CNS Flashcards
cerebrum
largest region, controlling conscious thought, complex movements, and memory
has 2 layers
-outer layer- grey matter contains neuron cell bodies.
inner white matter that contains axons encased in myelin sheaths
frontal lobe
controls movement, language, and other higher thinking functions
temporal
contains the auditory, taste, olfaction and memory
parietal
integrates sensory information related to movement and posture
occipital
contains the vision center
diencephalon
integrates sensory information and motor commands. (thalamus, hypothalamus, pineal gland, part of epithalamus)
thalamus
transfer impulses received from sensory neurons to the correct region of the cerebrum.
hypothalamus
controls many aspects of internal homoeostasis, including body temperature, water balance, and overall metabolism
pineal gland
releases melatonin, to regulate day-night cycles
brain stem
directly attaches the brain to the spinal chord
pons
contains the neurons responsible for controlling breathing ( along with the medulla)
medulla oblongata
lowest part of the brain stem, merging into the spinal cord (controls heart rate, blood pressure, swallowing, vomiting and breathing.)
why does the CNS has more protection than any other part of the body ?
due to the size and complex shape of neuron they are unable to undergo mitosis making them irreplaceable
protection of the CNS
flat bones of skull underneath that the meninges is found
the meninges is formed by three layers
dura mater- outermost layer and thickest
arachnoid mater- network of blood vessels
pia mater- innermost layer
after the meninges what next ?
cerebrospinal fluid- similar to plasma, circulates through a series of ventricles throughout the brain. (provides a watery cushion that protects nervous tissue from trauma)
- a blood- brain barrier, made of capillaries, only allows water, glucose, and amino acids into the brain area. (wastes, proteins, and cells are kept out)
spinal cord
a continuation of the brain stem down the back towards the pelvis.
bone, meninges and CSF provide protection.
spinal nerves
mixed nerves that carry both motor, somatic and autonomic signals to the body from the spinal cord
reflexes
rapid involuntary response to a stimulus. these actions occur more quickly because they by pass the brain (reflex arc)
reflex arc
begins with a stimulus at a sensory neuron (pain, heat)
the signal is then sent to an interneuron located in the spinal cord, which then activated a motor neuron.A neurotransmitter is released at a cholinergic synapse- the muscle contracts in response to the neurotransmitter and the reflex is completed `
cranial nerves
12 pairs of nerves, mostly from the head and neck that attach directly to the brain by passing the spinal cord
part of the autonomic nervous system
list the 12 cranial nerves
1.) olfactory (sensory)
2.) optic (sensory)
3.) oculomotor (eye muscle motor)
4.) trochlear (eye muscle, motor)
5.) trigeminal (facial sensory)
chewing muscles( motor)
6.) abducens Eye muscles (motor)
7.) facial (taste sensory) facial muscles (motor )
8.) vestibulocochlear (balance and hearing) sensory
9.) glossopharyngeal taste sensory, swallowing motor
10.) vagus ( sensory and motor neurons that affect sweating, peristalsis, HR, opening, the larynx for speech and breathing)
11.) accesory nerves- neck and upper back muscles (motor)
12.) hypoglossal tongue( motor)
encephalitis
inflammation of the brain itself, caused by a foreign substance or a virus.- headache, drowsiness, nausea, fever
meningitis
inflammation of the meninges (membranes) of the brain and spinal cord. -fever, stiff neck
alzheimer’s disease
degenerative disease that cause a gradual loss of neuron cell bodies and synapses in the cerebral cortex- affects new memories first
brain tumors
masses of cells that overgrow in specific areas of the brain. symptoms very depending on the region affected
stroke
blood clot or ruptured blood vessels interrupts blood flow to a specific part of the brain
brain cells die due to the lack of O2
concussion
traumatic brain injury caused by an impact that is not absorbed by CSF and damages the brain itself