Test 4 Flashcards
What are the functions of the nervous system
sensation, integration, and response
Explain the concept of integration
the process of processing information and is carried out by the cns
what is the concept of “All or none”
The strength of a response of a nerve cell is not dependent upon the strength of the stimulus
( -55mV)
how does stimulation of the neuron secrete of neurontransmitter
A neurotransmitter can influence neurons in one of three ways: it can excite, inhibit, or modulate them.
describe the function of the synapse
connects neurons so that information can be transferred
describe the structure of the synapse
there are three different types
Axosomatic -between axon terminals of one neuron and soma
Axodendritic -between axon terminals of one neuron and dendrite of other
Axoaxonal -axon to axon connection (less common)
Describe the development of the brain from the embryonic ectoderm
starts at the neural tube then the forebrain, midbrain, and hindbrain form then the secondary brain vesicles for which the correspond which the adult brain structures
list the major parts of the brain and their functions
Cerebrum - Indicates and coordinates movement and also regulates temperature
Brain stem - houses the mid-brian, pons, and medulla. It connects the cerebrum with the spinal cord
Cerebellum - coordinates voluntary muscle moments and maintains posture, balance, and equilibrium
list the major parts of the spinal cord and their functions
Cervical - control head and neck, diaphragm, and head
Thoracic - control chest and abdominal muscles
Lumbar - control leg muscles
Describe the function of the cerebellum
helps coordinate and regulate a wide range of functions and processes in both your brain and body
sensory imput
The response in a sensory organ (eyes, ears, nose, tongue, and skin) when it receives stimuli
integration
when the nervous system processes and interprets sensory input and make decisions about what should be done
motor output
conduction of signals from the CNS, and is carried out by a group of effector cells, the muscle cells or gland cells
central nervous system (CNS)
the brain and spinal cord
- integrating sensory info and coordinating conscious and unconscious activity
peripheral nervous system (PNS)
the portion of the nervous system consisting of nerves, ganglia, sensory receptors
somatic nervous system
( voluntary nervous system )
divisions of the peripheral nervous system that provides the motor innervation of skeletal muscles
Autonomic nervous system (ANS)
( involuntary nervous system )
efferent division of the peripheral nervous system that innervates cardiac and smooth muscles
what are astrocytes
physically protects neurons, helps with learning and memory
Found in the CNS
what are the microglial cells
defend the cells
Found in CNS
what are ependymal cells
produces cerebrospinal fluid; helps with circulation
Found in CNS
what are oligodendrocytes
responsible for production of myelin sheath
Found in CNS
what are satellite cells
provides structural support
Found in PNS
what are schwann cells
surround axons
Found in PNS
voltage
measure of potential energy generated by separated charges
current
flow of electricity from one point to another
what is the current equation
voltage / resistance
resistance
what is getting in the way of the current
how many NA and K ions go in and out of the sodium-potassium pump
2 K ions pump into the cell and 3 NA ions come out
what are the three ions channels
voltage-gated, ligand-gated channels and mechanically
voltage gated
open and close in response to change in membrane potential
ligated- gated channels
open when neurotransmitter latches onto receptors
mechanically gated
open in response to physical stretching of membrane
electrochemical gradient
measure of the free energy available to carry out the useful work of transporting the molecule across the membrane
Depolarization
Na goes in which creates depolarization (+40mV)
membrane potential
brief depolarization caused by changes in currents
refractory period
prevent signals from traveling both directions down the axon at once
synapse
the meeting point between 2 neurons
what are the 2 types of synapses
electrical and chemical
what is a electrical synapse
fast message involves gap junctions
what is a chemical synapse
a controlled and slower message
More abundant and uses neurotransmitters
presynaptic neuron
cell that sends the message or signal
presynaptic (axon) terminal
transmit message, holds synaptic vesicles which holds neurotransmitters
postsynaptic neuron
receiving cell communication
list the steps of the neurotransmitter
- ATP races along the axon of the neuron activating Na and K
- voltage-gated calcium channels open and release calcium into the neuron cytoplasm
- Ca+ ions cause synaptic vesicles to fuse with the cell membrane and send chemical messengers
Excited
depolarize postsynaptic neuron by making the inside more positive, which brings it closer to AP threshold
inhibitory
hyper polarizes postsynaptic neuron making the inside more negative which moves it away from the AP threshold
- the message doesn’t get passed
what is Broca’s area responsible for
speech and language
what is Broca’s aphasia
when someone has some ability to understand speech but can’t produce words
what is the function of the brain
thinking, feeling and remembering
what is the function of the spinal cord
conducts 2 way signals to brain and rest of the body
list the layers of meninges
dura mater, arachnoid, and pia matter
where is cerebrospinal fluid found
between the arachnoid and pia mater
list the stages of embryonic development
- neural tube
- lower end of the tube stretches which forms spinal cord. The cranial end begins to expand and divides into 3 parts. prosencephalon, mesencephalon, and rhombencephalon
- prosencephalon divides into 2 parts, telencephalon and diencephalon
- rhombencephalon forms into 2 parts, metencephalon and myelencephalon
what forms the brain stem and cerebellum
metencephalon, myelencephalon and mesencephalon
what creates the brain stem and what are its functions
mid-brain, pons and medulla oblongata
controls involuntary movement and relays info to body
what is the function of the cerebellum
coordinates muscle movement
In the brain stem what part has the highest level of function
Mid-brain
what does the diencephalon form and what is its function
thalamus, hypothalamus, epithalamus, and mammillary bodies
function: regulates homeostasis, alertness and reproductive activity
what does the telencephalon turn into
the cerebral hemisphere
gyri are …
little creases
sulci are…
large grooves
how do both sides of the brain interact
through the corpus callosum
what does the frontal lobe do
movement, motor skills and cognitive function
what does the occipital lobe do
process vision
what does the parietal lobe do
process sensation of touch, pain and pressure
what does the temporal lobe do
sort out certain auditory info including language
what is the function of sensory function
sensory receptors that detect stimuli
what is the function of motor function
carries out the responce
what are the two categories of the PNS
somatic and automatic nervous system
what are the two subdivisions of the ANS
sympathetic and parasympathetic
myelin sheath
multi-layered lipid and protein covering that surround axons
myelin
fatty substance produced by oligodendrocytes and Schwann cells
Norepenephrine
have a role in regulating mood
dopamine
very active in emotional responses and addictive behaviors
serotonin
involved in mood, sleep cycle, appetite and sensory perception
what forms the spinal cord
anterior median fissure, posterior median sulcus, central canal, and gray and white matter
Anterior median fissure
very deep groove of internal spinal cord
Posterior median sulcus
very shallow groove of internal spinal cord
Central canal
tunnels through center of spinal canal; filled with CSF
Anterior gray horns
gray matter of spinal cord containing somatic motor nuclei
thermoreceptors
respond to change in temp.
photoreceptors
react to light
chemoreceptors
pay attention to chemicals
mechanoreceptors
respond to pressure, touch and vibration
nociceptors
fire only when pain is detected
what are the steps of the reflex arc
1 - receptors sense a stimulus
2 - sensory neuron transmits signal up the PNS to the CNS
3 - integration center decodes the signal
4 - motor neuron sends directions back to the site of the stimulus
5 - effector cells respond by contracting and secreting
innate reflex action
super fast motor response to a startling stimulus
learned reflexes
come from experience
afferent (sensory) division
collecting data and it to CNS
efferent (motor) division
sends motor info to pns
