Objective 1

List the functions of the urinary system and explain how they

contribute to homeostasis.

Unit 1 - Objective 1

Functions of the Urinary System

• Filtration of the blood– Occurs in the glomerulus of the kidney

nephron

– Contributes to homeostasis by removing toxins or waste

Unit 1 - Objective 1

Functions of the Urinary System

• Reabsorption of vital nutrients, ions and water– Occurs in most parts of the kidney

nephron

– Contributes to homeostasis by conserving important materials

Unit 1 - Objective 1

Functions of the Urinary System

• Secretion of excess materials– Assists filtration in removing material

from the blood

– Contributes to homeostasis by preventing a build-up of certain materials in the body such as drugs, waste,etc.

Unit 1 - Objective 1

Functions of the Urinary System

• Activation of Vitamin D– Vitamin D made in the skin is converted

to Vitamin D3 by the kidney

– Active Vitamin D (D3) assists homeostasis by increasing calcium absorption from the digestive tract

Unit 1 - Objective 1

Functions of the Urinary System

• Release of Erythropoietin by the kidney– Erythropoietin stimulates new RBC

production

– New RBC’s assist homeostasis by insuring adequate Oxygen and Carbon Dioxide transport

Unit 1 - Objective 1

Functions of the Urinary System

• Release of Renin by the kidney– Renin stimulates the formation of a

powerful vasoconstrictor called Angiotensin II

– Angiotensin II assists homeostasis by causing vasoconstriction which increases blood pressure

Unit 1 - Objective 1

Functions of the Urinary System

• Release of Prostaglandins– Prostaglandins dilate kidney blood

vessels

– Dilated blood vessels contribute to homeostasis by maintaining blood flow in the kidneys

Unit 1 - Objective 1

Functions of the Urinary System

• Secretion of H (+1) and reabsorption of HCO3 (-1)– Eliminates excess hydrogen ions and

conserves buffer material such as bicarbonate

– Contributes to homeostasis by controlling acid/base conditions in body fluids

Unit 1 - Objective 1

Objective 2

Given a diagram of the Urinary System, you will recognize and label the following parts: kidney, ureters, bladder, urethra, internal and external sphincters.

Unit 1 - Objective 2

Urinary System

Renal arteryKidney

Ureter

Urinary Bladder

Renal Vein

For sphincters, see next slide

Urinary System

Internal urethral sphincterExternal Urethral Sphincter

Male Sphincters Female Sphincters

Objective 3

Given a diagram of the kidney you will label and give the functions of the following structures: renal vein, renal artery, capsule, cortex, medulla, pyramids, renal papilla, calyx, pelvis, ureter, renal column and nephron

Unit 1 - Objective 3

Kidney Diagram

Capsule

Renal VeinRenal ArteryCortex

Pyramid

PapillaCalyx

Pelvis

Ureter

Column

Medulla

Nephron

Functions of Kidney Structures

Examine the kidney structures in the following slides and note the particular functions.

Unit 1 - Objective 3

Functions of Kidney Structures

• The Renal Artery– Transports oxygenated blood from the

heart and aorta to the kidney for filtration

Unit 1 - Objective 3

Functions of Kidney Structures

• Renal Vein– Transports filtered and deoxygenated

blood from the kidney to the posterior vena cava and then the heart

Unit 1 - Objective 3

Functions of Kidney Structures

• Renal Column– A passageway located between the renal

pyramids found in the medulla and used as a space for blood vessels

Unit 1 - Objective 3

Functions of Kidney Structures

• Nephron– The physiological unit of the kidney used

for filtration of blood and reabsorption and secretion of materials

Unit 1 - Objective 3

Functions of Kidney Structures

• Capsule– The outer membrane that encloses,

supports and protects the kidney

Unit 1 - Objective 3

Functions of Kidney Structures

• Cortex– The outer layer of the kidney that contains

most of the nephron; main site for filtration, reabsorption and secretion

Unit 1 - Objective 3

Functions of Kidney Structures

• Medulla– inner core of the kidney that contains the

pyramids, columns, papillae, calyces, pelvis and parts of the nephron not located in the cortex; used for salt, water and urea absorption

Unit 1 - Objective 3

Functions of Kidney Structures

• Renal Pyramids– Triangular shaped units in the medulla that

house the loops of Henle and collecting ducts of the nephron; site for the counter-current system that concentrates salt and conserves water and urea

Unit 1 - Objective 3

Functions of Kidney Structures

• Renal Papilla– The tip of the renal pyramid that releases

urine into a calyx

Unit 1 - Objective 3

Functions of Kidney Structures

• Calyx– A collecting sac surrounding the renal

papilla that transports urine from the papilla to the renal pelvis

Unit 1 - Objective 3

Functions of Kidney Structures

• Renal Pelvis– Collects urine from all of the calyces in

the kidney

Unit 1 - Objective 3

Functions of Kidney Structures

• Ureter– Transports urine from the renal pelvis to

the bladder

Unit 1 - Objective 3

Objective 10

Give the cause and describe the disease process for the following: renal calculi (kidney stones); cystitis; gout; Glomerulonephritis (Bright’s Disease); incontinence.

Unit 1 - Objective 10

Disorders of the Urinary System

• Renal Calculi (kidney stones)– caused by the crystallization of calcium,

magnesium or uric acid salts that precipitate in the renal pelvis.

– If the calculi become large and travel down the ureter, they can cause excruciating pain which radiate from the flank to the anterior abdominal wall on the same side.

Unit 1 - Objective 10

Disorders of the Urinary System

• Cystitis– typically caused by bacteria from the anal

region, but, can also be caused by sexually transmitted diseases and various chemical agents

– can lead to inflammation, fever, increased urgency and frequency of urination and pain

Unit 1 - Objective 10

Disorders of the Urinary System

• Glomerulonephritis ( Bright’s Disease)– caused by inflammation of the glomeruli

due to an abnormal immune response (autoimmune, streptococcal antibody complexes).

– Inflammation of the glomeruli leads to faulty filtration (passage of blood cells and proteins) and possible kidney failure.

Unit 1 - Objective 10

Disorders of the Urinary System

• Incontinence– caused by loss of the ability to control

voluntary micturition (releasing urine from the bladder) due to age, emotional disorders pregnancy, damage to the nervous system, stress, excessive laughing and coughing

– leads to wetting of clothing, discomfort and embarassment

Unit 1 - Objective 10

Objective 11

Describe the process involved in dialysis therapy.

Unit 1 - Objective 11

Dialysis Therapy

Dialysis is a process that artificially removes metabolic wastes from the blood in order to compensate for kidney (renal) failure. Kidney failure results in the rapid accumulation of nitrogen waste (urea, etc.) which leads to azotemia. Uremia and ion disturbances can also occur. This condition can cause acidosis, labored breathing, convulsions, coma and death.

Unit 1 - Objective 11

Dialysis TherapyThe most common form of dialysis is hemodialysis which uses a machine to transfer patient’s blood through a semipermeable tube that is permeable only to selected substances. The dialysis machine contains an appropriate dialysis fluid that produces a diffusion gradient. This gradient allows abnormal substances to diffuse from the patient’s blood and produce a “cleaning” effect.

Unit 1 - Objective 11

Dialysis TherapySome key aspects of hemodialysis are: - blood is typically transferred from an arm artery

- after dialysis, blood is typically returned to an arm vein

- to prevent clotting, blood is typically heparinized

- dialysis sessions occur about three times a week

- each dialysis session can last four to eight hours!

- long term dialysis can lead to thrombosis (fixed blood clots),

infection and death of tissue around a shunt (the blood access

site in the arm)

Unit 1 - Objective 11