Module 1: Nervous System Part 1 Flashcards
1
Q
- What is the difference betweenanatomyandphysiology?
A
- Anatomyfocuses on the structure of the body.Physiologylooks at how the body parts function together. The physiology of the body depends on the anatomy of the body.
2
Q
- The function of the nervous system is to integrate and control the other body systems. Explain how the nervous system does this.
A
- The nervous system receives and processes information and sends out signals to the muscles and glands to elicit an appropriate response. In this way, the nervous system integrates and controls the other systems of the body.
3
Q
- List the 2 parts of the nervous system.
A
- CNS and PNS (central nervous system and peripheral nervous system)
4
Q
- How are the parts of the central nervous system protected?
A
- Theskullprotects the brain and thevertebraeprotect the spinal cord.
5
Q
- Collections of cell bodies inside the central nervous system are called_____, and the collection of nerve axons in the central nervous system are called_____.
A
- nuclei, tracts.
6
Q
- What is included in the peripheral nervous system?
A
- The PNS includes the cranial nerves and the spinal nerves.
7
Q
- Collections of cell bodies inside the peripheral nervous system are called_____, and the collection of nerve axons in the peripheral nervous system are called_____.
A
- ganglia, nerves.
8
Q
- What are the 2 divisions of the peripheral nervous system?
A
- Afferent, efferent
9
Q
- Describe the movement of nerve impulses in the peripheral nervous system.
A
- The peripheral nervous system receives impulses from the sensory organs via the afferent division and then relays signals or impulses from the central nervous system to muscles and glands via the motor or efferent division.
10
Q
- What are the 2 divisions of the efferent division of the peripheral nervous system?
A
- Somatic system and the autonomic system.
11
Q
- What is controlled by the somatic and autonomic nervous systems?
A
- The somatic system controls the movements of skeletal muscles, skin, and joints. The autonomic system nerves control the glands and smooth muscles of the internal organs.
12
Q
- What are the 2 divisions of the autonomic nervous system?
A
- sympathetic and parasympathetic nervous systems.
13
Q
- What is the function of the sympathetic nervous system?
A
- The sympathetic nervous system activates and prepares the body for vigorous muscular activity, stress, and emergencies.
14
Q
- What is the function of the parasympathetic nervous system?
A
- The parasympathetic nervous system generally operates during normal situations, permits digestion, and conserves energy.
15
Q
- List 3 unusual characteristics of neurons.
A
- Neurons do not undergo mitosis (cell division), require enormous amounts of fuel being able to survive just minutes without oxygen and can last an entire human lifetime.
16
Q
- List the 3 parts that all neurons contain.
A
- The dendrites, the cell body, and the axon.
17
Q
- Describe the structure and function of the neuron cell body.
A
- Synthesizes all nerve cell products, consists of a large nucleus with surrounding cytoplasm containing the normal organelles
18
Q
- Describe the structure and function of the dendrite.
A
- Numerous short extensions that emanate from the cell body which receive information from other neurons conducting those nerve impulses toward the cell body.
19
Q
- Describe the axon, including the number in each neuron, function, structure and organelles.
A
- Conducts nerve impulses away from the cell body to its axon terminals where it is emitted across a synapse to the dendrite of another neuron. Axons are composed of organelles like the cell body but lack rough endoplasmic reticulum.
20
Q
- Describe the function and site of synthesis and storage of neurotransmitters.
A
- One of the main functions of the cell body is to manufacture neurotransmitters, which are chemicals stored in secretory vesicles at the end of axon terminals.When neurotransmitters are released by the axon terminal vesicles, they carry the transmission of the nerve impulse from one neuron to another.
21
Q
- What is a synapse?
A
- A synapse is a gap between two neurons.
22
Q
- A post-synaptic neuron is a neuron that is found ____ the synapse.
A
- After
23
Q
- ______neurons have three or more extensions from the cell body and have one axon and many dendrites.
A
- Multipolar
24
Q
- _________ neurons have a central cell body with two extensions.
A
- Bipolar
25
Q
- _____neurons have one extension off the cell body which branches into two: one central process running to the CNS and another peripheral process running to the sensory receptor.
A
- Unipolar (pseudounipolar)
26
Q
- ______neurons are unipolar and function to carry information from the peripheral to the central nervous system.
A
- Sensory
27
Q
- These types of neurons are also called association neurons.
A
- Interneurons
28
Q
- _____ neurons send messages from the central nervous system to the peripheral.
A
- Motor
29
Q
- What is the function of neuroglial cells?
A
- Neuroglial cells are support cells, helping to support neurons to enable them to thrive in their needed environment.
30
Q
- What are the peripheral nervous system neuroglial cell types?
A
- Schwann cells; satellite cells
31
Q
- True or False: Axons cannot regenerate in the peripheral nervous system.
A
- False
32
Q
- True or False: Myelin sheath is continuous and has no gaps.
A
- False
33
Q
- List the four types of support neuroglial cells in the central system and a function of each.
A
- Ependymal cells circulate cerebrospinal fluid and allow fluid exchange between brain, spinal cord and cerebrospinal fluid (CSF). Oligodendrocytes act as the insulation for central nervous system axons. Astrocytes control chemical environment of neurons by wrapping around the blood capillaries, forming the blood brain barrier. Microglial cells protect the CNS by scavenging dead cells and infectious microorganisms.
34
Q
- What is the technical term used to describe a nerve impulse and what causes the impulse?
A
- A nerve impulse is called an action potential and is caused by the movement of unequally distributed ions on either side of an axon’s plasma membrane.
35
Q
- An axon’s membrane is polarized with a resting potential of -70 mV. Explain what this means and what maintains this resting potential.
A
- The axon plasma membrane is polarized, meaning that one side has a different charge than the other side. This difference called a resting potential means that the charge on the inside of the axon’s cell membrane is 70 millivolts less than the outside of the membrane. A sodium- potassium pump using active transport carries ions across the plasma membrane and because three Na+ ions are pumped out as two K+ ions are pumped in a relative positive charge develops and is maintained on the outside of the membrane.
36
Q
- What are the four steps of an action potential in order?
A
- Resting Potential, Depolarization, Repolarization, Afterpolarization (hyperpolarization)
37
Q
- Describe what happens to the charges on the axon cell membrane duringdepolarizationand what causes this to happen.
A
- Sodium gates open and sodium rushes into the axon and the inside becomes more positive than the outside causing the membrane potential to become more positive.
38
Q
- Describe what happens to the charges on the axon cell membrane duringrepolarizationand what causes this to happen.
A
- The sodium gates close and potassium gates open allowing potassium to rush out of the axon. This returns a negative charge to the inside of the axon re-establishing the negative potential.
39
Q
- Describe what happens during afterpolarization.
A
- The potassium gates that open during repolarization are slow to close and there is an afterpolarization undershoot of the potential.
40
Q
- What causes the difference in intensity of a sensation?
A
- Due to the number of neurons stimulated and the frequency with which they are stimulated.
41
Q
- True or False: An impulse from a neuron moves in both directions.
A
- False
42
Q
- What is meant by neuron signals beingelectrochemicalin nature?
A
- The signal moves from electrical (through the neuron) to chemical (in the synapse) to electrical again once the signal reaches the next neuron.
43
Q
- What is the chemical portion of neuron signal transmission?
A
- Neurotransmitters.
44
Q
- How is an impulse passed from one nerve cell to another?
A
- There is a minute fluid-filled space, called a synapse, between the axon terminal of the sending neuron and the dendrite of the receiving neuron. When a nerve impulse reaches the end of an axon, neurotransmitters are released into the synapse. These bind with a receptor on the next neuron, opening Na+ gates in the receiving dendrite which causes depolarization and the impulse is carried.
45
Q
- What prevents continuous stimulation of a nerve synapse and how is this accomplished?
A
- The short existence of neurotransmitters in the synapse prevents continuous stimulation. Some synapses contain enzymes that rapidly inactivate neurotransmitters and other synapses rapidly absorb the neurotransmitter.
46
Q
- What neurotransmitter helps regulate emotional responses and muscle tone?
A
- Dopamine
47
Q
- What neurotransmitter is found at the neuromuscular junctions?
A
- Acetylcholine
48
Q
- Once ACh is released in the NMJ, what happens to cause muscle contraction to occur?
A
- Acetylcholine binds to receptors on the muscle fiber that cause sodium channels to open. Sodium rushes into the muscle cell, triggering an action potential which reaches the sarcoplasmic reticulum. Calcium ions are released from the sarcoplasmic reticulum of the muscle cell causing the muscle to contract.
49
Q
- Define the term reflex. Give an internal and an external example.
A
- Reflexes are nearly instantaneous, automatic, involuntary motor responses to stimuli occurring inside or outside of the body. A Internal reflex is the regulation of blood sugar by the hormones. An external example is touching a very hot object and immediately withdrawing your hand.
50
Q
- Sensory information travels into the spinal cord via the _______ of a nerve
A
- Dorsal root
51
Q
- What is the gray and white matter of the spinal cord?
A
- Gray matter contains the cell bodies of neurons. The white matter of the spinal cord contains the axons of neurons.
52
Q
- What does the DRG contain?
A
- Contains the cell bodies of sensory neurons.
53
Q
- Sensory neurons synapse on cells in the _______ of the spinal cord.
A
- Posterior horn
54
Q
- Motor neuron cell bodies are in the _______ of the spinal cord.
A
- Anterior horn
55
Q
- Motor neurons (axons) leave the spinal cord via the ____.
A
- Ventral root
56
Q
- When does a ventral root transition to a spinal nerve?
A
- both sensory and motor neurons from the ventral and dorsal roots join together immediately exiting the vertebrae
57
Q
- Label the components of the cross section of a spinal cord.
A
- See figures in module.
58
Q
- Why is a spinal reflex faster than a conscious decision to move by the brain?
A
- Spinal reflexes are faster not only because they involve fewer neurons, but also because the electrical signal does not have to travel to the brain and back. Spinal reflexes only travel to the spinal cord and back which is a much shorter distance.
59
Q
- List the 5 components of a reflex arc.
A
- The receptor, the afferent neuron, the integration center, the efferent neuron and the effector.
60
Q
- The stretch reflex utilizes what type of specialized receptor to detect over-stretch?
A
- Muscle spindles
61
Q
- What is the purpose of the stretch reflex?
A
- Stretch reflexes are a special type of muscle reflex which protect the muscle against increases in length which may tear or damage muscle fibers.
