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Flashcards in Nervous System Deck (34):
1

Functions of nervous System

1. Collect information
2. process and evaluate information.
3. Initiate response to information

2

Structural organization

Central Nervous system: brain spinal cord
Peripheral Nervous system: nerves, ganglia, receptors

3

Functional organization

Sensory--> somatic (aware), Visceral (attached to organs)

Motor--> Somatic (skeletal), Autonomic (involuntary)

4

Nervous Tissue

Neurons: transmitting and signaling cells.
Glial Cells: Supporting cells

5

Characteristics of neurons

Excitable.
Conductivity.
Secretion (make and release neurotransmitters).
Extreme longevity.
Amitotic (except in brain where learning occurs).

6

Structure

Cell body. (soma)
Dendrites. (receive input from other neurons or sensors)
Axon. (conducts AP)
Axon terminals. (Ending in synaptic knob)

7

Structural classification

Mulitpolar (many dendrites and one axon)
Bipolar (1 dendrite, one axon)
Unipolar (one branching extension with dendrites on end)
anaxonic (no axon, tons of dendrites)

8

Classification by function

Sensory/afferent-bring info in
interneuron: link between sensors and motor neurons
Motor/ Efferent- soma in CNS,

9

Endoneurium

Areolar CT insulate neurons in nerve

10

Perineurium

Dense Irregular CT, surround fasicles

11

Epineurium

Dense Irregular CT, surround entire nerve

12

Nerves can have both motor and sensory neurons

.

13

Ganglion

Collection of neuron cell bodies

14

Collection of neuron cell bodies

ganglion

15

Astrocytes

Most abundant in brain.
Form Blood brain barrier.
Wrap perivasvular feet around capillaries preventing passive passage of materials into brain.
Help control composition of extracellular fluid.
Help form framework for neurons.
Guide normal brain development,
Occupy space of dying neurons

16

Ependymal cells

Associated with capillaries and form cerebral spinal fluid (in choroid plexus)
Epithelial cells

17

Microglial cells

the only immune cells in brain

18

Oligodendrocyte

makes myelin sheath in CNS

19

Most abundant in brain. Form Blood brain barrier. Wrap perivasvular feet around capillaries preventing passive passage of materials into brain. Help control composition of extracellular fluid. Help form framework for neurons. Guide normal brain development, Occupy space of dying neurons


Astrocytes


20

Associated with capillaries and form cerebral spinal fluid (in choroid plexus)
Epithelial cells

Ependymal cells

21

the only immune cells in brain

Microglial cells

22

makes myelin sheath in CNS

Oligodendrocyte


23

RMP of neurons

-70mV

24

Stages of Chemically gated channels

Open or closed

25

Stages of voltage gated channels

open, closed and resting, closed and inactive
Allows for conductility and propagation of AP in one direction

26

Channels and pumps through entire neuron

Na+/K+ pumps and Na, K leak channels

27

Receptive segment

Chemically gated Na+, K+, Cl- channels.
Binding of neurotransmitters produce a graded potential with can be inhibitory or excitatory.

28

Initial Segment

voltage gated Na, K channels.
Sum up graded potential, if the threshold is it, an AP starts

29

Initial Segment

voltage gated Na, K channels.
Sum up graded potential, if the threshold is it, an AP starts

30

Conductive segment

voltage gated Na, K channels.
Propagation of AP, entire length of axon to transmissive segment.
voltage gated channel open at -55mV. Na rushes in, K leas out for a self propagating AP. Voltage channels become inactive after depolarization at 30mV

31

Transmissive segment

Voltage gatedCa Channels, Ca pumps.
Ap releases neurotransmitters from vesicles when Ca is released into the knob.

32

Transmissive segment

Voltage gatedCa Channels, Ca pumps.
Ap releases neurotransmitters from vesicles when Ca is released into the knob.

Transmissive segment opens VGCC

33

Absolute refractory period

no additional stimulation with open Na+ channels

34

Relative refractory period

VGNC closed and resting, but in hyperpolorized state so further from threshold