Anatomy of the brain

Brain stem function

sustains vegetative functions, like respiration, circulation, and digestion, regulates postural muscle reflexes, controls degree of cortical alertness, plays a role in sleep-wake cycle

brain stem location

near the base of the brain, which links the brain to the spinal cord. consists of the midbrain, pon, and medulla

cerebellum function

maintains proper position of the body in space, subconscious coordination of movement, and has a key role in learning skilled motor tasks

hypothalamus structure and location

collection of nuclei and associated fibers that lie beneath the thalamus

hypothalamus function

controls homeostatic functions that are important for maintaining the stability of the internal environment (body temp, fopod intake, thirst, urine output, controls anterior pituitary hormone secretion, and produces posterior pituitary hormones) and an important link between the autonomic nervous system and endocrine system

cerebral cortex lobes

occipital, temporal, partietal, frontal

occipital lobe function

visual cortex

temporal lobes

auditory cortex

parietal lobes

responsible for the reception and perception of somatosensory input

frontal lobes

responsible for voluntary motor movement

central sulcus

a prominent groove (sulcus) on the lateral surface of the brain that separates the frontal and parietal lobes. divides the primary motor cortex (precentral gyrus) from the primary somatosensory cortex (postcentral gyrus)

somatosensory cortex

site for initial processing and perception of both somethetic and proprioceptive input

ascending sensory input in the somatosensory cortex

received from the opposite side of the body

primary motor cortex

controls voluntary movement mainly muscles on the opposite side of the body

basal nuclei function

• inhibiting muscle tone throughout the body

• selecting, maintaining purposeful motor activity

• suppressing unwanted patterns of movement

• coordinates slow, sustained contractions

basal nuclei structure

consists of several masses of gray matter located deep within white matter

putamen basal nuclei lesion

cause chorea, involuntary flicking motions of the hands, face, and shoulders

globus pallidus basal nucleus lesion

cause athetosis, writhing motions of the hands, arms, neck, and face

substantia nigra basal nuclei lesions

cause rigidity and tremor (aka Parkinson’s disease)