Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Brain Higher Functions

• Diencephalon• Cerebellum• Cerebral

Hemispheres

“2-oval skull” (includes regions of higher functions)

Cerebral hemispheres

Cerebellum

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Diencephalon(integrates conscious and unconscious activity)

• Between cerebral hemispheres

• Mostly thalamus and hypothalamus

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Thalamus (relays sensory information and emotional state)

• Five groups of nuclei– Anterior group—limbic system– Medial group—hypothalamus

emotion center to cerebrum frontal lobe

– Ventral group—touch and proprioceptive information relayed to cerebral cortex

– Posterior group—optic and auditory information to cerebral cortex

– Lateral group—emotional state feedback from limbic system; integrates with sensory information

Diencephalon

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Limbic systemDiencephalon

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Limbic system Diencephalon

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Hypothalamus• Superior to pituitary gland (gland is in sella

turcica)• Connected to pituitary by infundibulum

stalk

Diencephalon

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Hypothalamus function

• Feeding reflexes—licking, swallowing, etc.• Subconscious skeletal muscle movements—facial

expressions, sexual movements• Autonomic center—control medulla oblongata nuclei for

cardiovascular, respiration• Secretes oxytocin that stimulates smooth muscle of uterus,

mammary glands and prostate• Regulates body temperature• Controls pituitary gland by hormonal secretion—pituitary in

turn regulates many hormonal endocrine functions• Produces emotions/sensations/drives: e.g. thirst, hunger

(not really “sensations” from periphery)• Coordinates autonomic response to conscious input—

thought of fear produces accelerated heart rate, etc.

Diencephalon

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Pineal gland

• Regulates Cycles

• Secretes melatonin which helps regulate circadian and reproductive cycles

Diencephalon

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Cerebellum(posture and movement)

• Oval at back of cranial cavity• Convoluted surface of neural

cortex (like cerebrum)• Huge branching Purkinje cells

—each cell gets input from 200,000 synapses

• Internal branching looks like tree—called “arbor vitae (tree of life)

• Damage leads to “ataxia”—disturbance of muscular coordination

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Cerebrum(processing central for somatic/conscious information)

• Two cerebral hemispheres separated by longitudinal fissure (sagittal plane)

• Central sulcus divide (coronal plane) separates frontal lobe from parietal lobe

• Horizontal lateral sulcus (in transverse plane) separates frontal lobe from temporal lobe

• Parietal-occipital sulculs separates parietal lobe from occipital lobe

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Cerebrum overall organization

• Left side receives somatic sensory and controls somatic motor of right side of body (and vice versa)

• Two hemispheres have different specialized areas (not symmetrical)

• Correspondence of functions with regions is difficult—lots of overlap and ability to “fill in” if areas are damaged

• Corpus callosum is bundle of axons that link two sides

Cerebrum

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Cerebrum

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Cerebral function in brief

• Basal nuclei/ganglia (sometimes considered part of midbrain)– Deep in hemispheres– Subconscious control of skeletal muscle– Rhythmic movements—overall walking coordination

• Frontal Lobe (primary motor cortex)-voluntary control of skeletal muscle

• Parietal lobe (primary sensory cortex)—conscious perception from skin—touch, pressure, pain

• Occipital lobe (visual cortex)—conscious perception of visual field

• Temporal lobe (auditory cortex and olfactory cortex)—conscious perception of sound and smell

• All Lobes—integration and processing of sensory input to initiate conscious motor output

Cerebrum

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Cerebrum

Human Anatomy and Physiology I, Frolich, Higher Brain Functions

Interactive overview of basic regions of brain from PBS

[link]