1

Anatomy of the Lungs

Dr. Gondo GozaliDepartment of anatomy

2

Pulmonary Function Ventilation and Respiration Ventilation is the movement of air in

and out of the lungs Respiration is the process of gas

exchange, that is the movement of O2 from the atmosphere into the blood stream and the movement CO2 from the bloodstream into the atmosphere.

3

Pulmonary System

Consist of: Thorax Conducting airways Respiratory airways Pulmonary blood and lymph supply

4

Thorax Thoracic cage- cone shaped structure the is

rigid for protection but flexible to accommodate inhalation and exhale

12 thoracic vertebra with each a pair of ribs attached posterior

First 7 attached to sternum 8-10th attached by cartilage to ribs above 11-12th no attachment (float)

5

6

Pleurae Thin membrane that lines the outside of the

lungs and the inside of the chest wall Visceral pleura-adheres to the lungs, hilar

bronchi and major fissures Parietal pleura-lines the inner surface of

chest wall and mediastinum Separated by airtight space that contains a

lubricating fluid that allows the two pleura to glide against each other during breathing

7

Pleurae

8

Innervations of the pleura Parietal : Sensitive to pain

and temperature Innervated by the

intercostal nerves and phrenic nerve

Visceral : Not sensitive to

pain and temperature

Some sensory fibers travel with autonomic nerves that innervate the lungs

9

Vasculature Parietal

→ Intercostal→ Internal thoracic→ Pericardiacophereni

cs→ Anterior mediastinal

artery and veins

Visceral→ Bronchial vessels→ Pulmonary trunks

10

Lymphatic Parietal pleura

drain with those of the thoracic wall

Visceral pleura drain with lymphatics from the lung

11

Conducting Airways Upper airways-nasal and oral cavities, pharynx and

larynx Warms, Humidifies, and filters some irritants. Course

hairs in the nasal passage cleans the air of large inhaled particles during inhalation.

Epiglottis-Closes during swallowing of food or liquid to protect the trachea. Opens widely during inhalation to allow air to pass into the trachea onto the lower air passages

Trachea-hollow tube 11cm(4.5 in) in length and 2.5 cm (1in) in width Begins with the cricoid cartilage and ends at the bifurcation(major carina) from which the two mainstem bronchi arise.

12

The organs of the respiratory system extend from the nose to the lungs and are divided into the upper and lower respiratory tracts.

The upper respiratory tract consists of the nose and the pharynx, or throat.

The lower respiratory tract includes the larynx, or voice box; the trachea, or windpipe, which splits into two main branches called bronchi; tiny branches of the bronchi called bronchioles; and the lungs, a pair of saclike, spongy organs.

The nose, pharynx, larynx, trachea, bronchi, and bronchioles conduct air to and from the lungs.

The lungs interact with the circulatory system to deliver oxygen and remove carbon dioxide.

13

A. Nasal Passages The uppermost portion of

the human respiratory system, the nose is a hollow air passage that functions in breathing and in the sense of smell.

The nasal cavity moistens and warms incoming air, while small hairs and mucus filter out harmful particles and microorganisms.

14

B. Pharynx Air leaves the nasal passages and flows to the pharynx, a short, funnel-

shaped tube about 13 cm (5 in) long that transports air to the larynx. Like the nasal passages, the pharynx is lined with a protective mucous membrane and ciliated cells that remove impurities from the air.

The tonsils are strategically located to prevent these organisms from moving further into the body. One tonsil, called the adenoids, is found high in the rear wall of the pharynx. A pair of tonsils, the palatine tonsils, is located at the back of the pharynx on either side of the tongue.

Another pair, the lingual tonsils, is found deep in the pharynx at the base of the tongue. In their battles with disease-causing organisms, the tonsils sometimes become swollen with infection. When the adenoids are swollen, they block the flow of air from the nasal passages to the pharynx, and a person must breathe through the mouth.

15

C. Larynx Air moves from the pharynx to the larynx, a structure about

5 cm (2 in) long located approximately in the middle of the neck.

While the primary role of the larynx: Transport air to the trachea Producing sound Prevents food and fluid from entering the air passage to

cause choking Mucous membranes and cilia-bearing cells help filter air

When a person is breathing, the epiglottis is held in a vertical position, like an open trap door. When a person swallows, however, a reflex causes the larynx and the epiglottis to move toward each other, forming a protective seal, and food and fluids are routed to the esophagus.

16

D. Trachea, Bronchi, and Bronchioles

Air passes from the larynx into the trachea, a tube about 12 to 15 cm (about 5 to 6 in) long located just below the larynx. The trachea is formed of 15 to 20 C-shaped rings of cartilage. The sturdy cartilage rings hold the trachea open, enabling air to pass freely at all times. The open part of the C-shaped cartilage lies at the back of the trachea, and the ends of the “C” are connected by muscle tissue.

The base of the trachea is located a little below where the neck meets the trunk of the body. Here the trachea branches into two tubes, the left and right bronchi, which deliver air to the left and right lungs, respectively. Within the lungs, the bronchi branch into smaller tubes called bronchioles.

The trachea, bronchi, and the first few bronchioles contribute to the cleansing function of the respiratory system, for they, too, are lined with mucous membranes and ciliated cells that move mucus upward to the pharynx.

17

LUNGS

Cone shaped Total volume of 3.5-8.5 liters Superior portion is apex Inferior portion is base Apical portion rises above the clavicle Attached by hilum and pulmonary

ligament

18

Lobes and Segments Lungs are divided into lobes and segments Right lung is larger ad heavier: upper

middle and lower lobes Left lung divides into upper and lower

lobes. The lobes have a total of 18 segments:

10 on right and 8 on left - each has own bronchus

19

20

Fissure of the Lungs Right Lung

Horizontal fissure Oblique fissure Superior lobe Middle lobe Inferior lobe

Left Lung Upper lobe Lower lobe Lingulum Oblique fissure

21

22

Bronchial Tree

The two main stem bronchi are different

Left bronchi-narrower then right, angles into left lung at approximately 45 to 55 degrees

Right bronchi- wider than left and inters right lung at a 20-30 degrees

23

Bronchus Right

Larger Leaves the trachea at

25o angle Divides into

secondary bronchi before entering the lung

10 bronchopulmonary segment

Left Departs the trachea

at 45o angle Does not divide into

secondary bronchi until it reaches the lung

8 bronchopulmonary segment

24

25

The bronchopulmonary segments of the Right Lung

Right lung At the right there

are 10 segments

26

The bronchopulmonary segments of the Left Lung

Left lung At the left there

are 8 segments

27

Impressions of the right lung

28

Impressions of the left lung

29

Blood circulation

Pulmonary Circulation Pulmonary artery

carry blood to the lungs for oxygenated. These vessels are central in each bronchopulmonary segment and branch in a manner similar to the segmental bronchi. They are considered segmental in nature.

Pulmonary vein at the periphery of each segment and are

considered intersegmental.

30

31

Innervations of the lungs (1)

Sensory fibers from the lungs and visceral pleura travel with the vagus nerve

Preganglionic parasympathetic fibers travel in the vagus nerve through the pulmonary plexus to the level of the tracheobronchial tree where they synapse with postganglionics.

32

Innervations of the lungs (2) Sympathetic preganglionic from T1-6

synapse with postganglionics in the cervical and upper thoracic ganglia

Postganglionics the descend to the cardiac and pulmonary plexuses

Pulmonary plexus lies on the anterior and posterior aspects of root structure of the lungs.

The anterior and posterior of the lungs receive fibers from vagus and cardiac plexus

Posterior also receive from the thoracic sympathetic ganglion

33

Parasympathetic and sympathetic fibers of the Lungs

Parasympathetic fibers of the lungs: Vasodilators Bronchoconstrictors Secremotor in

function

Sympathetic fibers of the lung: Vasoconstrictor Bronchodilator Decreased

secretory function of mucus bronchial glands

34

Surface projections of the lungs Right Lung

Apex – 1 inch above medial 1/3 of the clavicle

Anterior border – slopes toward the midline, curves out between 4th and 6th costal cartillage

Inferior border – 6th costal cartillage and the lower end of sternum, 6th rib at the midclavicular line, 8th rib at the midaxillary line, 10th thoracic vertebra at the paravertebral line

Left Lung Same as right, except

the cardiac notch cruves 11/2 inches lateral to the sternum in the 5th ICS

Fissures Oblique – extends from

the spine of the scapula to the 6th costal cartilage

Horizontal – posterior to the 4th rib

35

T h a n k Y o u