Lecture Quiz One - Anat and Phys II Flashcards
(20 cards)
What are the functions– and how are the functions of neurons and neuroglia different from each other? Know micro anatomy terms, related transmission terms.
Neuron:
1. Neurons are nerve cells.
2. Neurons work with the help of their processes like axon and Dendron.
3. These are responsible for transmission of impulses by excitability.
Neuralgia:
1. Neuroglias are supporting cells.
2. Nerve cells remain in position due to supporting cells called neuralgia.
3. It forms supporting media for CNS and myelin in nerves devoid of Schwan cells.
How are the dendrites and axons different in structure and function?
Dendrites receive stimuli, or impulses, from other neurons and conduct this stimulation to the cell body. Dendrites also may be modified into sensory receptors that receive, or sense, stimuli such as heat, cold, touch, pressure, stretch, or other physical changes from inside or outside the body. Dendrites tend to be short, numerous, multibranched projections extend from the cell body. The axon conducts nerve impulses away from the cell body toward another neuron or an effector cell (a cell that does something when stimulated, such as a muscle or gland cell). In contrast to the short, numerous, branched dendrites, the axon is a single structure that can be very long. For example, a single axon in the horse may extend several feet from the spinal cord all the way to the lower leg. Axons are often covered by a fatty substance called myelin
During repolarization, what ion
channels open and what ion moves? Where does it move?
The potassium channels open and potassium moves out of the cell
What is threshold? What role does threshold play in the all or none principle?
Threshold is the number of sodium channels that must be opened in order for
depolarization to occur. A stimulus must be strong enough for this threshold to be
reached. According to the all or nothing theory, either the complete neuron depolarizes to its maximum strength or it does not depolarize at all (that is, the threshold is met or it isn’t).
What is the functional relationship between a neurotransmitter and a receptor? Will any
neurotransmitter stimulate any receptor?
The neurotransmitter molecules released by the synaptic knob bind with receptors and trigger a change in the postsynaptic cell.
However, the postsynaptic membrane receptors are very specific about which neurotransmitters they will bind. If the neurotransmitter and receptor are not matched, they will not bind to each other,
and no change will be triggered in the
postsynaptic cell. Thus synaptic transmission is only effective if receptors to the neurotransmitter exist on the postsynaptic cell’s membrane
What are the anatomic differences between the CNS and the PNS?
Be specific
and all
terminology.
CNS is brain and spinal cord
PNS extends outwards from the central axis toward the periphery of the body.
Cranial nerves originate directly from the brain.
Spinal nerves emerge from the spinal cord.
Which are afferent nerves: motor nerves or sensory nerves? Which are efferent?
Sensory nerves are afferent nerves
Motor nerves are efferent nerves
Know the function of the following cranial nerves: I, II, III, V, VII, X
I: Olfactory: smell
II: Optic: vision
III: Oculomotor: eye movement, pupil size, focusing lens
IV: Trochlear: eye movement
V: Trigeminal: Sensations from the head and teeth, chewing
VII: Facial: Face, scalp movement, salivation, tears, taste
X: Vagus: sensory from g.i. tract & resp tree, motor to larynx, pharynx, parasympathetic motor to the abdominal and thoracic organs
What kinds of functions are controlled by somatic vs autonomic nervous systems?
Somatic: actions under conscious or voluntary control.
Autonomic: controls & coordinates automatic functions
During depolarization, what ion channels open and what ion moves? Where does it move? Understand how depolarization works. what is the role of myelin? SALTATORY CONDUCTION
Na+ channel opens and Na+ flows into the cell. Myelin cloaks axons and speeds up depol by only allowing it at nodes of ranvier, thereby quickly jumping from node to node producing rapid conduction of nerve impulse.
During repolarization, what ion
channels open and what ion moves? Where does it move?
K+ channels open and K+ flows out of the cell. Finally, the sodium potassium pump kicks in to restore the resting state (slightly - w/higher K+ in cell)
What normally maintains the resting membrane potential of a neuron during the resting state?
The Na+/K+ pump
What is threshold? What role does threshold play in the all or none principle?
Threshold is the number of sodium channels that must be opened in order for
depolarization to occur. A stimulus must be strong enough for this threshold to be
reached According to the all or nothing theory, either the complete neuron depolarizes to its maximum strength or it does not depolarize at all (that is, the threshold is met or it isn’t).
What role do the synaptic cleft, presynaptic neuron, neurotransmitter, and postsynaptic
neuron play in the continuation of a depolarization wave from one nerve to another?
Neurons are the basic functional units of the nervous system. That is, they are the smallest pieces of the system that show basic nervous system functions such as responding to stimuli and conducting impulses from one part of the cell to another. The neuroglia, or glial cells (from the Greek glia, meaning “glue”), structurally and functionally support and protect the neurons. They outnumber neurons about 10 to 1, but they are not directly involved in the transmission of information or impulses through the nervous system. Rather, they are important parts of the infrastructure necessary for the neurons to do their jobs.
What is proprioception?
is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement.[1] It is provided by proprioceptors in skeletal striated muscles and in joints.
What is hyperalgesia?
Hyperalgesia is an increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves.
What are the parts of the pain pathway? Be specific
Transduction, transmission, modulation, perception
What are the various types/categories of sensory receptors?
- Pain receptors, which detects pain, and are located everywhere except the brain
- Thermoreceptors, which detect temperature, and are located in the skin, body core, and hypothalamus.
- Mechanoreceptors, which are sensitive to touch, pressure, stretching of muscles, sound, and motion, are located in the skin, skeletal muscle, and inner ears.
- Chemoreceptors, which are sensitive to chemicals in the external environment, are located in the taste buds and nose.
- Photoreceptors, which are sensitive to light, are located in the eyes.
What is the sensory receptor in the stretch reflex? What results from the stretch reflex arc
stimulation? Is t
his an ipsilateral or contralateral reflex?
A specialized structure within the muscle called the
muscle spindle. Muscle contraction
results. Ipsilateral.
Nociceptors
pain receptors. May be simple free nerve endings or more specialized.
