Homeostasis Flashcards
Define homeostasis
Homeostasis is the maintenence of a constant internal environment
Define negative feedback
It is the mechanism that counteracts changes in the internal environment and restores it towards the set norm
Explain the basic principles of homeostasis
- A stimulus results form a change inn the internal environment
- Receptors in the body are able to detect this change
- Body will respond with corrective mechanisms to reverse the direction of change. This is known as negative feedback.
- Internal environment is then returned to the set norm
Identify the structures in skin
Hairs, sweat glands, temperature receptors blood vessels and fatty tissue
What are the 2 main functions of the skin?
- Mechanical protection (epidermis): prevent entry of bacteria, separates internal body from environment
- Thermoregulation (dermis): enables human body temperature to remain close to set point of 37C
What is the function of sweat glands?
Secret sweat onto surface of skin, which evaporates and removes latent heat of vaporisation, cooling the body down
What is the function of temperature receptors?
Detect temperatures f surrounding skin, and generate nerve impulses to be sent to nervous system
What is the function of arterioles in skin?
Arterioles are capable of vasoconstriction and vasodilation to control the amount of blood flowing through the capillaries near the surface of the skin.
What is the function of adipose issue?
Provides additional thermal insulation and protection against mechanical shock.
What are the negative feedback mechanisms when body temp rises above 37C?
- vasodilation
- sweat glands more active
- decreased metabolic activity
What are the negative feedback mechanisms when body temp falls below 37C?
- vasoconstriction
- sweat glands less active
- shivering
- incensed metabolic activity
- contraction of hair erector muscle
