Respiratory System Anatomy

function of thoracic wall

• protect thorax and abdominal organs

• resist negative internal pressure by elastic recoil of lungs

• attachment for muscles of upper limb, neck, abdomen, back, respiration

borders of superior thoracic aperture

• posterior: T1 vertebra

• lateral: first pair of ribs and costal cartilages

• anterior: superior border of manubrium

structures within superior thoracic aperture

trachea, esophagus, vessels, nerves

superior thoracic aperture also known as

anatomical thoracic inlet

borders of inferior thoracic aperture

• posterior: T12 vertebra

• lateral: 11th and 12th pairs of ribs

• anterolateral: costal margin

• anterior: xiphisternal joint

describe costal margin

joined costal cartilages of ribs 7-10

structures within inferior thoracic aperture

diaphragm, inferior vena cava, esophagus

inferior thoracic aperture also known as

anatomical thoracic outlet

which ribs articulate only with their corresponding vertebral body

ribs 1-2, 10-12

which ribs do not articulate with transverse processes of their corresponding vertebra

ribs 11-12

1st sternocostal joint type

cartilaginous

2nd-7th sternocostal joint type

synovial plane

true ribs

ribs 1-7, attach directly to sternum through their own costal cartilage

false ribs

ribs 8-10. connection with sternum is indirect through costal margin

floating ribs

ribs 11-12, do not connect with sternum at all, no tubercles

true ribs also known as

vertebrosternal

false ribs also known as

vertebrochondral

naming intercostal spaces

based on rib that forms superior border of space

describe rib angle

weakest part of rib

describe costal groove

on inferior internal border of ribs, holds intercostal vein, artery, nerve

describe 1st rib

shortest with sharpest curve, grooves for subclavian vessels, scalene tubercle splits grooves

which groove of 1st rib is for the subclavian artery

proximal to head

which groove of 1st rib is for the subclavian vein

distal to head

which parts of vertebra typically articulate with heads of ribs

superior and inferior costal demifacets, costovertebral joint

which parts of vertebra typically articulate with tubercles of ribs

costal facets on transverse processes, costotransverse joint

location of manubrium

bodies of T3 and T4 vertebrae

location of sternal angle

interventricular disc between T4 and T5

location of sternum body

T5-T9 vertebrae

location of xiphisternal joint

T9 vertebra

location of xiphoid process

T10 vertebra

structures found at xiphisternal joint

superior level of liver, central tendon of diaphragm, inferior border of heart

movement of thoracic wall during typical inspiration

vertical increase as diaphragm descends during contraction

movement of thoracic wall during typical expiration

elastic recoil of lungs, diaphragm ascends during relaxation

movement of thoracic wall during forced inspiration

rib cage widens, vertical increase

movement of thoracic wall during forced expiration

rib cage narrows, vertical decrease

what structures of thoracic wall move like a bucket handle during inspiration

lower ribs

what structures of thoracic wall move like a pump-handle during inspiration

sternum, upper ribs

muscles responsible for pump handle and bucket handle motions

intercostal muscles

muscles involved in quiet inspiration

diaphragm, intercostal muscles

muscles involved in quiet expiration

none

muscles involved in forced inspiration

external intercostals, levatores costarum, serratus posterior superior, accessory muscles

muscles involved in forced expiration

anterolateral abdominal muscles, interosseous part of internal intercostals, transversus thoracis, serratus posterior inferior

accessory muscles of respiration

pectoralis major, pectoralis minor, serratus anterior inferior, scalenes

direction of external intercostal muscle fibers

inferoanteriorly

direction of internal intercostal muscle fibers

inferoposteriorly

direction of innermost intercostal muscle fibers

inferoposteriorly

origin of posterior intercostal arteries

supreme intercostal arteries and thoracic aorta

orign of anterior intercostal arteires

internal thoracic arteries and musculoprehenic arteries

origin of internal thoracic arteries

subclavian artery

origin of subcostal arteries

thoracic aorta

venous drainage path for throacic wall

11 posterior veins on each side and 1 subcostal vein, end in azygos/hemazygos system, superior vena cava

how does air move in lungs

volume of lungs increase with thoracic wall, less pressure in lungs compared to atmosphere

how does air move out of lungs

volume of lungs decrease with thoracic wall, more pressure in lungs compared to atmosphere

abdominal viscera involvement in inspiration

resist further descent and elevate/widen lower ribs through continued contraction of diaphragm

describe reverse action

fixed attachment from normal action moves towards mobile attachment from normal action

reverse action for sternocleidomastoid

elevate sternum for forced inspiration

reverse action for pectoralis minor for forced inspiration

elevate ribs

reverse action for pectoralis major for forced inspiration

elevate ribs and sternum

reverse action for serratus anterior for forced inspiration

rib attachments move toward scapula

structures within pulmonary cavities

lung, pleura

structures within mediastinum

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

purpose of pleural fluid

surface tension to hold lungs against chest wall

describer cervical pleura

dome over apex of each lung within pleural cavities, 2-3 cm above clavicle

where do visceral and parietal pleura join into one continuous sheet

pleural sleeve at root of lung

describe pulmonary ligament

continuation of pleural sleeve below the root of lung, between lung and mediastinum

describe costal pleura

inside of chest wall, made up of sternum, ribs, costal cartilage, intercostal muscles

describe mediastinal pleura

sides of parietal pleura along sides of mediastinum

describe diaphragmatic pleura

parietal pleura on top of diaphragm

describe costodiaphragmatic recess

meeting place of costal pleura and diaphragmatic pleura

describe costomediastinal recess

where costal pleura meets mediastinal pleura, behind sternum

purpose of recesses

reserve space for lungs to fill during deep inspiration

describe pain in visceral pleura

none, no sensation

describe pain in parietal pleura

very painful, intercostal and phrenic nerves

describe pain in costal and outer diaphragmatic pleura

pain over chest and abdominal wall, intercostal nerves

describe pain in mediastinal and central diaphragmatic pleura

referred pain in neck and shoulder, phrenic nerves (C3-5)

where to find midclavicular line

8th costal cartilage

where to find midaxillary line

10th rib

where to find scapular line

12th rib toward T12

location of pleura in relation to lungs

pleura is two ribs lower than lung

differentiate right and left lung

right lung has 3 lobes, left lung has 2 lobes, only right lung has horizontal fissure, both have oblique fissure, right is larger than left

define hilum

where lung root enters

location of oblique fissure of lungs

T2 spinous process to 6th costal cartilage

location of horizontal fissure

along 4th rib and costal cartilage

describe cardiac noth

space in left lung where apex of heart articulates

describe lingula

portion of left lung where apex of heart rests

location of apex of lungs

above 1st rib

differentiate anterior and posterior borders of lungs

anterior is thin and sharp, posterior is broad and round

location of pulmonary arteries on root of lungs

highest structure on left lung, can share highest position with bronchus on right lung

location of pulmonary veins on root of lungs

superior pulmonary vein most anterior structure, inferior vein most inferior structure

what holds open trachea and all bronchi

C shaped cartilage

location of trachea split into left and right main bronchi

sternal angle

differentiate right and left main bronchi

right is wider, shorter, more vertical

differentiate lobar bronchi from right and left

3 lobar bronchi on the right, 2 lobar bronchi on the left

bronchioles to alveoli from least to most complex

trachea, main bronchi, lobar bronchi, segmental bronchi, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveolar sac

first place of gas exchange

respiratory broncholes

basic structural unit of gas exchange in lung

pulmonary alveolus

which airway structures are within the lungs

terminal bronchioles, respiratory bronchioles, alveolar ducts, alveolar sac

describe bronchial arterial supply

bronchial arteries come off thoracic aorta for left lung and posterior intercostal artery for right lung

describe bronchial venous drainage

right lung drains into azygos vein, left lung drains into accessory hemiazygos vein, accessory hemiazygos vein drains into azygos vein, azygos vein drains into superior vena cava

explain steps of blood circulating in heart and lungs

1. deoxygenated blood enters right atrium through superior vena cava, inferior vena cava, coronary sinus

2. excess of this blood can also fill right auricle

3. blood travels through tricuspid valve to reach right ventricle

4. right ventricle contracts blood through pulmonary semilunar valve into pulmonary trunk

5. pulmonary trunk splits into two pulmonary arteries that go to each lung

6. oxygen in picked up within lung capillaries

7. four pulmonary veins bring oxygenated blood back to left atrium of heart

8. excess of this blood can also fill left auricle

9. blood travels through bicuspid valve to reach left ventricle

10. left ventricle contracts blood through aortic semilunar valve into aorta