Urinary system

Urinary system rides the body of..

Waste products

Kidneys play an important role in

Blood pressure, Volume and Composition

The urinary system is closely associated with..

Reproductive system

• shared embryonic development and adult anatomical relationship

• Collectively called the urogenital (UG) system

Functions of Kidneys to regulate what

• Regulates blood volume, pressure and osmolarity

• Regulates electrolytes and acid-base balance

• Regulates calcium levels by participating in calcitriol synthesis

Kidneys filter ..

• Blood and excrete toxic metabolic wastes

• Clears hormones from blood

Kidneys secrete…

Secretes erythropoietin, which stimulates the production of red blood cells

Kidneys detoxify..

Free radicals

Kidneys in starvation,…

they synthesize glucose from amino acids

Waste

any substance that is useless to the body or present in excess of the body’s needs

metabolic waste

waste substance produced by the body

Urea formation

• Proteins → amino acids → NH2 removed → forms ammonia

• Liver converts ammonia to urea

your body turns a toxic waste product into a much safer one so it can be removed

Uric acid

Product of nucleic acid catabolism

Creatinine

Product of creatine phosphate catabolsim

Blood urea nitrogen (BUN), and high and low BUN

Level of nitrogenous waste in blood

• Normal concentration of blood urea is 10 to 20 mg/dL

• High BUN: Can mean your kidneys aren't removing urea efficiently, but it can also happen from dehydration, a high-protein diet, or other causes.

• Low BUN: Can occur with low protein intake, certain liver problems, or overhydration.

Uremia and treatment

syndrome of diarrhea, vomiting, dyspnea, and cardiac arrhythmia stemming from the toxicity of nitrogenous waste

Treatment: hemodialysis or organ transplant

Excretion

Separating wastes from bodily fluids and eliminating them

Four body responses carry out excretion and what they excrete

Respiratory system

• Co2, small amount of other gases and water

Integumentary system

• Water, inorganic salts, latic acid, urea in sweat

Digestive system

• Water, salts, Co2, lipids, bile pigments, cholesterol, and other metabolic waste

Urinary system

• Many metabolic wastes, toxins drugs, hormones, salt, H+, water

Kidney position

Lie against posterior abdominal wall at level of T12 to L3

• Rib 12crosses the middle of the left kidney

Right kidney is..

Slightly lower due to larger right lobe of liver

Identify the structures associated with the kidneys and their functions

ureters, urinary bladder, renal artery and vein and adrenal grlands

retroperitoneal

means kidney is behind the peritoneum (the lining of the abdominal cavity).

Shape and size of kidney

About the size of a bar of soap

Lateral surface is convex and medial is concave with a slit called hilum

the hilum slit receives …

Renal nerves, blood vessel's lymphatics and ureter

Three protective connective tissues covering of kidney

Renal fascia

Perirenal fat capsule

Fibrous Capsule

Renal Fascia

Immediately deep to parietal peritoneum

• Binds it to abdominal wall

Perirenal fat capsule

Cushions kidney and holds it into place

Fibrous Capsule

Encloses kidney protecting it from trauma and infection

• Collagen fibers extend from fibrous capsule to renal fascia

• Still drop about 3cm when going from lying down to standing up

Renal Parenchyma

Glandular tissue that forms urine

• Appears C-shaped in frontal section

  • Encircles renal sinus

Renal Sinus

Cavity that contains blood and lymphatic vessels, nerves and urine collecting structures

• adipose fills the remaining cavity and holds structures in place

Two zones of renal parenchyma

Outer renal cortex

Inner renal medulla

Renal columns

Extensions of the cortex that project inward toward sinus

Renal pyramids

6 - 10 with broad base facing cortex and renal papilla facing sinus

Lobe of kidney

One pyramid and its overlaying cortex

Minor calyx

Cup that nestles the papilla of each pyramid

• collects urine

Major calyces

Formed by convergence of 2 or 3 minor calyces

Renal pelvis

formed by convergence of 2 or 3 major calyces

Ureter

a tubular continuation of the pelvis that drains urine down to the urinary bladder

Kidneys are only ___ of the body , but recive ___ of cardiac output

0.4% and 21%

Renal arteries divides into …

segmental arteries

interlobar arteries

up renal columns, between pyramids

Arcuate arteries

over pyramids

Cortical radiate

up into cortex

Branch into afferent arterioles

each supplying one nephron

• leads to a ball of capillaries - the glomerulus

Order of blood flow through the kidneys arteries before reaching the glomerulus

Renal artery → Segmental arteries → interlobar arteries → Arcuate arteries → cortical radiate arteries → Afferent arterioles → Glomerulus

Blood is drained from the

glomerulus by efferent arterioles

MOst efferent arterioles lead to ..

Peritublar capillaries

Some other efferents lead to

Vasa recta - a network of blood vessels within renal medulla

Capillaries then lead to …

Cortical radiate veins or directly into arcuate veins

Arcuate veins lead to …

interlobar veins

Interlobar veins lead to…

renal vein

Renal vein lead to…

empties into inferior vena cava

In the cortex convoluted peritubular capillaries brnach off of ______

Efferent arterioles supplying the tissue near the glomerulus, the proximal and distal ules

In the medulla the efferent arterioles give rise to…

the Vasa Recta, supplying the nephron loop portion of the nephron

Each kidney has about how many nephrons

1.2 million

Each nephron composed of two principal parts…

Renal corpuscle

Renal Tubule

Renal corpuscle

filters the blood plasma

Renal tubule

Long, coiled tube that converts the filtrate into urine

what encloses the glomerulus

two-layered glomerular capsule

Two-layer glomerulus capsule

perietal (outer0 layer of glomerular capsule is simple squamous epithelium

Visceral ( inner) layer of glomerular capsule consists of elaborate cells called podocytes

Podocytes

wrap around the capillaries of the flomerulus

capsular space

separates the two laters of the glomerular capsule

Vascular Pole

the side of the corpuscle where the afferent arterial enters the corpuscle and the efferent article leaves

Urinary Pole

The opposite side of the corpuscle where the renal tubule begins

Renal ( uriniferous) tubule

Duct leading away from the glomerular capsule and ending at the tip of the medullary pyramid

Renal ( uriniferous) tubule divided into four parts

• Proximal convoluted tubule (PCT)

• Nephron loop (Loop of Henle)

• Distal convoluted tubule (DCT)

• Glomerulus

Collecting duct receives

Fluid from many nephrons

Proximal convoluted tubule (PCT)

Arises from Glomerular capsule

• longest and most coiled

• Simple cuboidal epithelium with prominent microvilli for majority of absorption