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Nervous System- Gabriel Cruz P2 - Coggle Diagram
Nervous System- Gabriel Cruz P2
Major divisions and subdivisions of the nervous system (include all subdivisions of CNS
and PNS)
Peripheral Nervous System (PNS): Subdivisions and there functions are under neuroglia
Motor functions
Somatic nervous system: controls voluntary Skeletal muscles
Autonomic nervous system: controls involuntary effects like smooth and cardiac muscles & glans.
control sensory and Motor divisions
Made up of cranial & spinal nerves that connect the CNS to rest of body
able to regenerate their axons
Central Nervous System (CNS):
Responsible for integration of info & decision making
Subdivisions and there functions are under neurons subheading
Made up of brain n spinal cord
usually not able to regenerate there axon
Neuroglia
Ependymal cells: produce cerebrospinal fluid in CNS
Astrocytes: structural support, and form blood-brain barrier that protects brain tissue from chemical fluctuation and prevents entry of substances
Oligodendrocytes: form myelin sheath around axons in the brain and spinal cord
Microglia: function as phagocytes for bacterial cells and cellular debris and produce scar tissue in sites of injury
Types of Nerves
Motor neuron: impulse from CNS to effectors, axons called motor fiber
Mixed nerves: most nerves are this type & have both sensory and motor fibers
Sensory nerves: Impulse to CNS axon (sensory fiber)
Connective Tissue Coverings (!EpPEn!)
Perineurium: around fascicles (bundles) of nerve fibers.
Endoneurium: around individual nerve fibers (axons)
Epineurium: outer most coveringof a nerve
Cranial nerves
VI Abducens (Motor Type)
MF: impulse to muscle that move the eyes , & some SF w/ impulse associated w/ the condition of muscles.
VII Facial(Mixed)
MF: impulse to muscles of facial expression, tear glands, & salivary glands.
SF: Impulse associated w/ taste receptors of the anterior tongue
V Trigeminal (Mixed Type)
Maxillary division (Sensory fibers)
Impulse from upper teeth, upper gum, upper lip, lining of the palate, and skin of face.
Mandibular division
SF: Impulse from the skin of the jaw, lower teeth, lower gum, and lower lip.
MF: Impulse to muscles of mastication and to the muscles in the floor of the mouth.
Ophthalmic division (Sensory Fibers)
Impulse from the surface of the eyes, tear gland, scalp, forehead, and upper eyelids.
VIII Vestibulocochlear (Sensory)
Cochlear branch; impulse associated w/ sense of hearing
Vestibular branch; impulse associated a/ the sense of equilibrium
IV Tochlear
Motor Type, & Function: MF conduct impulses that muscles that move the eyes.
Some sensory fibers with impulse associated w/ the condition of muscles
IX Glossopharyngeal (mixed)
SF: impulse from the pharynx, tonsils, posterior tongue, and carotid arteries
MF: impulse to muscles of the pharynx used in swallowing and salivary glands
III Oculomotor
Primarily motor type, & Function: Motor Fibers(MF) conduct impulses to muscles that raise eyelids, move eyes, adjust the amount of light entering the eyes, & focus lenses
Some Sensory fibers conduct impulses associated with the condition of the muscle.
X Vagus(Mixed)
SF: impulse from pharynx, larynx, esophagus, & viscera of the thorax and abdomen
Somatic MF: impulse to muscles associated w/ speech and swallowing & Autonomic MF: impulse to heart, smooth muscle, & glands in the thorax and abdomen
II Optic
Sensory type, & Function: sensory fibers conduct impulses associated with the sense of vision.
XI Accessory (Motor Type)
Cranial branch; impulses to muscles of the soft palate, pharynx, and larynx
Spinal branch; impulse of the neck and back
I Olfactory
Sensory type, & Function: sensory fibers conduct impulses associated with the sense of smell
XII Hypoglossal (Motor type)
Impulse to the muscles that move the tongue
Compare & contrast the autonomic nervous system
Sympathetic Divisions
preganglionic fibers (short) rise from neurons on the gray matter in thoracic & lumbar regions in the spinal cord
active in conditions of stress or emergency & uses the fight or flight
paravertebral ganglia that is a chain of sympathetic ganglia close to the vertebral column on each side synapse w/ postganglionic neurons that long axons return to the spinal nerves and then proceed to a visceral effector.
Parasympathetic Division
preganglionic fibers (long) rise from brainstem and sacral region of the spinal cord, they extend out in cranial or sacral nerves, & synapse in terminal ganglia
active under normal, restful conditions (rest and digest)
Characteristics: work without conscious effort, controls motor function of smooth, cardiac muscle, and glands, and also controls heart rate, blood pressure, breathing rate, & body temp
Reflex arc (major parts & functions)
sensory neuron;Dendrite, cell body, & axon. Function:carries info from receptors into brain or spinal cord
Interneuron; Dendrite, cell body, & axon of a neuron within the brain or spinal cord. Function is to carry info from sensory neurons to motor neurons
Sensory receptors; detect changes
Motor neuron; Dendrite, cell body, and axon of a motor neuron. Function: Carries instructions from brain or spinal cord out to effectors
Functions: automatic responds to changes inside or outside of the body, that help maintain homeostasis
effectors; Muscle or gland. Function; responds to stimulation by motor neuron and produces reflexes or behavioral action
Description: Routes nerve impulses travel
Major parts and functions of the spinal cord
Parts
Lumbar enlargement: near the bottom and provides nerves for lower limbs
Cauda equina: forms at the bottom that tapers to a point inferiority, & have spinal nerves in lumbar & sacral area.
Cervical Enlargement: thick area @ top of spinal cord, and provides nerves for upper limbs
Function: transmit impulses to & from brain(ascending & descending tract), & house spinal reflexes(spinal reflexes that go through spinal cord)
Structure
31 segments which pair with spinal nerves, white/gray matter, dorsal root ganglia, posterior/anterior/lateral horn, and a central canal.
Major parts and functions of the brain
Diencephalon: process sensory input and controls homeostasis
Thalamus(relay center): sorting sensory info coming from parts of the nervous system to the cerebral cortex, general awareness like pain touch and temp, but does not process the sense of smell.
Hypothalamus: regulates; heart rate, blood pressure, body temp, water/electrolyte balance, hunger/body weight, digestive tract, sleep/wakefulness, and produces hormones.
Cerebellum: muscular activity
Structures: grey matter-cerebellar cortex, & white matter-arbor vitae
Functions: posture, ensures movement, skeletal muscle activity, & sensory info abt position of body part.
Cerebrum: associated with higher level of thinking
Surface
Sulci: grooves, & there are central sulcus, lateral sulcus, & occipital sulcus
Frissures: Deep grooves, & there are longitudinal (divides the brain & the right hemi controls the left and vise versa ) & transverse (divides the cerebrum and cerebellum)
Gyri: ridges for like the hills
Lobes
Parietal Lobe
Function: understand speech and choosing the right words
Located: posterior to the frontal lobe
Sensory Cortex- involved w/ cutaneous sense
Occipital Lobe
Function: controls vision & most posterior part of the brain
Frontal Lobe
Function: Higher level of intelligence (problem solving), self control, & emotions
Located in the front of the brain behind your frontal part of the skull.
Broca´s Area- muscles movement for speech
Motor Cortex- control voluntary muscle movement
Temporal Lobe
Function: speech, hearing, & smell (auditory)
Located on the sides of the brain
Wernicke´s area: helps with understanding of written, spoken language, & memory.
Cerebral Cortex (gray matter) that contain neuron cell bodies
Beneath is white matter that connect cell bodies of cerebral cortex w/ the rest of the nervous system.
General functions: personality, intelligence, integrates info for reasoning, stores info for memory, voluntary muscular movement, & sensory input.
Brainstem: coordinates and regulates visceral activities, and connects different parts of the nervous system
Pons
Contains centers that help regulate the rate and depth of breathing.
Medulla oblongata
transmit sensory & motor impulses btw brain and spinal cord
Vasomotor center: helps control blood pressure
Respiratory center: also helps rate and depth of breathing
Cardiac Center: alters heart rate
also controls coughing, sneezing, swallowing, &vomiting
Midbrain
Located btw diencephalon & pons
Main motor pathway bte verebrum and lower portions of the nervous system
Other structures:
Corpas Collosus: looks like a butterfly because it connects both hemispheres of the brain
Fanix
Ventricles cavities throughout the brain that contain cerebralspinal fluid
2 lateral ventricles, third and fourth ventricle
Pituinary glad, pineal gland,
Meninges: Outer Covering of the Brain
Arachnoid mater
Middle layer that contain cerebrospinal fluid
Pia mater
Inner most layer
Dura mater
Outer most layer, it is think because it is made out of tough dense connective tissue, & the sheath around spinal cord is separated from vertebrae by epidural space
Tissues (structure & function of neurons and neuroglia)
Neuroglia
Function of the neuroglia is a cell that supports the neurons by protecting and nourishment. Do not generate impulses
CNS Structures & Functions
Microglia: produce scar tissue, and are small cells that function as phagocytes for bacterial cells &cellular debris
Ependymal cell: make cerebrospinal fluid in CNS
Oligodendrocytes: function is to form myelin sheath around axon in brain & spinal cord.
Astrocytes: located btw blood vessels & neurons, function is to provide structural support & to form the formation of blood-brain barrier that protects brain from chemical fluctuations & protects entry of substances.
PNS Strunctures & Functions
Satellite Cells: in PNS protective coating around cell body
Schwann Cells: myelin producing of PNS
Neurons
Function of the neuron is to communicate with other neurons or tissues by electronic impulse
Structure & Function: Dendrites- short & branching, impulse to the cell, and have receptive surface for communication with other neurons.
Structure & Function: Axon (only 1)- impulse out of the neuron, & comes from thickening extending from cell body (axon hillock)
Structure & Function: Cell body (soma)- this part contains major organelles of the cell like the nucleus
Structure & Function: Myelin Sheath- called myelinated fibers that increase conduction speed of nerve impulse, & btw them are nodes of Ranvier that are narrow gaps.
Major Functions of the nerves
Thinking, movement, internal process of philology (function)
Sensory input: detect change in or external, Integration and processing (decision making): process and coordination, and the motor or effect: response to the decision.
Spinal nerves
Characteristics: 31 pairs of spinal nerves, all except the first pair are mixed nerves, & group from which they arise from (a sensory dorsal root & motor ventral root).
8 Pairs of cervical nerves, 12 pairs of the thoracic nerves, 5 pair of lumbar nerves, 5 pairs of sacral nerves, and 1 pair of coccygeal nerves
Plexuses
Brachial Plexuses (C5 – T1): lower cervical/ upper thoracic nerves, supply muscles/skin of arms, forearms and hands, & upper limbs- musculocutaneous, ulnar, median, radial and axillary nerves
Lumbosacral Plexuses (L1-S4): lower spinal cord, supply muscles and skin of lower abdomen, external genitalia, buttocks, & legs, & obturator, femoral, and sciatic nerves.
Cervical Plexuses (C1-C4): either side of the neck, supply muscles and skin of the neck, & phrenic nerves that control the diaphragm
Action potential & the Nerve Impulse
Most neurons are polarized that the charge inside membrane is different from the charge outside the membrane, but are also excitable since they can respond to changes by moving to a positive charge.
They have a resting potential of -70mV, higher has a greater concentration of sodium ions on outside then potassium ions on the inside
Action Potential; a stimulus open chemically gated Na+ channels, Na+ ions flow into the cell causing the neuron to become less negative, After is threshold stimulus which caused the potential to change to -55 mV, finally the threshold potencial reach the voltage gated Na+ channels and open causing the change to move to +30mV which caused our cation potential
Action potential occurs or it doesn't, and after reaching the potential it repolarize by to the original, and over shoots it (hyerpolarization)
An action potential causes an electrical current to slow across the axon
Neurotransmitters
Acetylcholine
CNS: controls skeletal muscle action
PNS: skeletal muscle contraction at neuronmuscular junction & may cause autonomic nervous system actions, depending on receptors
Monoamines
Dopamine
CNS: Sense of feeling good, but in some brain areas is associated with Parkinson disease
PNS: Limit actions in automatic nervous system
Serotonin
CNS: leads to sleepiness, but could be blocked by LSD, enhanced by selective serotonin reuptake inhibitor drug (SSRI)
Norepinephrine
CNS: Sense of feeling good if low it could lead to depression
PNS: Cause autonomic nervous system actions, depending on receptors
Histamine
CNS: Release in hypothalamus promotes alertness.
Events leading to Release of Neurotransmitters
2)Synaptic Knob becomes preamble to calcium ions, go inward
3)Calcium presences opens synaptic vesicles
1) Action potential passes along axon over synaptic knob
4)Synaptic vesicles release their neurotransmitter into the synaptic cleft.
Description: chemical messengers in a synapse, that convey eletrical impulse from a neuron to another cell
Classification of neurons
Functional Classification
Interneurons
multipolar neurons within CNS to form links btw neuron
cell bodies of some interneurons that are in a specialized masses called nuclei.
Motor neurons
Multipolar neuron
impluse from CNS to peripheral effectors (muscles or glands)
Sensory neurons
impulses from peripheral receptors to CNS
unipolar but some are bipolar
Structural Classification
Bipolar neurons
2 processes extending from the cell body one dendrite and one axon
Found in special sense like eye, nose, and ears
Unipolar neurons
peripheral process dendtrits are near peripheral body, & central process runs into CNS
Sensory neurons: cell bodies found in ganglia outside the CNS
One process extending from the body that is an axon which is split into 2 parts but is one
Multipolar neurons:
Many dendrites w/ 1 axon from the cell body
Most neuron cell bodies in CNS are multipolar most motor and interneurons