Respiratory and Lung Anatomy

Pharynx

Three parts: Nasopharynx, oropharynx, laryngopharynx

Hyoid Bone

Supports larynx, attachment site for muscles of larynx, pharynx, and tongue

Larynx

Cartilaginous portion ( Adams apple), is the voice box

Trachea

Windpipe, rings of cartilage prevent collapse

Primary Bronchi

• 2 branches directly from base of trachea

• 1 to each lung

• Rings of cartilage prevent collapse

Secondary Bronchi

• Branch from each primary

• 1 goes to each lobe of lung

• Plates of cartilage and smooth muscle

Tertiary Bronchi

• Branch from each secondary

• Each supplies air to a bronchopulmonary segment

• Less cartilage, more smooth muscle

Bronchioles

• Branch from each tertiary

• Within bronchopulmonary segment

• lack cartilage

• Only has smooth muscle

Terminal Bronchioles

• Branch from larger bronchioles

• Each delivers air to a single pulmonary lobe

• Only smooth muscle

Respiratory Bronchiole

• Branch from terminal bronchioles

• Deliver air to alveoli ( gas exchange surfaces)

• Smooth muscle only

Alveoli

• Site of gas exchange

• Covered with capillary beds

• Elastic fibers and surfactant help keep open

Right Lung

Has 3 lobes

R Superior Lobe

3 bronchopulmonary segments/ 3 tertiary bronchi

R Inferior Lobe

5 segments

R Middle Lob

2 segments

Left Lung

2 lobes

L Superior lobe

4 segments

L inferior Lobe

2 segments

Blood Supply

Each supplied by pulmonary arteries and pulmonary veins

Air supply

Each supplied by bronchi

Gas Exchange

• Occurs in pulmonary lobules

• Which contain alveoli covered with capillaries

Respiration steps

Breath in, gas diffuses, then transports O2 and CO2

Epithelia and Endothelia are

Bound by basement membrane

Surfactant Cells

Secrete surfactant that dirupts hydrogen bonds between water molecules to prevent alveoli collapsing. Breaks water tension. Line alveoli