-area between the cerebral hemispheres and the brain stem. Includes thalamus and hypothalamus
- medulla connects the brain with the spinal cord through large opening at base of the skull.
- (little brain) located immediately below the posterior part of the cerebral hemispheres, connected with cerebrum, brain stem and spinal cord by means of the pons.
3 layers of connective tissue that surround both the brain and spinal cord to form a complete enclosure.
- outermost - thickest, toughest (hard mother) has 2 layers and outer layer is fused to bones of cranium.
middle layer of meninges. Loosely attached by weblike fingers. Allows space for movement of CSF cerebrospinal fluid.
innermost layer around the brain ,Attached to nervous tissue of the brain and spinal cord. Follows all contours.,Delicate connective tissue. ,Holds blood vessels,Supply nutrients and oxygen to brain and spinal cord.
Function of CSF
to support nervous tissues, cushion shocks, carries nutrients to cell, transports waste away.,Flows out into subarachnoid space of the meninges.
-vascular network in each ventricle- forms CSF by filtration of the blood and by cellular secretion.
outer nervous tissue of the cerebral hemisphere is gray matter. Arranged in folds. Thin layer of gray matter- most highly evolved portion of brain, Responsible for conscious thought,reasoning, and abstract mental functions.
lies between frontal and parietal lobes of each hemisphere at right angles to the longitudinal fissure.
curves along the side of each hemisphere and separates the temporal lobe from the frontal and parietal lobes.
Internally- cerebral hemispheres are made of white matter.Consists of myelinated fibers that connect the cortical areas of each other with other parts of the nervous system.
Basal nuclei-basal ganglia-
masses of gray matter located deep within each cerebral hemisphere.,Work w/cerebral cortex to regulate body movement, muscles of facial expression.
band of white matter located at bottom of longitudinal fissure.,Band is a bridge between right and left hemisphere. ,Permits impulses to cross from one side to the other.
compact band of myelinated fibers that carries impulses between the cerebral hemispheres and the brain stem.
layer of gray matter forms surface of each cerebral hemisphere-impulses are received and analyzed.
Functions of Cerebral Cortex
Activities form the basis of knowledge. ,Memory- information can be recalled on demand.,Thought processes such as association, judgment and discrimination.,Conscious deliberation and voluntary actions
Frontal Lobe Functions
Primary motor area- provides conscious control of skeletal muscles.,2 areas important in speech.
occupies superior part of each hemisphere and lies posterior to the central sulcus.,Gyrus just behind the central sulcus in this lobe contains:
Parietal Lobe Functions
Primary sensory area- impulses from the skin : touch, pain, and temperature are interpreted. ,Estimation of distances, sizes and shapes take place here. Greater the sensation the more involved cortex is.
Temporal Lobe Functions:
auditory area- receiving and interpreting impulses from the ear.Olfactory area- sense of smell- located in medial part of temporal lobe. Stimulated by impulses arising from receptors in the nose.
Occipital lobe functions
Visual receiving area and visual association area, Interprets impulses arising from the retina of the eye.
Speech comprehension area-
wernicke area- functions in speech recognition and the meaning of the words.auditory
for spoken and written communication- lie anterior to the most inferior part of the frontal lobe's motor cortex.
Motor speech area.
- broca area- Speech muscles in the tongue, soft palate, and larynx controlled here.
Functions of Occipital lobe cortex
Visual images of language are received. Visual area lies anterior to receiving cortex, then interprets these visual impulses as words. Ability to read with understanding develops in this area.
Short term memory
- retention bits of information for a few seconds or perhaps a few minutes. After that time information is lost unless reinforced.
Fibrils form at
the synapses in the cerebral cortex. ,Enables impulses to travel more easily from one neuron to another.
interbrain- is located between the cerebral hemispheres and the brain stem.,Includes thalamus and hypothalamus. 2 parts of the thalamus form the lateral walls of the third ventricle.
Role of thalamus
is to sort out the impulses and direct them to particular areas of the cerebral cortex.
Located in the midline area inferior to the thalamus and forms the floor of the third ventricle.
Hypothalmus Helps maintain
homestasis by controlling body temperature, water balance, sleep, appetite and some emotions such as fear and pleasure.
Sympathetic and parasympathetic, controls pituitary, Influences heartbeat, Contraction and relaxation of blood vessels. ,Hormone secretion,Other vital body functions.
Mid brain Gray Matter
-Four rounded masses, hidden by cerebral hemispheres form superior part of midbrain.,Four bodies act as centers for reflexes involving,Eyes, and ears.
Midbrain White matter - anterior of midbrain
- conducts impulses between higher centers of cerebrum and lower centers of pons, medulla, cerebellum and spinal cord.
Lies between the midbrain and the medulla ,Anterior to the cerebellum ,Composed of myelinated nerve fibers which connect the tow halves of the cerebellum with the brain stem,
Located between the pons and the spinal cord. ,Appears white externally because of myelinated nerve fibers., Internally contains collection of cell bodies( gray matter) called Nuclei or centers. Vital centers.
Medulla Oblongata Controls
Respiratory center- Cardiac center- Vasomotor center Controls blood flow and blood pressure.
surrounds base of hair, band of muscle, contracts- goose bumps-Cells add color pigment to hair.
Dead, Cutaneous plates , made of keratin - produced by cells that originate in the outer layer of the epidermis, Protection- for toes and fingers
*Emotional state- can be created by nervous system. To have an influence on or affect a change in.
*middle layer of meninges. Resembling a cobweb. Used of the arachnoid membrane covering the brain and spinal cord.
**pertaining to sense of hearing. Of or relating to hearing, the organs of hearing, or the sense of hearing.
4. Brain Stem
**portion of brain that connects the cerebrum with the spinal cord, contains the midbrain, pons, medulla oblongata. the stemlike portion of the brain connecting the cerebral hemispheres with the spinal cord.
**largest part of brain. the main portion of the brain, occupying the upper part of the cranial cavity; its two hemispheres, united by the corpus callosum, form the largest part of the central nervous system in humans.
8. Dura mater
**outermost layer of meninges the outermost, toughest of the three meninges (membranes) of the brain and spinal cord.
**state of balance. the condition of balance between varying, shifting, and opposing forces that is characteristic of living processes.
11. Grey Matter
**nervous tissue, composed of unmyelinated fibers and cell bodies. Brownish-gray nerve tissue, especially of the brain and spinal cord, composed of nerve cell bodies and their dendrites and some supportive tissue.
** region controls pituitary, maintains homeostasis. The part of the brain that lies below the thalamus, forming the major portion of the ventral region of the diencephalon, and that regulates bodily temperature, certain metabolic processes, and other autonomic activities.
**efferent neurons, fibers that carry impulses from the central nervous system out to muscles and glands. Causing or producing motion.
** study of diseases of nervous system. the branch of medicine that deals with the nervous system, both normal and in disease.
*cranial nerve, sense of smell. Receptors in nasal muscosa. Of, relating to, or contributing to the sense of smell.
Eye socket. the bony cavity containing the eyeball and its associated muscles, vessels, and nerves.
Specialized cell or ending of sensory nerve that can be excited by a stimulus. a sensory nerve ending that responds to various stimuli.
** bending of light rays as they travel through a medium other than air. the deviation of light in passing obliquely from one medium to another of different density.
**neurons that carrie impulses from receptors, to the brain and spinal cord. Transmitting impulses from sense organs to nerve centers; afferent.
**point of junction between 2 neurons or between a neuron and an effector. Carries Out a response to stimulus. (leaping)the site of functional apposition between neurons, where an impulse is transmitted from one to another, usually by a chemical neurotransmitter released by the axon terminal of the presynaptic neuron.
**region of brain located in diencephalon- A large ovoid mass of gray matter situated in the posterior part of the forebrain that relays sensory impulses to the cerebral cortex.
22. White Matter
Whitish nerve tissue, especially of the brain and spinal cord, consisting chiefly of myelinated nerve fibers. ** nervous tissue composed of myelinated fibers.
coordinates and controls the body, then communicates with systems, That will conduct responses to internal and external changes.
Functions of Nervous system
Reacts to internal and external changes,Links with environment,Center of mental processes., Reacts in split seconds. Processes information and sends it to an appropriate area.
Autonomic Nervous System Processes:
Hormonal feedbacks, visceral , controls smooth muscle, heart glands, peristalsis, digestive juices.
Role of nervous system:
Detects and responds to stimuli, Brain and spinal cord act as switiching centers,Nerves carry messages to and from centers.
can be up to 3ft. long.,Sent to brain, interpret, response. Stimulus happens within seconds
end organs- internal and external-, all information send to brain and right back out (effector).Touch, pain, hot and cold. Etc.
Gap between nerve tissue-,Impulse will jump across,Electricity- junction point for transmission of nerve impulses.
Synapse Needs neurotransmitters:
ephinenphrine(norephinephrine), acetycoline,(adrenaline) noradrenaline, Need chemical to send it to the brain.
- concerned with brain and spinal cord, unmyelinated; no neurilemma, Taking impulses across selected synapses,Tissue, cell bodies of these neurons are scattered throughout., Several cell bodies- constantly conducting.,Hit with stimuli all the time. Brain very active
Myelinated, Concerned with impulses along fibers which goes both ways. Spinal cord- has tracks- bundles of nerve fibers which have the same origin and termination and function.
Nervous system at work
Electrical impulses sent along neuron fibers and transmitted between cells at junctions.
outermost layer, thickest, toughest, protection.,In spine- lines vertebrae,In brain- skull splits to allow passage of blood
allows for blood supply to the brain.,Directly attached to the cord and the brain.,Will dip in and out of brain- into all of those depressions.Extremely delicate. - a lot of vessels.
Cushion, protect, transport nutrients and waste ( away.) Supports nervous tissue, cushions from shock
forms CSF-formed by filtration of the blood and any cellular secretions (made) of clear fluid ; inside ventricles.
largest part of brain,Has 2 hemispheres - right and left, Center for all of our higher function, Thinking, reasoning, memory, judgement Responsible for our personality
Frontal Lobe Controls
voluntary muscle action.,Motor ability includes:,Writing,Speaking,Intellectualization,judgement,Forming concepts,Critical thinking, Controls speech
Upper part of each hemisphere Sensory area- interprets our general senses: Heat,cold, shape, feel ,distance, size, pain, touch,temperature,shapes,Help us to recognize body parts.-
most posterior, extends over cerebellum, Visual receiving area ,Interpret messages we get from eye to retina.,Involved with understanding the written word.
relay center for eye and ear reflexes,Serves as passageway to the higher brain centers, Conducts impulses from cerebrum down through midbrain, pons, medulla to spinal cord.
means bridge,White matter,Connects midbrain to medulla, link to cerebellum and rest of nervous system, Myelinated fibers,Transmits impulses to cerebellum to the cerebrum, maybe medulla to the spinal cord.
Medulla Oblongata controls
Respiratory center, controls muscles of respiration , Cardiac center- ,Vasomotor center- vessels, determines BP, Reflex action- hiccup, cough, sneezing, vomitting
Functions of Pinna-
oracle-, Captures sounds,Visible portion of ear,Made of cartilage,Directs soundwaves
creates tympanny- drums,Vibrates as sound enters ear, Vibrates and transmits sound waves to ossicles, Ear drum
Tympanic Membrane Covered with
skin on outside, Thin mucous membrane on inside, Separates external ear from middle ear.
smallest bones in our body 3 0f them, sealed off by tympanic membrane, these bones move, amplify and transmit , vibrate, conduct sound waves through middle ear to oval window or
connects middle ear to pharynx (throat), equalizes pressure on both sides of tympanic membrane,mucous membrane from pharynx to middle ear cavity.
contains receptors for hearing., Receptors organ of corti- organ of hearing.,Effected by gravity- keeps you on your feet.
Vestibular nerve and cochlear nerve will merge into one and make up the main nerve
cranial nerve 8 vestibulocochlear nerve 8 - (acoustics)
olfactory 1 found in nasal cavity, send off to olfactory nerve and off to the brain, Found in upper part of nasal cavity- mucosa, Stimulates appetite
Fit into a cavity in skull.- protects Eye cavity bones protection of eye eyelid, eyelashes and eyebrown, conjunctiva, lacrimal
Numbers begin anteriorly and proceed posteriorly,All arise from brain stem EXCEPT the first 2 pairs, and 9th pair and 12th pair supply structures of the head.
General sensory impulses of cranial nerves
pain, touch, temperature, deep muscle sense, pressure and vibrations and are Widely distributed throughout body.
Visceral motor impulses of cranial nerves
Produced involuntary control of glands and involuntary muscles. ( cardiac and smooth)
I - olfactory nerve(cranial)
carries smell impulses from receptors in the nasal mucosa to the brain.
3 branches transport general sense impulses From eye, upper jaw, and lower jaw ,// pain, temperature, touch
motor fibers to the muscles of mastication join the third branch, This nerve dentist anesthetizes to work on teeth.
VII- facial nerve(cranial nerve)
largely motor- muscles of facial expression and includes special sensory fibers for taste
Facial nerve VII
Contains secretory fibers to the smaller salivary glands Anterior 2/3 of tongue and Secretory fibers lacrimal glands.
VIII- vestibulocochlear nerve(cranial nerve)
carries sensory impulses for hearing and equilibrium from inner ear (Formerly called auditory or acoustic nerve)
IX-glossopharyngeal nerve(cranial nerve)
general sensory fibers from the back of the tongue and pharynx- SWALLOWING muscles, secretory fibers supply the largest salivary gland(parotid)
X- vagus nerve
longest cranial nerve. ( name means wanderer) Supplies most of the organs in the thoracic and cavities.
XI accessory nerve
One branch controls 2 muscles of the neck: the trapezius and sternocleidomastoid: other branch controls muscles of the larynx
XII- hypoglossal Nerve
carries impulses controlling muscles of the tongue, visceral, movement of tongue
Protects against infection, dehydration, Regulates body temp, Collects sensory information
Protection, chemically and mechanically, light barrier, cushions internal organs (adipose tissue), Excretion- water and salt through perspiration, Absorption- minimal amounts of water, Sun- Vit D.
regulates body temperature- gets rid of heat by evaporating body sweat- cooling mechanism.,Fat layer is insulator of heat loss. - warming mechanism, Receives environmental information- part of protection
Outermost layer- NO blood vessels,Constantly shed- dropping epidermis,Cells are very flat.- horny, Tough and dry,Stratified, squamous,Contains our pigment
Middle layer,Framework of connective tissues, Blood vessels, glands , nerve fibers, beginning of hair follicles., receptor organs, Receptor organs- nerves, Feel pain, hot cold, touch, pressure.
Composed of adipose tissue,Acts as an insulator, Stores energy, contains superficial fascia- protects organs -sits on top of organs.