Nervous System Flashcards
Central Nervous System
The part of the nervous system composed of the brain and spinal cord
Peripheral nervous system
Made up of sensory and motor neutrons. It connects the central nervous system to the rest of the body and detects and responds to change
Neurons
Nerve cell that carry electrical messages
Nerves
A bundle of neurons
Stimulus
Anything the body senses. They are detected by receptors
Receptors
Organs or cells that detect changes in your external or internal environment. When a receptor detects a stimulus, it sends messages to the control centre. There are 4 receptors
Photoreceptors
Detects light. Cones detect colour and rods detect black and white colours
Mechanoreceptors
Detects mechanical forces such as pressure or vibration
Chemoreceptors
Detect chemicals
Thermoreceptors
Detects temperature
Control centre
Receives messages from the receptors and uses this information to decide what the body needs to do. The control centres send signals to parts of the bodies called effectors. Eg. Brain
Effectors
Receives signals from the control centre. Eg. Glands, muscles
Response
Eg. If it is cold outside, the muscles are the effectors and shivering is the response.
Negative feedback
When the body acts against the stimulus
Positive Feedback
When the body amplifies the stimulus. Not useful in homeostasis but useful in childbirth and blood clotting.
Endocrine system
Uses hormones such as adrenaline, oestrogen and testosterone. Response is slow and long lasting.
Hypothalamus
Acts as a bridge between the endocrine system and nervous system.
Cell body
Main part of the neuron
Dendrites
Makes connections to other cells and receives chemical messages from other neurons
Axon
A cell that carries electrochemical messages along the cell
Myelin sheath
Fat and protein that helps to speed the transmission of a electrochemical message
Nerve impulse
A type of electrochemical message that travels along an axon
Motor neurons
Carries nerve impulses away from the central nervous system
Sensory neurons
Sends information back to the central nervous system
