Nervous System Flashcards Preview

Biology > Nervous System > Flashcards

Flashcards in Nervous System Deck (66)
Loading flashcards...
0

Two Major Components

Central Nervous System
Peripheral Nervous System

1

Three Functions of the Nervous System

Receives sensory input (internal and external) - PNS -> CNS
Processes and integrates information
Generates motor output

2

Central Nervous system consists of...

Brain and spinal cord

3

Neurons

Cells that transmit nerve impulses

4

Neuroglia (Glial Cells)

Support and nourish neurons; more numerous than neurons in brain

5

Two types of Neuroglia

Schwann cells
Oligodendrocytes

6

Schwann Cells

Form myelin sheath (insulators) of neurons in peripheral nervous system, leaving gaps called nodes of Ranvier

7

Oligodendrocytes

Form myelin sheath in central nervous system - "white matter"

8

Nervous Tissue

Located in the nerves, and conducts nerve impulses

9

Myelin Sheath

A lipid covering on long axons that acts to increase the speed of nerve impulse conduction, insulation, and regeneration in the peripheral nervous system

10

Nodes of Ranvier

Gaps between myelination on the axons

11

Saltatory Conduction

Conduction of the nerve impulse from node to node (don't have to open so many ion channels)

12

Multiple Sclerosis

Disease in which the myelin sheath is attacked by the immune system, causing malfunctioning of the nervous system and muscle weakness or paralysis

13

Three types of neurons

Sensory
Interneuron
Motor

14

Sensory Neuron

Transports nerve signals from sensory receptors to central nervous system

15

Receptor

Special structures that detect changes in the environment

16

Interneuron

Lie within central nervous system; composite input from sensory neurons and other interneurons, then communicate with motor neurons

17

Motor

Transport impulses from central nervous system to effector

18

Effector

Carry out responses to environmental changes

19

Dendrite

Many short extensions that carry impulses to a cell body

20

Cell body

Main cell where organelles and nuclei reside

21

Axon (nerve fiber)

Single, long extension that carries impulses away from the cell body (exception - sensory neuron)

22

Synapse

Small gap between the sending neuron (pre-synaptic membrane) and the receiving neuron (post-synaptic membrane)

23

How do signals get from sensory neurons to the brain and then to the right neurons to get muscles to move?

Sensor -> Afferent Pathway -> integration -> Efferent Pathway -> Motor

24

Nerve Impulses

Convey information in nervous system, i.e., action potential, via electrochemical signals

25

Resting Potential

Axon is NOT conducting a nerve impulse

26

State of a cell during resting potential

Inside of the cell has a negative charge, with more positive ions outside the membrane. There is more Na+ outside the cell than inside, but more K+ inside than outside (along with large anions - )

27

Action Potential

Rapid change in the axon membrane that allows a nerve impulse to occur

28

What occurs during the action potential stage?

Sodium gates open, letting Na+ in, and depolarization occurs - the interior of the axon loses negative charge and becomes positively charged (from -70 mV to 40 mV).

29

What occurs during the repolarization stage?

Action potential ends, and repolarization occurs - K+ moves out. But, Na+ and K+ are in the wrong place, so the sodium-potassium pump restores resting potential - actively pumps 3 Na+ out for every 2 K+ in.

30

When a nerve impulse reaches the end of the axon, it causes the release of what?

A neurotransmitter

31

Inhibitory Synapse

Promotes decrease in action potential

32

Excitatory Synapse

Promotes increase in action potential

33

How many known neurotransmitters?

Over 100

34

What does the response a neurotransmitter triggers depend on?

The receptor to which it attaches

35

Acetylcholine

Muscle stimulation/inhibition, memory formation, learning

36

Norepinephrine

Smooth muscle function, dreaming, waking, mood

37

Dopamine

Sense of reward/pleasure

38

Serotonin

Thermoregulation, sleeping, emotions, perception

39

The Central Nervous System is protected by what?

Bones, meninges, and cerebral spinal fluid

40

Meninges

Protective membranes that wrap around CNS

41

Cerebral Spinal Fluid

Space between meninges is filled with this fluid that cushions and protects the CNS

42

Spinal cord and brain consist of:

Gray matter
White matter
Ventricles

43

Gray matter

Neuron cell bodies, dendrites, and unmyelinated axons

44

White Matter

Bundles of axons with myelin sheafs

45

Ventricles

Spaces filled with cerebrospinal fluid (central canal of spinal cord)

46

What does the cerebrospinal fluid do?

Circulates slowly in the ventricles, supplies nutrients and removes wastes, and cushions the CNS by circulating in meninges.

47

Occipital Lobe

Controls the visual processing abilities

48

Central Sulcus

Divides the frontal and parietal lobes

49

Sulcus

"Valley" in the brain

50

Gyrus

"Ridge" in the brain

51

What does the central sulcus house?

The primary motor and somatosensory area.

52

Longitudinal fissure

Divides cerebrum into left and right hemispheres

53

Left hemisphere controls...

Language skills, math, and other logical and analytical abilities (as well as the right side of the body)

54

Right hemisphere controls...

Spatial skills, face and pattern recognition, and nonverbal thinking (as well as the left side of the body)

55

Three ways in which we study to brain

Injuries
Mapping
Imaging

56

What does brain mapping do?

Allows us to link a brain location to a specific function of the brain

57

Wernicke's Area

Located in the left temporal posterior section, it helps us understand written and spoken words

58

Broca's Area

Located in the left frontal section, it helps us speak and write

59

Short-term memory

Begins in prefrontal area, and precedes long-term memory

60

Long-term memory

Stored in the association areas of the cerebral cortex, and accessed by the hippocampus and relayed to the prefrontal area. Short term memories are integrated into existing knowledge (long term memory) via the hippocampus.

61

PNS - Somatic System - Functions

Voluntary - serves the skin, skeletal muscles, and tendons
Involuntary - knee-jerk reflex

62

PNS Autonomic

Regulates the activity of involuntary muscles (smooth and cardiac), and can be divided into parasympathetic and sympathetic sections

63

Most drug abusers take drugs that affect which neurotransmitter?

Dopamine. They artificially affect this reward circuit to the point they ignore basic physical needs in favor of the drug.

64

Sympathetic part of the PNS

Fight or Flight

65

Parasympathetic part of the PNS

Rest and Digest