Chapter 10 and 11.5 Flashcards
What are Microglia?
Neuroglial cells that preform phagocytosis.
-Remove bacterial cells and debris.
List the characteristics of the nasal nuclei and define it
Characteristics: * Receives input from the entire cerebral cortex.
* Relay station for motor impulses leaving the CNS.
Define: *‘Influences the intensity and fine control of many muscle movements, helps with balance and equilibrium with motor control.
What does the Amygdala do?
Assigns an emotional value to memories.
Where are Potassium and Sodium ions located in a resting cell?
Potassium ions are high on the inside.
Sodium ions are high on the outside.
What does the Oculomotor (III) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
innervates eye muscles; motor
What does the Vestibulocochlear (VIII) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
sense of hearing and equilibrium; sensory
In a resting neuron potassium and sodium ion concentrations are?
- Potassium ions are high on the inside.
- Sodium ions are high on the outside.
What does the abducens (VI) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
Innervates eye muscles; motor
What is Synaptic Transmission?
Nerve impulses are transferred from one neuron to the next through synaptic transmission
What are 2 ways neurotransmitters are removed from the synapse?
- Enzymes present in the synaptic cleft breakdown NTs, Acetylcholinesterase for Acetylcholine
- NTs are reabsorbed by the pre-synaptic knob.
What are ependymal cells?
Neuroglial cells that line the spaces in the CNS
(Brain & Spianl Cord), found with
Cerebrospinal fluid.
List the characteristics of Interneurons?
Located within the CNS
Link the sensory neuron to the motor neuron.
Provides integrative function.
What does the Optic (II) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
sense of vision; sensory
What is Hyperpolarization?
Beyond resting membrane potential.
What is the resting membrane potential and Threshold potential for a Neuron?
-70mV and 50mV
Define Neuron
Neuron - the functional unit of the nervous system
Each neuron is composed of a cell body and many cellular projections from the cell body.
Neuron Processes (Nerver Fibers) -
extensions from the cell body (Dendrites & Axon)
Define threshold stimulus.
Threshold Potential mins Resting Membrane Potential.
What are the four major regions of the brain?
* Cerebrum * Cerebellum * Diencephalon * Brain stem
What is a polarized membrane?
An electrical charged membrane.
What occurs during condution with myelinated nerve fibers?
NI jumps from node of Ranvier to node of Ranvier.
What does the Vagus (X) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
innervates visceral smooth muscle; mixed
What does the Glossopharyngeal (IX) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
moves tongue and pharynx muscles; mixed
List the characteristics of Motor Neuon.
Located within the PNS
Efferent neuorns
Carry motor impulses away from the CNs to the effectors.
Carries information from the CNS
What are the two divisions of the nervous system and their components?
Centeral Nervous System
- Brain and Spinal Cord.
Peripheral Nervous System
- Nervous that extend from brain and spinal cord to periphery of the body.
What is summation?
Several subthreshold stimuli received one after another hits threshold potential, triggering an action potential and begins a nerve impulse on a neuron.
What is the all or nothing response for a nerve cell?
If a nerve cell responds at all, it responds completely
What is memory?
Memory is the persistence of the learning with the ability to access that information.
What does the Facial (VII) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
innervates muscles of facial expression and taste sensation; Mixed.
Define Axonal Hillock
Trigger zone
Define Repolarization.
Returning to resting membrane potential.
Explain Intergrative Function
Occurs at CNS
Involves interpretation of incoming sensory impulse
Intergration occurs at interneurons
What does the Hippocampus do?
involved with episodic memory formation
Define Dendrites
Several dendrites per neuron
Short and branched
Receptive portion of neuron
Carry nerve impulses toward cell body.
What does the Accessory (XI) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
innervate neck muscles; motor
What are Oligodendrocyte?
Neuroglial cells that
produce myelin along the axons of the CNS
Explain Motor Function
Occurs vis PNS
Involves effectors and brings about the body’s response
Motor impulse is carried on a motor neuron
What makes a neuron have a resting membrane potential of -70mV?
It is the flow of ions across the membrane
What occurs during condiction with unmyelinated nerve fibers?
The NI must travel the length of the axon = slow transmission.
What are the three general functions of the Nervous System?
- Sensory input
- Integration
- Motor Function
Define the limbic system
Define:
* Recognizes life-threatening upsets in a person’s physical or psychological condition and counters them.
What does the Olfactory (I) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
sense of smell; sensory
Explain Sensory Input
Derived from the PNS
Sensory receptors transmit sensory impulses to the CNS
Sensory impulse are carried on sensory neuron.
List the characteristics of the limbic system
Characteristics:
* Includes the frontal and temporal cortex, basal and deep nuclei.
* Controls emotional experience and expression.
* Sense of smell
What does the Trigeminal (V) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
face sensation and muscle of mastication; mixed.
What are Astrocytes?
Provides nourishment to the neuon.
Aids in metabolism
Respond to brain injury and form the blood-brain barrier.
Define Depolarization.
To become less negative.
What are Schwann Cells?
Neuroglial cells that
produce myelin along axon in the PNS.
What is a nerve impulse?
The propagation of action potentials along a nerve fiber
- Also known as an electrical impulse
List the characteristics of the withdraw reflex and define it.
* Disynaptic reflex: contains all three.
* Cross-extensor type reflex: information arriving from one side of the spinal cord leads to events on the opposite side.
What is Potential differenance?
The difference in electrical charge between 2 points (inside and outside of membrane)
Determind by the flow of ions across the membrane.
What is the refractory period?
The period following a nerve impulse when a threshold stimulus cannot produce another nerve impulse.
List the five Neurogloical cells.
Schwann Cells
Oligodcendrocytes
Astrocytes
Microglia
Ependymal cells
Define Axon
One per Neuron
Long,thin process that branches
Carry impulse away from cell body
Terminations of axon branch form axonal terminal (synaptic knob).
What does the Trochlear (IV) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
innervates eye muscle; motor
List the characteristics of Sensory Neurons.
Part of the PNS
Afferent neurons
Carry sensory impulses from sensory receptors to the CNS
Input information to CNS
Receptors located throughout the skin and sense organs.
What does the Hypoglossal (XII) nerve do and what kind of nerve is it? (Sensory, Motor, or Mixed)
moves tongue; motor
Define Threshold potential.
The mininium potential need for reaction.
What is conduction?
The manner is which the nerve impulse runs down the neuron (Nerve fiber).
List the characteristics of the knee-jerk reflex and define it.
Characteristics:
* Contains only 2 neurons
* Does not contain the interneuron.
* Monosynaptic reflex
Define:
* Leads to extension at the knee due to contraction of the Quadriceps group.
The brain stem consists of what parts and together what function do they have?
- Midbrain
- Pons
- Medulla Oblongata
Serves as a pathway for fiber tracts running to and from the cerebrum and houses many cranial nerves
What does the thalamus do?
- Central relay station for incoming sensory impulses (except smell).
- Directs the impulse to the appropriate area of the cerebral cortex for interpretation.
What does the hypothalamus do?
Regulates:
- Heart rate and blood pressure
- Body temperature
- Ion balance
- Control of hunger and body weight
- Control of digestive movements and secretions
- Circadian rhythms
- Endocrine system control
What does the midbrain do?
Controls visual and auditory reflexes
What does the pons do?
“Bridge” or pathway of conduction tracts from higher brain to spinal cord.
What does the medulla oblongatta do?
- Contains an autonomic reflex center involved with maintaining homeostasis.
- Vasomotor Center- regulates smooth muscle activity.
- Cardiac Center – regulates heart activity; heart rate and blood pressure.
- Respiratory Center – regulates respiration.
What does the reticular formation do?
- Controls brain alertness.
- When RF activity is inhibited, it leads to sleep.
What does the cerebellum do?
Coordinates skeletal muscle activity (unconscious), posture and balance.
What does the frontal lobe do?
Carry on higher intellectual processes such as logic, consequences, reasoning, and overall rational thinking.
What does the parietal lobes do?
Sensory areas provide sensations of pain, temperature, touch, and pressure
What do the temporal lobes do?
- Sensory areas involved with hearing.
- Association areas interpret sensory experiences and remember visual scenes, music, and other complex sensory patterns.
What do the occipital lobes do?
Sensory areas are responsible for vision.
List the charactertistics of the Broca’s Area
- Motor speech area.
- Located in the left frontal lobe, above the temporal lobe.
- Controls muscle activity involved with speech.
List the characteristics of Wernicke’s Area
- Located where the parietal, temporal, and occipital lobes associate.
- Involved with word selection, phrasing, and word order during speech.
