Anatomy M1 Test 2 Thorax

Front 1

The internal aspect of the thoracic wall is covered by the

Back 1

endothoracic fascia which separates the internal muscles from the parietal pleura

Front 2

The Thoracic Cavity

Back 2

-surrounded by the thoracic wall

-contains the thymus, heart, lungs, distal part of the trachea, and most of the esophagus

Front 3

The Thoracic Cage

Back 3

an osteoocartilagenous structure

-portects the thoracic organs and some abdominal organs (liver)

Front 4

Bony thorax includes

Back 4

-thoracic vertebrae (12) and intervertebral discs

-Ribs (12 prs) and costal cartilages

-Sternum
-manubrium sterni
-body
-xiphoid process

Front 5

The bony structures define two distinct apertures in the thoracic cage

Back 5

1. Superior Thoracic Aperture (inlet)

2. Inferior Thoracic Aperature (Outlet)

Front 6

Thoracic Inlet
(superior thoracic aperture)

Borders

Back 6

Borders
-first pair of ribs and cartilages
-manubrium sterni (sup border)
-First thoracic vertebrae

Front 7

Thoracic Inlet
(superior thoracic aperture)

Contents

Back 7

-trachea

-esophagus

-Vagus (CN X), phrenic nerves (C3,4,5 cervical plexus)

-Apex of the lungs

Front 8

Thoracic Outlet
(Inferior thoracic aperture)

Borders

Back 8

Borders:
-12th thoracic vertebra (T12)
-the 12th pair of ribs
-Costal margin = c cartilages 7-10

Front 9

Thoracic cage important landmarks

Back 9

1. Xiphoid process = T10 or T11

2. Sternal angle (of louis) = lower border of T4

3. Costal cartilage of 2nd rib which correspondes directly to the manubriosternal joint

Front 10

Angle of Louis

Back 10

-angle formed btwn the manubrium and the body of the sternum (manubriosternal joint)

-marks the level of the 2nd costal cartilage for counting intercostal spaces

-denotes the level of the
A. Aortic Arch
B. Bifurcation of trachea (carina)
C. T4/T5 intervertebral disc

Front 11

Typical Ribs

Back 11

Ribs 3 - 9

*Rib 7 is the longest rib

Front 12

Atypical Ribs

Back 12

1, 2, 10, 11, 12

Front 13

True Ribs

Back 13

Ribs 1-7 articulate directly with the sternum through their costal cartilages

Front 14

False Ribs

Back 14

Ribs 8, 9, 10 share a common costal cartilage

Front 15

Floating Ribs

Back 15

Ribs 11-12 do not articulate anteriorly, they end among the muscles of the body wall

Front 16

Costal grove

Back 16

located on the inferior aspect of the ribs, shelters the intercostal neurovascular bundle (VAN)

Front 17

First Rib

Back 17

Short and broad

forms part of the thoracic inlet

grove for the SUBCLAVIAN vein and artery

Front 18

Bucket Handle/Pump Handle
movements of ribs

Back 18

-middle parts of the lower ribs move laterally when they are elevated
(bucket handle movement)

-when upper ribs are elevated, the AP diameter of the thorax is increase (pump handle) with greater excursion occurring inferiorly

-combo of movements that occur during inspiration increase the AP and transverse diameters of the thoracic cage

Front 19

Muscles of the Thoracic Wall

Back 19

-diaphragm
-serratus anterior
-serratus posterior sup and inf
-pec major and minor
-intercostal muscles
• External Intercostal
• Internal intercostal
• Innermost intercostal
---->innermost proper
---->subcostalis
---->sternocostalis

Front 20

External Intercostal Muscle

Back 20

-fibers run downward and forward
-external intercostal membrane at the costochondral joint

O: lower borders of ribs 1-11

I: Upper borders of ribs 2-12

N:Corresponding Intercostal N

A: Elevate the rib cage: Inspiration

Front 21

Internal Intercostal Muscle

Back 21

-fibers run down and backward
-internal intercostal membrane near the vertebrae

O Lower Borders of Ribs 1-11

I Upper borders of ribs 2-12

N: corresponding intercostal N

A: Expiration

Front 22

Innermost Intercostal Muscle

Back 22

3 parts
1. Innermost proper btwn ribs
2. Subcostalis: angle
3. Sternocostalis (transversus thoracis) near sternum

fibers run down and backward
-corresponding intercostal n
-expiration

Front 23

Serratus Ant

Back 23

O: Ribs 1-8

I: costal surface of scapula, superior and inferior angles and medial border of the scapula

N: Long thoracic nerve (C5,6,7)

A: Rotates the scapula, abducts the arm, elevates the arm above the horizontal, assists in respiration

Damage:
-winging of the scapula
-loss of elevation of arm
-problems with respiration

Front 24

Arteries of the Thoracic Wall

Back 24

-Internal thoracic artery (subclavian)

-Highest intercostal artery (costocervical trunk [subclavian])

-posterior intercostal arteries

-subcostal arteries

Front 25

Note to the Anterior Intercostal Arteries

Back 25

1. Anterior Intercostal arteries to ICS 1-6 come frome the internal thoracic artery

2. Anterior Intercostal arteries to ICS 7,8,9 come from the musculophrenic (internal thoracic)

3. No anterior intercostal arteries in ICS 10-11

Front 26

Veins of Thoracic Wall

Right Side

Back 26

-1st -- highest intercostal vein - braciocephalic vein

-2nd and 3rd = higher intercostal vein - azygos

-4th -11th azygos

-12 (subcostal veins) - azygos

Front 27

Veins of Thoracic Wall

Left Side

Back 27

-1st - highest -brachiocephalic vein

-2,3,4 = accessory hemiazygos vein

-5th - 11th + 12 = hemiazygos vein

-the accessory hemiazygos and hemiazgyos cross over to the right side independently, or may join as a unit, and ultimately drain in the azygos

-the accessory hemiazygos may drain into the brachiocephalic

Front 28

Endothoracic fascia

Back 28

-CT layer that functions to prevent the parietal pleura from rubbing against the innermost intercostal muscle.

-This fascia is thickened over the apex of the lungs (Sibson's fascia)

Front 29

Blood Supply of The Lungs

Back 29

Arterial:
-Bronchial arteries (thoracic aorta)
-Pulmonary arteries

Venous Supply:
-Bronchial veins drain into the azygos system and into the pulmonary veins

Lymphatic drainage:
-from the hilum to the pulmonary nodes to the tracheobronchial nodes

Front 30

Nerve Supply of the Lungs

Back 30

-Anterior and posterior plexuses of the vagus which cause bronchoconstriction and vasodilations, an increase glandular secretion
-
Sensory innervation = vagus

Sympathetic trunk = vasomotor innervation from T2-T5. These fibers produce bronchial dilation and vasoconstriction

Front 31

The Trachea Relationships

Structures Anterior to the Trachea

Back 31

-sternum

-thymus

-arch of the aorta

-origins of the brachiocephalic trunk and left common carotid artery

Front 32

The Trachea Relationships

Structures Posterior to the Trachea

Back 32

-esophagus

-azygos vein and right vagus, and pleura (on the right)

-Aortic arch, LCC, left subclavian artery and left vagus, left phrenic, and pleura (on the left)

Front 33

Blood Supply of the Trachea

Back 33

-Superior Thyroid artery (external carotid artery)

-Inferior thyroid artery (thyrocervical trunk [subclavian artery])

-bronchial arteries (thoracic aorta)

-Internal thoracic artery (subclavian artery)

Front 34

Nerve Supply of the Trachea

Back 34

-Vagus nerve (CN X)

-Sympathetic chain

Front 35

Right Main Bronchus

Back 35

-wider, shorter, and more vertical than the left main bronchus

-before entering the hilum of the right lung, it gives off the superior lobar bronchus

-on entering the hilum, it divides into a middle and inferior lobar branches

Front 36

Left Main Bronchus

Back 36

-narrower, longer, and more horizontal than the right main bronchus

-it passes to the left below the arch of the aorta and in front of the esophagus

-on entering the hilum of the left lung it divides into a superior and an inferior lobar branches

Front 37

Blood Supply of the Bronchus

Back 37

1.Bronchial arteries - they supply the conductive airway (non-respiratory)
-Two on the left from the thoracic aorta
-One on the right from the first posterior intercostal artery

2. Pulmonary arteries to the terminal portion of the bronchioles

3. Venous drainage is via the bronchial veins to the azygos and hemiazygos veins

Front 38

Nerve Supply to the Bronchi

Back 38

-Vagus nerve (parasympathetic)
***activation leads to broncho constriction and mucus secretion

-Sympathetic chain
***activation leads to bronchodilation

Front 39

Superior Mediastinum

Back 39

-extends inferiorly from the superior thoracic aperture to the horizontal plane passing through the angel of Louis and the inferior border of T4

-located posterior to the manubrium
-anterior to the first 4 thoracic vertebrae

Front 40

Contents of the Supeior Mediastinum

Back 40

1. Aortic Arch
-brachiocephalic trunk:
*RCC
*Right Subclavain artery
-LCC
-Left subclavian artery

2. Brachiocephalic veins = subclavian + internal jugular

3. SVC = R + L brachiocephalic veins

4. Thymus gland
5. Esophagus
6. Trachea
7. Thoracic duct

Front 41

Anterior Mediastinum of the Inferior Mediastinum

Back 41

-extends from the posterior surface of the sternum to the anterior surface of the pericardial sac

Front 42

Middle Mediastinum of the Inferior Mediastinum

Back 42

Heart
Pericardium
Main bronchus
Great vessels and phrenic nerves

Front 43

Anterior Mediastinum of the Inferior Mediastinum

Back 43

-located posterior to the pericardial sac and diaphragm, and anterior to the bodies of the inferior eight thoracic vertebrae (T5-T12)

Front 44

Phrenic Nerve

Back 44

-C3, C4, C5

-accompanied by the pericardiophrenic artery

-Right and left phrenic arteries

Front 45

Right Phrenic Nerve

Back 45

-Right of SVC and RA

-Anterior to the root of right lung

-Between the parietal pleura and fibrous pericardium

Front 46

Left Phrenic Nerve

Back 46

-between the left subclavian and LCC arteries

-lateral to vagus and aortic arch

-anterior to the root of the left lung

Front 47

Pericardium

Back 47

-a double-walled fibroserous sac that encloses the heart and the roots of its great vessels

-located in the middle mediastinum
-posterior to the body of the sternum and second to sixth costal cartilages
-anterior to the T5 to T8 vertebrae

Front 48

Pericardium Layers

Back 48

-attached to the sternum by the sternopericardial ligament, and to the diaphragm by the central tendon

1. Fibrous Pericardium--> tough external layer of fibrous tissue

2. Serous Pericardium--> internal double layered sac
-Parietal pericardium
-Visceral pericardium

Front 49

Parietal Pericardium

Back 49

-fused to the internal surface of the fibrous pericardium

Front 50

Visceral Pericardium

Back 50

-reflected onto the heart where it forms the epicardium

Front 51

Pericardial cavity

Back 51

=the potential space between the parietal and visceral pericardial layers

*virtual space

Front 52

Layers of Penetration of Pericardium/Heart

Back 52

-Pericardium
Fibrous Pericardium
-Serous sac
-Parietal layer
-Pericardial cavity
-Visceral layer (epicardium)
Heart
-Epicardium
-Myocardium
-Endocardium

Front 53

Pericardial Sinus

Transverse Sinus

Back 53

-recesses that develop during embyronic folding of the pericardial sac

-located behind the aorta and pulmonary trunk, and in front of the left atrium and superior vena cava

-important surgically during bypass procedures
-a digit and a ligature can be passed through the transverse sinus btwn the great arteries and pulmonary trunk

Front 54

Pericardial Sinus

Oblique Sinus

Back 54

-between the pulmonary trunk and inferior vena cava

Front 55

Pericardium Nerve Supply

Back 55

-parietal fibrous pericardium is supplied by the phrenic nerve (C3,4,5)
[located btwn the parietal pleura and fibrous pericardium]
-also the vagus nerve

-visceral layer is supplied by the coronary plexus

Front 56

Blood Supply of the Pericardium

Back 56

-Pericardiophrenic artery ( internal thoracic)

-musculophrenic artery (internal thoracic)

-Pericardial branches from the bronchial, esophageal and superior phrenic arteries (thoracic aorta)

-visceral pericardium is supplied by the coronary arteries (ascending aorta)

Front 57

Pericardiocentisis

Back 57

-large bore needle at left sternal margin ICS 4 (ICS 5 or 6)

-paraxiphoid approach, avoid internal thoracic artery

Front 58

The Heart: Important Info

Back 58

-located in the middle mediastinum, oriented obliquely and deviated 2/3 to the left and 1/3 to the right of the median plane

-Apex of the heart is inferolateral (7-9 cm from the median plane and just medial to the midclavicular line) at IC 4 and IC5 space
*pg 55 of notes corresponds to costal cartilage 6

-posteriorly it extends from T5-T8 (supine) and T6-T9 (erect)

Front 59

Coronary grove or sulcus

Back 59

-encircles most of the superior part of the heart and separates the atria from the ventricles

Front 60

Division of ventricles

Back 60

-indicated on the surface by the anterior and posterior interventricular groves

Front 61

Arterial Blood Supply of the Heart

Back 61

-Right coronary

-left coronary

-branches from these arteries anastomose at several areas
-Nodal anastomoses
-about the conus arteriosum
-circumflex
-anterior interventricular septum
-posterior interventricular septum

Front 62

Right coronary

Back 62

-ascending aorta

-right atrial branch (gives off the SA branch-nodal)
-coronal branch
-right marginal branch (with the small cardiac vein)
-posterior intervetricular artery (clinically posterior artery descending) PAD
*accompanies the middle cardiac v

Front 63

Left Coronary

Back 63

-circumflex (gives off the left marginal artery)

-anterior interventricular artery (clinically, left anterior descending-LAD)
-during its course, one or two diagonal branches may arise and descend diagonally across the anterior surface of the LV, it accompanies the great cardiac vein

Front 64

Venous drainage of the heart

Back 64

-all the veins of the heart drain into the coronary sinus EXCEPT the anteior cardiac veins which drain directly into the Right Atrium

Front 65

Venous Blood Drainage of the Heart

Anterior Surface

Back 65

1. Anterior Cardiac veins: RA

2. Small cardiac vein:
-drains the RV
-accompanies the marginal artery
-drains into the coronary sinus

3. Great Cardiac Vein
-accompanies the LAD
-tributary of the coronary sinus

Front 66

Venous Blood Drainage of the Heart

Posterior Surface

Back 66

1. Middle cardiac vein
-travels with the left posterior interventicular ascending artery, drains into the Coronary Sinus

2. Oblique vein
-coronary sinus

3. Coronary sinus
-lies in the posterior atrioventricular sulcus
-drains the right atrium

Front 67

Tributaries of the Coronary Sinus

Back 67

-Great Cardiac vein

-Small cardiac vein

-Middle cardiac vein

-oblique cardiac vein

Front 68

Ligamentum Arteriosum

Back 68

-it is a vestigial duct that communicates the aortic arch with pulmonary trunk or left pulmonary artery

-it obliterates after birth
-located at angle of Louis
-extends from the aortic arch to the pulmonary trunk or left pulmonary A

-left recurrent laryngeal nerve hooks under the ligament at the angle of Louis

-right recurrent laryngeal nerve passes under the right subclavian artery

Front 69

Right Atrium

Back 69

-fossa ovalis

-limubus of the fossa ovalis

-crista terminalis: free smooth edge of the pectinate muscle

-opening of tricuspid valve

-opening of coronary sinus (Thebesian valve)

-opening of SVC/IVC

-opening of the anterior cardiac veins

Front 70

Right Ventricle

Back 70

-Tricuspid vlave

-Pulmonary trunk

-Papillary muscles

-Moderator band or septomarginal trabecula

-Chordae Tendineae
-prevent backflow of the blood into atrium
-prevent eversion of valves during ventricular contraction
-attach from the papillary muscles to the cusps of the tricupsid valve

Front 71

Left Ventricle

Back 71

-bicuspid valve

-opening of the ascending aorta

***the trabeculate carneae is all the structures in the ventricles except the cusps, papillary muscles, chortae tendineae, and septomarginal trabecula

Front 72

Left Atrium

Back 72

-pectinate muscle

-opening of the pulmonary veins

-opening of the bicuspid valve

Front 73

Auricles

Back 73

-right and left

-ear-like appendages which function like a "storage" are for blood absorbing excess hydraulic volume

Front 74

Pulmonary Trunk

Back 74

-it leaves the RV

-it crosses the root of the ascending aorta to continue upward to the left of the aorta

-it divides inot a left and right pulmonary arteries at the sternal angle of Louis

*the beginning of the left pulmonary artery is attached to the aortic arch by ligamentum arteriosis

Front 75

Ascending Aorta

Back 75

-begins behind the right auricle and pulmonary trunk

-two branches
1. Right coronary artery
2. Left coronary artery

-Aortic valve is similar to the pulmonary valve except for the presence of the openings for the coronary arteries behind the two coronary cusps

Front 76

Tricuspid Valve

Back 76

-3 cusps
Anterior, posterior, septal

-on right between RA and RV

-behind the right 1/2 of the sternum opposite ICS 4

-attached to the papillary muscles by the chordae tendinae

Front 77

Mitral valve

Back 77

-anterior and posterior cusps

-on the left between LA and LV

-behind the left 1/2 of sternum opp costal cartilage 4

-attached to the papillary muscles by the chordae tendinae

Front 78

Aortic Semilunar Valve

Back 78

-ascending aorta

-nodules, lunula, fibrous ring

-Left 1/2 of sternum opp ICS 3

Front 79

Pulmonary Semilunar valve

Back 79

-pulmonary trunk

nodules, lunula, fibrous ring

-behind the medial end of the 3rd left costal cartilage

Front 80

The Sinoatrial Node SA

Back 80

-collection of specialized cardiac muscle fibers (nodal tissue) located in the wall of the right atrium which initiate the impulses for contraction

-natural pacemaker (60-100/min)

-located superior to the crista terminalis at the junction of the anteromedial aspect of the SVC and the right auricle

-subepicardial

-supplied by a branch of the right coronary artery

Front 81

The Atrioventicular Node (AV)

Back 81

-it is a smaller collection of nodal tissue located in the interatrial septum on the ventricular side of the orifice of the coronary sinus

-beats 40-60 times/min

-the AV node is submyocardial, it is supplied by a branch of the right coronary artery

Front 82

AV Bundle of His

Back 82

-extends from the A-V node into the septal wall of the RA to the upper membranous part of the ventricular septum where it divides inot a right and left branches

-right branch goes to the RV by passing through the septomarginal band

-left branch ends in the LV

-allows ventricular contraction to proced from the apex to the base of teh heart for efficient ejection

-supplied by the LAD

Front 83

Innervation of the heart

Back 83

1. supplied by the ANS from the vagus (parasympathetic)
-slows HR and reduces the force of contraction, causes constriction of coronary arteries

2. The sympathetic trunk (T1-T5)
-increases HR and force of contraction causing dilation of the coronary arteries -->more O2 and nutrients to the myocardium

Front 84

Cardiac plexus

Back 84

-formed by branches from both the vagus and sympathetic trunks

-lies anterior to the bifurcation of the trachea
-posterior to the aortic arch
-superior to the bifurcation of the pulmonary trunk

Front 85

Contents of the Posterior Mediastinum

Back 85

-Thoracic aorta
-Esophagus
-Azygos venous system
-Thoracic duct
-Vagus Nerves
-Splanchnic nerves

*located posterior to the pericardial sac and diaphragm, and anterior to the bodies of the ineferior eight thoracic vertebrae (T5-T12)

Front 86

Thoracic Aorta

Back 86

-extends from the arch of the aorta to T 12

-enters the aortic opening of the diaphragm (with the azygos, thoracic duct, and greater splanic nerve) and turns into the abdominal aorta
-starts left to the vertebral column, descending anterior to it behind the esophagus

Parietal branches and visceral branches

Front 87

Parietal branches of the thoracic aorta

Back 87

-Posterior intercostal arteries 2-11

-Subcostal artery

-superior phrenic artery

Front 88

Visceral branches of the thoracic aorta

Back 88

-Bronchial arteries

-Pericardial artery

-Mediastinal artery

-Esophageal artery

Front 89

Esophagus

Back 89

-extends from C6 - T10, from the lower end of the pharynx to the cardiac opening (region) of the stomach

-lies behind the trachea and left atrium
-deviates to the left
-posterior to the left main bronchus and it enters the diaphragm at T10 with the vagus and esophageal branch of the left gastric

Front 90

Blood Supply of the Esophagus

Back 90

-inferior thyroid artery
-bronchial arteries
-esophageal arteries
-phrenic arteries
-esophageal branch of the left gastric artery

Front 91

Venous drainage of the Esophagus

Back 91

-into adjacent veins (azygus)

-Anastomoses exist between the esophageal veins and the left gastric veins. Important link between the portal and systemic circulation

Front 92

Nerve Supply of the Esophagus

Back 92

-Vagus (esophageal plexus)

-Anterior branch - left vagus nerve

-Posterior branch -right vagus nerve

-Sympathetic fibers

-Pain fibers (sympathetic)

Front 93

Thoracic Duct

Back 93

-extends from the upper abdomen to the neck

-begins at L2 as the cisterna chyli

-passes through the diaphragm in the aortic opening at T12

-ascends right of the aorta between the azygos and the thoracic aorta

-at T5 or T6 it corsses over to the left behind the esophagus

-behind the subclavian artery forms an arch which enters the left internal jugular vein or the left jugular and left subclavian vein

Front 94

Right Lymphatic Duct

Back 94

Drains the:
1. Right upper extremity
2. Right Thoracic cavity
3. Right side of head and neck

-enters the right internal jugular vein

Front 95

Right Vagus Nerve

Back 95

-enters the diaphragm at T10

-Posterolateral to the brachiocephalic trunk

-lateral to the trachea

-posterior to root of the right lung

-medial to right phrenic

Front 96

Left Vagus Nerve

Back 96

-enters the diaphragm at T10

-between the LCC and left subclavian arteries

-crosses the left side of the aortic arch

-posterior to the root of the lung (pulmonary and esophageal plexuses)

***It is crossed by the left phrenic below the aortic arch (phrenic becomes medial and vagus becomes lateral)

Front 97

Splanchnic Nerves

Back 97

-preganglionic sympathetic nerve fibers which originate in the thorax and pierce the diaphragm to terminate in the collateral ganglia in the abdomen

-postganglionic nerve fibers from these collateral ganglia distribute to much of the abdominal viscera

Front 98

Greater Splanchnic Nerve

Back 98

-T5-T9

-enter the abdomen through the aortic opening

-synapses in the celiac ganglion

Front 99

Lesser Splanchnic nerve

Back 99

-T10- T11

-synapses in the superior mesenteric ganglion

Front 100

Lowest Splanchnic Nerve

Back 100

- T12

-synapses in teh aortorenal ganglion

Front 101

Sympathetic Trunk and Ganglia

Back 101

-nerve "strands alongside of the vertebral column
-ganglia are flat expansions along the course of the chain

Three Parts
1. Ganglia
2. Trunk
3. Chain

Front 102

ANS

Back 102

-classically described as the visceral motor system

-consists of fibers that innervate involuntary (smooth) muscle

-modified cardiac muscle (the intrinsic stimulating and conducting tissue of the heart)

-glands
---------------------------------------------------
-visceral efferent fibers of the ANS are accompanied by visceral afferent fibers, play an important role in the regulation of visceral function as they conduct visceral pain impulses

Front 103

Conduction of impulses from the CNS to the effector tissues or organs involves a series of 2 neurons in both systems

Back 103

1. The cell body of the 1st presynaptic, or preganglionic neuron is located in the gray matter of the CNS

2. Its axon synapses only on the cell bodies of postsynaptic, or postganglionic neurons, the 2nd neurons in the series

-the cell bodies of the 2nd neurons are located in the autonomic ganglia outside the CNS with fibers terminating on the effector organ

Front 104

Distinctions between the Sympathetic (thoracolumbar) and Parasympathetic (craniosacral) divisions of the ANS

Back 104

anatomical distinction:
based primarily on the location of the presynaptic neurons

functional distinction:
norepinephrine as a transmitter by the sympathetic division and acetylcholine by the parasympathetic division

Front 105

ANS involves two neurons between the CNS and effector

Back 105

Neuron #1 is presynaptic
Neuron #2 is postsynaptic

-since synapses occur in the ANS ganglia, neuron #1 is preganglionic and #2 is post ganglionic

#1 is myelinated
#2 is unmyleinated

#1 always produces ACh as its NT, and #2 usually produces ACh or NE

Front 106

Subdivisions of the ANS

Back 106

-Sympathetic:
neuron #1 is short relative to neuron #2

Parasympathetic
neuron # 1 is long and #2 is short

-actions are usually antagonistic to each other

Sympathetic
-fight or flight

Parasympathetic
-rest and digest

Front 107

Cell bodies of the preganglionic neurons of the sympathetic division of ANS are located in

Back 107

-intermediolateral cell columns (IML) of the spinal cord

-part of the gray matter extending between T1 and L2 or L3

-also referred to as lateral horns

Front 108

Paravertebral Ganglia

Back 108

-linked to form the right and left sympathetic chains or trunks on each side of the vertebral column extending its length

-superior cervical ganglion (paravertebral) lies at the base of the skull

-ganglion impar forms inferiorly where the two (right and left) trunks unite at the level of the coccyx

Front 109

Prevertebral Ganglia

Back 109

-located at the level of the plexuses that surround the origins of the main branches of the abdominal aorta

-Celiac ganglia-associated with the celiac trunk

-Superior mesenteric ganglion - associated with the superior mesenteric artery

Inferior mesenteric ganglion - associated with the inferior mesenteric artery

Front 110

Within the sympathetic trunks, preganglionic fibers follow one of three possible paths

Back 110

1. Enter and synapse immediately with a postsynaptic neuron of the paravertebral ganglion at the same level

2. Ascend or descend in the sympathetic chain to synapse with a post synaptic neuron of a higher or lower paravertebral ganglion

3. Pass through the sympathetic trunk without synapsing, continuing on to an abdominopelvic splanchnic nerve to reach the prevertebral ganglion

Front 111

Major effect produced by preganglionic fibers innervating the adrenal medullae

Back 111

-release of epinephrine and norepinephrine into the general circulation

Front 112

Major effects prodcued by sympathetic postganglionic fibers in spinal nerves

Back 112

-constriction of cutaneous blood vessels, reduction in circulation to the skin and to most other organs in the body wall

-accleration of blood flow to sk. muscles and brain

-stimulation of energy production and use by sk. muscles

-release stored lips from subcut adipose tissue

-stim of secretion by sweat glands

-stimulation of the arrector pili

-dilation of pupils and focusing for distant objects

Front 113

Major effects produced by postganglionic fibers entering the thoracic cavity in sympathetic nerves

Back 113

-acceleration of heart rate and increasing the strength of cardiac contractions

-dilation of respiratory passageways

Front 114

Sympathetic Nervous System Summary pg 91

Back 114

-Neuron #1 (preganglionic) is short, #2 postganglionic is long

-synapses occurs in paravetebral chain ganglia or prevertebral collateral ganglia

-#1 releases ACh, #2 usually NE

-prepares for emergency action, excitatory to many organs, in hib to others (digestive)

Front 115

Cranial parasympathetic outflow

Back 115

-in the gray matter of the brainstem

-fibers exit the CNS within cranial nerves III, VII, IX, and X

Front 116

Sacral Parasympathetic outflow

Back 116

- in the gray matter of the sacral segments of the spinal cord (S2-S4)

-fibers exit the CNS through the vetnral roots of spinal nerves S2-S4 and the pelvic splanchnic nerves that arise from their ventral rami