Autonomic Nervous System

Question 1

Somatic System

Answer 1

1 nerve whose cell body is located in CNS & whose axon extends uninterrupted &raquo_space; skeletal (site of first peripheral cell synapse)
(PREganglion)

Question 2

Autonomic System

Answer 2

two peripheral nerves - first has cell body in CNS - but axon innervates second neuron (POSTganglion)

Question 3

Autonomic is broken down in to…?

Answer 3

1. Sympathetic -thoraco-lumbar

2. Parasympathetic -cranio-sacral

Question 4

Sympathetic

Answer 4

Mobilizes resources for emergency
(flight or fight)

Preganglionic  fibers  (short)  -  paravertebral  sympathetic ganglion  chain
Postganglionic  fibers  (long)  ->  visceral  organs

Adrenal medulla = special case - preganglion neurons extend &raquo_space; adrenal medulla

there synapse with postganglionic neurons
that make adrenal medulla secretory cells

Question 5

Parasympathetic

Answer 5

Long preganglionic fiber : short postganglionic fiber
Promotes vegetative function

(example: stimulates digestion/absorption; stimulates gastric secretion/motility)

Some are cranial nerves (example: vagus stimulation decreases heart rate)

Ganglia are within or near effectors

Question 6

*

Answer 6

Autonomic nervous system is efferent
BUT - afferents are an essential part of autonomic reflex arc.

Sympathetic and parasympathetic work against each other (opposites) to maintain homeostasis

Question 7

Neural Transmitters

Answer 7

A. Cholinergic  Nerves  -  Acetylcholine
    -  ACh receptors  
     1.	 Muscarinic 
     2. Nicotinic  
B. Adrenergic  Neurons - Nonepinephrine/ nonadrenal
    - Alpha
    - Beta
** Both Beta and Alpha incr. blood pressure in different ways

Question 8

Nerves - Acetylcholine

3 things

Answer 8

1. Somatic neuromuscular synapse
2. All autonomic ganglia- (swelling of a part of the nervous system)
3. Parasympathetic - postganglionic neurons
   
   • Acetylcholinesterase - destroys ACh

Question 9

ACh receptors

Answer 9

1. Muscarinic -
   postganglionic parasympathetic & sympathetic neurons

Stimulated by muscarine (toadstool poison)

Blocked by atropine &raquo_space; decr. salivation, decr. sweat rate, incr. heart rate, decr. gut motility

2. Nicotinic - Very lethal
   A. Pre/postganglionic synapses
   B. Somatic neuromuscular synapses
   **If you inhibit nicotinic causes a greater effect on animal health
   Stimulated by nicotine
   Blocked by curare (binds to ACh receptors

Question 10

Adrenergic Neurons

Answer 10

Most sympathetic postganglionic neurons secrete norepinephrine

BUT - postganglionic sympathetic neurons go to sweat glands, skeletal muscle blood vessels-Secrete ACh

Adrenergic transmission to postsynaptic terminal
alpha & beta postganglionic receptors

Question 11

Alpha Neurons

postganglionic receptors

Answer 11

Stimulates smooth muscle &raquo_space; vasoconstriction (constrict blood vessels to incr. blood pressure) & relaxation of intestinal smooth muscle

Question 12

Beta Neurons

postganglionic receptors

Answer 12

Increases heart rate
Increases vasodilation
Increases strength of heart contraction

Beta blockers used to reduce hypertension (decr. heart rate and blood pressure)

Question 13

What does cyanide do?

Answer 13

Cyanide action - on final cytochrome of chain

|&raquo_space; NO electron transport &raquo_space; NO ATP

Question 14

7 Basic Regions of Brain

Answer 14

Forebrain

1. Cerebrum
2. Diencephalon

Brainstem

3. Medulla
4. Pons
5. Midbrain
6. Reticular Formation
7. Cerebellum

Question 15

Cerebrum

2 parts

Answer 15

1. Cerebral cortex - highly folded outer cellular layer
   Most complex integrated area of nervous system
2. Subcortical nuclei - deep in cerebral hemispheres
   Important for coordination & muscle movement

Question 16

Functions of Cerebrum:

Answer 16

Forebrain
1. Sensory - compares & evaluates input + integrates information into perception

2. Somatic - control of voluntary movement
3. Integrative -consciousness & mental activities
4. Memory

Question 17

Diencephalon

2 parts

Answer 17

Forebrain

1. Thalamus
2. Hypothalamus

Question 18

Cerebral cortex

Answer 18

Highly folded outer cellular layer

Most complex integrated area of nervous

Question 19

Subcortical nuclei

Answer 19

Deep in cerebral hemispheres

Important for coordination & muscle movement

Question 20

Thalamus

Answer 20

a relay station for sensory information into cerebrum

Question 21

Hypothalamus

Answer 21

links transducers of neural & endocrine system

Question 22

Brainstem

Answer 22

upper continuation of spinal cord

Question 23

Brainstem includes:

4 regions

Answer 23

1. Medulla
2. Pons
3. Midbrain
4. Reticular Formation

Question 24

Medulla

Answer 24

cardiac, vasomotor, respiratory centers

Question 25

Pons

Answer 25

contains cell bodies & neurons | that send information from cerebral cortex to cerebellum

Question 26

Midbrain

Answer 26

eye movement - subconscious control of posture

Question 27

Reticular Formation | What is it and its functions?

Answer 27

net-like complex that is the core tissue through the entire brainstem - functions include integration & regulation of information + consciousness & modification of spinal reflexes

Question 28

Cerebellum

Answer 28

latin for little brain Contains 10% of brain material but 50% of all brain neurons Control of - Skeletal muscles - Coordination - Skilled movement - Equilibrium - Posture

Question 29

3 Protective layers surround CNS (meninges)

Answer 29

1. Pia Mater 2. Arachnoid 3. Dura Mater

Question 30

Pia Mater

Answer 30

Inner most layer next to CNS - It is a single layer of cells (fibroblast) joined to brain & spinal cord

Question 31

Arachnoid

Answer 31

middle layer - spider-web appearance Thin layer of cells (fibroblasts) Traps CSF between it & pia mater (subarachnoid space)

Question 32

Dura Mater

Answer 32

outer most membrane next to inner bone surface Much thicker layer (fibroblasts) - that serves to protect CNS

Question 33

Cerebrospinal Fluid What is it? and 4 steps associated with it?

Answer 33

Clear, colorless within subarachnoid space, central canal of spinal cord, & ventricular system of brain No blood cells + little protein 1. Produced by ventricles 2. A dynamic Fluid 3. Shock absorber - CNS 4. Conduit (Construction) for some brain proteins

Question 34

Where is Cerebrospinal fluid produced? and where does it enter the system?

Answer 34

Produced by ventricles in the CHOROID PLEXUS>> which flows down ventricles>> subarachnoid space via a pressure gradient Enters venous system at ARACHNOID VILLA

Question 35

What type of process is the replacement of dynamic fluid? What happens when there is an obstruction?

Answer 35

Replaced several times daily by an ACTIVE process Flow obstruction produces hydrocephalus (water on the brain) = Fatal

Question 36

Blood- Brain Barrier

Answer 36

Tight junctions in cells of brain capillary wall Prevents large proteins, toxins, most drugs (ex. antibiotics) from passing >>> brain

Question 37

The solubility of the following material to cross Hermembrane - Glucose and many Amino Acids - Lipid soluble material - Morphine - Herion

Answer 37

Glucose & many AA - penetrate easily via transporter proteins Lipid-soluble material enters easily (Alcohol rapidly crosses the membrane) Morphine - highly lipid-insoluble (poor passage) Heroin - highly lipid-soluble (easy passage) - then converted to morphine once in the brain.