L1 - intro to the human brain Flashcards
role of afferent / sensory neurones
carry information from receptors to CNS
role of efferent / motor neurones
carry information from CNA to peripheral effectors
interneurons
link afferent neurons to efferent neurones with CNS
- important in reflex arches
dendrites
receives action potention
axon
conducts action potential
cell body
processes and integrates action potential before sending it along the axon
myelin sheath
insulator substance allowing for faster conduction
relationship between size of axon and speed of current
the size of the axon is proportional to how fast the action potential is conducted
squid axon
very big
conducts electricity very fast
rabbit nerve
very small
requires myelination for faster conduction
which type of nerve requires myelination
rabbit nerve
types of neuron
bipolar
pseudo-unipolar
multipolar
bipolar neuron
2 projections arising from the cell body
- axon and dendrites
where are bipolar neurones found
organs which deal with special senses
multipolar neuron
multiple projections from the cell body
which is the most numerous type of neuron
multipolar neuron
pseudo-unipolar neuron
only one projection from the cell body
- immediately after this however, this projection splits into 2
advantages of a pseudo-unipolar neuron
allows information to bypass the cell body (directly from dendrites to axon)
somatic
voluntary actions
autonomic
involuntary actions
sympathetic
fight or flight
parasympathetic
rest and digest
sub-divisions of the CNS
- cerebrum
- brainstem
- cerebellum
- spinal cord
what is the corpus callosum
connects the 2 hemispheres
divisions of the cerebrum
inner and outer brain
outer brain
telencephalon / cerebral hemisphere
inner brain
diencephalon
brainstem
midbrain
pons
medulla oblongata
where is the cerebellum located
posterior to the brainstem
what does the corpus callous consist of
white matter
white matter
a collection of axons
what marks the surface of the cerebral hemispheres
gyri and sulci
gryi
ridges
sulci
grooves
what makes up the cerebral cortex
grey matter
grey matter
a collection of cell bodies
what are the cerebral hemispheres separated by
longitudinal fissure
lissencephaly
smooth brain
- a lack of gyri and sulci
clinical presentations of lissencephaly
- psychomotor retardation
- muscle spazms
- difficulty swallowing
- deformed hands, fingers or toes
- unusual facial appearance
- failure to thrive
names of gyri
pre-central and post-central gyri
functions of the pre-central gyrus
motor cortex (initiate motor control)
which lobe is the pre-central gryus part of
frontal
functions of the post-central gyrus
sensory cortex (receive sensory innervation)
which lobe is the post-central gryus part of
parietal lobe
which gyrus is located in the frontal lobe
pre-central gyrus
which gyrus is located in the parietal lobe
post-central gyrus
structures within the diencephalon
thalamus
hypothalamus
