Thorax

• costovertebral joints: ribs and vertebrae
• sternocostal
• sternoclavicular
• costochondral
• interchondral
• intervertebral

12

T1-T11

T12

• external intercostal
• internal intercostal
• inner most intercostals
• serratus posterior superior
• serratus posterior inferior

• Origin: inferior border rib above
• Insertion: superior border rib below
• innervation: intercostal nerves
• Actions- External: elevate ribs in passive and active respiration
• Internal: depress ribs in active expiration

• Origin: nuchal ligamnet, spinous process of C7-T3
• Insertion: superior border of ribs 2-4
• Innervation: intercostal nerves 2-5
• Action: elevate ribs

• Origin: spinous process of T11-L2
• Insertion: inferior borders of ribs 8-12
• Innervation: intercostal nerves 9-12 and T12 nerve
• Action: depress ribs

• -diaphragm moves down, thoracic cage goes up
• -Volume increases and pressure decreases

• -volume decreases and pressure increases
• -pressure in lungs is greater than atmospheric pressure

Diaphragm, external intercostal

no muscles used

diaphragm, external intercostal, sternocleidomastoid, pectoralis minor and scalenes

internal intercostal and all abdominal muscles

• 2 lateral pulmonary cavities
• 1 central mediastinum

lungs and pleura

heart, great vessels, trachea, esophagus, thymus and lymph nodes

covers lungs and attaches to surfaces

lines pulmonary cavities, attaches to thoracic wall, mediastinum and diaphragm

Oxygenate the blood- bring oxygenated air close to deoxygenated venous blood

• 3,2
• 2,1

• main bronchus
• pulmonary weins and arteries
• bronchial vessels
• lymphatic vessels
• nerves

• trachea sends primary bronchus to each lung (right and left primary bronchus)
• -primary bronchus branches into bronchial tree
• -each bronchus divdies into secondary bronchi( 2 on left 3 on right)
• -each branch then divides into tertiary bronchi that supply broncho pulmonary segments

tertiary-->Terminal bronchioles-->Respitory bronchioles-->Alveoli which is basic unit of gas exchange

carbon dioxide moves from red blood cell through alveolar capillary membrane to the alveolus and oxygen travels from alveolus through alveolar capillary membrane to red blood cell

• each lung is supplied by pulmonary artery
• only de-oxygenated artery in body

• each lung is drained by 2 pulmonary vein
• all 4 pulmonary veins drain into left atrium
• only oxygenated vein in body

superior vena cava, brachiocephalic veins, artch of aorta, trachea, esophagus, vagus nerves and phrenic nerves

5

• lies in the middle mediastinum
• two thirds lies left of midline

• coronary sulcus
• anterior interventricular sulcus
• posterior interventricular sulcus

separates atria from ventricles

external boundary b/w right and left ventricles

external boundary b/w ventricles on posterior surface

surrounds and protects the heart

• 1. Fibrous pericardium
• 2.Serous pericardium

• Superficial layer
• tough
• protection
• anchors heart in place

• deeper layer
• thinner then fibrous
• parietal layer: fuse to fibrous pericardium
• visceral layer: attaches to heart

• contain pericardial fluid which reduces friction
• (b/w two layers of serous)

• epicardium
• endocardium
• myocardium

• external layer
• composed of CT

• middle layer
• 95% of heart wall

inner layer

• superior vena cava
• inferior vena cava
• coronary sinus

right auricle, anterior wall, posterior wall, inter atrial septum, fossa ovalis, tricuspid valve

small pouch allows increased volume

internal muscular ridges called pectinate muscles

IVC, SVC and coronary sinus enter

oval depression in septum

seperate the atria

blood lows from right atrium into right ventricle through tricuspid valve

trabeculae carneae

interventricular

attached to tricuspid valve which is then attached to papillary msucles

pulmonary semilunar valve and then blood goes to pulmonary trunk which divides into right and left pulmonary arteries which supply right and left lungs

bicuspid valve

left ventricle

• Av valves (b/w atria and ventricles)-prevent blood from returning to atria once gone to ventricles
• semi-lunar (b/w ventricles and arteries)-prevent blood pumped from the heart from returning

anterior interventricular branch (or left descending artery) and circumflex branch

posterior interventricular branch and marginal branch

• blood drains from myocardium into coronary sinus by way of veins
• -great cardiac vein
• -middle cardiac vein
• -small cardiac vein
• -anterior cardiac veins

• Brachicephalic veins
• superior vena cava
• arch of aorta
• brachicephalic trunk

drains head and arm blood into SVC

returns blood from all structures superior to diaphragm except heart and lungs

• brachiocephalic trunk (right)
• left common carotid artery
• left subclavian artery

• right common carotid artery
• right subclavian artery

• Vagus(X)
• Phrenic(C3,4,5)

• goes to heart
• come from medulla and goes down posterolateral to common carotid arteries
• enters mediastinum posterior to sternoclavicular joints and brachicephalic veins

• goes to diaphragm
• -enters mediastinum b/w subclavian vein and brachiocephalic vein

• posterior intercostal arteries
• bronchial
• mediastinal
• esophageal
• pericardial
• superior phrenic
• celiac trunk

right, left

superior vena cava

back, thoraco-abdominal walls and mediastinal viscera

• Sa node
• AV node
• atrioventricular bundle
• right and left bundle branches
• purkinje fibres
• electrocardiogram

contract, relax

muscle is contracting

muscle is relaxing

• diastole-chambers relaxed while ventricles fill with blood
• atria systole- atria contract to complete filling of ventricles
• ventricle systole-blood get pumped out of heart

listening to sounds with stethoscope