Central Nervous System Flashcards
What are the two parts of the nervous system?
- Central nervous system
- peripheral nervous system
What makes up the CNS?
- Brain
- spinal cord
What makes up the PNS?
- connections to CNS e.g. muscles
- Cranial nerves
- Spinal nerves
- Autonomic nervous system
What are the 3 types of neurons?
- Afferent
- Efferent
- Inter
What does an afferent neuron do?
Carry information from periferal receptors to CNS
What does an efferent neuron do?
- Carry impulses away from CNS
What do interneurons do?
Relay information
What type of neuron is the blue one?
- afferent
What type of neuron is the green one?
- inter
What type of neuron is the red one?
efferent
What are the 3 types of nerves?
- sensory
- motor
- mixed
What neurons (mostly) make up a sensory nerve?
sensory
What neurons (mostly) make up a motor nerve?
motor
What are the 3 main parts of the brain?
- cerebrum
- cerebellum
- brain stem
What does ‘gyri’ mean
what is a sulci?
Why does the brain have gyri and sulci?
Huge surfance area of cerebral cortex must fold to fit in the skull.
What are the 6 lobes of the brain?
- frontal
- 2 x temporal
- 2 x parietal
- occiptal
What are the 2 groups of bones that make up the skull?
- Neurocraniam
- Viscerocranium
What is the purpose of the neurocranium bones?
protect the brain
What is the purpose of the viscerocranium bones?
assist in formation of the face
What are the 6 neurocranial bones?
- frontal
- parietal
- occipital
- temporal
- sphenoid
- Ethmoid
Where is the cerebellum?
little one in back
What is the function of the cerebellum?
Coordiation of movement
What are the 3 parts of the brain stem?
- medulla oblongata
- pons
- midbrain
What is the blue region?
Pons
What is the red region?
midbrain
What is the purple region?
Medulla oblongata
What are ‘tracts’?
- group of nerve processes with common connections and functions
What is the function of a first-order neurone?
Sends axon into brainstem
What is the function of a second-order neurone?
Projects axon to the thalamus
What is the function of a third-order neurone?
Projects axon to specific area of cerebral cortex
How are sensory pathways organised?
first/second/third order neurons
How are motor pathways organised?
Upper/lowe motor neurone
What is the role of the upper motor neurone
The neuron begins in the motor cortex, and projects the axon down the brainstem to the ventral horn (which is part of the spinal cord)
What is the role of the lower motor neurone?
Projects signal from ventral horn to the relevant muscle group
What information is conveyed via the cranial nerves?
‘special senses’
* olfaction
* vision
* taste
* hearing
* balance
What information is conveyed via the spinal nerves?
somatic senses
* peripheral information
What does the somatosensory system do?
handles
* touch
* temperature
* body position
What does decussate mean?
cross over
What is the difference in the role of the dorsal horns vs ventral horns?
- dorsal: recieve sensory
- ventral: send motor
Where are tracts located?
In the white matter of the spinal cord
What tract is the pink?
Spinocerebellar
What tract is the blue?
Spinothalmic
What tract is the purple?
Dorsal column
Where do most of the fibres in the corticospinal tract come from?
Motor areas
damage to them -> stroke
How does neurone decussate location affect the damage from spinal cord injuries?
Some neurones decussate immediately and some do it when closer to the medulla.
This means that injuries further down the spinal cord are more likely to damage one side of the body, and injuries further up are more likely to damage both.
What is the effect of a unilateral lesion in the cerebral hemisphere or brainstem?
contralateral paralysis
What is the effect of a unilateral lesion in the spinal cord?
Ipsilateral limb paralysis
