Ureters

Urinary bladder

Urethra

Regulates the content of blood plasma to maintain

'dynamic constancy' or homeostasis, of the

internal fluid environment

within normal limits.

• Roughly oval with a medial indentation (lima bean)
• Approx. 11 cm x 7 cm x 3 cm
• Left kidney often larger than right
• Right located a little lower
• Both kidneys in retroperitoneal position
• Between T12 and L3

Concave notch on medial surface where

vessels and tubes enter kidney

The renal pelvis narrows as it exits the kidney

to become the ureter.

True or False

The renal pelvis acts as a collection basin to drain urine from the kidney

A tube running from each kidney to the urinary bladder

* about 28-24 cm in length, composed of 3 layers: mucous lining, muscular middle layer, & fibrous outer layer

3 openings

2 ureters & the urethra (the trigone)

• Reservoir for urine before it leaves the body
• Aided by the urethra, it expels urine from the body

Small mucous membrane

lined tube extending from the trigone to the

exterior of the body

Voiding

Micturition

After leaving the bladder, passes through the prostrate gland where it is joined by two ejaculatory duct, ending at the urinary meatus.

Approx. 20 cm long and is part of the urinary and reproductive system

How much urine can the average bladder hold before it causes a moderately distended sensation

& the desire to void?

How many nephrons are there in each kidney

in a normal person?

1.25 million

(2.5 million in a body)

First part of the renal tubule nearest to Bowman's capsule, follows a winding, convoluted course

** also known as the proximal tube

A nephron with a Henle loop that does not dip into the medulla but remains almost entirely within the cortex; 

they constitute approx. 85% of the total nephrons

1. Filtration
2. Tubular reabsorption
3. Tubular secretion

Which 2 hormones reduce water loss

(or less urine is produced)?

ADH

Aldosterone

Related to the total amount of solutes other than sodium excreted in urine; in general,

the more solutes, the more urine

What % of water is contained in the composition of urine?

What composes the other %?

95%

* other substances are Nitrogenous Wastes:

Urea

Uric acid

Ammonia

Creatinine

obstruction of urine flow causing backup and

swelling of the renal pelvis

Secreted by the adrenal cortex

Increases distal tubule absorption of sodium, thereby raising the sodium concentration of blood and thus promoting reabsorpotion of water (less urine produced)

Network of fine capillaries surrounded by

the Bowman capsule

The microscopic functional unites, comprise the

bulk of the kidney

* each nephron is made of 2 regions (renal corpuscle & renal tubule) & connects to a shared collecting duct

95% water

Balance consists of:

1. Nitrogenous wastes
2. Electrolytes
3. Toxins
4. Pigments
5. Hormones
6. Abnormal constituents