Brain structure = NS Flashcards
Cerebellum
involved in movement and coordination + posture
Diencenphalon
involved in regulation of the autonomic and endocrine
Brainstem
Involved in sensory-motor relays and vital autonomic function
Spinal cord
Relays information from the body to the brain
Cerebral hemispheres
Responsible for processing and memory
Cerebrum structure
bulk of the brain, divided into two hemispheres
separate: connected by white matter tract called corpus colosseum
Corpus colossum
large bundle of neuronal axons that pass between L + R hemispheres (allows communication)
Grey matter
outer layer of brain
cell bodies of neurones
White matter
Axons of these neurones
signals conducted from one area of grey matter to another
Myelin
insulates, surrounds neurone axons
fatty - white colour
Increases speed + distance at which signal can transverse along nerve
Cerebral cortex
motor area in 1 hemisphere controls movements
On which side of the body?
Opposite side
How many lobes is the hemisphere split into?
4 hempispheres
Name the 4 lobes in the hemisphere:
- Frontal
- Parietal
- Occipital
- Temporal
Role of the frontal lobe:
-planning movements
-generates nerve impulses that imitate movements
-working memory
Role of parietal lobe:
-Generates sensory info e.g. auditory/ visual/ somatosensory/ proprioceptive info
Role of occipital lobe:
-visual cortex located
-primary visual cortex
-well defined map of visual - info received from outside world
Role of temporal lobe:
-auditory cortex
- receives auditory info
Cerebella lesion/ injuries, symptoms?
Difficulty performing rapid alternations movements
Dienccephalon
Receives sensory inputs from every part of the bod (except for a-factory inputs - sense of smell)
regulating the endocrine and autonomic systems
Diencephalon sits on top of brain stem and compromises the following parts:
-thalamus
-sub-thalamus
-hypothalamus
-epithalamus
Thalamus position
More SUPERIOR (above) portion of diencephalon
sensory info ascending cerebral cortex
Composition of thalamus
numerous thalamic nuclei - functional speciality
Thalamus respoinsibilities
- medication sensation
- motor activities
- cortical crucial learning
- memory
Hypothalamus position
extends INTERFERIORLY + ANTERIORLY (below/infront) the thalamus
INFERIOR to the hypothalamus
Hypothalamus function
facilitate homeostasis =
nervous + endocrine organ, numerous functions
- automatic contact centre
-regulation of body temp - reg of food intake
- reg of water balance + thirst
- reg of sleep-wake cycles
- control of endocrine system
Sub-thalamus position
INFERIOR to the thalamus and lateral (to the side) of the hypothalamus
Sub-thalamus MAIN strutcure
Sub-thalamus > subthalamatic nucleus
- processing that occurs in basal ganglia
Epiothalamus
-relay station between sense + cerebral cortex
- pineal gland is part of epithalamus
Brainstem (3 parts)
- Medulla oblongata (elongated)
- Midbrain
- Pons (bridge)
Midbrain position
Most SUPERIOR, located INFERIOR to thalamus
Midbrain compositions
Fibres linking different components of the motor systems
Cerebellum, basal, ganglia
Contains nuclei involved in voluntary moments, motor junctions, coordination of visual + auditory reflexes
-regulation of rhythms, thermoregulation
Pons
- contains storage bulge
- inferior to midbrain
- SUPERIOR to medula oblongata + ANTERIOR to cerebellum
- white matter tracts + nuclei, relay signals from forebrain to cerebullum
Medulla
oblongata; most INFERIOR of brainstem + is continuous with spinal cord
- white matter structures in the medulla (PYRAMIDS) contains motor fibres of the cortiopinal and curticebullar tracts = descending signals from brain to medulla and spinal cord
Medulla contains nuclei - functions
- regulate cardiovascular system
- respiratory rhythm + digestion
Spinal cord position
- connects brain to rest of body
- two way conduction system; provides neuronal pathways to form brain
- spinal cord extents from medulla in brainstem to LOWER SPINE
Spinal cord synapse occur between….
CNS + PNS
Whats is a synapse?
Junction (conjunction) between the nerve cells across the junction that signals are sent from are nerve cell to another through chemical transmission.
Sensory neurones:
-enter spinal cord from the periphery through the dorsal horns
-incoming neurones synapse with grey matter of either the spinal cord on the medulla
-axons of ascending neurones extend into the white matter tracts to accord to brain
Motor neurones:
-cell bodies of lower motor neurones muscle within the ventral horn
-axons exit spinal cord through these horns
- upper motor neurones that descend from brain in the white mater tracts
- axons extend with grey matter where their axons terminals synapse their axon terminals synapse with fewer motor neurones in ventral horns
Interneurone; crucial role to spinal cord and reflexes =
small, unmylinated interneurones may synapse between sensory neurones that enter dorsal horn + motor neurones that exit ventral horn
White matter -
Tracts contain axons of ascending or descending neurones which carry signals to or from brain
Ascending tracts -
- axons of sensory neurones which relay sensory inputs from the PNS to thalamus
Ascending tracts - orginisation
Organised by type of info - sensory info - touch, small, sound, being relayed + body location that it e.g axons that carry touch info - from upper limb travel in dame area of same ascending tract
Descending tracts
Contains axons of upper motor neurones replaying motor commands from motor cortex or automatic centre in brain the PNS
Descending tracts organised:
Ascending / descending tracts organised according to type of info the carry and the ultimate their commands
Spinal nerves
Dorsal + ventral roots
- dorsal roots + ventral roots connect the nerve fibres from PNS to CNS
Dorsal
afferent (carry sensory into the CNA from PNS)
Ventral
Efferent (carry motor info from the CNS to PNS)
Dorsal root ganglion; part of dorsal root contains….
call bodies of sensory nerve fibres
Spinal nerve - dorsal and ventral roots join to form spinal nerve
Spinal nerve is a wired nerve, carries both sensory + motor neurones
How many pairs of spinal cords do humans have?
31 pairs
