respiratory system :Larynx, Trachea and Lungs

The Larynx

voice box; passageway for air moving from pharynx to trachea; contains vocal cords

opposite the 3rd, 4th, 5th and 6th cervical vertebrae

ts lower end is continuous with ithe trachea at the level of the sixth cervical vertebra.

Larynx boundaries

epiglottis , cricoid cartilage.

laryngeal inlet., hyloid bone,

hyloid bone,

attachs to the temporal bones and supports the base layer of the tounge

epiglottis

A flap of tissue that seals off the windpipe and prevents food from entering.

cricoid cartilage.

the ring-shaped structure that forms the lower portion of the larynx

laryngeal inlet.

opening that connects the pharynx and larynx

laryngeal cartilages types

Single:

Thyroid cartilage.

Cricoid cartilage.

Epiglottis cartilage.

Paired:

Arytenoid cartilages.

Corniculate cartilages.

Cuneiform cartilages.

Thyroid cartilage.

A firm prominence of cartilage that forms the upper part of the larynx; the Adam's apple.

Arytenoid cartilages.

Pyramid-like cartilaginous structures that form the posterior attachment of the vocal cords.

Corniculate cartilages.

attached to arytenoid cartilages like a pair of little horns

Cuneiform Cartilages

support soft tissue between arytenoids and epiglottis

Trachea:

Allows air to pass to and from lungs. It is called also the windpipe.

C-shaped hyaline cartilage (non-collapsible).

It is lined with pseudo-stratified columnar ciliated epithe

Both ends of the cartilage is connected with smooth muscle which is called trachealis.

trachealis muscle

Consists of smooth muscle fibers that connect posterior parts of cartilage rings

Contracts during coughing to expel mucus

Bronchial tree:

branched airways that lead from the trachea to the microscopic air sacs called alveoli.

bronchi which are extra-pulmonary. (anything situated, occurring, or originating outside the lungs)

primary bronchus will divide into lobar (secondary) bronchi,

primary bronchus

a pair of branches of the trachea that lead to the right and left lung; consist of incomplete rings of cartilage and are lined by pseudostratified ciliated columnar epithelium

lobar (secondary) bronchi

branch from main bronchi; 2 on left, 3 on right

will divided into multiple segmental (tertiary) bronchi.

segmental (tertiary) bronchi.

supported by crescent-shaped cartilage plates

10 on right, 8 on left

Air passage ways connecting trachea with alveoli.

Warms and moistens incoming air.

Lungs

two spongy organs, located in the thoracic cavity enclosed by the diaphragm and rib cage, responsible for respiration

right lung

3 lobes (superior, middle, inferior) 600 gm, is broader and shorter, pushed up by the liver.

has two main fissures—the oblique (major) fissure and the horizontal (minor) fissure.

left lung

2 lobes: superior and inferior. 550 gm, is longer and narrower

has one main fissure, the oblique (major) fissure.

a prominent cardiac notch, and the lingula

cardiac notch

a concave space on the left lung in which the heart lies

Lingula

The region of the left lung that corresponds with the right middle lobe.

oblique (major) fissure

Divides upper and lower lung portions.

horizontal (minor) fissure

Divides right upper and middle lobes.

Borders of lungs

anterior, posterior, inferior

apex of the lung

tip or uppermost portion of the lung.

Area above the impression of Ist rib

It is covered by the cervical pleura above which lies the suprapleural membrane.

cervical pleura

-extends through the superior thoracic aperture into the root of the neck

-forms a cup-shaped pleural dome over the apex of the lung

suprapleural membrane.

The thickening of the fascia over the apex of the lung

base of the lung

lowest part of the lung, resting on the diaphragm

Right side- right lobe of liver

Left side- left lobe of liver, fundus of stomach and spleen.

costal surface of the lung

pressed against the ribcage

Related to lateral thoracic wall.

Separated by costal pleura & endothoracic facia

Upper 6 ribs in midclavicular line, 8 in the midaxillary line, and 10 in midscapular line

costal pleura

covers the inner surface of the rib cage

endothoracic fascia

CT layer separating the parietal (costal) pleura from the internal surface of the thoracic wall.

medial surface of lung

the concave, vertically oriented inner surface facing the mediastinum and heart. It contains the lung hilum

Forms root of the lungs.

Covered with pleura (parietal becomes visceral)

parietal pleura

outer layer of pleura lying closer to the ribs and chest wall

parietal pleura parts

costal pleura, mediastinal pleura, diaphragmatic pleura, cervical pleura

visceral pleura

inner layer of pleura lying closer to the lung tissue

lung hilum

on mediastinal surface; site for attachment of blood vessels, bronchi, lymphatic vessels, and nerves

.

superior pulmonary vein.

The most anterior

the inferior pulmonary vein.

The most inferior

the bronchus

most posterior

The right pulmonary artery

anterior to the bronchus

the left pulmonary artery

superior to the bronchus.

Bronchopulmonary segment

Pyramidal portion of lung supplied by each tertiary bronchi

Bronchopulmonary segment right : upper lobe

Has apical , anterior & posterior segments.

Bronchopulmonary segment right: middle lobe

Has medial & lateral segments

Bronchopulmonary segment right: lower lobe

Has superior, anterior basal, posterior basal, medial basal & lateral basal segments.

Bronchopulmonary segments left: upper lobe

Has apical, posterior, anterior , superior lingular & inferior lingular segments.

Bronchopulmonary segments left: lower lobe

Has superior , anterior basal, medial basal posterior basal & lateral basal segments.

blood flow of lungs

The pulmonary artery carries deoxygenated blood into alveoli (gas exchange) and then into pulmonary veins, which carry oxygenated blood into the left atrium, into the left ventricle, into the aorta, and into bronchial arteries to the lung tissue.

Blood supply of the lungs:

Pulmonary artery = major supplier of blood to the lungs

provides deoxygenated blood for gas exchange

Bronchial artery = supplies nutrients and removes waste from bronchi

provides collateral blood flow to remainder of lung parenchyma