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Karlie Casillas P.5 Nervous - Coggle Diagram
Karlie Casillas P.5 Nervous
Major functions of the nervous system
Send messages from various parts of your body to your brain, and from your brain back out to your body to tell your body what to do
Reception of general sensory info (touch, pressure, temperature, pain and vibration
Receiving and perceiving special sensations (taste, smell, vision, sounds
Response generation
Major divisions and subdivisions of the nervous system
Divisions of Autonomic nervous system
Parasympathetic division
: promotes maintenance functions, conserves energy
Sympathetic division
: mobilizes body during activity
Role of Parasympathetic division
: keeps body energy use as low as possible
Directs digestion
"rest and digest" system
Role of the Sympathetic Division
mobilizes body during activity
"fight or flight" system
Tissues (structure and function of neurons and neuroglia)
Neuroglia function to support, project, and nourish neurons.
The main parts of a neuron include the cell body, dendrites and axon
The cell body contains the nucleus
They help in transmitting the nerve impulse
Neuroglia are the supporting cells and neurons are like the communication network of the body where as neuroglia facilitates the functioning of the communications network.
Classification of neurons
Senrosy, motor and interneurons
Sensory Neurons
: nerve cells that are activated by sensory input from the environment
Motor Neurons:
cells in the brain and spinal cord that allow us to move, speak, swallow and breathe by sending commands from the brain to the muscles that carry out these functions.
Interneurons
: a type of neuron that are located between sensory and motor neurons
Connective Tissue Coverings
The epineurium
is the outermost layer of connective tissue layer that encloses the whole nerve and help in its protection.
The perineurium
is the connective tissue sheath that surrounds several primary fascicles. The perineurium protects the endoneurial tubes and provides resistance to external forces.
The Endoneurium
is the intrafascicular connective tissue, it plays and important role in fluid pressure
Major parts and functions of the brain
Major parts
: Cerebum, cerebellum, brain stem
4 lobes
: frontal, parietal, Temporal and occipital
Functional areas:
motor areas, sensory areas and association areas
Brain is needed to survive
It performs
higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning
and fine control of movement
Major parts and functions of the spinal cord
Protected by bone, meninges and CSF
Function: provides two-way communication to and from brain and body
-Major reflect center: reflexes are initiated and completed at spinal cord
Spinal nerves attach to spinal cord by 31 paired roots
Ventral (anterior) median fissure
Dorsal (posterior) median sulcus
Action potential and the Nerve Impulse
An action potential also called a nerve impulse is an electrical charge that travels along the membrane if a neuron
Cranial Nerves
There are 12 Cranial nerves
1)Olfactory Nerves - smell
2) Optic - vision
3)Oculomotor nerve- raise eyelids, pupillary contristction, change lens shape
4) Trochlear nerve- primariy motor nerve that directs eyeball
5)Trigimenal nerve- largest Cranial nerve (chewing)
6) Abducens - primary motor nerve innervating lateral rectus muscle (eyeball)
7) Facial nerve- chief motor nerves of face for facial expression (taste)
8)Vestibulochlear - hearing and balance
9) Glossopharyngeal - motor: depress tongue, and pharnx for swallowing , conduct taste
10) Vagus nerve- only Cranial nerve to extend beyond head and neck;motor fibers help regulate activities of heart, lungs and abdominal viscera
11) Accessory nerve- formed from C1-C5 of spinal cord; innervates trapezius and sternocleidmastoid
12) Hypoglossal nerve - innervates muscles of tongue (swallowing & speech
Spinal nerves
31 pairs
8
pairs of cervical nerves (C1-C8)
12
pairs of thoracic nerves (T1-T12)
5
pairs of lumbar nerves (L1-L5)
5
pairs of sacral nerves (S1-S5)
1
pair of tiny coccygeal nerves (C0)
Ventral roots
- contain motor(efferent) fibers from ventral horn motor neurons that innervate skeletal muscles
Dorsal roots
- contain sensory (afferent) fibers from sensory neurons in Dorsal root ganglia that conduct impulses from peripheral receptors
Neurotransmitters
Major neurotransmitters of ANS are acetylcholine (ACh) and norepinephrine (NE)
ACh
is released by
cholinergic
fibers at- all ANS preganglionic axons and all parasympathetic postganglionic axons
NE
is released at
adrgenic
fibers at - almost all Sympathetic postganglionic axons
Effects of neurotransmitter depends on whether it binds to
cholinergic receptor
or
adrenergic receptor
Compare and contrast the autonomic nervous system
Autonomic nervous system:
(ANS) consists of motor neurons that innervate smooth muscles, cardiac muscle and glands
Also called involuntary nervous system
Somatic Nervous system:
innervates skeletal muscle
They differ in
effectors
and
efferent pathways
and ganglia
SNS
: cell body in CNS and a single thick myelinated group A axon extends in spinal cord or Cranial nerves directly to skeletal muscle
ANS
: pathway uses a two-neruon chain
-They both have higher brain centers that regulate and coordinate both systems
Most spinal and many Cranial nerves contain both somatic and autonomic fibers
Reflex arc (major parts and functions
1. Receptor :
site of stimulus action
2. Sensory neuron
: transmits afferent impulses to CNS
3. Integration center:
either monosynaptic or polysynaptic region within CNS
4. Motor neuron
: conducts efferent impulses from integration center to effector organ
5. Effector:
muscle fiber or gland cell that response to efferent impulses by contracting or secreting
Somatic reflexes
- activate skeletal muscle
Autonomic (visceral ) reflexes
- activatevisceral effectors (smooth or cardiac muscle or glands)
Disorders/diseases
Cerebral palsy:
neuromuscular disability involving poorly controlled or paralyzed voluntary muscles
Anencephaly
: cerebrum and parts of brain stem never develop because neural fold fails to fuse
Spina bifida
: incomplete formation of vertebral arches
Autonomic neuropathy:
damage to autonomic nerves that ois a common complication of diabetes mellitus
Drugs of abuse (mouse arty)
Heroine: turns off dopamine inhibition, and dopamine floods synapse
Ecstasy: mimics serotonin, and is taken up by serotonin transporters
Marijuana : THC mimics anadamide and binds to cannabinoid receptors
Methamphetamine: meth enters the dopamine vesicles forcing the dopamine molecules out
Alcohol: delivers a sedative touch, and binds to glutamate receptors preventing it from exciting
Cocaine: cocaine blocks transporters and overstimulates the cell
LSD: interacts with particular receptors, not in same way