Homeostastis and response Flashcards
(26 cards)
Definition of homeostasis
maintenance of an internal environment within an organism
Things that need to be maintained-
Temperature
Water levels
Blood glucose levels
How does a negative feedback loop work?
If something rises or falls receptors detect change and adjust the levels back to ideal
What is a neurone
A neurone is an individual nerve cell that carries information via electrical impulses
Describe the process of a voluntary response
A stimulus is detected by a receptor
Is then passed along neurones to the Central Nervous System
This then coordinates a response from an effector through the motor neurone
What is the central nervous system made of
Brain and spinal cord
Neurone that detects a stimulus
Receptor
Neurone that carries impulses to the central nervous system
Sensory Neurone
Neurone that carries impulses away from the central nervous system
motor neurone
What are the 4 main areas of the brain?
Hypothalamus
Cerebral cortex
Cerebellum
Medulla
Role of the cerebral cortex (highly folded big bit)
Language
Memory
Consciousness
Role of the cerebellum
Balance
Co-ordinates movement
Role of the medulla
Controls breathing and heart rate
Role of the pituitary gland
It is the master gland
It produces LH and FSH hormones
Role of the hypothalamus
Thermoregulation- maintaining body temperature
What are the 8 main parts of the eye
Ciliary muscle
Suspensory Ligaments
Optic Nerve
Retina
Iris
Cornea
Pupil
Lens
Role of suspensory ligament
Controls the shape of the lens
Loosens for near objects
Tightens for far objects
Role of retina
Contains receptor cells that are sensitive to light and colour
Role of optic nerve
Carries impulses to the brain
Role of Ciliary Muscle
controls shape of the lens
Contracts for near objects
Relaxes for far objects
Role of the lens
Focuses light onto the retina
Role of cornea
Refracts light
Role of iris
it is a muscle which controls the diameter of the pupil
What two types of photoreceptors does the retina contain?
Rod cell and Cone Cell
