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Marisol Matias Nervous Period:5 - Coggle Diagram
Marisol Matias Nervous Period:5
Major functions of the nervous system
Sensory function
: Detects changes in stimuli both outside & inside of body like temperature, pressure, touch. Sensory neurons & receptors are involved in the sensory functioning.
Motor function
: The muscles and glands are activated to respond to decisions. Effectors and motor neurons are involved in the motor functioning
integration
: the process sensory information for decision making. The brain and spinal cord is involved in the integration
Major divisions and subdidvisions
Central Nervous System (CNS)
: Brain & the spinal cord
Peripheral Nervous System (PNS)
Sensory (afferent) division
:
Somatic Sensory
: Touch, pain, temperature, vibration
Visceral sensory
: Stretch, pain, chemical changes, temperature
Motor (efferent) division
Somatic nervous system (SNS)
: Motor innervation of all skeletal muscles
Autonomic nervous system (ANS)
: Motor innervation of smooth muscle, cardiac muscle, & glands
Sympathetic division
: More complex and innervates more organs
Parasympathetic division
: Also called craniosacral division due to the fibers originating from brain stem & sacral region of spinal cord
Tissues
Neurons
: transmit nerve impulses all throughout the body. A neuron contains a cell body with a nucleus in the center, dendrites which receive signals from other neurons, axons where it transmits the signals to other muscles, neuron, or glands, and the axon terminal, which release neurotransmitters.
Neuroglia
: supports and protects the neurons.
Astrocytes
: Abundant, versatile, and highly branched. These cling to neurons, synaptic endings, and capillaries. These support neurons, control chemical environment, and process info in the brain.
Microglial Cells
: These are small, ovoid cells. They touch and monitor neurons . Microglial cells migrate towards injured neurons and can transform to phagocytize microorganisms and neuronal debris
Ependymal Cells
: Lines central cavities of brain and spinal column. They form permeable barrier between CSF in cavities & tissue bathing CNS cells.
Satellite Cells
: Satellite cells surround neuron cell bodies in the PNS. They function similar to the asrtocytes in PNS
Oligodendrocytes
: Are branched cells. They process and wrap CNS nerve fibers, forming insulating myelin sheaths
Schwann Cells
: These cells surround all peripheral nerves fibers & form myelin sheaths. They are similar in function to oligodendrocytes and are vital to regeneration and damaged peripheral fibers
Classification of neurons
Multipolar Neurons
: 3 or more processes (1 axon, others dendrites)
Bipolar Neurons
: 2 Processes (1 axon, 1 dendrite)
Unipolar
: 1 T-like process (2 axons)
Connective tissue coverings
Meninges
1. Dura Mater
: The toughest thick top layer of the brain. It consists of a dense connective tissue.
2. Arachnoid Mater
: Is the middle layer with spider-like extensions. It is separated from the dura Mater by the subdural space. The subarachnoid space contains CSF and largest blood vessels.
3. Pia Mater
: is the most inner layer and it is a delicate connective tissue clinging tightly to the brain. It contains many tiny blood vessels that feed the brain.
Coverings of peripheral nerves
Endoneurium
: Loose connective tissue enclosing axons and Schwann cells
Perineurium
: Coarse connective tissue that bundles fibers into fascicles
Epineurium
: Tough fibrous sheath around all fascicles to form nerve
Major parts & functions of the brain
Cerebellum
: Functions in maintaining balance and coordination, motor learning and voluntary movements.
Cerebrum
: The cerebrum consists of 4 lobes; frontal, parietal, temporal, and occipital. The
frontal
lobe helps with cognitive thinking, problem solving and controls voluntary movements. The
parietal
lobe processes sensory info & is used for spatial awareness and navigation. The
temporal
lobe processes auditory info and language. The
occipital
lobe processes visual information
Brain stem
: The brain stem is built in three structures. The
pons
, responsible for the regulations of breath and sleep cycles. The
midbrain
, responsible for the control of visual and auditory reflexes while also maintaining alertness. The
Medulla oblongata
, responsible for controlling blood pressure heart rate breathing and coordinates vomiting, swallowing, and coughing.
Diencephalon
:
Thalamus
: acts as a relay station for info coming into the cortex. Sorts, edits, and relaysascending input such as impulses from the hypothalamus, impulses from the cerebellum, and impulses for memory.
Hypothalamus
: The main visceral control and regulating center vital to homeostasis
Epithalamus
: dorsal portion of the diencephalon. Contains the pineal gland. extends from the posterior border, and secretes melatonin that helps regulate sleep-wake cycles.
Limbic system
: The structures like the hypothalamus, amydgala, hippocampus, and other interconnected structures allow emotion regulation, drives, and memory formation
Ventricular system
: Ventricles filled with cerebrospinal fluid (CSF). It protects the brain by providing a cushion and supplies nutrients while also removing wastes.
major parts & functions of the spinal cord
:
Structure
Gray Matter
: It is a butterfly shape. It contains dendrites, cell bodies, and unmyelinated axons. This part processes and integrates motor and sensory info. The
Ventral Horn
send out motor commands, the
dorsal horn
receives the sensory input, and the
lateral horn
controls autonomic functions
White Matter
: Contains myelinated axons. It transmits signals between the brain and the body. The
ascending tracts
carry sensory info to the brain, and the
descending tracts
carry motor commands from brain to body
Central canal
: The center of the spinal cord containing CSF.
Major parts
Cervical region (C1-C8)
: the top part of the spinal cord. Controls signals to the neck, diaphragm, & shoulders.
Thoracic (T1-T12)
: The middle part of the spinal cord. Regulates the signals to the abdomen and chest muscles.
Lumbar (L1-L5)
: The lower section of the spinal cord. It controls the signals to the lower back, legs, and hips.
Sacral (S1-S5)
: Section near the pelvis; controls signals to the legs, feet, pelvis, and genital areas
Coccygeal (C0)
: The tailbone of the spinal cord. It has very little function
Action potential & nerve impulse
1. Resting State
: All gated Na+ and K+ channels are closed. Only leakage channels for Na+ and K+ are open. This maintains the resting membrane potential
2. Depolarization
: Na+ channels open. Depolarizing local currents open voltage-gated Na+ channels. At threshold (-55 to -50mV), positive Feedback causes opening of all Na+ channels
3. Repolarization
: Na+ channels are inactivating, and K+ channels open. The Na+ channel inactivation gates close. This causes the membrane permeability to Na+ to decline its resting state. The AP spike stops rising. Voltage-gated K+ channels open, then K+ exits cell down its electrochemical gradient
4. Hyperpolarization
: Some K+ channels remain open, Na+ channels reset. Some K+ channels remain open, allowing excessive K+ efflux. This causes the inside of the membrane to become more negative then in the resting state. Causes the hyperpolarization of the membrane.
Cranial nerves
1. Olfactory Nerve (I)
: A sensory nerve that plays a role in the sense of smell
2. Optic Nerve (II)
: A sensory nerve that plays a role in vision
3. Oculomotor Nerve (III)
: A motor nerve that plays a role in controlling pupil constriction, eye movements, & lens shape
4. Trochlear Nerve (IV)
: A motor nerve that plays role in directing the eyeball
5. Trigeminal Nerve (V)
: A mixed nerve of both sensory and motor nerves that moves the eye up and down. Has 3 divisions:
Ophthalamic (V1)
Maxillary (V2)
Mandibular (V3)
6. Abducens Nerve (VI)
: A motor nerve responsible for moving the eye laterally
7. Facial Nerve (VII)
: A mixed nerve that is responsible for facial expression, parasympathetic impulses to lacrimal & salivary glands. It is also a taste function from anterior 2/3 of the tongue.
8. Vestibulocochlear Nerve (VIII)
: A sensory nerve responsible for hearing & balance
9. Glossopharyngeal Nerve (IX)
: A mixed nerve that is responsible in conducting taste from the back of the tongue general sensory impulses. Its motor function includes innervating the part of the tongue & pharynx for swallowing
10. Vagus Nerve (X)
: A mixed nerve responsible for the autonomic control of lungs, digestive tract,& heart. Also received sensory input from the thoracic and abdominal organs.
11. Accessory Nerve (XI)
: A motor nerve responsible for controlling the muscles sternocleidomastoid & Trapezius
12. Hypoglossal Nerve (XII)
: A motor nerve responsible for controlling the movements of the tongue
Spinal nerves (31 pairs)
Cervical Nerves (C1-C8
: 8 pairs; Serves the Shoulders, neck, arms, hands, diaphragm
Thoracic Nerves (T1-T12)
: 12 pairs; Serves the upper back, chest, abdomen
Lumbar Nerves (L1-L5)
: 5 pairs; Serves the hips, thighs, lower back, legs
Sacral Nerves (S1-S5)
: 5 pairs; Serves Buttocks, legs, feet, pelvis
Coccygeal Nerve (C0)
: 1 pair; Serves the tailbone
Neurotransimtters
Excitatory
Glutamate
: The most abundant neurotransmitter. Used for learning and memory
Acetylcholine
: Active & involved in the muscle activation, memory, and attention
Norepinephrine
: Flight or flight response. Affects alertness
Inhibitory
GABA
: Main inhibitory neurotransmitter. Prevents over excitement in the brain and reduces anxiety
Glycine
: Inhibits excessive nerve signals. Can be found in spinal cord and brain stem
Dual Effect
Dopamine
: Plays a role in the motor, pleasure, and reward center.
Serotonin
: Regulates sleep, mood, appetite, and temperature
Endorphines
: Acts as pain killers
Compare & contrast ANS
Parasympathetic
: The rest and digest system. PNS effects are localized to specific organs. PNS dominates during relaxation and rest; normalizes breathing; conserves energy' preganglionic contains ACh; postganglionic contains ACh
Sympathetic
: The fight or flight system. increases heart rate & force of contraction; preganglionic contains ACh, and postganglionic contains NE; improves oxygen intake
Reflex arc
1. Receptor
: The site of the stimulus action
2. Sensory Neuron
: Transmits afferent impulse to the CNS
3. CNS Intergration Center
: Processes the information and determines the appropriate response
Effector
: Muscle fiber or gland cell that responds to efferent impulses by contracting or secreting
Motor Neuron
: Transimits efferent impulses from integration center to the effector organ
Disorders/diseases
Multiple Sclerosis
: An autoimmune disease that affects yound adults. This disease causes the myelin sheaths to be destroyed in the CNS. The myelin turns to hardened lesions called sclerosis. The impulse conduction slows and ceases.
Symptoms
: Visual disturbances, weakness, & speech disturbances.
Treatment
: Drugs that modify immune system activity.
Phantom limb pain & Hyperalgesia
: Long lasting or intense pain like limb amputation can lead to hyperalgesia, chronic pain & phantom limb pain
Autonomic Neuropathy
Damage to autonomic nerves, a common complication of diabetes mellitus. Early signs include sexual dysfunction.
Symptoms
: Dizziness after standing suddenly, urinary incontinence, sluggish eye pupil, impaired sweating. To prevent, maintain good blood glucose levels.
Cerebrovascular Accident:
Occurs when blood flow to a portion of the brain is halted.
Causes or Risk factors:
Certain types are hereditary, diabetes, increasing age.
Symptoms
: severe headache, loss of coordination & balance, change in alertness.
Treatment Options
: Hospitalization, blood thinners, rehabilitation
Autism
: A brain disorder that makes it difficult to communicate.
Causes or risk factors
: Family history, hereditary, mostly males.
Symptoms:
repeated behaviors, anxiety, unusual attachment to object or routine.
Treatment
: Coping skills, behavioral management, medication
Alzheimer's Disease
: A form of dementia associated with age.
Causes or Risk factors
: Hereditary, age over 60, high insulin levels.
Symptoms
: memory loss, confusion & disorientation, mood and behavior changes.
Treatments
uncurable, stem cells, psychological coping skills.
Spinal cord injury
: damage to the spinal cord.
Causes or Risk factors.
Direct injury or disease, weakend vertebral column, assault, fall, or accident.
Symptoms
: Weakness, Spastic muscles, paralysis.
Treatment
: Surgery, bed rest, physical therapy
Meningitis
: Infection in the meninges surrounding the brain.
Causes or Risk factors
: Drug allergies, tumors, irritation.
Symptoms
: nausea & vomiting, fever and chills, irritation.
Treatment options
: Antibiotics, meds to treat symptoms, prevention with vaccines
Multiple Sclerosis: An autoimmune disease that damages the myelin sheath
:
Causes or Risk factors
: Hereditary, family history, nerve damage caused by inflammation.
Symptoms
: Muscle weakness, spasms, tremors.
Treatment options:
No known cure, assitive devices, steroid treatments.
Drug of Abuse
Alcohol
: Affects the areas of the brain involved in memory formation, decision making, and impulses control. The neurotransimtters that the drugs interferes with is GABA and glutamate
Marijuana
: When marijuana enters the brain, THC mimic anadomine and binds to the cannabinoid receptor, turning off the release of the inhibitory neurotransmitter. When an individual consumes this drug, it slows down movements and allows for relaxation and calmness. It also removes any unneeded short-term memories.
Ecstasy
: Affects the serotonin pathways that are responsible for sleep, mood, perception, and appetite and also interacts with the reward pathway.
Methaphetamine
: When the Meth drug enters the brain, meth mimics dopamine, allowing dopamine transporters to let it in. Meth enters the vesicles, kicking out the dopamine. Dopamine then binds again and again, overstimulating the cell. When an individual consumes this drug, they feel pleasure and exhilaration because it works directly on the brain's reward pathway.
Cocaine
: It concentrates in the reward pathway and also affects part of the brain which controls voluntary movement. When an individual consumes it, they might be unstill or fidgety.
LSD
: When LSD enters the brain, it chemically resembles serotonin, so then it binds onto the serotonin receptors. LSD interacts with particular receptors. When it does this, it can sometimes inhibit them or excite them. When an individual consumes this drug. they may experience feelings of wakefulness and evoke a startle response to unexpected stimuli.
Heroine
: Affects the parts of the brain that are responsible for transmission of pain signals, emotional attachment, and stress response. It produces immediate feelings of sedation and well being to the individual consuming it.