Urinary System Flashcards
Composition of urinary system
- Kidneys (1 pair)
- Ureters (1 pair)
- Bladder (1 structure)
- Urethra (1 structure)
Functions of urinary system
- Regulates fluid and electrolyte balance of body
- Removes waste products of metabolism from body
- Functions as endocrine organs: synthesizes and secretes erythropoietin rennin
General structure: kidney
- Capsule covers the surface (connective tissue)
- Outer layer (cortex) and inner layer (medulla)
- Renal pyramids contained in the renal medulla group into 10-18 pyramidal structures
- Renal pelvis forms branches called major calyces
- Major calyces form branches called minor calyces
- The renal pyramid connects the minor calyces with its apex which points toward the renal pelvis and the base forms the interface with the cortex
- At the base of the medullary pyramid, parallel arrays of tubules called medullary rays penetrate the cortex
- Granular cortical tissue between medullary rays is termed cortical labyrinth
- The cortex between medullary pyramids are called renal column
The upper part of the ureter which projects into the kidney forms the
Renal pelvis
A medullary pyramid and the associated cortical tissue
Kidney lobe
A medullary ray and the surrounding cortical labyrinth
Kidney lobule
Each lobule is made up of numerous
Uriniferous tubules
Uriniferous tubule is divided into two parts
- Nephron
- Collecting tubule and duct
The nephron of the uriniferous tubule is divided into 2 parts
- Renal corpuscle
- Renal tubule
The renal tubule of the nephron is divided into 3 parts
- Proximal Convoluted tubule
- Loop of Henle
- Distal Convoluted tubule
The structural and functional unit of the kidney
Nephron
The convoluted tubule of the nephron consists of
- Proximal convoluted tubule
- Distal convoluted tubule
The part of the nephron responsible for the filtration of plasma
Renal corpuscle
Key point for exam (structures of the renal corpuscle)
Afferent arteriole of the renal corpuscle forms branches from the
Capillary network
The glomerular capsule is made of
Simple squamous epithelium
This structure is derived from the afferent arteriole and drained by the efferent arteriole
Glomerulus
Difference between the afferent arteriole and efferent arteriole of the glomerulus
Diameter for afferent arteriole is large and the diameter for efferent arteriole is small
The endothelial cells in the glomerular capillary are
Fenestrated
The double walled epithelial chamber having an internal/visceral layer and an external/parietal layer
Glomerular capsule
The renal filtration barrier consists of
- Endothelium of the glomerular capillaries
- Basement membrane
- Filtration slit membrane
Proximal convoluted tubule under light microscope
Wall:
Simple cuboidal/pyramidal shaped cells
Proximal convoluted tubule under light microscope
Lumen surface:
Has brush border
Proximal convoluted tubule under light microscope
Nucleus:
Small, round, located in the base
Proximal convoluted tubule under light microscope
Cytoplasm
Strongly acidophilic
Proximal convoluted tubule under light microscope
Basal surface:
Having basal striations
Proximal convoluted tubule under electron microscope
Lumen/free surface:
Has well, developed microvilli
Proximal convoluted tubule under electron microscope
Basal surface:
Basal striations or extensive infolding
Distal convoluted tubule under light microscope
Wall:
Simple cuboidal epithelium
Distal convoluted tubule under light microscope
Lumen surface:
Has few brush border (luminal surface is smooth)
Distal convoluted tubule under light microscope
Nucleus:
Small, round, located in the apical position
Distal convoluted tubule under light microscope
Cytoplasm:
Less acidophilic
Distal convoluted tubule under electron microscope
Few mitochondria
Proximal convoluted tubule functions in
The reabsorption of useful materials
Distal convoluted tubule functions in
- Absorption of sodium ions and secretion of potassium ions
- Secrete hydrogen and ammonium into tubular urine
- Hormone regulation (aldosterone & antidiuretic hormone ADH)
The activity of the collecting duct is controlled by
Aldosterone and ADH
The juxtaglomerular apparatus/ complex comprises of
- Juxtaglomerular cell
- Extraglomerular mesangial cell
- Macula densa
Juxtaglomerular cell can help to regulate
Blood pressure of the human body using the hormone renin
Cells of the juxtaglomerular apparatus that are part of the distal tubule wall, with cells that become tall and columnar
Macula densa
Duct associated with the nephron, but not a structure of it
Collecting duct
These cells make up the visceral layer of the Bowman’s capsule
Podocytes
