脑功能101

niuniuma

自从和自闭症打交道后，比以前更有兴趣的学习大脑，神经，学以立刻致用。会发现很多自闭的表现在这里都能找到其原因。（我争取有空把它翻译一下）。原始的连接在这
http://people.moreheadstate.edu/fs/m.mcmurr/231-L25.html

III. CEREBRUM
The surface of the cerebrum is called the CEREBRAL CORTEX. It is composed of 2-4 mm of gray matter which contains billions of nerve cell bodies.

Nearly the entire surface of the cerebrum is marked by elevated ridges of gray matter called GYRI (singular = GYRUS), which are separated by shallow grooves called SULCI. The LONGITUDINAL FISSURE is a deep median groove that separates the cerebrum into right and left halves called CEREBRAL HEMISPHERES. The left and right cerebral hemispheres are functionally different。

The gray matter of the CEREBRAL CORTEX of each cerebral hemisphere is further subdivided by deep sulci into 5 LOBES: the FRONTAL, PARIETAL, TEMPORAL, OCCIPITAL, & INSULA. Notice that the INSULA is actually below the surface of the brain. The lobes and some of the prominent gyri are landmarks for functional areas of the brain.

(Functional areas of the cerebral cortex):
The SENSORY AREAS of the CEREBRAL CORTEX receive sensory impulses from sensory receptors and then interpret the information.

1. PRIMARY SOMATOSENSORY AREA (POSTCENTRAL GYRUS of each PARIETAL LOBE): receives & interprets sensory input from cutaneous receptors (touch, pressure, pain, temperature) and proprioceptors. The map of the primary somatosensory area in the postcentral gyrus of each cerebral hemisphere. Notice how the mouth and hands are the most "sensitive" parts of the body.

2. PRIMARY VISUAL AREA (OCCIPITAL LOBE): receives visual information from the retina of the eyeballs; interprets shape, color & movement.

3. PRIMARY AUDITORY AREA (TEMPORAL LOBE): sound waves stimulate sound receptors of the inner ear and impulses are transmitted to this area; interprets pitch, rhythm and loudness.

4. PRIMARY GUSTATORY AREA (base of the POSTCENTRAL GYRUS of each PARIETAL LOBE): involved in the conscious awareness of taste.

5. PRIMARY OLFACTORY AREA (TEMPORAL LOBE): conscious awareness of odors.

The ASSOCIATION AREAS are involved in integration of incoming sensory information. They associate new sensory information with memories of past sensory experiences.

1. SOMATOSENSORY ASSOCIATION AREA (PARIETAL LOBE): integrates & interprets different somatosensory sensations so that you recognize what is being felt.

2. VISUAL ASSOCIATION AREA (OCCIPITAL LOBE): interprets and evaluates visual stimuli and relates them to past visual experiences, so that you recognize what you see.

3. AUDITORY ASSOCIATION AREA (TEMPORAL LOBE): interprets sound and relates it to past auditory experience, so that you recognize what you hear.

4. WERNICKE'S AREA (TEMPORAL LOBE):  usually located in the left hemisphere.  Interprets speech;  translates words into thoughts.

4. GNOSTIC AREA (Common Integrative Area) (areas 5, 7, 39 & 40): integrates all information from primary sensory areas and association areas into a comprehensive understanding of the situation. For example, you walk in the house and smell something cooking. You hear the crackle of something frying in grease. You walk in the kitchen and see chicken frying on the stove. Your gnostic area's interpretation: you're having chicken for supper!

5. PREFRONTAL CORTEX (ANTERIOR FRONTAL LOBE): association area involved with reasoning, learning (cognition), personality, production of abstract ideas, judgment, social behavior, planning, and conscience.

The MOTOR AREAS of the cerebral cortex control SKELETAL MUSCLE CONTRACTIONS.

1. PRIMARY MOTOR AREA (PRECENTRAL GYRUS of each FRONTAL LOBE): controls voluntary muscle contractions on the CONTRALATERAL (opposite) side of the body. (the map of the primary motor area of the precentral gyrus). Notice how the face and hands receive more motor control from the brain, to control the precise contractions needed for facial expression, speech and hand movements.

2. PREMOTOR AREA (FRONTAL LOBE): controls learned motor skills that are repetitive or patterned (playing a guitar or piano, writing, typing).

3. FRONTAL EYE FIELD AREA (FRONTAL LOBE): controls extrinsic eyeball muscles that control voluntary movements of the eyes.

4. BROCA'S AREA (FRONTAL LOBE): motor speech area; controls speech muscles. Notice how close the Broca's area is to the Wernicke's area (which interprets speech).

The CEREBRAL WHITE MATTER which is deep to the cerebral cortex, accounts for about 60% of the cerebral hemispheres. It consists of myelinated axons in bundles of large TRACTS that allow communication between cerebral areas or between the cerebral cortex and other areas of the brain.

The CORPUS CALLOSUM is a large TRACT (bundle of myelinated axons) that allows communication between the cerebral hemispheres.  (frontal section).

BASAL GANGLIA: The BASAL GANGLIA are paired masses of GRAY MATTER, composed of clusters of neuron cell bodies, located deep within the cerebral white matter of each cerebral hemisphere. The basal ganglia are important in controlling subconscious movements, such as arm swinging during walking. They also regulate muscle tone for specific body movements.

IV. THE CEREBELLUM
The cerebellum is the second-largest portion of the brain. It is located posterior to the brain stem and inferior to the occipital lobes of the cerebral hemispheres. The cerebellum is shaped like a butterfly. It consists of 2 lateral lobes, the CEREBELLAR HEMISPHERES, that are connected medially.

Like the cerebrum, the cerebellum has a thin outer CORTEX of gray matter, which is heavily convoluted and arranged in slender, parallel ridges. Beneath the gray matter are WHITE MATTER TRACTS, called the ARBOR VITAE (Latin for "tree of life").

The cerebellum receives sensory input from PROPRIOCEPTORS in muscles, tendons and joints, EQUILIBRIUM RECEPTORS in the inner ear, and VISUAL RECEPTORS in the retina to collect information on posture, equilibrium and body movements. The cerebellum coordinates subconsious contractions of skeletal muscles required for coordination, posture and balance.

V. DIENCEPHALON: THALAMUS & HYPOTHALAMUS
The THALAMUS is an oval structure that is superior to the brain stem and measures about 3 cm (a little over an inch) in length. It makes up about 80% of the diencephalon and consists of mostly GRAY MATTER.

THALAMUS FUNCTIONS: The thalamus serves as a RELAY STATION for most sensory impulses going to the sensory areas of the cerebral cortex. For example, auditory impulses from the inner ear are relayed by the thalamus to the primary auditory area in the temporal lobe of the cerebral cortex. Touch sensation impulses from the skin are routed by the thalamus to the primary somatosensory area of the postcentral gyrus (parietal lobe of the cerebral cortex). The thalamus also transmits information from the cerebellum and basal ganglia to the primary motor area of the cerebral cortex in order to coordinate skeletal muscle movements..

The HYPOTHALAMUS is a small portion of the diencephalon inferior to the thalamus. The hypothalamus is the main visceral (autonomic) control center of the body.  Each brightly colored region in FIG. 18.10 represents a NUCLEUS (cluster of neuron cell bodies). Each nucleus has a specific control function. The hypothalamus controls blood pressure, rate and force of the heart beat, and peristaltic movement of the digestive tract. The hypothalamus contains the body's "thermostat", which monitors body temperature. If you are too hot, the hypothalamus makes you sweat. If you are too cold, the hypothalamus makes you shiver. The hypothalamus also controls your feelings of thirst and hunger. The hypothalamus produces regulatory hormones that stimulate or inhibit hormone secretions of the ANTERIOR PITUITARY. The hypothalamus also produces its own hormones (what are they?), which are released by the POSTERIOR PITUITARY into the bloodstream. Notice the TRACT (bundle of nerve fibers) in FIG. 22.3 that runs from the hypothalamus through the infundibulum to the posterior pituitary.

VI. THE BRAIN STEM: MEDULLA OBLONGATA, PONS & MIDBRAIN
The MEDULLA OBLONGATA  is the most inferior part of the brain stem. The medulla oblongata is continuous with the spinal cord. It is about 3 cm long and superior to the foramen magnum.

The MEDULLA OBLONGATA contains all ASCENDING and DESCENDING TRACTS that run between the spinal cord and the brain. These tracts make up the WHITE MATTER of the medulla oblongata. On the anterior side of the medulla are two triangular structures called the PYRAMIDS. The PYRAMIDS consist of large MOTOR (DESCENDING) TRACTS that originate in the cerebral cortex and descend to the spinal cord. Just above the foramen magnum of the skull, the motor nerve fibers in the left pyramid cross to the right, and the motor nerve fibers in the right pyramid cross to the left. This area of crossing over of motor nerve fibers is called the DECUSSATION OF THE PYRAMIDS. The crossing over of the motor tracts at the decussation of the pyramids means that each cerebral hemisphere controls movements on the opposite (CONTRALATERAL) side of the body. In other words, the motor areas in the right cerebral hemisphere control contractions on the left side of the body and the motor areas in the left cerebral hemisphere control contractions on the right side of the body.

The medulla oblongata also contains sensory nerve fibers from the ASCENDING TRACTS in the spinal cord. Nerve fibers carrying sensory information cross over from left to right (and right to left) in the medulla. This means that the medulla oblongata relays the sensory information coming from the spinal cord to the CONTRALATERAL side of the cerebral cortex. In other words, sensations from the right side of the body go to the primary somatosensory area in the left cerebral hemisphere (and vice versa). See also FIG. 19.4a, p. 599 (also note the THALAMUS sending the sensory input to the primary somatosensory area of the cerebral cortex).

The MEDULLA OBLONGATA contains vital REFLEX CENTERS:
1. CARDIOVASCULAR CENTER: regulates rate & force of heartbeat and vasoconstriction/vasodilation of blood vessels.
2. RESPIRATORY CENTER: controls basic breathing rhythms.

The MEDULLA OBLONGATA also contains NONVITAL REFLEX CENTERS: vomiting, hiccuping, swallowing, coughing, sneezing.

The PONS is directly superior to the medulla oblongata and anterior to the cerebellum. It measures about 2.5 cm (an inch) in length. It acts as a bridge of nerve fibers between the spinal cord and the brain. It also connects different parts of the brain with each other. The pons contains RESPIRATORY CENTERS that help control breathing movements.

The MIDBRAIN extends up from the pons to the lower portion of the diencephalon. It is about 2.5 cm in length. The midbrain relays voluntary motor nerve impulses from the motor areas of the cerebral cortex to the spinal cord. It also relays sensory nerve impulses from the spinal cord to the thalamus.

秋爸爸

专业术语太多，非你翻了不可。