Urinary System - Unit 4 Flashcards
Where are the Kidneys located?
They lie behind the peritoneum on the posterior abdominal wall on either side of the vertebral column.
- Extend from T12-L3
- The right kidney is slightly lower than the left
What is the Renal capsule?
Part of the External Kidney Anatomy
- Dense irregular connective tissue that surrounds each kidney.
What is the Perirenal fat?
Part of the External Kidney Anatomy
- Adipose connective tissue, deep to the renal capsule.
What is the Renal fascia?
Part of the External Kidney Anatomy
- Thin layer of dense irregular connective tissue.
- Anchors kidneys to surrounding structures.
What is the Pararenal fat?
Part of the External Kidney Anatomy
- Adipose connective tissue.
- Engulfs (superficial to) the renal capsule and acts as cushioning.
What is the Hilum?
Part of the External Kidney Anatomy
It’s what connects your lungs to their supporting structures
- Renal artery and nerves enter and the renal vein and ureter exit kidneys
- Opens into the renal sinus
What is the Cortex?
Part of the Internal Kidney Anatomy
- The outer area of the kidneys extending from the renal capsule
* Renal Columns extends into the medulla
What is the Medulla?
Part of the Internal Kidney Anatomy
- The inner area of the kidneys, consists of several cone-shaped Renal Pyramids
What are Renal Pyramids?
Part of the Internal Kidney Anatomy
- Base is near the cortex
- Apex, called the Renal Papilla points toward the renal hilum.
Explain the Renal Sinus.
Part of the Internal Kidney Anatomy
Has 2 parts
- Minor Calyx: small funnel-shaped chamber surrounding the papilla. (8-20)
- Major Calyx: several minor calyces converge to form larger funnel-shaped chambers. (2-3)
What is the Renal Pelvis?
Part of the Internal Kidney Anatomy
- Enlarge chambers that take urine to the ureter.
What is the Nephron? Explain.
It’s the basic structural and functional unit of the kidney. 1.3 million in each kidney.
Has 4 components that are located in both the renal cortex and renal medulla.
- Renal Corpuscle
- Proximal Convoluted Tube
- Loop of Henle
- Distal Convoluted Tube
What is the Renal Corpuscle?
It’s the blood-filtering component of the nephron of the kidney. Has 2 components.
- Glomerulus: A network of capillaries. Blood enters through afferent arterioles, and exits through efferent arterioles.
- Bowman’s Capsule: 2 layered covering with a space in between called the capsular space.
Explain the 2 layers of Bowman’s Capsule.
Parietal Layer (outer)
- Simple squamous epithelium, becomes cube-shaped at the ends.
Visceral Layer (inner)
- Specialized podocytes that wrap around the glomerular capillaries, permeable layer.
What is the Filtration Membrane in Bowman’s Capsule? Explain the different parts.
The first stage of urine formation occurs in here when fluid from blood in capillaries moves across the filtration membrane into the lumen inside Bowman’s capsule.
- Fenestrae: window-like openings in the endothelial cells of the glomerular capillaries.
- Filtration slits: gaps between the cell processes of the podocytes.
Explain part 1 of the structure of the Nephron.
Proximal Tubule:
- simple cuboidal epithelium
- many microvilli project into the lumen
Loops of Henle:
- first part similar to proximal tubule
- latter part is simple squamous epithelium and is more thinner
Ascending Limb:
- first part is simple squamous epithelium and thin
- distal part is thicker and simple cuboidal
Explain part 2 of the structure of the Nephron.
Distal Convoluted Tubule:
- simple cuboidal
- very few microvilli
Collecting Ducts:
- Simple cuboidal epithelium
- Not part of the nephron
Both contain specialized epithelial cells: Principal & Intercalated cells
What are Principal & Intercalated cells?
Specialized epithelial cells
- Principal cells: have receptors that bind aldosterone and antidiuretic hormone
- Intercalated cells: have alpha and beta cells that help regulate urine pH and blood pH
What is the Juxtaglomerular Apparatus? What cells does it contain?
Specialized structure that helps regulate filtrate formation and systemic blood pressure.
- Granular cells: smooth muscle cells of the afferent arteriole, produce an enzyme called Renin (regulates blood pressure)
- Macula Densa cells: located in the wall of the distal convoluted tubule. Detect changes in NaCl concentration
Explain the first 5 parts of the blood flow to the kidneys. (1-5)
(Arterial supply)
1. Renal Arteries: branch from abdominal aorta
- Segmental Arteries: branch from renal
- Interlobar Arteries: ascend within renal columns toward the cortex
- Arcuate Arteries: branch and arch over the base of the pyramids
- Interlobular arteries: project into the cortex and give rise to afferent arterioles
Explain the second 5 parts of the blood flow to the kidneys. (6-10)
(Part of circulation involved with urine formation)
6. Afferent Arterioles: supply the glomerulus
- Glomerulus
- Efferent Arterioles: exit the renal corpuscle
- Peritubular Capillaries: from a plexus around the proximal and distal tubules
- Vasa Recta: specialized parts of peritubular capillaries
Explain the third 5 parts of the blood flow to the kidneys. (11-15)
(Venous drainage)
11. Interlobular Veins
- Arcuate Veins
- Interlobar Veins
- Renal Veins
- Inferior Vena Cava
What is the function of the Urinary Track? What are the different parts?
It’s responsible for transporting and storing the urine produced in the kidneys until it’s appropriate to eliminate from the body.
Consist of:
- Ureters
- Urinary bladder
- Urethra
Explain the Ureters.
Long fibromuscular tubes that conduct urine from the kidneys to the urinary bladder. Originating from the renal pelvis and extending inferiorly to the posterior side of the urinary bladder.
Consists of 3 tissue layers: (labeled most deep to superficial)
- Mucosa
- Muscularis
- Adventitia
