Quiz #4 - CNS - The Diencephalon and Cerebrum (A&P)

1. Functional anatomy of Brain Regions
a. Diencephalon
i. Thalamus
1. Contains 12 major nuclei that serve as relay centers for information to and from
the cerebral cortex.
2. Called the gateway to cerebral cortex
ii. Hypothalamus
1. Small inferior portion of diencephalon
2. 2 bottom protrusions called mammillary bodies
3. Contains 12 nuclei
4. Lots of functions:
a. Controls autonomic nervous system
i. Sends autonomic signals through midbrain and reticular formation to
visceral organs
b. Regulates body temperature
i. Receive info from thermoreceptors and use it to control body temp
effectors like sweat glands
ii. Fever is produced when hypothalamus resets body temp to higher value
c. Regulates hunger and thirst
i. Detects molecules in blood and can use this info to stimulate hunger and
thirst
d. Regulates sleep-wake cycles
e. Controls endocrine system
i. Secretes hormones that control the pituitary gland.
ii. Pituitary gland secretes hormones that control other endocrine glands
f. Controls emotional responses
i. Part of the limbic system
1. Involved in pleasure, rage, and fear
g. Controls motivational behavior
i. Eating, sex drive
h. Formation of memory
i. Along with hippocampus
b. Cerebrum
i. Four important regions
1. Basal nuclei(ganglia)
a. Deep gray matter of the cerebrum
i. Surrounds lateral ventricles
ii. Contains
1. Striatum

a. Caudate nucleus
b. Putamen
2. Globus pallidus
b. Work with motor centers in cerebral cortex and substantia nigra to start,
stop and regulate intensity of voluntary movements
c. Degenerative conditions of the Basal nuclei cause Dyskinesia
i. Means “bad movements”
ii. Causes abnormal movements
iii. Parkinson’s disease and Huntington’s disease
2. Cerebral white matter
a. Association fibers
i. Carries info within the same hemisphere
b. Commissural fibers
i. Carries info between the right and left hemispheres
c. Projection fibers
i. Carries info to and from cerebral cortex
3. Cerebral cortex
a. Lobes contain specific regions of gray matter or cortex for processing and
perception of specific types of information
b. Frontal lobe
i. Pre-frontal cortex
ii. Pre-central gyrus has primary motor cortex
1. Initiation of skeletal muscle movements
iii. Association areas
iv. Broca’s area for speech movements
1. Left side only
v. Gustatory cortex
1. Processing and perception of taste
c. Parietal lobe
i. Post-central gyrus has primary somatosensory cortex
ii. Processing and perception of somatic senses (touch, pain, etc..)
d. Temporal lobe
i. Olfactory cortex
1. Processing and perception of odorants
ii. Auditory cortex
1. Processing and perception of sounds
iii. Wernicke’s area
1. Auditory and visual aspects of speech
2. On left side in most people
e. Occipital lobe
i. Visual cortex
1. Processing and perception of light and images

f. The Limbic System
i. Creates, stores, and retrieves memories
ii. Sends out info that produces emotional responses
iii. Cerebral structures
1. Cingulate gyrus
2. Septal nuclei
3. Amygdala
a. Processes fear
b. Generates sympathetic response to fear (in reticular
formation)
c. Over active amygdala in PTSD
4. Hippocampus
a. Site of memory storage and retrieval
iv. Diencephalon structures
1. Anterior thalamic nuclei
2. Hypothalamus
v. Connecting tracts
1. Fornix
2. Anterior commissure