What is the functions of the Nervous System?
- Sensory input-gether info
- Integration-takes input and tells you what it means
- Motor output-response to input by activating effector organs(muscles and glands)
What is in the Central Nervous System (CNS) and the function?
Consist of brain and spinal cord, and functions as the command center for the nervous system. It interpets input and dictates a response.
What is in the Peripheral Nervous System (PNS) and the function?
Consist of nerves that extend from the brain and spinal cord. It's function is to carry nerve impulses from the the brain and spinal cord to the rest of the body.( Connects the body to the CNS)
What is the Sensory or afferent division?
Takes input from the skin, skeletal muscles and joints called somatic afferent fibers and takes input from visceral organs called visceral afferent fibers.
What is the Motor or efferent division?
Transmits impulses from CNS to effector organs(muscles, glands), make a motor response.
What are 2 motor division and what do they do?
- Somatic nervous system-impulses from CNS to skeletal system (voluntary)
- Autonomic nervous system (ANS)-regulate activity of smooth muscles, cardiac muscles, and glands (involuntary).
What are the2 subdivisions of the ANS and what do they do?
- Sympathetic division-mobilizes the body systems during activity (fight or flight)
- Parasympathetic division-conserve energy, promotes housekeeping functions during rest
What are the 6 Neuroglia and their functions?
- ependymal cells
- Satellite cells
- Schwann cells
What do astrocytes do?
They have a role in exchanges between capillaries and neurons, dertermine permeability of capillaies, in guiding young neurons, and synapse formation.
What do microgilia do?
They have a protective role because the immune system has no part of the CNS.
What do ependymal cells do?
They have cilia that helps to circulate CSF to cushion the brain and spinal cord.
What do oligodendrocytes do?
They insulate the fibers with myelin sheaths.
What do Satellite cells do?
They make exchanges between capillaries and neurons, determine permeablity of capillaries, guide young neurons, and synapse formation.(same as astrocytes)
What do Schwann cells do?
They surround and form myelin sheaths around larger nerve fibers in the PNS.
What is the difference between a nerve, nerve fiber, and a neuron?
A nerve is an organ that has blood tissue, axons, and blood tissue. A nerve fiber is 1 axon and is as long as the nerve is. A neuron is a nerve cell.
What are the 3 kinds of neurons based on function?
What are the 3 kinds of nrurons based on structure?
What direction to signal go in a nerve and a neuron?
- Nerve-both ways
- Neuron-one way
Difference between nerve damage and neuron death?
Nerve damage is damage to the axon. Neuron death is destruction of cell body.
What is the difference between gray and white matter?
- Gray matter is unmyelinated, is on the surface of the brain, and is for processing (thinking), impulses are rapid.
- White matter is myelinated, move signals from point A to B, and is inside the brain.
What is the difference between gated ion channels on dendrites and those on axons?
Dendries are chemically gated, and axons are voltage gated
Why can we react to a pain reflex before we actually feel pain?
processes in your gray matter are rapid
What are the 3 functions and structural types of neurons?
- Bipolar-special sence organs
- Multipolar-integration and motor
What are neurofibrils?
Bundles of intermediate filaments in maintaining cell shape and integrity throughout the cell body.
What are tarcts?
Tracts are bundles of neurons in the CNS
What are bundles of neurons called in the PNS?
What are dendrites?
branching neuron process that carries impulse to the cell body
What are axons?
carries impulses away from the nerve cell body
What is a nerve fiber?
What is the function of the axon?
To conduct impulses and tramsmit them typically away from the cell body along the plasma membrane or axolemma.
What happen when the impulse reaches the axon terminal?
It causes neurotransmitters, signaling chemically stored in vesicles to be released into the extracellular space.
An axon containts the same organelles as dendrites and cell body except what?
Nissl bodies and golgi apparatus, the structure involved with protein synthesis and packaging.
What is anterograde movement?
Movement toward the axon terminal
What is retrogade movement?
movement away from the axon terminal
In dealing with neuron regions what do each do?
- receptive region-input
- conduction region-action
- secretory region-output
What is voltage?
measure of potential energy by seperated charges, difference in charges
What is a current?
flow of ions
What is resistance?
something that blocks the flow of ions
What are laekage or nongated channels?
Channels that are alway open
What are gated channels?
protiens that form a molecular gate that changes shape to open and close the channel in response to a specific signal
What are voltage gated channels?
open and close in response to the membrane potential
What is a chemmically gated channel?
open when the appropriate chemical (neurotransmitter) binds to the channel
What is mechanically gated channel and give an example?
opens in response to physical deformation of the receptor such as in a touch or pressure. Example: skin
What is the electrochemical gradient?
Flow of ions from a high to low concentration or toward the opposite charge.
What is the voltage of a resting membrane potential of a neuron?
Resting membrane potential
K+ flows out of the cell and Na+ trickles in the cell. The sodium-potassium pump first ejects 3 Na from the cell and transports 2 K+ back into the cell.
What is depolarization?
reduction in membrane potential: the inside of the cell becomes less negative (moves closer to zero)
What is hyperpolarization?
occurs when the membrane potential increases becoming more negative
What is the voltage of a action potential?
At resting no ions move through voltage gated channels. Depolarization is caused by Na flowing into the cell. Repolarization is caused by K+ flowing out of the cell. Hyperpolarization is caused by K+ continuing to leave the cell.
What is threshold?
Whan depolarization at the stimulation site reaches a certain critical level.
What is the voltage of threshold?
between -55 and -50 mV
What is the absolute refractory period?
From the opening of Na channels until the Na channels begin to resetto original resting state
What is relative refractory period?
Follows the absolute refactory period, when Na channels are at rest, some K+ channels are still open and repolarization is occuring.
What are ventricles?
They are hollow filled with CSF and lined with ependymal cells.
What do the lateral ventricles do?
They are C-shaped chambers that reflact the pattern of cerebral growth.
What is the subarachnoid space?
Fluid filled space surrounding the brain
Elevated ridges on the brain surface are called what?
Shallow groove on the brain's surface are called what?
What does the longitudinal fissure do?
It seperates the hemispheres of the brain into left and right sides
What is the transderse cerebral fissure?
It seperates the cerebral hemisphere from the cerebellum
What are the 5 lobes of the brain?
What is called the "executive suite" and why?
cerebral cortex because it is where our conscious mind is found
What are the 3 functions of the cerebral cortex?
- motor area
- sensory area
- association area
The primary (somatic) motor cortex is in the frontal lobe, what does it do?
It allows us to control the voluntary movements of our skeletal muscles.
What side of the brain controls the right side of the body and what side of the brain controls the left side of the body?
The right side of the brain controls the left side of the body and the left side of the brian controls the right side of the body.
What do the left and right sides of the brain do?
The left side is for logic, and the right side is for creativeness
What does the frontal lobe do?
voluntary skeletal muscle movement, repetitious or patterns like typing or playing an instrument, speech, and voluntary eye movement, memory, judgement
Where in the frontal lobe is broca's area and what is it for?
left hemisphere only and for speech production
What does the parietal lobe do?
sensory receptor in the skin sense the the position of skeletal muscles, joints and tendons, patterns, faces
What is spatial discrimination?
neurons ability to identify the body region being stimulated
What does the occipital lobe do?
It is the primary visual cortex for vision, patterns, faces
What does the temporal lobe do?
- smell (olfactory cortex)
- hear (auditory cortex)
What are the 4 parts of the motor area?
- primary (somatic) motor cortex
- premotor cortex
- broca's area
- frontal eye field
What the 8 sensory area?
- primary somatosensory cortex
- somatosensory association cortex
- visual area
- auditory area(hear)
- olfactory cortex(smell)
- gustatory cortex (tast)
- visceral sensory area
- vestibular cortex(equilbruim)
What are the 3 fibers that help white matter communicate between cerebral areas and between cerebral cortex and lower CNS?
What are commissures?
fibers that connect between the two hemispheres in the grey area allowing the brain to function as a whole.
What are association fibers?
Fibers that connect different parts of the same hemisphere
What are projection fibers?
they enter the cerebral cortex from lower brain or cord and decend from the cortex to lower areas
What is the larges commissure?
What are basal nuclei?
bundle of nerve cells that recive input from the cerebral cortex
What is in the diencephalon?
What is the function of the thalamus?
relay station for sensory impulses, inputs from the subcortical motor nuclei and cerebellum, and impulses to association cortices from lower centers
What is the function of the hypothalamus?
maintain water balance, eating behavior, gastro activity, body temp, pituitary gland
What is the function of the epithalamus?
secrete hormones from the pineal gland
What are the 3 major regions of the brain stem?
- medulla oblongata
What does the midbrain do?
contain visual and auditory reflex centers, involved in pain suppression
What do pons do?
What do medulla oblongata do?
regulate repiratory rhythm, heart rate, blood pressure, coughing, sneezing, swallowing, vomiting
What does the cerebellum do?
processes and interupts impulses from motor and sensory area to make a smooth, well timed movement occur
What are some high mental functions of the brain?
- sleep and wake cycles
What protection does the brain have?
- blood-brain barrier
What are menings?
Menings are connective tissue that cover and protect the brain
What consist of menings?
- dura mater
- arachnoid mater
- pia mater
What is dura mater?
sheet of fiberous tissue that hold the brain to the skull
What does CSF do?
it supports and cushions the brain and cord and nurish them
What does the blood-brain barrier do?
It is a protective mechanism that helps maintain a stable envirnoment for the brain like allow water, respiratory gases, nutrients, and fatty soluble molecules to enter nural tissue and prevents water soluble, potentially harmful substances out.
What are some types of head trama?
What is a cerebrovascular accident(CVA)?
A sroke that results when blood circulation to brain is impaired and brain tissue dies.
What can a CVA a cause as a result?
- sensory deficits
- speech impairment
What is Alzheimer's disease?
It is a degenerative disease in which amyloid peptides and neurofibrillary tangle.
What can happen as a result from having Alzheimer's disease?
slow to loss of memory, loss of motor control and dementia
What is Parkinson's and Huntington's disease?
They are a neurodegenerativw disorder of the basal nuclei that invole a neurotransmitter dopamine(to much or to little)
What can happen because of having Parkinson or Huntington's disease?
Can cause abnormal movements