MIDTERM: UNIT 2 NERVOUS TISSUE pt1

Question 1

functions of the nervous system

Answer 1

sensory
integrative
motor

Question 2

divisions of the nervous system

Answer 2

NERVOUS SYSTEM

1. central nervous system
   - brain
   - spinal cord
2. peripheral nervous system
   - motor (somatic and autonomic)
   - sensory

autonomic: sympathetic, parasympathetic, enteric

Question 3

CNS

Answer 3

brain
spinal cord

Question 4

PNS

Answer 4

• cranial nerves
• spinal nerves
• ganglia
• enteric plexuses in small intestine
• sensory receptors in skin

Question 5

________: carry sensory info from receptors in skin/other organs —> _______ aka _______

• cell bodies are located outside of the spinal cord
• skin

Answer 5

AFFERENT NEURONS
- central nervous system aka sensory neurons

Question 6

• regulates involuntary body responses
• blood vessels

Answer 6

AUTONOMIC DIVISION

Question 7

• voluntary movement by skeletal muscles
• skeletal muscles

Answer 7

SOMATIC DIVISION

Question 8

• carry motor info from brain —> _______ aka _______
• cell bodies are located in the ______ of the spinal cord

Answer 8

EFFERENT NEURONS
- peripheral nervous system aka motor neurons
- ventral horn

Question 9

components of the nervous tissue

Answer 9

neuron
neuroglia

Question 10

• Forms complex process networks within the brain and the spinal cord.
• Connects all regions of the body to the brain and spinal cord.
• Provides functions of sensing, thinking, remembering, controlling muscle activity, and regulating glandular secretions.
• Does not regenerate.

Answer 10

neuron

Question 11

• Relatively smaller cells than the neuron. More abundant than the neuron by about 25 times.
• Nourishes, supports, and protect the neurons. “GLUES” the nervous tissue together.
• Cannot generate or propagate action potentials.
• Can divide throughout an individual’s lifetime.
• Brain tumor derived from glia are termed as ________.

Answer 11

• gliomas

NEUROGLIA

Question 12

types of neuroglia found in CNS

Answer 12

1. astrocytes
2. oligodendrocytes
3. microglia
4. ependymal cells

Question 13

• Star-shaped cells; largest among all neuroglia.
• Contain microfilaments that support neurons.
• In the embryo, responsible to regulate the growth and interconnection among neurons in the brain.
• Maintain appropriate chemical environment for the generation of nerve impulses.
• Plays a roles in learning and memory.

Answer 13

astrocytes

Question 14

• Resembles astrocytes but are smaller.
• Responsible for forming and maintaining the _______ around CNS axons. One oligodendrocyte myelinates several axons.

Answer 14

• myelin sheath

OLIGODENDROCYTES

Question 15

• Function as _______

They remove cellular debris formed during normal development of the nervous system and phagocytize _______ and damaged nervous tissues.

Answer 15

• phagocytes
• microbes

MICROGLIA

Question 16

• Produce, possibly monitor, and assist in the circulation of CSF.

Answer 16

EPENDYMAL CELLS

Question 17

types of neuroglia found in PNS

Answer 17

1. schwann cells
2. satellite cells

Question 18

• Encircles PNS axons by forming __________

One cell of this myelinates a single _____.

Answer 18

• myelin sheath
• axon

SCHWANN CELLS

Question 19

• Provides structural support.
• Regulates exchange of materials between ________ and ________

Answer 19

• neuronal cell bodies
• interstitial fluids

SATELLITE CELLS

Question 20

COLLECTIONS OF NERVOUS TISSUE

Answer 20

1. clusters of neuronal bodies
   - ganglion
   - nucleus
2. bundle of axons
   - nerve
   - tract
3. gray and white matter

Question 21

• Refers to a cluster of neuronal cell bodies located in the PNS

Answer 21

ganglion

CLUSTERS OF NEURONAL CELLS

Question 22

• Refers to a cluster of neuronal cell bodies located in the CNS

Answer 22

nucleus

CLUSTERS OF NEURONAL CELLS

Question 23

• Bundle of axons located in the PNS.
• ______ nerves connect the brain to the periphery
• ______ nerves connect the spinal cord to the periphery

Answer 23

• Cranial
• Spinal

NERVE (BUNDLE OF AXONS)

Question 24

• Bundle of axons located in the CNS

Answer 24

TRACT (BUNDLE OF AXONS)

Question 25

* Composed primarily of myelinated axons.

Answer 25

WHITE MATTER

Question 26

* Contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia. * ________ impart a gray color.

Answer 26

- Nissl bodies GRAY MATTER

Question 27

- fundamental units of the brain and nervous system. - Responsible for receiving sensory input from the external world, for sending motor commands to our muscles, and for transforming and relaying the electrical signals at every step in between

Answer 27

neurons (nerve cells)

Question 28

structural classifications

Answer 28

multipolar neurons bipolar neurons unipolar neurons

Question 29

electrical signals

Answer 29

Manner of communication between neurons: - graded potentials - action potentials

Question 30

- Happens primarily in _________ - Happens in the cell body of the neuron - Propagated along _______ - Involves movement of ions in voltage-gated channels - Depolarizing OR repolarizing - ________ is present - Presents depolarization and repolarization - Always consisted depolarization repolarization phase - Duration is relatively _______

Answer 30

- dendrites - axons - Refractory period - longer ELECTRICAL SIGNALS Manner of communication between neurons: (1) GRADED POTENTIALS (2) ACTION POTENTIALS

Question 31

voltage-gated ___ channels are in the resting state and voltage-gated ___ channels are closed

Answer 31

- Na+ - K+ RESTING MEMRANE POTENTIAL

Question 32

causes depolarization to threshold

Answer 32

stimulus

Question 33

- voltage-gated ___ channel activation gates are opened - voltage-gated ___ channels are open; ___ channels are inactivating

Answer 33

- Na+ - K+; Na+ ABSOLUTE REFRACTORY PERIOD

Question 34

- voltage-gated ___ channels are still open; ___ channels are in the resting state

Answer 34

- K+ - Na+ RELATIVE REFRACTORY PERIOD

Question 35

ACTION POTENTIAL a. In response to a signal, the soma end of the axon becomes ________. b. the depolarization spreads down the axon. meanwhile, the first part of the membrane ________. because Na+ channels have opened, the membrane cannot _______ again. c. the action potential continues to travel down the axon

Answer 35

- depolarized - repolarizes - depolarize

Question 36

→ Describes the transmission of impulse across the ________. → ______ is the area of connection between 2 neurons or a neuron and the effector organ.

Answer 36

- INTERPHASE - Interphase SYNAPTIC NEUROTRANSMISSION

Question 37

◦ Serves as messengers that enable neurons to communicate with one another. ◦ Synthesized in neuronal bodies of nerve terminals; stored in vesicles until they are released into the synapse. ◦ The release of neurotransmitters is activated by membrane depolarization and calcium influx into the cell. ◦ Acetylcholine, Epinephrine, Dopamine, Serotonin, Histamine, etc. ◦ After exocytosis, the neurotransmitter may activate presynaptic and postsynaptic receptors.

Answer 37

NEUROTRANSMITTERS

Question 38

When ______________ reaches threshold, an action potential is generated (excites the neuron). Thereby the neuron is triggered to release its _______.

Answer 38

- excitatory postsynaptic membrane potential - neurotransmitters EXCITATORY NEUROTRANSMITTERS

Question 39

- hyperpolarizes the neuronal membrane and inhibits the firing of action potentials

Answer 39

inhibitory postsynaptic membrane potential INHIBITORY NEUROTRANSMITTER

Question 40

motor: pyramidal neuron of motor cortex sensory: sensory neuron of cortex

Answer 40

brain

Question 41

motor: motor neuron of ventral horn sensory: sensory neuron in dorsal root ganglion

Answer 41

spinal cord

Question 42

PNS

Answer 42

- neuromuscular junction - muscle fiber or myocyte - myelin sheath - ruffinian corpuscle - pacinian corpuscle