week 2 - cns Flashcards
what is CNS made up of
brain and spinal cord
left hemisphere of brain functions
logic, numbers and language
sensory and motor pathways for right side of body
right hemisphere of brain functions
creativity, imagination and rhythm
sensory and motor pathways for right side of body
corpus callosum
neural bridge of nerve fibres that joins hemispheres - communicate between
forebrain (3 components)
cerebrum, thalamus, hypothalamus
hindbrain (3 components)
cerebellum, pons, medulla
brainstem (3 components)
midbrain, pons, medulla
midbrain function
controls higher functions such as eye movement and the auditory system
pons function
roles in consciousness and posture
medulla function
controls basic, life-sustaining functions such as breathing and heart rate
cerebellum structure
two mounds of folded tissue posterior to the brainstem
connected to the brainstem by three peduncles
peduncles
bands of neurons resembling a stalk
cerebellum function
motor functions and motor learning
motor skills stored in cerebellar memory
thalamus
The majority of information passing to the cerebral hemispheres passes through the thalamus first. The thalamus then relays the information to the relevant part of the cerebrum.
hypothalamus functions
function is homeostasis
does this by input info to medulla
autonomic nervous system origin
other functions are achieved by stimulating pituitary gland to release hormones
cerebral cortex structure and function
is the grey matter of hemispheres
humans hemisphere surface is convoluted to increase SA
functions include intelligence, personality, planning and organisation, motor function
sulci
infoldings of brain. Often used to demarcate (mark the boundary of) different functional areas.
gyri
sticky out bits between sulci. These are areas of functional grey matter. Adjacent gyri may have very different functions
frontal lobe function
movement, decision making, problem solving and planning
pre central gyrus
subsection of frontal lobe
primary motor cortex - executes voluntary motor movement
parietal lobe (somatosensory cortex)
receive and process sensory information
post central gyrus
primary somatosensory cortex - detects touch, temperature, pressure, pain
occipital lobe
visual processing
visual information is sent to parietal and temporal lobe for further processing
temporal lobe
memory, emotion, hearing, language
structures of limbic system are located here
meninges
layer of tissue that physically separates CNS from body
pia mater
adheres to brain and dips down into sulci
arachnoid mater
middle layer
dura mater
outermost, tough layer
cerebrospinal fluid
clear fluid that is lower in proteins, cells and most ions (except Na+, Cl-, Ca2+) than plasma
produced by choroid plexus (specialised epithelium)
lines cavities (ventricles) within the brain
arachnoid granulations
where CSF is reabsorbed into the venous circulation
aqueducts
link ventricles so CSF can circulate through brain
vertebral canal
protects spinal cord
made up of vertebral foramen stacked on top of each other to make a canal the whole length of vertebral column
vertebra consist of two parts
body and arch
what is the vertebral arch made up of
2 pedicles, 2 lamina, 2 transverse processes, 1 spinous process, 4 articular processes
intervertebral discs
forms a fibrocartilaginous joint between two adjacent vertebrae
allows slight movement and absorbs shock
annulus fibrosus
in vertebrae - outer fibrous ring made up of laminae of fibrocartilage to withstand compression
nucleus pulposus
gel-like centre that helps distribute pressure evenly across the disc to act as a shock absorber.
ascending pathways
travel from the body to the brain. They tend to carry sensory information, such as touch, pain, and proprioception (body awareness)
descending pathways
travel from the brain to the body. They tend to carry motor instructions, to initiate and control movement
dorsal root
nerves enter spinal cord from body
ventral root
nerves exit spinal cord
ventral median fissure
deep groove used to identify the anterior surface of spinal cord
dorsal column
Ascending sensory neurons carrying fine touch and proprioception information from the limbs
lateral column
descending motor tracts from the cerebral cortex
anterolateral fasciculus
ascending sensory neurons carrying pain and temperature fibres
lumbar puncture/spinal tap
remove CSF from spinal canal from below L1
high white blood cells in spinal CSF
infection such as meningitis
high red blood cells in spinal CSF
brain haemorrhage or stroke
