Functions of the Brain

• Cerebellum:
• coordinates complex movements, monitors muscles to ensure fluid movements

• center for monitoring muscle contractions and aiding in motor coordination.
• the evaluation of certain kinds of sensory input, and monitoring muscle movement is only part of its broader function.
• Some spatial perception also resides here.
• The cerebellum is also a timekeeping center of the brain.
• The cerebellum also helps to predict how much the eyes must move in order to compensate for head movements and remain fixed on an object.
• Language output also involves the cerebellum.
• Many children with attention-deficit/hyperactivity disorder (AD/HD) have abnormally small cerebellums.

• Frontal Lobe:
• controls voluntary motor activity, higher mental processing, emotional
• behavior, and speech output

• It is chiefly concerned with voluntary motor functions, motivation,
• foresight, planning, memory, mood, emotion, social judgment, and
• aggression.

• Temporal Lobe:
• primary hearing and smell areas, memory, speech perception and recognition

It is concerned with hearing, smell, learning, memory, and some aspects of vision and emotion.

• Thalamus:
• primarily for relay of sensory information to cortex, relay of motor information for movement planning
• the “gateway to the cerebral cortex.”
• includes signals for taste, smell, hearing, equilibrium, vision, and such general senses as touch, pain, pressure, heat, and cold.
• plays a key role in motor control by relaying signals from the cerebellum to the cerebrum and providing feedback loops between the cerebral cortex and the basal nuclei.
• involved in the memory and emotional functions of the limbic system.

• Mammillary Body:
• involved in regulation of autonomic functions, emotional behavior, and memory

relay signals from the limbic system to the thalamus.

• functions in visual attention, visually tracking moving objects, and
• such reflexes as blinking, focusing, pupillary dilation and
• constriction, and turning the eyes and head in response to a visual
• stimulus.

• receives signals from the inner ear and relays them to other parts of
• the brain, especially the thalamus. Among other functions, they mediate
• the reflexive turning of the head in response to a sound, and one's
• tendency to jump when startled by a sudden noise.

• Cerebral Aqueduct:
• narrow midline channel between 3rd and 4th ventricles,
• filled with cerebrospinal fluid

• Cerebral Peduncle:
• forms ventrolateral portion of midbrain on each side, consists of
• substantia nigra and cerebral crus.

Cerebral Crus: controls voluntary movement

Degeneration of substantia nigra leads to Parkinson's Disease.

• a pair of inferior peduncles connected to the medulla oblongata, a pair of middle peduncles to the pons, and a pair of superior peduncles to the midbrain.
• These consist of thick bundles of nerve fibers that carry signals to and from the cerebellum.

• Longitudinal Fissure: deep groove that separates right and left hemispheres,
• contains falx cerebri

• Olfactory Bulb:
• expanded anterior end of olfactory tract, site of synapse for olfactory neurons
• (CNI) after their axons pass through the cribiform plate

• Corpus Callosum:
• large myelinated fiber tract connecting right and left hemispheres, forms floor
• of longitudinal fissure

• Septum Pellucidum:
• thin sheet of non-neuronal tissue separating right and left lateral ventricles

• Lateral Ventricles: cavity with coroid plexus that produces cerebrospinal
• fluid, communicates with paired structure of opposite side and with 3rd
• ventricle via interventricular foramen, has anterior/posterior/and and inferior
• extensions (horns).

• Optic Chiasma:
• white matter tract composed of axons of retinal ganglion cells from both eyes
• traveling to thalamus and other brainstem nuclei, axons from each retina cross
• in chiasm to enter opposite optic tract

• Pons: involved in control of sleep and respiration,
• transfer of information to and between cerebellar hemispheres (latin Pons =
• Bridge)

• Include sensory roles in hearing, equilibrium, and taste, and in facial sensations such as touch and pain; as well as motor roles in eye movement, facial expressions, chewing, swallowing, urination, and the secretion of saliva and tears.
• The reticular formation in the pons contains additional nuclei concerned with sleep, respiration, and posture.

Medulla Oblongata: contains respiratory, cardiac, and vasomotor centers

include the senses of touch, pressure, temperature, taste, and pain; chewing, salivation, swallowing, gagging, vomiting,respiration, speech, coughing, sneezing, sweating, cardiovascular and gastrointestinal control, and head, neck, and shoulder movements.

• Occipital Lobe:
• primary visual area

• Parietal Lobe:
• reception of general sensory information, tactile object recognition, language,
• verbatim repetition of terms

It is the primary site for receiving and interpreting signals of the general senses described later in this chapter; for taste (one of the special senses); and for some visual processing.

• Meninges:
• protection of brain and spinal chord (dura = hard, mater = mother)

• The arachnoid mater is a transparent membrane over the brain surface, visible in the caudal half of the cerebrum.
• The pia mater is a very thin, delicate membrane that closely follows all the contours of the brain, even dipping into the sulci. It is not usually visible without a microscope.

• Hypothalamus: master control center for endocrine system,
• secretes releasing and inhibiting hormones that control anterior pituitary
• gland, produces hormones that are transported to and stored in posterior
• pituitary gland, controls autonomic nervous system, regulates body temp & food/water
• intake, regulates emotional behavior, maintains sleep/wake cycle

The hypothalamus is the major control center of the autonomic nervous system and endocrine system. It plays an essential role in the homeostatic regulation of nearly all organs of the body.

• Pituitary Gland:
• anterior pituitary produces the following hormones: thyroid stimulating,
• prolactin, adrenocorticotropic, growth, lutenizing, melanocyte stimulating, and
• follicle stimulating.

• Posterior pituitary stores and releases: antidiuretic
• hormone and oxytocin

• Pineal Gland:
• secretes melatonin (involved in sleep/wake cycle), modified activity in
• endocrine organs

may have involvement with sexual maturity.