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Amy Arteaga Period 7: Nervous System - Coggle Diagram
Amy Arteaga Period 7: Nervous System
Major functions of the nervous system
Central
Nervous System: CNS: responsible for integration of info. & decision-making
Somatic
nervous system: controls voluntary skeletal muscles
sensory input, intergration, processing, decision making, output(response)
Autonomic
nervous system: controls involuntary effectors(smooth & cardiac muscles/glands)
1) SENSORY funcion; provided by sensory receptors that detect internal/external changes
2)INTEGRATION function; coordination of sensory info. in CNS that processes decision making
3)MOTOR function; Effectors/mucles respond to decisions made in CNS
Major divisions and subdivisions of the nervous system (include all subdivisions of CNS
and PNS)
Peripheral nervous system(PNS);
cranial nerves
Spinal nerves
Somatic nervous system (SNS)
: part of motor division of PNS; controls voluntary skeletal muscles
Autonomic nervous system (ANS)
: part of motor division of PNS; controls involuntary effectors such as smooth and cardiac muscles and glands
cranial and spinal nerves connect CNS to rest of body, contain sensory(afferent) and motor(efferent) divisions
central nervous system(CNS)
Brain
Spinal cord
Sensory (afferent) division:
division of PNS responsible for relaying information to the CNS
Motor (efferent) division
: division of PNS responsible carrying out instruction from the CNS
Classification of neurons
Unipolar neurons
: have one process splits in to 2, one function as axon
Bipolar neurons
: have many dendrites and one axon; found mostly in CNS
Multipolar neurons
: have many dendrites and one axon; found mostly in CNS
Dentrite
: neuron that receives info. from other neuron
Tissues (structure & function of neurons and neuroglia)
Neuroglia
: "nerve glue"; cells that support, nourish , and insulate neurons; 4 types in CNS and 2 types in PNS
Motor neuron:
multipolar neurons that conduct impulse from CNS to peripheral effectors
Interneuron
: link between sensory and motor neurons
Neuron
: nerve cell; cells that communicate via electrical impulses, contains a cell body
Microglia
- small cells that function as phagocytes producing scar tissuue(CNS)
Oligodendrocytes
: form myelin sheath around axons in brain & spinal cord(CNS)
Ependymal
cells- produce cerebrospinal fuid in CNS
Astrocytes
- between blood vessels and neurons, structural support
Schwann cells
; myelin-producing neuroglia of PNS
Satellite cells
: provide protective coating around cell bodies of nuerons in PNS
sensory neurons
: transmit info from sensory organs to central nervous system
dentrites
: part of neuron that receives messages from other neurons
axon
; part of neuron that takes info away from cell body, releases neurotransmitters that are sent into synaptic cleft.
Connective Tissue Coverings
Dura matter:
outermost layer of meninges
Meninges
: 3 membrane layers lying between the skull bones, vertebrae, brain, and spinal cord
Eracnoid mater:
middle layer of meninges
Pia mater:
innermost layer of meninges
Myelin
: fat that speeds the message along an axon
neuroglia
: supporting cells of nervous system
Major parts and functions of the brain
Cerebral hemisphere:
mirror half sections of the cerebrum
structures
Gyrus(gyri):
ridges, bumps, or hills of the brain
Sulci(sulcus):
grooves, dips, or valleys of the brain
Lateral sulcus:
separates temporal
Central sulcus
: separates frontal and parietal
fissures
: deep folds or grooves of the brain
Longitudinal fissure:
separates right and left hemisphere.
Cerebellum
: coordinates muscular activity; posterior portion of the brain; coordinates muscular activity and balance
Brainstem
: bottom portion; connects brain to spinal cord; coordinates and regulates visceral activities and connects different parts of nervous system
Diencephalon
: processess sensory input & controlshomeostasis processes
Parietal lobe:
top portions of cerebrum; cutaneous(skin) senses; functions in understanding of speech and words
Cerebrum
: largest portion; associated w/ higher mental functions, sensory & motor functions
Temporal lobe
: side portions of the cerebrum; auditory (hearing) and smell area
Occipital lobe
: back portion of cerebrum; visual area
Frontal lobe:
front portion of cerebrum; controls higher intellectual processes such as problem solving and planning), emotions
Wernickes area:
located on the left side of temporal lobe; helps in understanding written and spoken language
Broca's area:
located on the left side of frontal lobe; controls muscle movement for speech
Cranial nerves
Abducens
: primarity motor; impulses to muscles that move eyes,
Facial
; mixed; impulses associated w/ taste receptors of anterior tongue. Motor fibers associate w/ facial expression, fear glands, & salvary glands.
Trigeminal
; opthalmic division(surface of eyes, tear glands, scalp, forehead, Maxilllary division(sensory fibers conduct impulses from upper tetth, gum, lip,palate), Mandibular division(from skin of jaw, lower teeth, gum, lip, mastication, floor of mouth
Vestibular and Cochlear
branch: sensory; associated w equilibrium, sense of hearing
Trochlear
: primarily motor: impulses to muslces that move eye, associated w/ condition of muscles
Glossopharyngeal
; mixed; impulses from pharynx, tonsils, posterior tongue, & carotid arteries, swallowing, salvary glands.
Oculomotor
: Primarily motor: conduction of muscles, motor function conducts impulses to muscles moving eyelids, focus lenses
Vagus
; mixed; associated w/ speech, swallowing, sending impulses to heart, smooth muscle, glands, thorax, abdomen,
Optic
: sensory: impulses associated w/ vision
Accesory
(cranial & spinal branch): primarity motor; conduct impulces to mucles of soft palate, pharynx, larynx. Conduct impulses of neck & back
Olfactory
: sensory; sensory fibers conduct impulses
Hypoglossal
; primarily motor; impulses to muscles moving tongue
*12 pairs of nerves arising from the brain
Major parts and functions of the spinal cord
Dura matter:
outermost layer of meninges
Epidural space
: space between spinal cord and vertebrae and brain and skull bones
Meninges
: 3 membrane layers lying between the skull bones and vertebrae and the brain and spinal cord
Eracnoid mater:
middle layer of meninges
Pia mater:
innermost layer of meninges
Gray mater:
butterfly-shaped area of spinal cord; houses interneurons and neuron cell bodies
White mater:
made up of bundles of myelinated nerve fibers
dorsal root gangalia:
located on the sensory neuron of spinal; houses cell bodies of sensory neuron of the spinal cord(outside spinal cord)
Posterior horns:
contain axons of sensory neurons and cell bodies of interneuron; upper wings of gray matter
Anterior horns:
contains cell bodies of motor neurons; bottom wings of gray matter
Lateral horns:
contain sympathetic nerve fibers; middle side portions of the gray matter
Central canal:
center of gray matter; contains cerebrospinal fluid
Functions
Ascending tract
: carry sensory information to the brain
Descending tract:
carry motor information from brain to effect organs
Spinal reflex:
controlled reflex arc that passes the spinal cord
Transmit impulses to & from brain, & to house spnal reflexes lies at base of cerebrum connecting cerebrum to lower portions of nervous system
Midbrain
: contains motor pathways between cerebrum & lower portions of nervous system*located between diencenphalon & pons
Pons
; contains centers that help regulate rate & depth of breathing; lies between mid brain and medulla oblongata
Medulla oblongata:
transmits all ascending & descending impulses between brain and spinal cord.
Ependymal
cell: goal cells that make spinal fluid
Action potential & the Nerve Impulse
Process of impulse conduction:
charge when threshold potential is reached and Na+ channels open; +30mV
1)Neuron membrane maintains resting potential
2)Threshhold stimulus received
3)Sodium channels in the trigger zone of axon open
4)Sodium ions diffuse inward, depolarizing axon membrane
5)Potassium channels in the axon membrane open
6)Potassium ions diffuse outward, repolarizing axon membrane
7)The resulting action potential causes a local electric current that stimulates adjacent portion of axon membrane
8) A series of action potentials occurs along the axon
Repolarization
: after action potential cell returns to resting potential
Hyperpolirization
: a slight overshoot at end of depolarization and is below -70mV (6)
Refractory Period:
time during an after action potential where another action potential cannot be reached
Axon-->synapse-->dentrite-->cell body
Spinal nerves
Dorsal Root
: sensory root arising from the posterior (top) portion of the spinal cord
Ventral root
: motor root arising from the anterior (bottom) portion of the spinal cord
*31 pairs of nerves arising from the spinal cord
Cervical nerves
: 8 pairs
Lumbar
nerves; 5 pairs
Thoratic
nerves; 12 pairs
Sacral
nerves: 5 pairs
coccygeal
nerves; 1 pair
Brachial Plesuses
: (c5-T1); network of nerves in lower cervical and upper thoracic regions,
Cervical plexuses:
(c1-c4) control diaphram, lie on either side of neck,
Lumbosacral Plexuses
(L1-S4); network of nerves arising from the lower spinal cord.
ALL except the first pair are mixed nerves
Neurotransmitters
chemical messengers in synapses
Norepinephrine
: neurotransmitter released by most
sympathetic
postganglionic fibers
Acetylcholine
: neurotransmitter released by
parasympathetic
postganglionic fibers
*neurotransmitters include acetylcholine, amino acids, neuropeptides
Monoamines
: stimulate skeletal muscle contraction at neuromuscular junctions, may exite/inhibit ANS
Compare & contrast the autonomic nervous system
connects the central nervous system to viscera, and controls subconscious actives.
two subdivisions of ans; sympathetic and parasympathetic (fight or flight, rest and digest)
Sympathetic division:
division of autonomic nervous system which in conditions of stress or emergency (fight or flight )
parasympathetic division:
division of autonomic nervous system which is active under normal, restful conditions (rest and digest)
Sympathetic neuron
: form thoratic & upper lumbar regions of spinal cord
Parasympathetic neurons
: form brain and sacral region of spinal cord
Reflex arc (major parts & functions)
simplest of routes nerve impulse travels; causes an involuntary action
Sensory neuron
: carries information from sensory receptor toward CNS
Sensory receptor:
detects changes that are internal or external
Interneuron
: carries information from sensory to motor neurons
Motor neuron:
carries instruction from brain/spinal cord to the effector organs
Effector
: carries instruction to the effector organs
Patellar refle
x: knee jerck
Withdrawal reflex
: pulling away of a hand in response to touching something painful
receptor, sensory/afferent neuron-->central nervous system, --> motor/effector neuron, -->effector(muscle/gland)