B10 The nervous system, eye and brain Flashcards
What is homeostasis
The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function
What 2 conditions need to be maintained for optimum enzyme action
pH
Temperature
What is negative feedback
When a change away from the ideal triggers a reaction to bring the change back to normal
What 3 things need to be controlled by negative feedback
Water levels
Body temperature
Blood glucose concentration
What are receptors
Detect changes in the internal or external environment
What are stimuli
A change in the environment
What is an effector
A muscle of gland that brings out a response
What is a coordinator
Areas that receive and process information from receptors
Give 5 examples of coordinators in the body
Brain
Pancreas
Nervous system
Endocrine system
Spinal cord
Describe the function and structure of the sensory neurone
Connects the receptor to the CNS
Has a nucleus
Myelin sheath for insulation
Has axon
Cell body is in the middle
Describe the function and structure of the motor neurone
Connects CNS to muscles/glands
Has a nucleus
Myelin sheath for insulation
Has axon
Cell body is at the end
How does the body respond to a stimulus
The receptor cell detects the stimulus
An electrical impulse is sent via nerves along the sensory neurone to the CNS
The CNS coordinates the response
An electrical impulse is sent along the motor neurone to a muscle or gland
This triggers a response
What is the central nervous system made up of
Spinal chord and brain
What are the 4 sense organs and what receptors do they contain
Eyes-Light
Ears-Sound, pressure
Nose-Chemical(smell)
Skin-Pain, pressure, change in temperature
Name 2 effectors and how they respond to impulses
Muscles-Contract
Glands-Secrete hormones