3. The Nervous System Flashcards
Central Nervous System
Brain and spinal cord
Peripheral Nervous System
Nerves extending all around the body
Reflex
A fixed response to a stimulus
Voluntary reflexes
Involves the brain
Involuntary reflexes
Doesn’t involve the brain
Stimulus
A detectable change in the physical/ chemical enviroment of an organism
Reflex arc
A reflex arc is a neural pathway controlling a reflex
Process of a reflex arc
Receptors in skin detect stimulus
Impulses along sensory neurone to spinal cord
Impulses intergrated by CNS
Impulses along sensory neurone to spinal cord
Response is generated
Dendrites
Receives communication from other neural cells through their tree like projection
Cell body/ Stoma
Encapsulates nucleus
Nucleus
Contains genetic information that controls the neuron
Shywann Cell
Helps to form the myelin sheath and speeds up transmission of nerve impulses
Nodes of Ranvier
Allows impulses to jump (saltatory conduction) to speed up responses
Axon Terminals
Connects the neuron to target cells such as effector cells and nerve cells
Myelin Sheath
Outer coating of the axon to protect and maintain the axon
Gial Cell
Come in many different forms
Their role is to protect and support nerve cells
They surround and are in direct contact with neuron
Synapse
A synapse is a junction between 2 neurons
Synaptic Cleft
Space between two neurones where substances can be transferred
Synaptic Fatigue
Caused by pre synaptic neuron being overstimulated causing damage
Lack of neurotransmitters
Canine Epilepsy
Effects certain breeds (certain stimuli and triggers can bring on seizures)
The Autonomic Nervous System
Part of the PNS, consists of sympathetic and parasympathetic divisions
Controls organ functions dependant on information received
Functions of the Nervous System
Receive stimuli from internal/external environments
Analyse and interpret the stimuli and information
Bring about a necessary response
Tongue
Receptor: chemoreceptor
Function: taste buds detect chemicals in food
Ears
Receptor: mechanoreceptors
Function: cilia detect movement of the eardrum and ossicles which allow hearing