Chapter 26 Urinary System

What are the three functions of urinary system?

1. Excretion - Removal of metabolic wastes from body fluid

2. Elimination - Discharge of wastes from body

3. Homeostatic regulation - Solute concentration of blood (pH)

What are the Homeostatic function of urinary system

Regulate blood volume and blood pressure

Regulating plasma ion concentrations

Stabilize blood pH

Conserving valuable nutrients

Assisting liver in detoxification

What is the main function of the excretory system?

Maintain homeostatic and involves excretion of metabolic wastes.

What are the three metabolic wastes?

Urea

Creatinine (breakdown of creatine phosphate)

Uric acid ( from recycling of nitrogenous bases)

What is the most abundant waste in the body

Urea

What are the organs of the urinary system, and what are the functions?

Kidneys - Produces urine

Ureters - Transport urine toward the urinary bladder

Urinary bladder - temporarily stores urine prior to urination

Urethra - Conducts urine to exterior (in males transports semen)

Define Urination or micturition

Process of eliminating urine

What does Retroperitoneal mean?

Give an example

Retroperitoneal means behind the peritoneal

A example would be kidneys protected y floating ribs 11th and 12th)

(True or false) Left kidney is slightly superior to the right kdney

True

In terms of the internal kidney, what do the pyramids empty urine to?

The pyramids empty urine into the minor calyx

In terms of the internal kidney what do the major calyx drain?

The major calyx drains the minor calyx

In terms of the internal kidney, what do the major calyx drain into?

The major calyx drains into the renal pelvis

In terms of the internal kidney, what does the renal pelvis empty into give the order?

Renal pelvis empties into the ureter, to the bladder, then to the urethra, than to toliet.

(True or false) Blood flows to the kidneys via the renal artery.

True

(True or false) Blood that’s been filtered gets drained from those areas back into the renal vein to the vena cava, to the heart

True

Define Afferent arterioles & Efferent arterioles

Afferent arterioles - Blood going IN

Efferent Arterioles - Brings blood BACK into the kidneys into renal vein.

Trace the path of blood flow

Renal artery → Segmental artery → Interlobar artery → Arcuate artery → Cortical radiate artery → Afferent arteriole → Glomerulus → Efferent arteriole → Peritubular capillaries → Venule → Cortical radiate vein → Cortical radiate vein → Arcuate vein → Interlobar vein → Renal vein.

In terms of the 2 nephrons which nephron is more prevalent?

Which nephron do most of the work?

Cortical Nephrons are more prevalent

Juxtamedullary nephrons do most of the work1

what is the function of squamous cells

Squamous cells allow for diffusion.

what is the function of cuboidal cells?

Cuboidal cells are for secretion.

Where does filtration occur?

Filtration occurs at the renal capsule

What is the glomerulus surrounded by?

What is filtered in blood that goes into the bowmans capsule?

Glomerulus is surrounded by the Bowmans capsule.

Water, ions, fatty acids, amino acids are all filtered.

What are the functions of PCT

In terms of the loop of Henle, what does the descending limb’s function, and the ascending limbs?

The descending limbs function is that allows for water to leave the urine to go back into the body.

The ascending limbs allow for sodium to leave.

In the distal convoluted tubule of a nephron, what is its function?

Distal convoluted tubule reabsorbs of ions and regulated pH levels.

What is the primary functions of collecting duct’s

Main function of the collecting ducts are to

• receive form other nephrons and empty into renal pelvis.

• Adjustment of pH, sodium ions, aldosterone

What is the function of ADH in the collecting ducts function?

ADH controls permeability, if there is not enough water, it helps us retain water.

Give the signs of Normal Urine

Normal urine is

• pH levels of 4.5 - 8

• Water content is 93 -97%

• Color should be pale yellow

• Clear

• NO bacterial content

Define Urinalysis

Urinalysis is the Analysis of a urine sample

What is the Ureters?

What is it made out of?

The ureters is the passageway for urine to flow from kidneys to bladder.

Ureters is made out of transitional epithelium.

What type of muscle is the Urinary bladder made out of?

What do the 3 points of the urinary bladder act like

Urinary bladder is made out of smooth muscle.

the 3 points of the urinary bladder acts like a funnel for the urine.

(True or false) Male urethra is longer than females?

(True or false) Male urethra function is to transport urine and sperm?

True

True

(True or false) female urethra have more UTI since it is more exposed?

True

(True or false) External urethra spincter is in both sexes, acts like a valve, and we have control over it.

True

In terms of the urinary reflex does it need info from the brain?

Yes it does

In terms of Urinary reflex, define urine voiding reflex.

Urine voiding reflex is when the bladder contains 200mL of urine, which causes urge to urinate.

What two age demographics dont have control over urination.

Infants

Elder

What are the 7 structures of a nephron?

1. Glomerulos - Filters blood form filtrate.

2. Bowmans capsule - Collects from the glomerulos

3. Proximal convoluted tubule - Reabsorbs most water, nutrients, salts

4. Descending limb of loop of Henle - Reabsorbs water

5. Ascending limb of loop of Henle - Reabsorbs salts

6. Distal Convoluted Tubule - Adjust salt, water, pH levels.

7. Collecting duct - Collects urine carries towards the renal pelvis

What are the 3 basic processes that form urine?

1. Glomerular filtration - Blood filtered in the glomerulus, water and small substances enter bowmans capsule

2. Tubular reabsorption - Useful substances (water, glucose, and salts) are returned to the blood

3. Tubular secretion - Additional waste and excess substances are moved from the blood into the tubule to be removed in urine.

Define concurvent multiplication

Concurvent multiplication creates salt concentration gradient in the kidney medulla allowing water to be reabsorbed and urine to become concetrated.

What are the 2 hormonal influence on the volume and concentration of urine

ADH - increases water reabsorption by the kidneys

Aldosterone - Increase sodium reabsorption producing less urine and increase blood volume.

Trace the pathway of urine formation in the nephron.

Glomerulus → Bowman's capsule → Proximal convoluted tubule (PCT) → Descending limb of Loop of Henle → Ascending limb of Loop of Henle → Distal convoluted tubule (DCT) → Collecting duct → Renal pelvis.

Trace the pathway of urine starting with the blood vessels all the way to the toilet.

Renal papilla → Minor calyx → Major calyx → Renal pelvis → Ureter → Urinary bladder → Urethra → Outside the body (toilet).

Explain the structure of the Ureters

Two narrow, msucular tubes connecting kidneys to urinary bladder.

Explain the structure of the urinary bladder

Hollow, muscular organ

Trigon acts as a funnel

Explain the structure of the Urethra

Tube connects urinary bladder to outside of body

Explain the voluntary and involuntary regulation of the urination

Involuntary - As bladder fills stretch receptors detect pressure sending signals to spinal cord.

Voluntary - External urethral sphincter is controlled voluntarily, you consiously relax it to urinate.

Define micturition reflex

Occurs when bladder stretches as it fills with urine, triggering bladder contractions to release urine.