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The Brain and the Cranial Nerves

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Brain
Occupies the cranial cavity and is covered by membranes, fluid, and the skull bones. It is divided into distinct areas
Cerebrum
Diencephalon
Brain Stem
Cerebellum
Cerebrum
largest and most complex part of the brain, made up of the left and right hemispheres and is divided by the longitudinal fissure (which is a deep groove)
Longitudinal Fissures
the gap/separation between the left and right cerebral hemispheres.
Diencephalon
between cerebral hemispheres and the brain stem, 2 main parts thalamus and hypothalamus
Thalamus
Region of the brain located in the diencephalon; chief relay center for sensory impulses traveling to the cerebral cortex.
Hypothalamus
Region of the brain that controls the pituitary and maintains homeostasis by controlling body temperature, water balance, sleep, appetite and some emotions such as fear and pleasure. Both the sympathetic and parasympathetic divisions of the ANS are under the hypothatlamic control. It influences the heart beat, the contraction and relaxation of blood vessels, hormone secretions and other vital body functions.
Brain Stem
Portion of the brain that connects the cerebrum with the spinal cord; contains the midbrain, pons, and medulla oblongata.
Midbrain
upper portion of the brainstem that is inferior to the center of the cerebrum. - INVOLVED IN THE EYE AND EAR REFLEXES
Pons
area of the brain between the midbrain and medulla; connects the cerebellum with the rest of the central nervous system.- CONNECTING LINK FOR OTHER DIVISIONS
Medulla Oblongata
part of the brain stem that connects the brain with the spinal cord - CONTAINS VITAL CENTERS FOR RESPIRATION, HEART RATE AND VASOMOTOR ACTIVITY
Cerebellum
small section of the brain located under the cerebral hemispheres; functions in coordination, balance, and muscle tone.
Meninges
are the 3 layers of connective tissue( Dura mater, Archonoid, Pia matter) that surrond both the brain and spinal cord to form a complete enclosure
Dura Mater
the outermost (and toughest) of the 3 meninges and has 2 layers - outer layer is fused to the cranial bones and the 2nd layer - in certain places separate to form the dural sinuses
Dural sinuses
dural layers not fused together; collect venous blood from brain and direct it into the internal jugular veins of the neck
Arachnoid
the middle of the 3 meninges and has a weblike fibers, allowing a space for movements of cerebrospinal fluid between the 2 membranes
Pia mater
is the innermost layer around the brain, is attached to the nervous tissue of the brain and spinal cord and follows all the contours of these structures - it holds blood vessels that supply nutrients and oxygen to the brain and spinal cord.
Cerebrospinal Fluid
is a clear liquid that circulates in and around the brain and spinal cord - the functions of the CSF is to support nervous tissue and to cushion shocks that would otherwise injure these delicate tissue. The CSF also carries nutrients to the cells and transports waste products from the cells.
Arachnoid villi
structures that return cerebrospinal fluid to the venous blood in the dural sinuses
Ventricles
One of the brains 4 chambers in which CFS is produced - the lateral ventricle - which are one and two - is the largest, the 3rd is surrounded by Diencephalon and the 4th ventricle which is located between the brain stem and the cerebellum.
Choroid plexus
a vascular network in each ventricle that forms CSF by filtration of the blood and by cellular secretion.
Interventricular Foramina
between the lateral ventricles and the 3rd ventricle in the brain, helps transport CSF
Cerebral aqueduct
Passageway for CSF between 3rd and 4th ventricle
Cerebral Hemispheres
the right and left halves of the cerebrum, Two almost symmetrical halves, separated by longitudinal fissure. Each is divided into four anatomical areas called lobes.
Lobes
Frontal, Parietal, Temporal, Occipital
Cerebral Cortex
the outer nervous tissue of the cerebral hemispheres that is gray matter - this thin layer of gray matter is the most highly evolved portion of the brain and is responsible for conscious thought, reasoning, and abstract mental functions.
Gyri
elevated ridges on the cerebral cortex
Sulci
shallow grooves on the cerebral cortex
Central sulcus
A fissure that divides the frontal lobe from the parietal lobe.
Lateral Sulcus
Divides frontal and parietal lobes from the temporal lobe
Basal nuclei
deep masses of cerebral gray matter located in the cerebral hemisphere - these neurons work with the cerebral cortex to regulate body movement and the muscles of facial expression - THESE NEURONS SECRETE THE NEUROTRANSMITTERS DOPAMINE.
Corpus Callosum
is an important band of white matter located at teh bottom of the longitudinal fissure - this band is a bridge between the right and left hemispheres, permitting impulses to cross from one side of the brain to the other.
Internal Capsule
is a compact band of myelinated fibers that carries impulses between the cerebral hemispheres and the brain stem.
Frontal Lobe
PRIMARY MOTOR AREA -Controls Skeletal Muscles- also 2 areas important in speech
Parietal Lobe
PRIMARY SENSORY AREA - where impulses from the skin, such as touch, pain and temperature are interpreted.
Temporal Lobe
AUDITORY AREA AND OLFACTORY AREA - receiving and interpreting impulses from the ear and it is stimulated by the impulses arising from the receptors in the noses
Occipital Lobe
VISUAL RECEIVING AREA - visual association are for interpreting impulses arising from the retina of the eye.
Wernicke area
controls language reception-a brain area involved in language comprehension and expression;usually in the left temporal lobe
Broca area
An area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech
Memory
is the mental faculty for recalling ideas.
Short Term Memory
is the retention of bits of info for a few seconds or perhaps a few minutes, after which info is lost unless reinforced.
Long Term Memory
refers to the storage of info that can be recalled at a later time.
Limbic System
Involved in emotional states and behavior. , a doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres; associated with emotions such as fear and aggression and drives such as those for food and sex. Includes the hippocampus, amygdala, and hypothalamus.
Hippocampus
located under the lateral ventricles which functions in learning and the formation of long-term memory.
Reticular Formations
Basic functions; alertness, sleeping patterns, wakefulness
PET
POSITRON EMISSION TOMOGRAPHY - which visualizes the brain in action
CRANIAL NERVES
12 PAIRS - MESSAGES belonging to one of the 4 categories:
-Special Sensory Impulses - smell, taste, vision and hearing
-General sensory Impulses - Pain, touch, temperature, deep muscle sense, pressure, and vibrations
-Somatic motor Impulses - voluntary control of skeletal muscles
- Visceral Motor Impulses - involuntary control of glands and involuntary muscles ( cardiac and smooth muscles).
I. Olfactory Nerve
carries smell inpulses from receptors in the nasal mucosa to the brain.
II. Optic Nerve
carries visual impulses from the eye to the brain
III. Oculomotor Nerve
concerned with contraction of most of the eye muscles.
IV. Trochlear Nerve
Supplies one eyeball muscle
V. Trigeminal
Carries sensory impulses from eye, upper jaw, and lower jaw toward the brain
VI. Abducens
Controls eyeball muscle
VII. Facial
Controls muscles of the facial expression: carries sensation of taste; stimulates small salivary glands and lacrimal glands.
VIII. Vestibulocochlear
carries sensory impulses for hearing and equilibrium from the inner ear toward the brain
IX. Glossopharyngeal
carries sensory impulses from the tongue and pharynx (throat); controls swallowing muscles and stimulates the parotid salivary gland.
X. Vagus
Supplies most of the organs in thoracic and abdominal cavities; carries motor impulses to the larynx (voice box) and pharunx.
XI.Accessory
Controls Muscles in the neck and larynx
XII. Hypoglossal
Controls muscles on the tongue.