Isaiah Castro, Period 1
Nervous
Major Functions of the Nerous System
Major divisions and Subdivisions of the Nervous System
Tissues
Classification of Neurons
Connective Tissue Coverings
Major parts and functions of the Brain
Major parts and functions of the Spinal Cord
Action potential and the Nerve impulse
12 Cranial Nerves
Spinal Nerves
Neurotransmitters
ANS vs SNS
Reflex Arc
Disorders associated with Nervous System
Drugs
The nervous system is the master system of the body, it has cells that communicate through electrical and chemical signals with rapid specific and immediate responses.
SENSORY INPUT: info gathered by receptors by external and internal changes.
INTEGRATION: processing and interpreting of sensory input.
MOTOR OUTPUT: activation of effector organs as a response to stimuli.
Neurons: excitable cells that transmit electrical signals.
Neuroglia: small cells that surround and wrap delicate neurons.
Central Nervous System
Control center
Peripheral Nervous System
Nerves that extend from brain and spinal cord.
Sensory (afferent) Divison
Motor (efferent) Division
SOMATIC SENSORY FIBERS: Conveys impulses from skin, skeletal muscles, and joints to CNS
VISCERAL SENSORY FIBERS: Conveys impulses from visceral organs to CNS.
Transmits impulses from CNS to effector organs
SOMATIC NERVOUS SYSTEM: Somatic motor nerve fibers send impulses from CNS to skeletal muscle.
AUTONOMIC NERVOUS SYSTEM: regulates smooth muscle, cardiac muscle and glands.
Autonomic Nervous System:
-SYMPATHETIC NERVOUS SYSTEM: Controls active functions
-PARASYMPATHETIC NERVOUS SYSTEM: Calms the body, conserving its energy.
Neuroglia:
-ASTROCYTES: Cling to neurons, synaptic endings, and capillaries; support & brace neurons.
-MICROGLIAL CELLS: Small, ovoid cells with thorny processes that touch and monitor neurons.
-EPENDYMAL CELLS: Range in shape from squamous to columnar; line the central cavities of the brain and spinal column.
-OLIOGODENDROCYTES: Branched cells; forming insulating myelin sheaths in thicker nerve fibers
Structural Classification:
-MULTIPOLAR: Three or more processes (1 axon w/dendrites).
-BIPOLAR: Two or more processes (1 axon, 1 dendrite).
-UNIPOLAR: 1 T-like process (2 axons).
Functional Classification:
-SENSORY: impulses from sensory receptors toward CNS in PNS.
-MOTOR: impulses from CNS to effectors in CNS.
-INTERNEURONS: lie between motor and sensory neurons.
ENDONEURIUM: Loose connective tissue encloses axons and their myelin sheaths.
PERINEURIUM: Coarse connective tissue bundles fibers into fascicles.
EPINEURIUM: Tough sheaths around all fascicles to form nerve.
CEREBRAL HEMISPHERES, DIENCEPHALON, BRAIN STEM, and CEREBELLUM.
-GRYI: Ridges.
-SULCI: Shallow grooves.
-FISSURES: Deep grooves.
Diencephalon:
-THALAMUS: Relay station for information coming to cortex.
-HYPOTHALAMUS: Forms cap over brain stem.
-EPITHALAMUS: Dorsal portion of diencephalon.
5 Lobes
-FRONTAL: Expresses language and voluntary movement.
-PARIETAL: Processes somatosensory information from the body.
-TEMPORAL: Processes auditory information and encodes memory.
-OCCIPITAL: Visual perception, including color, form, and movement.
Midbrain: Motor movement, particularly movements of the eye, auditory and visual processing.
Pons: The respiratory rhythm of breathing.
Medulla Oblongata: Transmits signals between the spinal cord and the higher.
Functions of the Brain:
-Limbic Formation: Structures the medial aspect of cerebral hemisphere.
-Reticular Formation: Through central core of the brain stem.
Meninges:
-DURA MATER: Strongest outer most layer.
-ARACHNOID MATER: Spiderweb like extensions and second layer.
-PIA MATER: Delicate tissue that clings to brain, inner most layer.
Gray commissure: Bridge of gray matter.
Cuada equina: Collection of nerve roots.
Denticulate ligaments: Cervical and lumbar enlargement.
Spinal Cord Cross Section:
-Ventral Horns: Somatic neurons
-Dorsal Horns: Receives sensory input.
-Lateral Horns:Sympathetic neurons
In Gray Matter:
-Ventral Roots: Bundle of motor neuron axons.
-Dorsal Roots: Sensory input to cord.
-Dorsal Root Ganglia: Cell bodies of sensory neurons.
1 OLFACTORY NERVES: nerves.
2 OPTIC NERVES: visual function.
3 OCULOMOTOR NERVES: raises eyelid.
4 TROCHLEAR NERVES: directs eyeball.
5 TRIGEMINAL NERVES: three divisions (Opthalmic, Maxillary, and Mandibular).
6 ABDUCENS NERVES: innervating lateral rectus muscle.
7 FACIAL NERVES: sensory.
8 VESTIBULOCOCHLEAR NERVES: auditory.
9 GLOSSOPHARYNGEAL NERVES: conducts taste.
10 VAGUS NERVES: taste buds.
11 ACESSORY NERVES: spinal accessory nerve.
12 HYPOGLOSSAL NERVES: swallowing and speech.
-REFRACTORY PERIODS: Time in which neurons cannot trigger AP
-RESTING STATE: All gates are closed.
-DEPOLARIZATION: Na+ channels open.
-REPOLARIZATION: Na+ channels inactivating and K+ channels open.
-HYPERPOLARIZATION: Some K+ channels remain open and Na+ channels reset.
-All-or-None: AP either happens completely or not at all.
-CONTINOUS CONDUCTION: Slow conduction occurs in nonmyelinated axons.
-SALTATORY CONDUCTION: Only in myelinated axons.
31 Pairs of Spinal Nerves
-8 cervical nerves (C1-C8).
-12 thoracic nerves (T1-T12).
-5 lumbar nerves (L1-L5).
-5 sacral nerves (S1-S5).
-1 coccygeal nerve (C0).
Acetycholine (ACh): released at neuromuscular junction and degraded by enzyme acetcholinesterase (AChE)
Amino Acids: strings of amino acids that have diverse functions.
Peptides: Monomers of nucleic acids that effect both CNS and PNS.
-Opioids: (Morphine, Heroin, Vicodin, Demerol, Odeine, etc.) Can cause a warmth of pleasure with many symptoms and major withdrawls; bad flue, diarrhea and vomiting.
-Inhalents: (Solvents, Aerosol Sprays, Gases) Damages brain causing many symptoms or death.
-MDMA: (3, 4 Methylenedioxy-methamphetamine, Ectasy) Can increase energy and cause feelings of euphoria and can effect the involuntary actions.
-Nicotine: (Cigaretts, E-cigaretts, Cigars, Pipe, Snuff, Chewing Tobacco, Nicotine Gum or Patches) Delivers harmful substances to body resulting in cancer, heart disease, stroke, emphysema, and COPD, the withdrawls include cravings, difficulty concentrating, irritability, and sleep disturbances.
-Psychedelics: (Psilocybin mushrooms, Peyote Cactus; Mescaline, LSD) Causes hallucinations, effecting increased body temp., heart rate, blood pressure, dilated pupils, lose of appetite, nausea, paranoia, panic, and sleeplessness.
-Dissociative Drug: (Ketamine, PCP, Dextromethorphan) can cause detatchment, fever, seizures, coma or death.
ANS:
-EFFECTOR: Innervates cardiac muscles, smooth muscles, and glands.
-TWO PATHWAYS: Preganglionic, and postganglionic
-TARGETS: preganglionic fibers release ACh, postganglionic fibers release norepinephrine or ACh at effectors, effect is either stimulatory or inhibitory, depending on type of receptors.
-Autonomic Neuropathy: Damage to autonomic nerves.
-Multiple Sclerosis: Autoimmune disease that affects primarily young adults, which destroy myelin sheaths in CNS.
-Cerebral Palsy:Poorly controlled or paralyzed voluntary muscles.
-Anencephaly: Undeveloped parts of the brain stem, due to neural folds failing to fuse.
-Spina Bifida: Incomplete formation of vertebral arches; involves lumbosacral region.
-Hypertension: High blood tension.
-Raynaud's Disease: Exaggerated vasoconstriction in fingers and toes.
-Autonomic Dysreflexia: Uncontrolled activation of autonomic neurons in quadriplegics.
-Receptor: Site of stimulus action.
-Sensory Neuron: Transmits afferent impulses to CNS.
-Integration Center: Monosynaptic or polysynaptic region within CNS.
-Motor Neuron: Efferent impulses from integration center to effector organ.
-Effector: Muscle fiber organ gland cell responds to efferent impulses by contracting or secreting.
SNS
-EFFECTOR: Somatic nervous system innervates skeletal muscles.
-TWO PATHWAYS: Cell body in CNS, and a single, thick myelinated group a axon extends in spinal or cranial nerves directly to skeletal muscle.
-TARGETS: All somatic motor neurons release ACh, effect is always stimulatory.
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