~BPw

Ce Lung functions

(1) Absorption of oxygen
(2) Removal of carbon dioxide
(3) Heat regulation

Se Skin is secondarily an organ of excretion. Some of its other functions
are:

ae Protection of body structures
b. Sensory surface
e. Regulation of body temperature

Excretory function of skin is carried on by (a) sweat glands;
(b>) sebaceous glands.

ae Sweat glands: Over entire surface of body. Simple tubular glands
coiled at the end, Amount of secretion varies with: {a) condition
of atmosphere; (b) physical and psychical status. Usually acid in
reaction contains urea, uric acid, creatinin, and sulphates.

Inereased by:

(a) Muscular activity
(b) Heat

(ce) Emotion

(a) Drugs

Decreased by:

(a) Lower temperature
(b) Emotion

be. Sebaceous glands: Simple glands all over surface of skin, usually
associated with hairs. Secretion (sebum) an oily semi-liquid mater-
ial. Contains: fats, soaps, cholesterin, cell debris, and inorganic
salts.

4, Intestines are important organs of excretion as well as of nutrition.
They carry off the useless remains of diet and also the waste products
from cell physiology.

The somi-liguid chyme is passed along intestines by peristaltic action.
As it progresses through the small’ intestines the portions acceptable to
the body cells are absorbed into the blood lymph streams. When the larg
intestine (colon) is reached the movements favor free absorption of water
leaving behind a pasty mass called feces.

Defecation is partly volitional and partly automatic due to stimuli
arising from distention of the rectum. Defecation occurs by the voli-
tional opening of the muscular sphincters controlling the anus.