A&P 2.16 Autonomic Nervous System Flashcards Preview

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Flashcards in A&P 2.16 Autonomic Nervous System Deck (33)
1

Membrane potential

Difference in electrical charge across the plasma membrane caused by differing concentrations of ions

2

Resting membrane potential

- 70 mV. Inside number. Outside are different numbers

3

Local potential

Minor shifts from resting potential but no action potential

4

Excitation

When sodium triggers gated channels to open and allow sodium into the cell causing depolarization

5

Structures of the nervous system

CNS - brain and spinal cord

PNS - nerves and sensory receptors

6

Basic divisions of the nervous system

CNS

PNS - SNS & ANS

7

SNS

Somatic - skin, skeletal muscles, fascia and joints

8

ANS

Autonomic - viscera, blood vessels, smooth muscles

Sympathetic - fight or flight

Parasympathetic - rest or digest

9

Motor Effectors of the somatic divisions

Skin
Skeletal muscles
Fascia
Joints

10

Motor Effectors of the autonomic divisions

Smooth muscle - organs- viscera
Cardiac muscles
Glands

11

Major functions of the ANS

To regulate everything that is not skeletal muscle (smooth muscles, glands, cardiac ) via the sympathetic and parasympathetic systems

TO INCREASE TONE IN ONE DIVISION YOU MUST DECREASE TONE IN THE OTHER

12

Most structures in the ANS are

Dually innervated

13

Autonomic effector tissues and organs

Viscera - organs

Eyes
Heart
Respiratory structures
Blood vessels
Liver
Digestive glands

14

Motor pathways of the somatic divisions

Motor neuron runs from CNS and synapses directly with skeletal muscle fiber

ACh always neurotransmitter

Excitatory - contraction always

Voluntary

ONE NEURON

15

Motor pathways of the autonomic division

Motor neuron from CNS to another motor neuron (ganglion) to synapse with autonomic effector (2 synapses)

ACh (acetylcholine ) or NE (norepinephrine ) neurotransmitter

Excitatory or inhibitory

Involuntary

TWO SYNAPSES

16

Ganglia

A group of neural cell bodies found in the PNS

17

Ganglia are necessary because

So many different target tissues are affected all at one time in the ANS due to parasympathetic and sympathetic

18

The ANS has how many synapses?

2 - two motor neurons

Preganglionic and post ganglionic

19

1st synapse uses what neurotransmitter

ACh used in both sympathetic and parasympathetic

20

Neurotransmitter used in 2nd synapse

Sympathetic uses NE because it is longer lasting and will maintain fight or flight longer

Parasympathetic uses ACh and is short lived

21

Pre and post ganglionic nerves allow the body to

Affect multiple target tissues at multiple levels at the same time with the release of limited neurotransmitters

22

Two different efferent divisions of the ANS

Sympathetic and parasympathetic

22

Structure of sympathetic division

Pre ganglionic neurons arise from spinal nerves T1-L3 (thoracolumbar division)

Ganglia are close to the spinal cord

Pre ganglionic neurons are short and synapse with MANY post-ganglionic fibers: DIVERGENT

Post-ganglionic neurons are LONG and go to MANY effectors

23

Sympathetic chain

Sympathetic ganglia - chain of ganglia near spine

24

Structure of the parasympathetic division

Pre-ganglionic neurons arise from the cranial nerves III, VII, IX, X and spinal nerves from S2-S4 (craniosacral division)

Ganglia are FAR from the spinal cord (close to the effectors)

Pre-ganglionic neurons are LONG and synapse with FEW post-ganglionic fibers: CONVERGENT

Post-ganglionic neurons are SHORT and go to a SINGLE effector

25

Sympathetic division response

Pupils dilate
Heart rate, force (contraction), and bp increase
Respiratory passages dilate
Blood vessels to GI tract and kidneys constrict
Blood vessels to skeletal muscles, cardiac muscle, brain, liver and adipose tissue dilate
Liver cells BREAK DOWN glycogen into glucose and release glucose into the blood
Nonessential activities are inhibited (e.g. Salivary and other digestive secretions, GI tract mobility)

26

Parasympathetic division response

Pupils constrict
Heart rate, force (contraction) and BP decreases
Respiratory passages constrict
Blood vessels supplying GI tract and kidneys dilate
Blood vessels to skeletal muscles, cardiac muscle, brain, liver, and adipose tissue constrict
Liver cells SYNTHESIZE glycine from glucose and absorb glucose from the blood
Salivary and other digestive secretions and GI tract mobility are stimulated

27

Somatic versus Autonomic

effectors

S - skeletal muscles

A - cardiac muscle, smooth muscle, glands

28

Somatic versus Autonomic

type of control

S - mainly voluntary

A - mainly involentary

29

Somatic versus Autonomic

neural pathway

S - one motor neuron: extends from CNS and synapses directly with a skeletal muscle fiber

A- two motor neurons: one from CNS to ganglion, one from ganglion to effector

30

Somatic versus Autonomic

neurotransmitter

S - acetychlorine

A - acetychlorine or norepinephrine

31

Somatic versus Autonomic

action of neurotransmitter on effector

S - always exicitory

A - excitory or inhibitory

32

Tensor fascia latea

A, I, O

O - superior attachment - ASIS and adjacent lateral and posterior surface of the ilium

I - the IT band and the lateral condyle of the tibia

A - flex the hip, medially rotate the hip, abduct the hip and help stabilize the knee

Named for action: tenses the broad bandage