Thorax, Heart, & Lungs

Question 1

Thorax

Answer 1

Size & shape change
Superior border - 1st rib
Inferior border - diaphragm

Question 2

Diaphragm

Answer 2

Domed muscle w/ attachments on ribs, costal cartilages, and lumbar vertebrae
Contracts to increase thoracic volume

Question 3

Intercostals

Answer 3

Three muscle layers

• Innermost intercostals
• Internal intercostals (oriented superomedially & terminate to fascia in posterior thorax)
• External intercostals (oriented inferomedially & terminate to fascia in anterior thorax)

Question 4

Pleural Cavity

Answer 4

LUNGS

Question 5

Mediastinum

Answer 5

Central mass tissues in the thorax

• Heart, great vessels, major nerves (Vagus & phrenic)
• Thoracic duct (lymphatic), azygos, & hemiazygos veins
• Sympathetic trunk

Question 6

Superior Mediastinum

Answer 6

Contains cardiac great vessels, trachea, & esophagus

Area behind manubrium

Question 7

Anterior Mediastinum

Answer 7

Begins below aortic arch at T4-5

Anterior to heart

Question 8

Middle Mediastinum

Answer 8

Heart

Phrenic nerve travel across pericardial sac

Question 9

Posterior Mediastinum

Answer 9

Begins below aortic arch at T4-5
Contains bronchi, descending aorta, & esophagus
Thoracic duct (lymphatic channels) drains ISF & fat
- Azygos vein R
- L accessory hemiazygos & hemiazygos vein
Sympathetic chain SNS fight or flight response

Question 10

Inferior Mediastinum

Answer 10

Contains anterior, middle, & posterior mediastinum

Question 11

Parasympathetic Innervation

Answer 11

Vagus (cranial nerve X)
All thoracic PSNS motor signals travel via the Vagus
Long pre-ganglionic axons synapse in ganglia
Synapse on or near the target organ
Short post-ganglionic axons travel into target organ

Question 12

Cardiac Anatomy

Answer 12

RA → tricuspid valve → RV → pulmonary valve → pulmonary arteries → pulmonary veins → LA → mitral valve → LV → aortic valve → aorta

Question 13

Coronary Arteries

Answer 13

Coronary = crown

L anterior descending
R coronary artery
Circumflex branch

Question 14

Aortic Valve Auscultation

Answer 14

2nd intercostal space

R sternal margin

Question 15

Tricuspid Valve Auscultation

Answer 15

5th intercostal space

L sternal margin

Question 16

Pulmonary Valve Auscultation

Answer 16

2nd intercostal space

L sternal margin

Question 17

Mitral Valve Auscultation

Answer 17

5th intercostal space

Midclavicular line

Question 18

Cardiac Electrical Conduction

Answer 18

Polarization & depolarization EKG

SA node → AV node → AV bundle → L & R bundle branches → Purkinje fibers

Question 19

Atria

Conduction Velocity

Answer 19

1 m/sec

Question 20

AV Node

Conduction Velocity

Answer 20

0.01-0.05 m/sec

Question 21

His-Purkinje

Conduction Velocity

Answer 21

2-4 m/sec

Question 22

Upper Respiratory System

Answer 22

Mouth
Nasal cavity
Pharynx
Larynx

Question 23

Lower Respiratory System

Answer 23

Trachea
Bronchi
Lungs

Enclosed in thorax
Ribs, spine, & diaphragm border

Question 24

Conducting Zone

Answer 24

DEAD SPACE

Larynx & trachea

Question 25

Respiratory Zone

Answer 25

Gas exchange | Bronchioles & alveoli

Question 26

Left Lung

Answer 26

``` 2 lobes - Superior - Inferior Lingula Only oblique fissure ```

Question 27

Right Lung

Answer 27

``` 3 lobes - Superior - Middle - Inferior Horizontal & oblique fissure ```

Question 28

Breathing is a _____ process

Answer 28

Mechanical

Question 29

What causes air to enter the lungs?

Answer 29

PRESSURE Diaphragm contracts decreasing Palv Ribs & sternum elevate laterally & anteriorly Inspiration Patm > Palv

Question 30

Expiration

Answer 30

Diaphragm relaxes Palv > Patm Air moves out

Question 31

Vagus nerve innervates _____

Answer 31

Lungs | Dilates & constricts bronchi

Question 32

Phrenic nerve innervates _____

Answer 32

Diaphragm

Question 33

Thorax Muscles | Scalene

Answer 33

Pull on 1st & 2nd ribs to raise ribs similar to bucket handles ↑thoracic volume lateral & anterior

Question 34

Thorax Muscles | Intercostal

Answer 34

"Dynamic ligaments" Transfer scalene action to all ribs WOB

Question 35

Thorax Muscles | Serratus Anterior & Pectorals

Answer 35

Heavy respiration when arms fixed