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Giselle Rojas Period 3 Nervous System - Coggle Diagram
Giselle Rojas Period 3 Nervous System
MAJOR FUNCTIONS OF THE NERVOUS SYSTEM
MAJOR ASPECTS: sensory input, integration, and processing (decision making), and motor output (response)
MAJOR FUNCTIONS: thinking, movement, internal process of physiology
SENSORY FUNCTION: provided by sensory receptors, which detect internal or external changes
Information travels from receptors to sensory neurons, which transport information into the CNS
INTEGRATIVE FUNCTION: coordination of sensory information in the CNS
processing of this information is the basics for decision making
MOTOR FUNCTION: nerve impulses (CNS) are conducted along motor neurons to effectors
effectors are muscles or glands that respond to decisions made in the CNS
DISORDERS/DISEASES
CEREBROVASCULAR ACCIDENT (stroke)
occurs when blood flows to a portion of the brain is halted
AUTISM
brain disorder that makes it difficult to communicate
ALZHEIMERS DISEASE
a form of dementia associated with age
SPINAL CORD INQUIRY
damage to the spinal cord
MENINGITIS
infection in the meninges surrounding the brain
MULTIPLE SCLEROSIS
autoimmune disease that damages the myelin sheath
DRUGS OF ABUSE
HEROINE
NEUROTRANSMITTER IT INTERFERES: dopamine/inhibitory
responsible for the transmission of pain signals, stress response, and emotional attachment
ECSTASY
NEUROTRANSMITTER IT INTERFERES: serotonin
responsible for mood, sleep, perception, and appetite
MARIJUANA
NEUROTRANSMITTER IT INTERFERES: dopamine/inhibitory
removes unnecessary short term memories, slows down movement, making people feel relaxed and calm
METHAMPHETAMINE
NEUROTRANSMITTER IT INTERFERES: dopamine
is highly addictive because it works directly on the brains reward pathway, making the user feel intense pleasure and exhilaration
ALCOHOL
NEUROTRANSMITTER IT INTERFERES: GABA inhibitory
affects areas of the brain involved in memory formation, decision making and impulse control
COCAINE
3 more items...
MAJOR DIVISIONS/SUBDIVISIONS
CENTRAL NERVOUS SYSTEM (CNS)
Made up of the brain and spinal cord
responsible for integration of information and decision-making
PERIPHERAL NERVOUS SYSTEM (PNS)
made up of cranial and spinal nerves that connect the CNS to the rest of the body
contains sensory afferent and motor efferent divisions
MOTOR FUNCTIONS
SOMATIC NERVOUS SYSTEM: controls voluntary skeletal muscles
AUTONOMIC NERVOUS SYSTEM: controls involuntary effectors (smooth and cardiac muscles and glands)
TISSUES
NEURONS: cells that communicate, via electrical impulses, with other neurons or other tissues
NEUROGLIA: cells that support, nourish, protect, and insulate neurons
NEURON (nerve cell) STRUCTURE
a neuron contains a cell body, tubular cytoplasm-filled dendrites, and a tubular, cytoplasm-filled axon
The cell body (soma) contains major organelles including nucleus
dendrites conduct impulses toward the cell body; they are short and branching, and they provide the receptive surface for communication with other neurons
the axon conducts impulses away from the cell body; it arises from a thickening extending from the cell body, called the axon hillock
CLASSIFICATION OF NEURONS
SENSORY (afferent) NEURONS: conduct impulses from peripheral receptors to the CNS; usually unipolar, although some are bipolar
INTERNEURONS (association or internuncial neurons): multipolar neurons lying within the CNS that form links between other neurons; the cell bodies of some interneurons aggregate in specialized masses called nuclei
MOTOR (efferent) NEURONS: multipolar neurons that conduct impulses from the CNS to peripheral effectors (muscles or glands)
NEUROGLIA
FUNCTIONS: fill spaces, structurally support, protect, and insulate neurons
do not generate or conduct nerve impulses
4 types in CNS, 2 types in PNS
AUTONOMIC NERVOUS SYSTEM
portion of the PNS that functions constantly and independently, without conscious effort
controls visceral motor functions of smooth muscle, cardiac muscle, and glands.
helps maintain homeostasis , responds to emotional stress, and prepares the body for strenous activity
controls heart rate, blood pressure, breathing rate, body temperature
CHARACTERISTICS
autonomic activities are regulated by reflexes that have sensory receptors in the viscera and skin
impulses are conducted to the brain or spinal cord; then motor impulses travel through cranial and spinal nerves, then through ganglia, and finally to effectors (muscles or glands)
2 divisions of the ANS, which exert opposing effects on target organs in many cases
SYMPATHETIC DIVISION: active in conditions of stress or emergency (fight or flight)
PARASYMPATHETIC DIVISION: active under normal, restful conditions (rest and digest)
CONNECTIVE TISSUE COVERINGS
EPINEURIUM: outer covering of a nerve
PERINEURIUM: covering around fasicles (bundles) of nerve fibers
ENDONEURIUM: covering around individual nerve fibers (axon)
CRANIAL NERVES
OLFACTORY
sensory
conducts impulses associated with the sense of smell
OPTIC
sensory
conduct impulses associated with the sense of vision
OCULOMOTOR
primarily motor
conduct impulses to muscles that raise eyelids, move eyes, adjust the amount pf light entering the eyes, and focus lenses
TROCHLEAR
primarily motor
motor fibers conduct impulses to muscles that move eyes
TRIGEMINAL
mixed
OPHTHALMIC DIVISION
conduct impulses from the surface of the eyes, tear glands, scalp, forehead, and upper eyelids
MAJOR PARTS AND FUNCTIONS OF THE BRAIN
4 MAIN PARTS OF THE BRAIN
CEREBRUM: largest portion; associated with higher mental functions, and sensory and motor functions
DIENCEPHALON: processes sensory input and controls many homeostatic processes
CEREBELLUM: coordinates muscular activity
BRAINSTEM: coordinates and regulates visceral activities, and connects different parts of the nervous system
STRUCTURES (cerebrum)
consists of 2 cerebral hemispheres, which are mirror images
CORPUS CALLOSUM: flat bundle of nerve fibers that connects the hemispheres
GYRI (singular is gyrus): ridges
SULCI (singular is sulcus): grooves
FISSURES (longitudinal and transverse): deep grooves
STRUCTURES (diencephalon)
the diencephalon lies between the cerebral hemispheres and above the midbrain
surrounds the third ventricle
main parts are the thalamus and hypothalamus
STRUCTURES (cerebellum)
located beneath the occipital lobes of the cerebrum posterior to the brainstem
made up of 2 hemispheres connected by the vermis
a thin layer of gray matter called the cerebellar cortex, lies outside a core of white matter called the arbor vitae
MAJOR PARTS AND FUNCTIONS OF THE SPINAL CORD
SPINAL CORD
begins at the base of the brain
CERVICAL ENLARGEMENT
a thickened area near top of spinal cord
provides nerves to upper limbs
LUMBAR ENLARGEMENT
a thickened region near the bottom of the spinal cord
gives rise to nerves that serve the lower limbs
STRUCTURE OF SPINAL CORD
consists of 31 segments, each of which connects to a pair of spinal nerves
white matter, made up of bundles of myelinated nerve fibers (nerve tracts), surrounds a butterfly-shaped core of gray matter housing interneurons and neuron cell bodies
cell bodies of sensory neurons that enter the spinal cord are found in the dorsal root ganglia outside the spinal cord
FUNCTIONS OF SPINAL CORD
transmit impulses to and from the brain, and to house spinal reflexes
ascending tracts carry sensory information to the brain; descending tracts carry motor information from the brain to muscles or glands
SPINAL REFLEXES: controlled by reflex arcs that pass through the spinal cord
NEUROTRANSMITTERS
ACETYLCHOLINE
LOCATION: CNS, PNS
CNS: controls skeletal muscle actions
PNS: stimulates skeletal muscle contraction at neuromuscular junctions; may excite/inhibit autonomic nervous system actions, depending on receptors
NOREPINEPHRINE
LOCATION: CNS, PNS
CNS: creates a sense of feeling good; low levels may lead to depression
PNS: may excite or inhibit autonomic nervous system actions, depending on receptors
DOPAMINE
LOCATION: CNS, PNS
CNS: creates a sense of feeling good; deficiency in some brain areas associated with parkinson disease
PNS: limited actions in autonomic nervous system; may excite or inhibit, depending on receptors
SEROTONIN
LOCATION: CNS
CNS: primarily inhibitory; leads to sleepiness, action is blocked by I.S.D
HISTAMINE
LOCATION: CNS
CNS: release in hypothalamus, promotes alertnesss
SPINAL NERVES
31 pairs of spinal nerves
grouped according to the level from which they arise
NUMBERED IN SEQUENCE
8 pairs of cervical nerves
12 pairs of thoracic nerves
5 pairs of lumbar nerves
5 pairs and sacral nerves
1 pair of coccygeal nerves
a ventral root and dorsal root unite to form a spinal nerve, which extends out of the vertebral canal though the inter-vertebral foramen
each dorsal root contains a dorsal root ganglion, which houses the cell bodies of sensory neurons entering the spinal cord