Nervous System Flashcards
Neurotransmitters
Chemical signal that allows nerve cells to communicate with each other
Sensory Input
Information gathered by sensory receptors.
Monitors internal and external changes.
Integration
Processing and interpretation of sensory input.
Motor Output
Activation of effector organs (muscles and glands).
Produces a response.
What is the CNS composed of? name the two functions
Composed of the brain and spinal cord located in the dorsal body cavity.
-Functions as the integration and control center.
-Interprets sensory input and dictates motor output.
Components of Peripheral Nervous System (2)
Spinal Nerves: Connected to and from the spinal cord.
Cranial Nerves: Connected to and from the brain.
Neurons
excitable cells that transmit electrical signals
Neuroglia (glial cells)
small cells that surround and wrap delicate neurons (helpers of neurons)
Afferent Nerves
carry signals from sensory receptors to the brain and spinal cord
Efferent Nerve
nerves that carry information away from the central nervous system, to the peripheral nervous system. ( motor output)
Autonomic Nervous System
regulates involuntary physiologic processes including heart rate, blood pressure, respiration, digestion, and sexual arousal. Part of PNS.
What is the autonomic nervous system divided into?
the sympathetic division and the parasympathetic division
Sympathetic System
is best known for its role in responding to dangerous or stressful situations.
Adrenaline
kills your sense of pain and ups blood pressure
Parasympathetic Nervous System
responsible for the body’s rest and digestion response when the body is relaxed, resting, or feeding.
Somatic Nervous System
consists of nerves that go to the skin and muscles and is involved in conscious activities.
Dendrites
the receiving or input portions of a neuron
axon hillock
connects soma to axon
Axon Terminals
Distal endings of axon
Terminal Boutons
found at the end of the axon, below the myelin sheath, and are responsible for sending the signal on to other neurons.
Myelin sheath
Composed of myelin, a whitish, protein-lipid substance
Function of Myelin *2
Protect and electrically insulate axon
Increase speed of nerve impulse transmission
Myelinated Fibers Characteristics
Long and Fast
Non Myelinated Characteristics
Short and slow
Anterograde
movement away from cell body
Retrograde
movement toward cell body
Astrocytes (7)
-Support and brace neurons
-Play role in exchanges between capillaries and neurons
-Guide migration of young neurons
-Control chemical environment around neurons
-Respond to nerve impulses and neurotransmitters
I6.nfluence neuronal functioning
7. Participate in information processing in brain
Microglial Cells
- actually macrophage
- crawls along nervous system and eats bad stuff
Ependymal cells
- Produce CSF (cerbrospinal fluid)
- Form permeable barrier between cerebrospinal fluid (CSF) in cavities and tissue fluid bathing CNS cell
Oligodendrocytes
forms insulating myelin sheaths around CNS fibers
Schwann Cells
form myelin sheaths around ONLY one axon in PNS
Resting Membrane Potential
the electrical potential difference across the plasma membrane when the cell is in a non-excited state
What is the charge of the inside of a cell?
between -70 and -90 milivolts
Sodium Potassium Pump
In each cycle, three sodium ions exit the cell, while two potassium ions enter the cell. This allows the cell to build a concentration gradient and have a negative charge.
Depolarization
- decrease in membrane potential (moves toward zero and above)
- sodium channels are opened and sodium rushes inside the channel (charge becomes more positive)
- Inside of membrane becomes less negative than resting membrane potential
–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
Thereshold
set charge that starts an action potential. depolarization occurs after.
Action Potential
signal that travels along cell membrane
If a graph bumps up, then it is?
hypopolarized (depolarized)
If a graph bumps down, what is it
hyperpolarization
Refractory Period
Wait for the sodium potassium concentration to become normal to do it again (through sodium potassium pumps)
Can you adjust number or size of action potentials?
Number of action potentials ; all action potentials are the same
Propagation
The movement of signals between neurons.
Axon diameter relation to nerves
Bigger nerves/ diameter are faster
Repolarization
potassium channels open and potassium rushes outside of the cell (dropping charge)
FAST
- stroke symptom acronym
- fac1al droop, arm weakness, speech difficulty, and time
What are strokes usually caused by?
blockage of cerebral arteries
tPA
-tissue plasminogen activator
-clot-dissolving medicine
Acetylcholine
- nerves use to talk to muscles
- released ay NMS
- generic
Seratonin
happiness
Dopamine
- excitement
GABA
- almost always inhibitory
- says stop don’t do it
Spatial Summation
two separate signals hit at the same time
Temporal Summation
a lot of signals come at the same time
Cephalization
Gray Matter
short, nonmyelinated neurons, and cell bodies outside of brain and inside of spinal cord
White Matter
Myelinated and nonmyelinated axons
Hydrocephalus
too much fluid in the brain
Gyri
ridges
Sulci
shallow grooves
What do gyri and sulci do?
Increases brain area
Fissures
deep grooves that separate lobes
Rhombencephalon
Developmental part of the brain responsible for keeping you alive. Includes pons, cerebellum, and medulla oblongata.
Cerebral hemisphere
Upper level thinking, decision making, and conscious thought
Precentral Gyrus
- primary motor gyrus
- Responsible for the initiation and control of voluntary motor movements on the contralateral side of the body.
Postcentral Gyrus
primary sensory gyrus
Broca’s area
motor speech area, in frontal lobe
Frontal lobe
executive decision making, personality, and movement
Temporal Lobe
processing auditory information and with the encoding of memory
- sense of taste, smell, and hearing
- emotion
Parietal Lobe
receiving and processing sensory input such as touch, pressure, heat, cold, and pain
- some spatial awareness
- starts out in postcentral gyrus
Autonomic Nervous System innervation and pathway
Innervate smooth muscles, cardiac muscle, and glands
- has Efferent pathways and ganglia
Wernicke’s Area
processes language
Cerebellum
coordinates movement and balance
Corpus callosum
a thick bundle of nerve fibers that connects the two cerebral hemispheres, allowing them to communicate
What is the most inferior cranial nerve?
12
Oh once one takes the anatomy final, very good vacations are heavenly
Olfactory
Optic
Oculumotor
Trochlear
Trigeminal
Abducens
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Accessory
Hypoglossal
Olfactory Nerve
controls sense of smell
- sensory nerve
- like an extension of brain so loss of smell can indicate alzheimers
Optic Nerve
sight and sensory
Optic Chiasma
sensory nerve - this is where your left and right vision share
Oculomotor Nerve
- most of eye movement
- constrict irises, move eyeball
- motor nerve
Trochlear Nerve
- motor nerve
- moves eye (superior oblique)
Abducens nerve
- moves lateral rectus
- motor
Trigeminal Nerve
- motor and sensory nerve
- facial feeling
What are the three divisions of the trigeminal nerve?
- Opthalmic
- Maxillary
-Mandibular
Facial Nerves
- controls facial muscles
- motor and sensory
Vestibulocochlear
- balance and hearing nerve
- feeling of acceleration or spinning
- Sensory nerve
Glossopharyngeal
- motor nerve and sensory nerve
- innervates part of the tongue so helps with swallowing and technically taste
Vagus nerve
- regulates heart
- one cranial nerve that leaves head and neck
- sensory and motor
Accessory Nerve
- motor nerve
- shoulder and neck
Calcium
chemical that triggers neurotransmitter’s exocytosis
Longitidunal Fissure
Separates two hemispheres
Transverse Cerebral Fissure
Separates cerebrum and cerebellum
Central sulcus
the groove that separates the frontal and parietal lobes
