Week 9: The neural system Flashcards
What are the two categories of PNS division?
Afferent Efferent
What type of neurons are afferent PNS division?
Sensory neurons
What type of neurons are efferent PNS division?
Motor neurons
Define sensory function
To sense change in the internal external environment through sensory receptors (afferent neurons)
Define integrative function
To analyse the sensory information, store some aspects and make decisions (interneurons)
Define motor function
To respond to stimuli by initiation of action (efferent neurons)
How many cranial nerves are there in the brain?
12 pairs
How many spinal nerves are there in the spinal cord?
31 pairs
In the afferent peripheral nervous system (PNS) division, where do the impulses go to and from?
From the receptors to the CNS (skin to CNS)
In the efferent peripheral nervous system (PNS) division, where do the impulses go to and from?
From the CNS to the effectors (CNS to muscle)
What are interneurons?
Pass afferent transmission to efferent response without need for brain involvement
What are the two types of nervous systems of the efferent division?
Autoomic (involuntary processes) Somatic (motor neurons)
What is the function of the afferent neurons?
To sense change in the internal and external environment through sensory receptors (sensory function)
What is the function of interneurons?
To analyse the sensory information store some aspects and make decisions (Integrative function)
What is the function of the efferent neurons?
To respond to stimuli by initiation of action (motor function)
What are the two types of main tissue?
Neurons Neurogila
Neurons are the __________ of the nervous system?
Functional units
What do neurons do?
Convert stimuli to nerve impulses
What is the function of the neurogila?
Protect and support the neurons
What are the two components of the motor unit?
Alpha-motorneuron Muscle fibres innervated by the alpha-motorneuron
How are the type I muscle fibres described?
Slow
How are the type IIa muscle fibres described?
Fatigue resistant
How are the type IIb muscle fibres described?
Fast fatiguing
How many alpha-motorneurons is each muscle fibre connected to?
One
Label the diagram and describe its function
Dendrites Picking up signals
Label A and describe its function
Axon hillock Nerve impulse generated (initiation of the action potential takes place)
Label B and describe its function
Axon Carriers electrical impulse away from cell body
What is the myelin sheath?
A fatty substance that surround the axon of some nerve cells, forming an electrical insulator
What are the four nerve fibre groups?
A-alpha A-beta A-delta C
What nerve fibres are myelinated?
A-alpha A-beta A-delta
How does the size of the fibre effect the conduction velocity?
Larger the size the faster the velocity
What type of structural classification of neuron is this?
Multipolar neuron
What type of structural classification of neuron is this?
Bipolar neuron
What type of structural classification of neuron is this?
Unipolar neuron
What is the resting membrane potential?
-70 mV
What determines the action potential of the membrane?
The concentration of ions inside and outside the cell (Na+ and Cl-)
Label the action potential graph
Depolarisation
Repolarisation
Hyperpolarisation
What are the two types of signal summation?
Spatial summation Temporal summation
