Central Nervous System Flashcards
What are components of nervous system?
CNS and PNS
CNS: brain and spinal cord
PNS: nerves (cranial and spinal) and ganglia outside brain and spinal cord
What is brain composed of?
Forebrain: cerebral hemispheres and diencapahlon
Midbrain
Hindbrain: pons, medulla, cerebellum
What is the function of fontal lobes?
Regulating and initiating motor function, language, cognitive functions (executive function [e.g. planning], attention, memory
What is function of parietal lobe?
Sensation (touch, pain), sensory aspects of language, spatial orientation and self-perception
What is function of temporal lobe?
Processing auditory information
What is function occipital lobe?
Processing visual information
What is contained within the limbic lobe?
limbic lobeincludes the amygdala, hippocampus, mamillary body, and cingulate gyrus
Concerned with learning, memory, emotion, motivation and reward
Where does the insular cortex lobe lie ?
Deep within lateral fissure
What is the insular cortex concerned with?
visceral sensations, autonomic control, and interoception, auditory processing, visual-vestibular integration
What are three layers of meninges?
Three layers, dura, arachnoid and pia mater
Describe the dura
thick, composed of 2 layers
periosteal - layer of periosteum
meningeal - durable, dense fibrous membrane
Describe the arachnoid
thin, transparent, fibrous membrane
Describe the pia?
thin, translucent & mesh-like
Where is the CSF?
Produced in choroid plexus of lateral, 3rd and 4th ventricles
What does the CSF occupy?
ventricular system and sub-arachnoid space
~125 ml volume and 500 ml produced each day
Where is the CSF reabsorbed?
Reabsorbed via arachnoid villi (granulations) into superior sagittal sinus
What is the difference between CSF and plasma?
Lower pH, less glucose, protein and potassium than plasma
What is the spinal cord composed of?
Composed of segments – each gives rise to a pair of mixed spinal nerves (cervical, thoracic lumbar, sacral, coccygeal)
How many pairs are in cervical nerves?
8
How many pairs are in thoracic nerves?
12
How many pairs are in lumbar nerves?
5
How many pairs are in sacral nerves?
5
How many Paris are in coccygeal?
1
Where do nerves
emerge from?
Intervertebral formanina
Relationship between nerves and foramina changes between cervical and thoracic regions
Where do nerves C1-C7 emerge from?
Above vertebrae (i.e C3 comes out between C2 and C3)
Where do never C8-Co1 emerge from?
Below vertebrae (i.e T11 comes out between T11 and T12)
Where are the spinal cord enlargements?
- Cervical enlargement (innervation of upper limbs) C5
- Lumbar enlargement (innervation of lower limbs) L2
What are the major descending pathways?
- Major pathway for voluntary movement is the corticospinal tract
- Composed of upper motor neurons in primary motor cortex and lower motor -neurons in brainstem and spinal cord
What are the major ascending pathways?
- Main pathways forsensation are the dorsal column pathway and the spinothalamic tract
- Dorsal column pathway is for fine touch, vibration and proprioception (position) from the skin and joints.
- Spinothalamic pathway is for pain, temperature (and crude touch) from the skin.
What are the ascending tracts for sensory?
- Dorsal columns (fine touch, proprioception, vibrators
- Lateral spinothalamic tract (pain temp)
- Ventral spinothalamic tract (crude touch)
What re the descending tracts for motor?
- Lateral corticosponal tract (motor)
- Ventral corticosponal tract (motor)
What happens in corticospinal tract?
Approximately 85% of fibres decussate (cross) in the medulla
What is the vestibulospinal brainstem motor tract?
provides information about head movement and position and mediates postural adjustments
What is the tectospinal brainstem motor tract?
orientation of the head and neck during eye movements
What is the reticulospinal brainstem motor tract?
control of breathing and emotional motor function
What is the rubrospinal brainstem motor tract?
innervate lower motor neurons of the upper limb
