Nervous Flashcards
What is the name of the star shaped glial cells which supply nutrients to neurons, ensheath blood capillaries and transmit information?
Astrocytes
What does integrating and coordinating mean?
Senses environment and produces an appropriate response.
Astrocytes - shape and function?
Are star shaped cells which supply nutrients to neurons, ensheath blood capillaries and transmit information.
What glial cells perform immune system functions and engulf debris/micro organisms?
Microglia
Microglia function?
Perform immune system functions and engulf debris/micro organisms.
What are the glial cells which line fluid filled spaces of the brain and spinal cord and circulate the CSF using cilia?
Ependymal cells
Ependymal cells function?
The glial cells which line fluid filled spaces of the brain and spinal cord and circulate the CSF using cilia.
What are the glial cells which support nerve fibres and ensheath them in myelin in the CNS?
Oligodendrocytes
Function of oligodendrocytes?
The glial cells which support nerve fibres and ensheath them in myelin in the CNS.
What is the function of a Schwann cell?
Support nerve fibres
Ensheath them in myelin
Similar to Oligodendrocytes
What is the structure and function of the myelin sheath?
Lipid wrapped around an axon.
Increases conduction velocity.
What happens if cells are not myelinated?
Weakness, un-coordination, visual and speech impairment caused by an auto immunity or infection.
What are the four neural zones?
Input zone, summation zone, conduction zone, output zone.
What is in the input zone? What is the function of the input zone?
Comprises of the dendrites and cell body.
Receives chemical signals from other neurones.
What is the structure and function of the summation zone?
Axon hillock
Decides whether to transmit signal or not.
What is the structure and function of the conduction zone?
An axon
Carries the electrical signal between brain areas, to and from the spinal cord, or to and from peripheral sensory receptors.
What is the structure and function of the output zone?
The axon terminals
Contact with other neuronal input cells
Release neurotransmitter
What are the three morphological types of neurones? Cve an example for each.
Multipolar - CNS
Bipolar - Eye
Pseudo unipolar - Sensory Cell
What are the three types of synapses?
Axodendritic, axosomatic, axoaxonic
Afferent vs efferent?
Afferent is toward CNS
Efferent is toward effectors
What is a nucleus and what type of matter is this?
Collection of cell bodies in the CNS, grey
What is a tract and what type of matter is this?
Axons in the CNS, white.
What are ganglia and nerves?
Ganglia - cell bodies
Nerves - axons
Both in the PNS
Autonomic subdivisions based off information flow?
Afferent and efferent.
Information flow based on control?
Somatic and autonomic.
Information flow based on anatomy?
Central and peripheral
Describe the somatic efferent pathway in the PNS
One neuron, myelinated. Uses ACH and ends at skeletal muscle at a NMJ.
Define a reflex.
A predictable, reproducible, automatic response to a sensory stimulus.
Which reflex is mono synaptic? Where is the cell body?
Stretch reflex. Cell body in dorsal root ganglion.
What do ipsilateral and contra lateral refer to?
Ipsilateral is the withdrawal muscle action.
Contralateral is the stabilisation of the other muscle groups.
Which reflex has an inter neuron?
Withdrawal reflex.
Describe the function of the prefrontal, pre motor and primary motor (pre central gyrus).
Prefrontal is the desired goal, pre motor is the motor program, pre central is the execution of the desired movement.
Where in the pre central gyrus is the head controlled?
Lateral
How many neurons does the corticospinal pathway have?
Two
Where does the primary neuron of the corticospinal pathway synapse?
At the spinal cord
Where does the secondary neuron of the corticospinal pathway synapse?
At the effector
Where does the primary neuron of the corticospinal pathway have its cell body?
In the motor cortex.
Describe the path of the corticospinal pathway.
Primary neuron has it’s cell body in the motor cortex, crosses over in the medulla. It synapses in the spinal cord. The secondary neuron synapses on the effector.
What are the two extra pyramidal tracts, and what types of movements do they take care of.
Reticulo and Rubro spinal. (Bros flex)
Performs automatic movements such as walking chewing and smiling.
What modalities does the medial lemniscal pathway take?
Touch and proprioception
Where does the medial lemniscal pathway cross over?
In the medulla.
What type of neurons does the proprioception pathway have?
1a, the fastest.
What happens when there is a contraction of the muscle in terms of proprioception?
The Golgi tendon causes relaxation, which protects from tearing. Located at the ends of muscles.
What happens when there is a lengthening of muscles in terms of proprioception?
Muscle spindles located in the middle of muscles activate the stretch reflex shortening the muscles, retaining posture.
Where is the cell body of the primary neuron of the lemniscal pathway?
Dorsal root ganglion.
Where is the cell body of the secondary neuron in the lemniscal pathway.
In the medulla prior to crossing over.
Where is the cell body of the tertiary cell neuron in the lemniscal pathway?
Thalamus.
Describe the lemniscal pathway.
Sensory information creates an AP, travels up primary neuron, cell body in DR ganglion. Synapses in the medulla.
The secondary neuron crosses in the medulla, and then travels up the medial lemniscal pathway, and synapses in the thalamus.
The tertiary neuron travels to the post central gyrus , where it synapses.
What modalities travel in the spinothalamic pathway?
Pain and temperature.
Where does the spinothalamic pathway cross over?
Spinal cord.
Out of acute and chronic pain, which axons are myelinated?
Acute
Where does the primary neuron in the spinothalamic pathway send an offshoot?
Reticular formation - arousal
Where does the secondary neuron of the spinothalamic pathway send an offshoot to?
Limbic system - emotion.
Where does the primary neuron in the spinothalamic pathway synapse?
In the spinal cord.
Where does the secondary neuron in the spinothalamic pathway synapse?
Thalamus.
Where does the tertiary neuron in the spinothalamic pathway synapse?
In the somatosensory sensory area (post central gyrus).
Describe the spinothalamic neuronal pathway.
Sensory information produces AP, which travels up primary neuron, which has its cell body in the DR ganglion and synapses in the spinal cord.
The secondary neuron has its cell body in the spinal cord, where it crosses over and travels up the spinothalamic pathway to the medulla where it synapses.
The tertiary neuron has its cell body in the thalamus and synapses in the somatosensory area (post central gyrus).
Where would feeling in the legs synapse in the post central gyrus?
Medially.
What is the role of the parietal lobe in terms of sensory information?
Association and perception.
What levels does the sympathetic system exit the vertebrae?
T1 to L1 (thoraculmbar).