module 13: diencephalon and cerebrum

where is the diencephalon located?

between the brainstem and cerebrum

what are the main 4 components of the diencephalon

1. thalamus

2. subthalamus

3. hypothalamus

4. hypothalamus

what is the largest portion of the dienchephlon

the thalamus

what does the thalamus look like?

2 oval gray masses connected by the interthalamic adhesion

what does the interthalamic adhesion do?

connects the 2 gray masses together

what does the thalamus do?

receives all major portions of sensory information (except smell) and sends it to the cerebral cortex

what does the medial geniculate nucleus do?

auditory impulses → takes information from innear ear and brings it to primary auditory area

what does the lateral geniculate nucleus do?

visual impulses - takes information fro. retnia and brings it to the primary visual area

where is the subthalamus located?

just inferior to the thalamus

what is the subthalamus made up of?

mostly white matter some gray matter

what does the subthalamic nuclei do?

controls motor function

what makes up the epithalamus?

the habenula and the pineal gland?

what is the job of the habenulla?

involved in behaviour - linked to rewards

what happens if you have disfunction in the habenulla?

this could lead to depression, addiction and schizophrenia

what is the pineal gland responsible for?

secretes melatonin

also linked to puberty

where is the hypothalamus located?

its the most inferior part of the dienchephalon

what is the infundibulum?

its a connecting stalk that connects the hypothalamus to the pituitary gland

what does the hypothalamus do?

it connects the nervous system to the endocrine system

what is the hypothalamus responisble for?

mood and emotion and visceral response to smell

what is the outer layer of the cerebrum called?

cerebral cortex (gray matter)

what is the inner layer of the cerebrum called?

cluster of nuclei - made up of gray matter

that do motor functions

what is the middle of the cerebrum called?

cerebral medulla - made up of white matter

what are the gyrus?

grooves at the top of the cerebrum - they form sulcus

what are sulcus and where are they located?

tthy are deep groves and they are located in between the gyrus

what does the longitudinal fissure do?

its a deep grove and it seperates the brain into right and left hemispheres

what does the central suclus do?

separates the parietal and frontal lobe

what does the precentral gyrus do?

where we have the located of the primary motor cortex so it initiates motor functions

what does the postcentral gyrus do?

where the primary somatosensory cortex is located - so where sensory information synapses except vision hearing and smell

what are the 4 lobes in the cerebrum

1. frontal lobe

2. parietal lobe

3. occipital lobe

4. temporal lobe

whats the frontal lobe responisble for?

• motor functions

• agression and mood

what is the parietal lobe responsible for?

sensory information like touch, pressure etc - except sensory like taste vision smell

what is the occipital lobe responsible for?

reception and integration of visual input

what is the temporal lobe responsible for?

auditory input

olfactory

and memory

what is the insula responsible for?

homeostasis

taste

what is the cerebral medulla?

nerve tracts that connect the cerebral cortex to other parts of the CNS

what are the 3 main tracts found within the cerebrum?

1. association fibers

2. commissural fibers

3. projection fibers

what do association fibers do?

they connect areas of the cerebral cortex within the same hemisphere

what do commissural fibers do?

they connect the cerebral hemispheres (corpus collosum)

what do projection fibers do?

they connect the cerebrum and other parts of the brain and spinal cord

what happens when we have bundles of projection fibers?

we form the internal capsule