Copyright © 2010 Pearson Education, Inc.

Central nervous system (CNS) Peripheral nervous system (PNS)

Motor (efferent) divisionSensory (afferent)division

Somatic nervoussystem

Autonomic nervoussystem (ANS)

Sympatheticdivision

Parasympatheticdivision

Figure 13.1 Place of the PNS in the structural organization of the nervous

system.

Skeletalmuscle

Pg 484

Somatic Motor PathwayTo Skeletal Muscle

Primary Motor Cortex

Upper Motor N.

Lower Motor N.ACH

Nicotinic Rec.

Cross over at M.O.

Axons in Corticospinal Tracts

Anterior Horns

Root?Branch?

Reflexes

Involuntary

Sensory in to spinal cord motor back out

Copyright © 2010 Pearson Education, Inc.

The patellar (knee-jerk) reflex – a specific example of a stretch reflex

Musclespindle

Quadriceps(extensors)

Hamstrings(flexors)

Patella

Patellarligament

Spinal cord(L2 – L4)

3a

2

1

3b 3b

1 Tapping the patellar ligament excitesmuscle spindles in the quadriceps muscle.

2

3a The motor neurons (red) sendactivating impulses to the quadricepscausing it to contract, extending theknee.

Afferent impulses (blue) travel to thespinal cord, where synapses occur withmotor neurons and interneurons.

3b The interneurons (green) makeinhibitory synapses with ventral hornneurons (purple) that prevent theantagonist muscles (hamstrings) fromresisting the contraction of thequadriceps.

Excitatory synapseInhibitory synapse–

+

Pg 516

Proprioceptor detects stretch

1st order sensory

Posture

LMN

Direct/Monosynaptic

Copyright © 2010 Pearson Education, Inc.

+ Excitatory synapse– Inhibitory synapse

Quadriceps stronglycontracts. Golgi tendon organs are activated.

Afferent fibers synapsewith interneurons in the spinal cord.

Efferent impulsesto muscle with stretched tendon are damped. Muscle relaxes, reducing tension.

Efferentimpulses to antagonist muscle cause it to contract.

Interneurons

Spinal cord

1 2

3a 3b

Quadriceps(extensors)

Golgitendon

organHamstrings

(flexors)

Pg 517

Indirect/Polysynaptic

proprioceptor

1st order sensory

LMN

Copyright © 2010 Pearson Education, Inc.

Figure 14.1 Place of the ANS in the structural organization of the nervous

system.Central nervous system (CNS) Peripheral nervous system (PNS)

Motor (efferent) divisionSensory (afferent)division

Somatic nervoussystem

Autonomic nervoussystem (ANS)

Sympatheticdivision

Parasympatheticdivision

Pg 525

-Controls Cardiac and Smooth Muscle and Glands-Reflexes-Works with Endocrine Sys.

Fight or Flight Rest & Digest

-Dual Innervation-Hypothalamus

Brain Stem or Lateral Horn

Preganglionic N.

B

ACH

Nicotinic Rec.

Post-Ganglionic N.

C

Autonomic Nervous System Motor Pathway

Reflexes faster or slower than Somatic?

Copyright © 2010 Pearson Education, Inc.

Pterygopalatineganglion

EyeLacrimalgland

Nasalmucosa

Ciliaryganglion

Pterygopalatineganglion

Submandibularganglion Submandibular

and sublingualglands

CN III

CN VIICN IXCN X

Otic ganglion

Parotid gland

Heart

Lung

Liver andgallbladder

Stomach

Pancreas

Urinarybladderand ureters

Smallintestine

Largeintestine

S2

Pelvicsplanchnicnerves

Genitalia(penis,clitoris, and vagina)

Rectum

Celiacplexus

Inferiorhypogastricplexus

Cardiac andpulmonaryplexuses

S4

Preganglionic

Postganglionic

Cranial nerve

Pg 528

Parasympathetic/CraniosacralRest & Digest

3,7,9,10

Lat. Horn

Terminal Ganglia (ACH Nicotinic Receptor)

Post to Organ (ACH Muscarinic Receptor)

S2-S4

Preganglionic axons exit out the Ventral Branch (Ramus)

Long Short

Nicotinic

Muscarinic

4.28a&b

Copyright © 2010 Pearson Education, Inc.

Superiorcervicalganglion

MiddlecervicalganglionInferiorcervicalganglion

Sympathetic trunk(chain) ganglia

Pons

L2

T1

White ramicommunicantes

Liver andgallbladder

Stomach

Spleen

Kidney

Adrenal medulla

Smallintestine

Largeintestine

Genitalia (uterus, vagina, andpenis) and urinary bladder

Celiac ganglion

Inferiormesenteric ganglion

Lesser splanchnic nerveGreater splanchnic nerve

Superior mesenteric ganglion

Lumbarsplanchnic nerves

EyeLacrimal gland

Nasal mucosa

Blood vessels;skin (arrector pilimuscles andsweat glands)

Salivary glands

Heart

Lung

Rectum

Cardiac andpulmonaryplexuses

PreganglionicPostganglionic

Sacralsplanchnicnerves

Pg 532

Sympathetic/ThoracolumbarFight or Flight

Lat. Horns T1-L2

Gray Rami

Autonomic NervesNE to Alpha or Beta

PreAortic G.Autonomic N.

NE to Alpha or Beta

Copyright © 2010 Pearson Education, Inc.

Spinal cord

Dorsal root

Ventral root

SympatheticTrunk (chain) ganglion

Sympathetictrunk

Rib

Ventral ramusof spinal nerve

Gray ramuscommunicansWhite ramuscommunicans

Thoracicsplanchnic nerves

(a) Location of the sympathetic trunk Pg 530

T1-L2

ACH to Nic.

ACH to Nic.

Dorsal & Ventral Br.

Muscarinic

Alpha or Beta

Alpha or Beta

Aka Adrenaline & Noradrenaline-Bind to same receptors as NE-Enhances sympathetic effects-Lasts Longer

Alpha Smooth (Exc.)

Beta Smooth (Inh.) Cardiac (Exc.)

4.29a&b

Clicker Question: Which of the following statements are true?

1. The parasympathetic division shows less divergence than the sympathetic does so it’s effects are more localized and specific.2. Skeletal muscle has nicotinic receptors on it to respond to stimulation.3. The parasympathetic n.s. shuts down then the sympathetic n.s. is active, and vice versa.4. Pelvic splanchnic nerves are preganglionic axons that branch out of dorsal branches (rami) of sacral spinal nerves.5. Norepinephrine released by sympathetic postganglionic neurons binds to beta receptors on the smooth muscle of the stomach.

A. 1,2,3,5 B. 1,3,4 C. 2,4,5 D. 1,2,5