Urinary System

What is the urinary system also known as?

Excretory System

What is the function of the urinary system?

Responsible for removing certain waste and excess water from the body and for maintaining the body’s homeostasis.

What is homeostasis?

The self-regulating process by which biological systems maintain a stable, constant internal environment despite changing external conditions.

What makes up the urinary system

• 2 kidneys

• 2 ureters

• 1 bladder

• 1 urethra

Describe the kidney

2 bean-shaped organs located on either side of the vertebral column, behind the upper part of the abdominal cavity and separated from this cavity from the peritoneum.

What is the kidney protected by?

Ribs and heavy cushion of fat.

What helps keep the kidney in position?

Connective tissue.

What does the kidney consist of?

Each kidney is enclosed in a mass of fatty tissue, called adipose capsule and covered externally by a touch, fibrous tissue, called the renal fascia or fibrous capsule.

What are the two main sections of the kidney?

Cortex and Medulla

Medulla:

The inner section of the kidney, contains most of the collecting tubules, which carry urine from the nephrons through the kidney.

Cortex:

The outer section of the kidney, contains most of the nephrons, which aid in the production of urine.

Nephrons:

Microscopic filtering units located in the kidney.

How many nephrons are in one kidney and in total?

More than 1 million nephrons per kidney. 2 million in total because we have 2 kidneys.

What do the nephrons consist of?

Glomerulus, Bowman’s capsule, proximal convoluted tubules, distal convoluted tubule and collecting duct.

What does the renal artery do?

it carries blood to the kidney, branches of the artery pass through the medulla (middle) to the cortex (outer).

Glomerulus:

Cluster of capillaries.

As the blood passes through the glomerulus what is happening and what substances are included in this action?

It filters out water, mineral salts, glucose, metabolic products and other substances that are filtered out of the blood.

What isn’t filtered out?

Red blood cells and proteins.

What happens to the filtered blood after the glomerulus

The filtered blood leaves the glomerulus and eventually makes its way to the renal vein, which carries it away from the kidney.

Bowman’s capsule:

A C-shaped structure that surrounds the glomerulus and is the start of the convoluted tubule.

• The substance filtered out in the glomerulus this new section of the nephron (Bowman’s capsule).

What is happening as the material passes through various sections of the tubules?

As these materials pass through the various sections of the tubules, substances needed by the body are reabsorbed and returned to the blood capillaries.

What happens as the filtered material passes through the tubules?

Most of the water and wastes remain in the tubules and become known as the concentrated liquid called urine.

What happens to this urine?

The urine then enters collecting ducts located in the medulla, collecting ducts empty into the renal pelvis, which is a funnel-shaped structure that is the first section of the ureter.

Ureters:

2 muscular tubes, approximately 10-12 inches in length.

• Extends from the renal pelvis of each kidney to the bladder

What does the urine move to from what and how.

Peristalsis moves the urine through the ureter from the kidney to the bladder.

What is peristalsis?

Wavelike movement to push things forward (How food moves in the digestive system).

Bladder:

A hollow, muscular sac that lies behind the symphysis pubis and at the midline of the pelvic cavity.

What lines the bladder?

It has a mucous membrane lining arranged in a series of folds, called rugae.

What happens to the rugae when the bladder fills out and expands with urine?

It disappears.

What makes up the walls of the bladder and what does it do with the urine?

3 layers of visceral (smooth) muscle form the walls of the bladder, which receives the urine from the ureter and stores the urine until it is eliminated from the body.

Urethra:

A tube that carries the urine from the bladder to the outside.

What is the external opening of the urethra called?

Urinary meatus

Is the male and female urethra different, if yes how so?

Yes

• Males: 8 inches

• Females: 1.5 inches

Who is more prone to a UTI and why?

• Women: They have smaller smaller urethra.

• Catheters: Direct pathway for bacteria to enter the bladder.

• Sexually Active People: Sexual activity can move bacteria into the urethra.

Urine:

Liquid waste products produced by the urinary system.

• Approximately 95% water

• Waste products dissolved in this liquid are urea, uric acid, creatine, mineral salts and various pigments.

What excess product can be found in urine and what does it mean?

Excess useful products, such as sugar can also be found in the urine, but it usually indicates a disease.

Polyuria:

Excessive urination

Oliguria:

Below normal amounts of urination.

Anuria:

Absence of urination.

Hematuria:

Blood in the urine.

Pyuria:

Pus in the urine.

Nocturia:

Urination at night.

Dysuria:

Painful urination.

Retention:

Inability to employ the bladder.

Incontinence:

Involuntary urination.

Proteinuria:

Protein in the urine.