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Concept Map:Nervous Angel Martinez Anat/Phys-P5-Franco - Coggle Diagram
Concept Map:Nervous
Angel Martinez Anat/Phys-P5-Franco
Major Functions of the Nervous System
Sensation
Receives information about the environment to gain input about what is happening outside the body (or, sometimes, within the body)
Response
The nervous system produces a response on the basis of the stimuli perceived by sensory structures.
Integration
Stimuli that are received by sensory structures are communicated to the nervous system where that information is processed
Cranial Nerves
VI Abducens
Type:Primarily Motor
Motor fibers conduct impulses to muscles that move the eyes.
VII Facial
Type: Mixed
Sensory fibers conduct impulses associated with taste receptors of the anterior tongue. Motor fibers conduct impulses to muscles of facial expression, tear glands, and salivary glands.
V Trigeminal
Type:Mixed
Maxillary division: Sensory fibers conduct impulses from the upper teeth, upper gum, upper lip, lining of the palate, and skin of the face.
Mandibular division Sensory fibers conduct impulses from the skin of the jaw, lower teeth, lower gum, and lower lip.
Ophthalmic division: Sensory fibers conduct impulses from the surface of the eyes, tear glands, scalp,
forehead, and upper eyelids.
VIII Vestibulocochlear
Type:Sensory
Vestibular branch:Sensory fibers conduct impulses associated with the sense of equilibrium.
Cochlear branch:Sensory fibers conduct impulses associated with the sense of hearing.
IV Trochlear
Type:Primarily Motor
Motor fibers conduct impulses to muscles that move the eyes.
IX Glossopharyngeal
Type:Mixed
Sensory fibers conduct impulses from the pharynx, tonsils, posterior tongue, and carotid arteries.
Motor fibers conduct impulses to muscles of the pharynx used in swallowing and to salivary glands.
III Oculomotor
Type:Primarily Motor
Motor fibers conduct impulses to muscles that raise eyelids, move eyes, adjust the amount of light entering the eyes, and focus lenses.
X Vagus
Type:Mixed
Autonomic motor fibers conduct impulses to the heart, smooth muscle, and glands in the thorax and abdomen.
Sensory fibers conduct impulses from the pharynx, larynx, esophagus, and viscera of the thorax and abdomen.
Somatic motor fibers conduct impulses to muscles associated with speech and swallowing;
II Optic
Type:Sensory
Sensory fibers conduct impulses associated with the sense of vision.
XI Accessory
Type:Primarily Motor
Cranial branch:Motor fibers conduct impulses to muscles of the soft palate, pharynx, and larynx.
Spinal branch:Motor fibers conduct impulses to muscles of the neck and back.
I Olfactory
Type:Sensory
Sensory fibers conduct impulses associated with the sense of smell.
XII Hypoglossal
Type: Primarily Motor
Motor fibers conduct impulses to muscles that move the tongue.
Connective Tissue Coverings
Meninges
Three (3) Layers (External to Internal)
Pia Mater
Delicate connective tissue that clings to the brain; contains tiny blood vessels that feed (into) the brain; thin, transparent layer
Arachnoid Mater
Middle layer; spiderweb-like extensions; separated from the dura mater by the subarachnoid space
Dura Mater
Strongest and most durable meninx; milky white appearance; most superficial layer
Functions
Cover and protect the brain and spinal cord (CNS)
Protect blood vessels and enclose venous sinuses
Contains and holds cerebrospinal fluid (CFS)
Form partitions in the skull
Nerve Connective Tissue
Epineurium
Tough fibrous sheath around all fascicles to from the nerve
Perineurium
Coarse connective tissue that bundles fibers into fascicles
Endoneuronium
Loose connective tissue that encloses axons and their myelin sheaths (Schwann Cells)
Spinal Nerves: A total of 31 pairs of spinal nerves control motor, sensory, and other functions
Five (5) pairs of lumbar nerves (L1 - L5)
Five (5) pairs of sacral nerves (L1 - L5)
Twelve (12) pairs of thoracic nerves (T1 - T12)
Eight (8) pairs of cervicle nerves (C1 -C8)
One (1) pair of tiny coccygeal nerves (C0)
Major Parts + Functions of Brain
Brain Structures
Cerebrum
Lobes
Frontal Lobe
Motor movements
Parietal Lobe
Processes touch and senses
Temporal Lobe
Processes audio
Occipital Lobe
Processes visual cues
Cerebellum
Balance, coordination, and judgement
Brainstem
Midbrain
Associated with vision, hearing, motor control, sleep, and wake up cycles, alertness, and temperature regulations.
Pons
Contains tracks that carry signals from the cerebrum to the cerebellum. Also contains tracts that carry sensory signals.
Medulla Oblongata
Contains cardiac, respiratory, vomiting, and vasomotor centers regulating heart rate, breathing, and blood pressure.
Diencephalon
Hypothalamus
It regulates metabolic processes, body temperature, hunger, fatigue, etc…
Thalamus
Regulates sleep, alertness and wakefulness.
Fissures & Sulci
Transverse Fissure
Central Sulcus
Longitudinal Fissure
Ventricles
Lateral Ventricles
Third Ventricle
Fourth Ventricle
Classification of Neurons
Structural
Multipolar
Multipolar neurons have multiple dendrites and a single axon.
Bipolar
An axon and one dendrite extending from the cell body toward opposite poles.
Unipolar
Have one axon
Functional
Sensory
Function: Transmits impulses from sensory receptors toward the CNS
Motor
Function: Carry impulses from CNS to effectors; multipolar
Interneuron
Function: Shuttle signals through CNS pathways; most are entirely within the CNS
Reflex Arc
A reflex action is an automatic (involuntary) and rapid response to a stimulus, which minimises any damage to the body
Integration center: is a region in the brain, usually the hypothalamus, that signals a part of the body to respond to a stimuli.
Motor neuron: These neurons transmit impulses from the spinal cord to skeletal and smooth muscles
Sensory Neuron
Function:Tansmits impulses from a receptor, such as those in the eye or ear, to a more central location in the nervous system,
Effector target: actively responds to a stimulus and effects some change
Sensory Receptor
Function: to help us learn about the environment around us
Major parts and functions of the spinal cord
Divided in to three major parts
Thoracic (chest)
Lumbar (lower back)
Cervical (Neck)
Protection: Three layers of tissue protect the spinal cord
Arachnoid mater: The arachnoid mater is the middle layer of spinal cord covering.
Pia mater: The pia mater is the layer that directly covers the spinal cord.
Dura mater: This is the outermost layer of the spinal cord’s meninges. It is a tough, protective coating
Functions
Carrying information to the brain:
The spinal cord nerves also transmit messages to the brain from the body, such as sensations of touch, pressure, and pain.
Reflex responses:
The spinal cord may also act independently of the brain in conducting motor reflexes.
Carrying signals from the brain:
The spinal cord receives signals from the brain that control movement
Tissues (Structure & Function of Neurons + Neuroglia)
Neuroglia
CNS
Microglial Cells
can transform into a phagocytic macrophage and help in cleaning the neuronal debris.
Ependymal Cells
Ependymal cells are ciliated and line the central cavities of the brain and spinal cord where they form a fairly permeable barrier between the cerebrospinal fluid that fills these cavities and the tissue cells of the CNS.
Astrocytes
They support and brace the neurons and anchor them to the nutrient supply lines. They also help in the guiding the migration of young neurons.
Oligodendrocytes
Oligodendrocytes line up along the nerves and produce an insulating cover called myelin sheath.
PNS
Satellite Cells
Surround neuron cell bodies in PNS; function similar to astrocytes
Schwann Cells
Surround all peripheral nerve fibers and form myelin sheaths in thicker nerve fibers--similar function to oligodendrocytes; vital to regeneration of damaged peripheral nerve fibers
Neurons:
Neurons are highly specialized nerve cells that generate and conduct nerve impulses.
Dendrite
The receiving part of the neuron. Dendrites receive synaptic inputs from axons, with the sum total of dendritic inputs determining whether the neuron will fire an action potential.
Cell body (Soma)
The neuronal cell body consists of a nucleus and rough endoplasmic reticulum
Axon
The long, thin structure in which action potentials are generated; the transmitting part of the neuron.
Action potential & the Nerve Impulse
A neuron remains at rest until stimulated.
A stimulus can change resting potential in either directio
An excitatory stimulus opens chemically-gated Na+ channels, causing inside of neuron to become less negative.
Threshold stimulus: a stimulus strong enough to cause so many Na+ions to enter neuron, that potential changes from -70 to -55 mV
Voltage-gated Na+ channels open, changing charge to about +30 mV; this is called an action potential.
Change from negative to positive charge inside neuron is called depolarization, since now, inside and outside are both positive
Action Potential :Reaching an action potential is all-or-none response
It occurs when the charge reaches -55 mV.
Action potentials of a neuron are all of the same strength
Action potential either occurs or does not.
When action potential is reached, cell responds by returning to resting potential (-70 mV) by process of repolarization.
Repolarization returns the polarized state, and is accomplished by outward flow of potassium ions through potassium channels.
At end of repolarization, a slight overshoot called hyperpolarization occurs, in which potential dips below -70 mV.
Nerve Impulse
Neuron membrane maintains resting potential.
Threshold stimulus is received.
Sodium channels in the trigger zone of the axon open
Sodium ions diffuse inward, depolarizing the axon membrane
Potassium channels in the axon membrane open.
Potassium ions diffuse outward, repolarizing the axon membrane
The resulting action potential causes a local electric current that stimulates the adjacent portions of the axon membrane.
A series of action potentials occurs along the axon.
Compare and Contrast the Autonomic and Somatic Nervous System
ANS: The autonomic nervous system controls our internal organs and glands and is generally considered to be outside the realm of voluntary control.
The autonomic nervous system controls the function of our organs and glands, and can be divided into the sympathetic and parasympathetic divisions.
SNS: The somatic nervous system is associated with activities traditionally thought of as conscious or voluntary.
The somatic nervous system transmits sensory and motor signals to and from the central nervous system.
Neurotransmitters
Neurotransmitters are chemical messengers in the body. Their job is to transmit signals from nerve cells to target cells.
Inhibitory neurotransmitters decrease the chances of the target cell taking action. In some cases, these neurotransmitters have a relaxation-like effect.
Modulatory neurotransmitters can send messages to many neurons at the same time. They also communicate with other neurotransmitters.
Excitatory neurotransmitters encourage a target cell to take action
Chemicals
Endorphins inhibit pain signals and create an energized, euphoric feeling.
Epinephrine is involved in the body’s “fight or flight”
Dopamine:is important for memory, learning, behavior, and movement coordination.
Serotonin is an inhibitory neurotransmitter. It helps regulate mood, appetite, blood clotting, sleep, and the body’s circadian rhythm.
Acetylcholine: triggers muscle contractions, stimulates some hormones, and controls the heartbeat.
Major Divisions + Subdivisions of Nervous System (include all subdivisions of CNS and PNS)
Central Nervous System
Brain and Spinal Cord; Integrative and Control Centers
Brain
Limbic Systems
Reticular Formation
Reticular Activatiing System
Spinal Cord
Peripheral Nervous System
Two Divisions
Sensory (Afferent) Division
Visceral Sensory Fibers
Convey impulses from the visceral organs to the CNS
Somatic Sensory Fibers
Convey impulses from the skin, skeletal muscles, and joints to the CNS
Motor (Efferent) Division
Two (2) Divisions
Somatic Nervous System
Conscious control of skeletal muscles; mobilize body systems during activity; VOLUNTARY
Somatic nerve fibers conduct impulses from the CNS to skeletal muscles
Autonomic Nervous System
Two Subdivisions
Sympathetic
Mobilizes body systems during activity
Parasympathetic
Conserves energy; promotes "househeeping" functions during rest