3 Functions of Urinary System Kidneys carry out four functionsFilter nitrogenous wastes, toxins, ions, etc. from blood to be excreted as urine.Regulate volume and chemical composition of blood (water, salts, acids, bases).Produce regulatory enzymes.Renin – regulates BP/ kidney functionErythropoietin – stimulates RBC production from marrow.Metabolism of Vitamin D to active form.
4 Urinary System Two Kidneys Two Ureters Urinary Bladder Urethra Perform all functions except actual excretion.Two UretersConvey urine from Kidneys to Urinary BladderUrinary BladderHolds Urine until excretionUrethraConveys urine from bladder to outside of body
5 Renal Connective Tissue • Renal fascia- anchors the kidneys to nearby structures. It is dense connective tissue• Adipose capsule/Pararenal FatMass of fat tissue that surrounds renal capsuleFunctionsKeeps kidney in placeProvide cushion effects• Renal capsule- Layer of dense connective tissue that surrounds kidney and supports the soft internal tissues.
6 Position of the Kidneys Kidneys are located on either side of the vertebral column:left kidney lies superior to right kidneysuperior surface capped by adrenal gland
7 Location and Position of the Kidneys The kidney is positioned between the 12th thoracic and 3rd lumbar vertebrae.It is retroperitoneal (lies on the posterior abdominal wall, posterior to the peritoneum).Right kidney is lower than left kidney due to the shape of the liver.Lateral surface of kidney is convex while medial is concave.
8 External Anatomy of Kidney Average size – 12cm x 6cm x 3 cmWeights 150 grams or 5 ozSurrounded by three membranes (deep to superficial)Renal capsule – fibrous barrier for kidneys.Adipose capsule – fatty tissue designed for protection / stability.Renal fascia – dense fibrous connective tissue that anchors kidneys/ adrenals to surroundings.
9 External Anatomy of the Kidney Lateral surface- convexMedial surface is concaveRenal HilumIndentation where blood vessels, nerves and ureters enter and exit the kidneys.Renal SinusInternal cavity within kidney.
10 Internal Anatomy of the Kidney • Cortex - Superficial region of kidney.It is light and granular• Medulla - Deep central region of the kidney.Deep layerIt is darker• Renal pyramids- Cone shaped structure within the renal medulla.Base lies against cortexApex is the papilla• Renal column- Extensions of cortex that separate renal pyramids within the medulla.
11 Kidney Internal Anatomy Renal PelvisFlat funnel-shaped expansion of ureterMajor CalicesLarge cup-shaped branches of renal pelvisMinor CalicesCup-shaped divisions of major calicesSurround papilla of pyramid
12 Renal Lobe Consists of: One renal pyramid overlying area of renal cortexadjacent tissues of renal columns
17 Urinary Bladder A collapsible muscular sac Stores and expels urine - Full bladder – sphericalExpands into the abdominal cavity- Empty bladder – lies entirely within the pelvisProstate gland: Found in In males- Lies directly inferior to the bladder- Surrounds the urethra
18 Urinary Bladder Muscular sac that stores and expels urine Location Pelvic floorPosterior to public symphysisAnterior toRectum in malesVagina & uterus in females
19 Urinary Bladder and Urethra in Male and Female Trigone of the urinary bladder has three openings;- Two openings from the uretersOne opening to the urethra
20 Structure of the Urinary Bladder Male:PenisDual functionFemale:External urethral orifice