Please enable JavaScript.
Coggle requires JavaScript to display documents.
Daniel Sanchez p.2 06 Nervous - Coggle Diagram
Daniel Sanchez p.2 06 Nervous
Major functions of the nervous system
Sensory input
information from external and internal changes integration
Motor output
processes and interprets input
produces and reponses
major divisions and subdivisions of the nervous system (include all subdivisions of CNS
and PNS)
CNS:
brain and spinal cord of dorsal body cavity
integration and control center -> interprets sensory input and dictates motor output
Spinal cord, midbrain, medulla, pons, cerebellum, diencephalon, and the cerebral hemispheres
PNS
the portion of nervous system outside cns
consist mainly of nerves that extend from brain and spinal cord
Somatic nervous system (SNS): Voluntary somatic motor nerve fibers conduct impulses form cns to skeletal muscle
Automatic nervous system (ANS): involuntary consists of visceral motor berve fibers and regulates smooth muscle , cardiac and glands
Sympathetic and parasympathetic
Tissues (structure & function of neurons and neuroglia)
Neuroglia
Astrocytes : most abundant,versatile, and highly branched of glial cells. Cling to neurons, snypatic endings, and capillaries. support and brace neurons
Microglial cells: Small, ovoid cells with thorny processes that touch and monitor neurons. Migrate toward inured neurons. Can transform to phayocyte microorganisms and neuronal debris
Ependymal Cells: Range is shape from squamous to columnar, may be ciliated, and cilia beat to circulate CSF, line the central cavitities of brain and spinal column
Oligodendrocytes: branched cells, processes wrap CNS nerve fibers, forming insulating myelin sheath
Satellite cells: surround neuron cell bodies in PNS and function similar to astrocytes of CNS
Schwann cells: surround all peripheral nerve fibers and form myelin sheaths in thicker nerve fibers, similar to function as obligodendrocytes, and vital to regeneration of damaged peripheral nerve fibers
Neurons
Nuclei: clusters of neuron cell bodies in PNS
Ganglia : clusters of neuron cell bodies in PNS, CNS contains both neuron cell bodies and their processes, and PNS contains chiefly neuron processes
Tracts: bundles of neuron processes in CNS
Nerves: Bundles of neuron processes in PNS
Axon hillock: shaped area
Nerve fibers: long axons
Axon terminal: distal endings
Terminal: region that secretes neurotransmitters, which are released into extracellular space
Classification of neurons
Sensory: transmit impulses from sensory receptors toward CNS, and almost all are uni polar, cell bodies are located in ganglia in PNS
Motor: carry impulses from CNS to effector, multiploar, and most cell bodies are located in CNS
Interneourons: also called association neurons, lies between motor and sensory neurons, shuttle signals through CNS pathways
Connective Tissue Coverings
Epimysium
covers the entire skeletal muscle
Perimysium
around a fascicle
Endomysium
around single myocyte = muscle
Major parts and functions of the brain
Cerebrum: Your cerebrum interprets sights, sounds and touches. It also regulates emotions, reasoning and learning
Cerebellum: Your cerebellum maintains your balance, posture, coordination and fine motor skills
Brainstem: Your brainstem regulates many automatic body functions
Frontal lobes: The frontal lobes are in the front part of your brain, right behind your forehead. This is the largest lobe and it controls voluntary movement, speech and intellect.
Occipital lobes: These lobes in the back of your brain allow you to notice and interpret visual information. Your occipital lobes control how you process shapes, colors and movement.
Parietal lobes: The parietal lobes are near the center of your brain. They receive and interpret signals from other parts of your brain.
Temporal lobes: These parts of the brain are near your ears on each side of your brain. The temporal lobes are important in being able to recall words or places that you've been.
layers of the brain
Dura mater: The outermost layer lines your entire skull. Parts of the dura mater form folds that separate the right half of your brain from the left.
Arachnoid: The middle layer of the meninges is a thin, fragile layer of tissue that covers your entire brain.
Pia mater: The innermost layer contains blood vessels that run into your brain’s surface.
Thalamus: is a structure residing deep in your cerebrum and above your brainstem. This structure is sometimes referred to as the switchboard of the central nervous system.
Hypothalamus: Your hypothalamus sits below your thalamus. It's important in regulating various hormonal functions, autonomic function, hunger, thirst and sleep.
Neurons: send and receive electric nerve signals
Glial cells help maintain your brain, form myelin and provide nutrition to your brain.
Major parts and functions of the spinal cord
Cervical (neck).
Thoracic (chest).
Lumbar (lower back).
Spinal nerve: The posterior and anterior roots come together to create a spinal nerve. There are 31 pairs of spinal nerves. These control sensation in the body, as well as movement.
White matter: The white matter surrounds the gray matter in the spinal cord and contains cells coated in myelin, which makes nerve transmission occur more quickly.
Gray matter: The gray matter is the dark, butterfly shaped region of the spinal cord made up of nerve cell bodies.
Carrying signals from the brain: The spinal cord receives signals from the brain that control movement and autonomic 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.
Action potential & the Nerve Impulse
Action Potential:
Action Potential: long-distance signals of axons
Depolarization: decrease in membrane potential; inside of membrane becomes less negative than resting membrane potentials and probability of producing impulse increases
Hyperpolarization: increase in membrane potential (away from zero); inside of membrane becomes more negative than resting membrane potential, probability of producing impulse decreases, and principal way neuron send signals meaning of long-distance neural communication
Generating an action potential:
Resting state- all gated NA+ & K+ channels are closed
Depolarization : NA+ channels open
Re-polarization: NA+ channels are inactivating, & K+ channels open
Hyperpolarization: Some K+ channels remain open, & NA+ channels rest
Cranial nerves
l Olfactory Nerves
transmits information regarding a person’s sense of smell to the brain.
ll Optic Nerves
transmits information to the brain regarding a person’s vision.
lll Oculomotor Nevres
helps control muscle movements of the eyes.
lV Trochlear Nerve
also has a role in eye movement.
V Trigeminal Nerves
is the largest cranial nerve and has both motor and sensory functions.
Vi Abducens Nerves
The abducens nerve also helpsTrusted Source control eye movements.
It helps the lateral rectus muscle, one of the extraocular muscles, turn the gaze outward.
Vll Facial Nerves
The facial nerve also has both motor and sensory functions.
The facial nerve is consists ofTrusted Source four nuclei that serve different functions:
movement of muscles that produce facial expression
movement of the lacrimal, submaxillary, and submandibular glands
the sensation of the external ear
the sensation of taste
Vlll Vestibulocohlear Nerves
helpsTrusted Source with a person’s hearing and balance
lX Glossophargngeal Nerves
possesses trusted Source both motor and sensory functions.
X Vagus Nerves
The vagus nerve hasTrusted Source a range of functions, providing motor, sensory, and parasympathetic functions.
The sensory part provides sensation to the outer part of the ear, throat, heart, and abdominal organs. It also plays a role in taste sensation.
The motor part provides movement to the throat and soft palate.
The parasympathetic function regulates heart rhythm and innervates the smooth muscles in the airway, lungs, and gastrointestinal tract.
Xl Accessory Nerves
The accessory nerve provides trusted Source motor function to some muscles in the neck.
Xll Hypoglossal Nerves
nerve is a motor nerve that suppliesTrusted Source the tongue muscles. It originates in the medulla.
Spinal nerves
31 pairs of spinal nerves; all mixed nerves named for point of issue
8 pairs of cervical nerves ( C1-C8 )
12 pairs of thoracic nerves ( T1-T2)
5 pairs of lumbar nerves ( L1-L5)
5 pairs of sacral nerves (S1-S5)
1 pair of tiny coccygeal nerves (C0)
Ventral Roots: contains motor ( efferent) fibers from ventral horn motor neurons that innervate skeletal muscles
Dorsal Roots: contains sensory (afferent) fibers from peripheral receptors root ganglia that conduct impulses from peripheral receptors
Neurotransmitters
Acetylcholine (ACH)
used by many ANS neurons and some CNS neurons
synthesized from acetic acid & choline by enzyme choline
degraded by enzyme acetylcholinesterase (ACHE)
Dopamine
norepinephrine (NE), & epinephrine :made from amino acids
Serotonin
made from amino acid trytophon
Histamine
made from amino acid histidine
Amino Acid
makeup proteins, difficult to prove which are nerotransmitter
Peptides ( neuropeptides)
strings of amino acids that have diverse functions
Endorphins
beta endorphins, dynorphins, & enkephalins : act as natural opinates ; reduce pain perception
Purines
monomers of nucleic acids that have an effect in both CNS & PNS
Compare & contrast the autonomic nervous system
The somatic nervous system has sensory and motor pathways, whereas the autonomic nervous system only has motor pathways.
The autonomic nervous system controls internal organs and glands, while the somatic nervous system controls muscles and movement.
SNS is voluntary
ANS is involuntary
Reflex arc (major parts & functions)
Receptor : site of stimulus action
Sensory Neuron: transmits afferent impulses to CNS
Integration Center : either monosynaptic or polysynaptic region within CNS
4.Motor Neuron: conducts efferent impulses from integration center to effector organ
Effetor : muscle fibers or gland cells that responds to efferent impulses by contracting or secreting
Disorders/Diseases
Cerebrovascular Accident (Stroke)
Description: Occurs when blood flow to a portion of the brain in nailed
Causes or Risk Factors (3): Hereditary, blood vessels clogged burst, and Diabetes
Symptoms: Severe headache, loss or coordination & balance, and confusion/memory
Treatment Options (3): blood thinners, surgery to repair vessels
Autism
Description: Brain disorders that makes it difficult to communicate
Causes or risk factors: family history, hereditary (mostly in males), past medical issues
Symptoms : delay in learning to talk/communicate
Treatment Options: medication, coping skills, and specialized therapy
Alzheimer's disease
Description: a form of dementia associated with age
Causes or risk factors: hereditary 60+, high insulin levels, and past head trauma
Symptoms: memory loss, confusion, difficulty with walking and swallowing
Treatment Options: incurable, medication, and removing behavior triggers
Spinal Cord Injury
Description : damage to spinal cord
Causes or risk factors: direct injury or disease
Symptoms: weakness, pain/numbness, and Paralysis
Treatment Option: Meds to reduce swelling, surgery, bed rest
Meningitis
Description: infection in meningitis is surrounding the brain
Causes or risk factors: Bacteria, drug allergies, and tumors
Symptoms: Nausea and vomiting, fevers and chills, and stiff neck
Treatment Options: medication and vaccine
Multiple Sclerosis
Description: Autoimmune disease that damages the myelin sheath
Causes or risk factors: hereditary, nerve damage caused by inflammation
Symptoms: muscle weakness, tremors and spasms
Treatment Options: no known cure, medications to slow disease progress
Drugs of abuse (Mouse Party)
Heroine
Neurotransmitter: inhibit dopamine from being released
Body's natural opiates activate opiate receptors. Release of inhibitory neurotransmitters is shut down. Without inhibition, dopamine can be released
Heroin mimics natural opiates & binds to opiate receptors, turning off dopamine inhibition dopamine is allowed to flood synapse. producing immediate feelings of sedation of well being
Ecstasy
Serotonin transporters are responsible to removing serotonin molecules from the synaptic cleft after they have done their job
Ecstasy mimics serotonin & is taken up by serotonin transporters. In fact, ecstasy is more readily taken up than serotonin itself
This interaction with ecstasy alters the transporters become temporarily confused and start to do its job in reverse transporters start transporting serotonin out of cell
Marijuana
Before marijuana enters the system, inhibitory neurotransmitters are active in synapse. These neurotransmitters inhibit dopamine from being released
When activated by the body's own naive cannabinoid. Cannabinoid receptors turn off release of inhibitory neurotransmitters. Without inhibition, dopamine can be released.
RHC, activate chemical in marijuana, mimics around amide & bindss to cannabinoid receptors. Inhibition is turned off & dopamine is allowed to squirt into the synapse.
Methamphetamine
Dopamine transporters are responsible for removing dopamine from synaptic cleft. Because meth mimics dopamine, it is taken into the cell by dopamine transporters
Once inside the cell, meth enters the dopamine vesicles forcing the dopamine molecules out
The excess dopamine in the cell causes the transporters to short working in reverse, activating pumping dopamine out of cell and into synaptic
Alcohol
Inhibitory neurotransmitters, called GAB, are active throughout the brain. Neurotransmitters out to control neural activity along many brain pathways, when GABA binds to its receptors, cels less likely to fire
When alcohol enters the brain it delivers a double sedative punch. First, it interacts with GABA receptors to make them ever more inhibitory
alcohol particularly affect area of the brain involved in memory formation, decision making and impulse control
Cocaine
Dopamine, transporters are responsible for removing dopamine molecules from synaptic cleft after they have done their job
cocaine blocks these transporters, leaving dopamine trapped in the synaptic cleft. As a result dopamine binds again and again to the receptors overstimulating the cell
cocaine concentrates in reward pathways. however, it also active in part of brain controlling voluntary movements. This is way cocaine abusers are fidgety and unable to be still
LSD
LSD acts almost exclusively on serotonin neurons. LSD chemically resembles serotonin and elicits its effect by binding to serotonin receptors
There are several types of serotonin receptors in the brain. Each is responsible for performing specific functions
LSD interacts, with particular receptors, but not always in the same ways sometimes LSD many inhibits them. This is 1 reason why LSD has complex sensory effects