The nervous system Flashcards
What is the midsaggital section?
section cut down the centre of the brain
What is the cross section?
cross section - section cut at a right angle to a long structure
what is the function of the autonomic ns ?
regulates body’s internal environment, automatic
what is the function of the somatic ns ?
external environment, conscious and voluntary
what is the function of the sympathetic ns ?
prepares the organs for vigororous activity e.g increases breathing
what is the function of the parasympathetic?
energy conservation, non-emergency functions
what is the function of the spinal cord?
communicates with sense organs and muscles below the head
how is the spinal cord structured?
organised in a segmented structure with the sensory nerve entering and the motor nerve exiting
what happens if the spinal cord is cut?
the brain will lose all sensation from everything below the cut which is useful for anaesthetic
Explain how the reflex arc supports leg flexion (step by step)
- information is sent via the sensory nerve
- intrinsic neuron connection to the motor neuron and signals muscles to contract
- motor nerve converts information to the muscle and the muscle contracts
- this is done involuntarily, yielding high survival value
What are the three major divisions of the brain?
Forebrain
midbrain
hindbrain
Name the key components of the hindbrain
Medulla
reticular formation
pons
cerebellum
Medulla (hindbrain) function
controls some vital reflexes , tracts carrying signals between brain and body
reticular formation (hindbrain) function
arousal, sleep, attention , movement etc
pons (hindbrain) function
latin for bridge , axons from each hemisphere cross
cerebellum (hindbrain) function
balance, rhythm, coordination etc
name the components of the midbrain
tectum , tegmentum
tectum function (midbrain)
(visual and auditory functions)
tegmentum function (midbrain)
sensorimotor function
main components of the forebrain
thalamus , hypothalamus , basal ganglia, limbic system, cerebral cortex
thalamus function
sensory related except for olfactory info
hypothalamus function
regulation of motivated behaviour , release of hormones from pituitary gland
what is the largest division of the human brain ?
the forebrain
How is Parkinson’s disease treated?
the globes pallidus is a target for deep stimulation in Parkinson’s , reduces the disabling , electrodes implanted deep in the brain , electrically stimulated
limbic system function
regulates motivated emotions (amygdala, hippocampus, cingulate cortex and othe
describe the cerebral cortex
the outer surface are the cerebral hemispheres, it is deeply convoluted to increase surface of the cortex, there are large furrows and smacks furrows
how do neurons communicate across hemispheres ?
mainly through the corpus callopsm
What are the four lobes of each hemisphere?
occipital
parietal
temporal
frontal
Occipital lobe function
visual , main input from thalamic nuclei that receives visual input
parietal lobe function
recieves main input from touch sensations and muscle stretch receptors
temporal lobe function
auditory information
frontal lobe function
anterior proportion receives and integrates input from all sensory systems , higher cognitive functions
Describe the development of the nervous system
- Production of neurons and glia from stem cells
- Neurons move toward their eventual destinations in the brain
- Growth of axons and then dendrites
- Myelination continues for decades
- Formation of synapses, continues throughout life (synaptogenesis)
what does cell death and the activity of incoming axons result in?
neural darwinism e.g rearrangement of synapses
what do experiences lead to?
leads to increased dendritic and axonal branching
How does the nervous system compensate for brain damage?
increased sensitivity to remaining NTs (denervation supersensitivity) -compensation , chronic pain, axon sprouting
explain phantom limb syndrome
axons representing another body part sprout into synaptic sets originally innervated by amputated body part = phantom limb
what is myelination?
the process by which glia produce the insulating fatty sheaths that accelerate transmission in many vertebrate axons
