Lecture 1: Renal Anatomy and Glomerular Structure Flashcards
What are the three major functions of the kidneys?
Excretory organs
Regulatory Organs
Endocrine organs
List the four ways that kidneys are regulatory organs
- Maintain constant volume and composition of bodily fluids by varying excretion of solutes and water
- Regulation of blood pressure
- Acid-base balance
- Excrete some substances and recycle back to blood
What 3 hormones do the kidneys secrete?
- Renin
- Erythropoietin
- Active Vitamin D
Major anatomical differences of the bovine kidney
- Lobulated (~12 lobes)
- No renal pelvis
Major anatomical differences of the porcine kidney
Flat and pale
Major anatomical differences of the goat and sheep kidneys
Resemble dog kidney
Which hormone is secreted by kidneys?
A. Renin
B. Relaxin
C. Calcitonin
D. Ergocalciferol
A. Renin
What is the functional and structural unit of the kidney?
Nephron
What does a nephron consist of?
A glomerulus and renal tubule
What does the glomerulus consist of?
Glomerular capillary network emerging from an afferent arteriole and exiting via an efferent arteriole
What is the glomerular capillary network surrounded by?
Bowman’s capsule (or space)
What is continuous with the proximal convoluted tubule?
Bowman’s capsule (space)
What is the first step in urine formation?
Blood filtering from glomerular capillary network into Bowman’s space
What is the renal tubule?
Tubular structure lined with epithelial cells that function to reabsorb and secrete
What comes first in the renal tubule (after the Bowman’s capsule)?
Proximal convoluted tubule
What comes after proximal convoluted tubule?
Proximal straight tubule
What comes after proximal straight tubule?
Loop of Henle
What is first segment of Loop of Henle that comes after the proximal straight tubule?
Thin descending limb
What comes after thin descending limb?
Hairpin Turn
What comes after Hairpin Turn?
Thin ascending limb
What comes after thin ascending limb?
Thick ascending limb
What comes after thick ascending limb?
Distal convoluted tubule
What comes after distal convoluted tubule?
Collecting ducts
Name the parts of the Loop of Henle
- Thin descending limb
- Hairpin turn
- Thin ascending limb
- Thick ascending limb
What is special about the segments of the renal tubule?
They are functionally distinct and have cells with different ultrastructures
What are the two types of nephrons?
- Superficial Cortical Nephrons
- Juxtamedullary nehprons
List the characteristics of superficial cortical nephrons
Glomeruli in outer cortex with relatively short loops of Henle descending into only the outer medulla
List the characteristics of Juxtamedullary nephrons
- Glomeruli near the corticomedullary border
- Glomeruli larger which = higher glomerular filtration rates
- Long loops of Henle reaching deep into the inner medulla - essential to concentrate urine
What border are Juxtamedullary nephron glomeruli near?
Corticomedullary border
Cortex
Outer region of kidney
Medulla
Central region of kidney, has inner and outer portions
Papilla
Innermost tip of inner medulla
Blood enters kidneys through the?
Renal artery
What is the first artery after the renal artery?
Segmental artery
What comes after the segmental artery?
Interlobar artery
What comes after interlobal artery?
Arcuate artery
What comes after arcuate artery?
Cortical radiate artery
What comes after cortical radiate artery?
Afferent arteriole
Which arteriole is blood flow into kidney controlled with?
Afferent arteriole
What comes after afferent arteriole?
Glomerulus (capillaries)
What comes after efferent arteriole?
Peritubular capillaries
Explain the pathway of blood into the glomerulus
- Renal artery
- Segmental artery
- Interlobar artery
- Arcuate artery
- Cortical radiate artery
- Afferent arteriole
- GLomerulus
Peritubular capillaries branch from where?
Efferent arterioles
What are major functions of the peritubular capillaries?
- Surround nephron and absorb solutes + water from filtrate
- Some solutes secreted from capillaries into tubules
What is something special about the peritubular capillaries of Juxtamedullary nephrons?
They have Vasa recta
What do vasa recta do?
Participate in osmotic exchange to produce concentrated urine
What arteriole enters the glomerulus?
Afferent arteriole