PCAT Neuroscience

includes all the neural tissues in the body
supports blood vessels and connective tissue
includes brain, spinal cord and complex organs like the eye and the ear
where organisms receive and respond to stimuli

converts stimuli into electrochemical signals that are conducted through the nervous systems

cytoplasmic extensions that receive information and transmit toward cell body

contains the nucleus and controls the metabolic activity of the neuron

transmits impulses away from the cell body

Produced by glial cells
insulating sheath substance that allows axons to conduct impuses faster

produce myelin in the central nervous system and structural framework

produce myelin in the peripheral nervous system

maintain the integrity of the blood brain barrier, regulate nutrient and dissolved gas concentrations, and absorb and recycle neurotransmitters.

remove cellular debris and pathogens

line the brain ventricles and aid in the production, circulation, and monitoring of cerebral spinal fluid

surrounds the neuron cell bodies of the ganglia

immediate precursor to dopamine\
tryrosine is converted to DOPA with hydroxylatoin which undergoes decarboxylation to become dopamine

in the adrenal medulla through process of methylation

travel the length of the axon and invade the nerve terminals, causing a release of the neurotransmitter

potential difference (polarized) results in an unequal distribution of ions between the inside and outside of the cell (-70mV)

will transfer bidirectionally, information transfer will occur in one direction from dendrite to synaptic terminal, but refractory period prevent from backward travel of action potential

where ions are permeable in axon in PNS

gap between the axon terminal and the neuron called the pre-synaptic neuron before it synapse and the dendrites of another neuron are the post-synaptic neuron

diffuses across the synapse and acts on receptor proteins embedded in the post-synaptic membrane
lead to the depolarization of the post synaptic cell and consequent firing of an action potential
removed by taken up into a nerve terminal by a protein uptake carrier

inactivated by acetlycholinesterase
cause calcium channels to open

blocks post-synaptic acetulcholine receptors
leads to paralysis

prevent the release of acetylcholine from the presynaptic membrane
results in paralysis

nerve gases an din the insecticide Parathion
inhibits activity of acetylcholinesterase enzyme
no coordinated muscular contractions take place

no organized nervous system
may respond to touch, heat, light, and chemicals

simple nervous system called nerve net
limited centralization

earthworms
primitive central nervous system consisting of ventral nerve cord and an anterior "brain" of fused ganglia
nerve pathways lead from receptors to effectors

brains are similar to those of annelids but more specialized sends organs are present (eyes, and tympanum (ears))

sensory information about the external or internal environment to the brain or spinal cord

carry motor commands from the brain or spinal cord to various parts of the body (muscles, glands)

linking sensory and motor neurons in the brain and spinal cord

bundles of axons covered by connective tissue (plexus)

mass of neurons that resides in the skull
interprets sensory information forming motor plans and cognitive function
white matter (myelinated axons)
gray matter (cell bodies)

the forebrain consists of the telencephalon and the diencephalon

the cerebral cortex
highly convulted gray matter
processes and integrates sensory input and morto responses and is important for memory and creative thought

center for reception and integration of olfactory input

contains the thalamus and hypothalmus

relay and integration center for the spinal cord and cerebral cortex

controls visceral functions like hunger, thirst, sex drive, water balance, blood pressure and temperature regulation
has important role in endocrine system

the midbrain
the relay center for visual and auditory impuses
important for motor control

hindbrain and poserior part of the brain and consists of the cerebellum, the pons, and the medulla

helps to modulate motor impulses initiated by the cerebral cortex
maintenance of balance, hand-eye coordination and timing of rapid movements

act as a relay center to allow teh cortex to communicate with the cerrebellum

controls many vital functions like breathing, heart rate, and gastronintestinal acivity

midbrain, pons, and medulla constitute the brainstem

elongated extension of the brain which acts as the conduit for sensory information to the brain and motor information from the brain
integrates reflexes by itself
outer white matter
inner gray matter

where sensory information enters the spinal cord
cell bodies are contained at the dorsal root ganglia

where all motor information exists in the spinal cord

consists of nerves and ganglia
sensory nerves inter the CNS and motor nerves leave the CNS as part of the it
Somatic and Autonomic primary divisions each has both motor and sensory components

innervates skeletal muscles and is responsible for voluntary movement

it regulates the body's internal environment with out the aid of conscious control
includes both sensory and motor fibers
innervates cardiac and smooth muscle
comprised of sympathetic and parasympathetic nervous system

responsible for "fight or flight"
increases blood pressure and heart rate

acts to conserve energy and restore the body to resting activity levels after exertion "rest and digest"
lower heart rate and increase gut motility

innervates many of the thoracic and abdomina viscera
uses acetylcholine as its primary neurotransmitter

detects light energy (photons) and transmits information about intensity, color,and shape to the brain

white of the eye
thick opaque layer

beneath the sclera, helps suppy the retina with blood
dark pigmented area that reduces reflection in the eye

contains photoreceptors that sense light

bends and focuses light rays

where rays travel while diameter is controlled by the pigmented and muscular iris

responds to the intensity of light in the surroundings

suspended behind the pupil
shape and focal length of which is controlled by the ciliary muscles which focus the image onto the retina

transduce light into action potentials
two types cones and rods

respond to high-intensity illumination as are sensitive to color

detect low-intensity illumination and are important for night vision
pigment=rhodopsin absorbs a single wavelength

where photoreceptor cells synapse

where its axons bundle to form optic nerves which conduct visual information to the brain
photoreceptors not present in blind spot

in the retina wehre densely packed with cones
important for high acuity vision

helps maintain eye shape and optical properties

formed by the eye and exits through ducts to join the venous blood

nearsightedness
image is focused in front of the retina

farsightedness
image is focuses behind the retina

cause by an irregularly shaped cornea

lens become opaque, light cannot enter the eye, and blindness results

increase of pressure in the eye because of blocking of the outflow of aqueous humor