homeostasis Flashcards
define homeostasis
maintenance of a constant internal environment
what organs are involved in homeostasis?
- skin
- kidneys
- pancreas
- brain
define stimulus
any change occurring inside or outside the body detected by the brain
give an example of positive feedback
- blood clotting
- child birth
- fruitripening
give an example of negative feedback
- regulation of body temp
- fluid content
- blood pressure
what is the receptor for glucose level?
islets of langerhans
define vasodilation
a rise in body temp leads to a rise in the bloods as well causing the capillaries to dilate for an increase in supply to get rid of heat via sweat
what is the receptor for temp change
hypothalamus
what does the vasometer do when temp is cold?
sends order for vasocontraction
describe the skin
- largest organ of the body
- imp sense organ
- barrier to external environment
- regulates body temp
what is the epidermis?
outer layer of the skin
contains 3 layers
what is the cornified layer?
- made up of dead cells
-protects the body from water loss, mechanical thermal and chemical damages, invasion of microbes
what is the granual layers made of?
living cells
what is the malpighian layer?
- replaces dead cells from the cornified layer
- melanin as protection against uv rays
what are the functions of the epidermis?
-waterproof
- prevention on evaporation
- stop germ andar ana
- stop against mechanical energy
what is the dermis?
contains:
- blood vessels
- hair
- sweat glands
- temp receptors
- fatty tissue
- sebacious glands
define vasodilation
dilation of arteries
define vasocontraction
contraction of arterioles
describe the hair feature of the skin
- grows from the hair follicle
- hair eractus muscle at the base of the follicle
- contracts causing hair to stand
when does the hair erector muscle contract?
when the temp grows too low, causing a pocket of air to be made in the skin which insulates it
what is the movement of sweat when formed?
from the sweat gland to the duct and finally coming out the pore
how are temp receptors able to detect changes in enviroment?
- nerve ending in dermis and epidermis
- from sense organs
- hence able to detect changes
what does the fatty tissue do?
- insulate the body
- provide cushioning
- stores energy
what are the properties of the sebaceous gland?
- lubricates the hair
- secretes oil into the follicle
- has an antiseptic action
