The Human Nervous System: Cerebrum & Diencephalon

By: Shannon Ament, Katie Kelley, and Candice Ellis

Location of Diencephalon

⦿ between cerebrum’s hemispheres ⦿ encompasses the third ventricle between

the hemispheres of the cerebrum ⦿ part of limbic system

Functions of the Diencephalon

⦿ interprets sensory information ⦿ emotions ⦿ works in coordination with the cerebrum

Parts of the Diencephalon

⦿ thalamus ⦿ hypothalamus ⦿ optic tract/optic chiasma ⦿ infundibulum ⦿ posterior pituitary gland ⦿ mammillary bodies ⦿ pineal gland

Cerebrum Parts & Location ⦿ largest part of the brain ⦿ divided into L/R cerebral hemispheres

⦿ corpus callosum (“nerve fiber bridge”) connects the two hemispheres

⦿ separated by dura matter ⦿ cerebral cortex is a layer of “gray matter” on the outside of the

cerebrum has 75% of the nervous system’s neurons ⦿ surface covered with many convolutions (gyri, aka ridges)

⦿ shallow ridges = sulcus ⦿ deep ridges = fissure

⦿ the two lobes are connected by corpus callosum ⦿ main lobes:

⦿ frontal ⦿ parietal ⦿ temporal ⦿ occipital ⦿ insula

Cerebrum Functions

⦿ has several different areas that control different functions

⦿ motor ⦿ frontal lobes ⦿ motor speech (Broca’s) area ⦿ frontal eye field ⦿ another region just in front of primary

motor area controls hands/fingers

Cerebrum Functions (continued)

!⦿ sensory

⦿ cutaneous (sensation / touch) ⦿ visual (sight) ⦿ auditory (hearing) ⦿ taste ⦿ smell ⦿ sensory fibers, like motor fibers, cross over

also

Cerebrum Functions (continued)

!⦿ association

⦿ analyze / interpret sensory experiences ⦿ memory, reasoning, verbalizing, judgement, emotion ⦿ frontal lobes ⦿ parietal ⦿ temporal (and posterior ends of lateral fissures) ⦿ occipital

⦿ general interpretative area: temporal, parietal and occipital association areas meet near posterior end of lateral sulcus; plays primary role in overall complex thought processing

Alzheimer’s Disease

⦿ form of dementia ⦿ impact ability to think, perform normal tasks, and memory ⦿ progresses and gets worsens over time ⦿ the neurons eventually die, disabling the person’s mental

abilities ⦿ defined by the build-up of plaques (irregular protein

molecules) and tangles (proteins that twisted and attach onto the neurons) within the brain

⦿ these proteins make it difficult for the neurons to send messages to one another

⦿ causes ⦿ genetic factors ⦿ age

Alzheimer’s Disease (Continued)

⦿ symptoms ⦿ memory loss ⦿ difficulty in performing typical daily functions or problems ⦿ confusion ⦿ decreased judgement ⦿ mood change

⦿ treatment ⦿ incurable ⦿ medications slow down or stop the progression of the

disease for a short amount of time ⦿ other non-medicinal treatments may be used

⦿ i.e: exercise or diet regimens