (RAS system)
7) Activation of Vitamin D [25OHD > 1,25(OH) 2 D3]
8) Excretion of drugs, non-nutritive materials
Whats in the upper urinary system
Paired structures including
Kidneys
Ureters
Lower urinary system
Unpaired structures including bladder and urethra
Where are the kidneys located, and what are the structures surrounding them?
The kidneys are located from T12 to L3, with the right kidney being slightly lower. They are retroperitoneal, surrounded by fat and fascia, situated against the posterior abdominal wall in the paravertebral gutters. Nearby muscles include psoas major, quadratus lumborum, transversus abdominis, and the inferior diaphragm.
What is the blood supply to the kidneys?
Renal Vein: Joins the inferior vena cava (IVC). The left renal vein is longer and passes over the abdominal aorta and under the superior mesenteric artery.
Renal Artery: Branches off the abdominal aorta. The right renal artery is longer and runs under the IVC.
What are the key anatomical features and dimensions of the kidney?
Dimensions: 10 cm x 5 cm x 2.5 cm
Shape: Bean-shaped
Poles: Superior and inferior
Borders: Lateral and medial
Surfaces: Anterior and posterior
Hilum: Contains the renal vein, artery, and renal pelvis
Covering: Encased in a thick capsule
What are the internal structures of the kidney?
Cortex and Medulla: The outer and inner regions of the kidney.
Collecting System: Includes collecting ducts, renal papillae, minor calyces (calyx), major calyces, renal pelvis, and ureter.
What is the pathway of urine flow from the nephron to outside the body?
Nephron
Collecting Duct
Minor Calyx
Major Calyx
Renal Pelvis
Ureter
Bladder
Urethra
Out of the body
What are the main components of a nephron?
Renal Corpuscle
Convoluted Tubules
Loop of Henle
Collecting Duct
What are the parts of the nephron located in the cortex?
Convoluted Tubules + Blood Vessels
Renal Corpuscle (200 μm diameter sphere)
Medullary Rays (loops of Henle & collecting ducts)
what are medullary rays
are bundles of renal tubules that start in the kidney’s cortex and extend into the medulla. They look like streaks and help with urine processing.
simple cuboidal epithelium
run parallel
loop of henles and collecting tubules
In Medullary Rays: The lumen of the renal tubules within medullary rays is where the filtrate and urine flow as they move through the kidney’s filtering system
What type of epithelium is found in the Proximal and Distal Convoluted Tubules in the cortex
simple cuboidal epithelium
What is the primary function of the Proximal Convoluted Tubules?
Initial and major site of reabsorption
What type of epithelial cell lines the Proximal Convoluted Tubules?
Cuboidal epithelial cell lining
What are the specific modifications for absorption in the Proximal Convoluted Tubules?
Long microvilli on the apical surface
Basal striations
Numerous mitochondria in the basal region
What are the characteristics of the Distal Convoluted Tubules?
Length: Only 1/3 as long as proximal convoluted tubules
Epithelial Lining: Cuboidal epithelial cells
Specific Modifications:
Very few, short microvilli
Basal striations
Numerous mitochondria in the basal region
What type of epithelium lines the collecting ducts?
Simple cuboidal or columnar epithelium
What are the key features and pathway of the ureters?
Retroperitoneal
Approximately 25 cm long and 5 mm wide
Adjacent to the psoas major muscle and lumbar transverse processes
At the origin of the external iliac artery
Continuation of the renal pelvis to the bladder
What are the common sites of ureteric constriction
Uretero-pelvic Junction: Where the renal pelvis transitions into the ureter.
Pelvic Brim: Where the ureter crosses the bony pelvic brim.
Uretero-vesical Junction: Where the ureter enters the bladder.
Kidney Stones:
can cause obstruction and intense pain when they pass through or get stuck at these constriction sites.
Pain (Renal Colic): The pain radiates from the loin (lower back) to the groin (T1-L1)
What structures do the ureter pass under as it enters the bladder in males and females?
‘Water under the bridge’
Male: Passes under the vas deferens
Female: Passes under the uterine artery
What are the key histological features of the ureter?
Transitional Epithelium
Lamina Propria
Smooth Muscle
Adipose Tissue
What are the key anatomical features and functions of the bladder?
Function: Reservoir for urine
Highly distensible
Apex (Anterior): Urachus
Base (Posterior): Entry of ureters
Neck: Urethra exits
Surfaces: Superior and inferolateral surfaces
What are the internal features of the bladder?
Rugae: Foldings of the bladder lining that allow it to stretch.
Trigone:
A smooth, non-elastic area in the bladder.
Features:
Opening of 2 Ureters: Where urine enters the bladder.
Opening of 1 Urethra: Where urine exits the bladder.
What are the bladder relationships in males?
Superior: Bladder is below the intestines.
Anterior: Bladder is in front of the pubic bone.
Posterior: Bladder is behind the seminal vesicles, vas deferens, and rectum.
Inferior: Bladder is above the prostate gland.
