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Respiratory Anatomy Study Guide


Respiratory Anatomy Lab Assignment

   Respiratory System:

 Anatomy & Histology

Respiratory system

Conducting Zone

No gas exchange

Respiratory Zone

Gas exchange

I). Conducting zone  
A). Nose

1). External nose

  • Apex

  • Philtrum

  • External Nares or Nostrils

  • Alae

2). Nasal Cavity

Lined with:

  •  sweat glands

  •  sebaceous glands

  • hair follicles

divided by a nasal septum

a).  Mucosa

i.Olfactory Mucosa

   sense of smell

ii.Respiratory Mucosa

Secretes antibacterial enzymes and mucus.

Ciliated cells sweep material to pharynx.

Surface increased by scrolled nasal conchae

Nasal Cavity
b). Paranasal Sinuses
  • frontal
  • sphenoid
  • ethmoid
  • maxillary
paranasal sinuses
B). Pharynx

Connects the nasal cavity & the mouth

to the larynx (respiratory) &

 the esophagus (digestive)


1). nasopharynx

2). oropharnyx

3). layngopharnyx


C). Larynx

1). Functions to:

  •   Provide airway

  •   Switching station between food intake and air intake

  •   Voice production

2). Anatomy

a). cartilages

i. Thyroid Cartilage

ii. Cricoid Cartilage

iii. Epiglottis

iv. (3) Arytenoid Cartilages

v. (3) Corniculate Cartilages

b). Vocal ligaments

c).  Glottis

larnyx anatomy

3). Voice Production

i) Vibration

  Air passing over the vocal folds causes vibrations.


ii).  Pitch

  Length and tension of the vocal folds is controlled by muscle


iii).  Size of the glottis

  Wider the glottis opening deeper the sound because less the ligaments vibrate


iv).  Loudness

  function of force of expired air

D). Trachea

Surrounded by rings of hyaline cartilage for strength

The trachea is flexible but cannot collapse because of the rings.

(The esophagus can collapse).

When food is swallowed the esophagus widens into the tracheal space.


Very sensitive terminal cartilage ring.

Results in coughing when contacted by foreign material


lung anatomy
Trachea Histology


trachea histology



  • Lumen

  • Mucosa:  Epithelium

  • Submucosa: Connective tissue

  • Hyaline Cartilage

trachea cross section










This animation shows the smooth muscle contracting.

E). Primary Bronchi

left and right bronchi

F). Bronchial Tree

The bronchi sub divide into 2nd and 3rd bronchials and then continue to subdivide

23 pairs of branching passageways


bronchial tree










G). Bronchioles

Terminal bronchioles are the end of the conducting zone

II). Respiratory Zone  

A).  Respiratory Bronchioles

  Branch off of terminal bronchioles

  Contain few alveoli

B).  Alveolar ducts 

Consist of smooth muscle,

connective tissue and out pocketing alveoli

C).  Alveolar Sacs

  A bunch of alveoli

  (similar to a bunch of grapes)

D).  Alveoli

Individual Sac

Actual site of gas exchange

Alveolar Sacs

Structure of the alveoli

1). Type 1 cells

2). Pulmonary Capillaries

Cover the outside surface

3). Respiratory Membrane

4). Type II cells

produce surfactant

5). Alveolar Pores

Connect the alveoli together and equalize the air pressure and provide alternate air routes to alveoli with collapsed bronchioles

6). Alveolar macrophages

Maintain sterile alveolar surfaces



lung histology



  • Alveoli

  • type I cells

(epithelial cells that make up the alveoli)




III). Gross Anatomy  

A).  Left Lung

2 lobes



divided by an oblique fissure


Contains cardiac notch--Left lung indention that accommodates the heart


lung anatomy


B). Right Lung


3 lobes:



divided by a horizontal fissure


divided by an oblique fissure


lung anatomy
C). Innervations

Pulmonary plexuses supplies nerve fibers from the parasympathetic and some sympathetic systems

D).  Pulmonary Pleurae

Double membrane covers the thoracic wall & the lungs and is filled with pleural fluid


Lining of the chest


IV). Blood Supply

A.  Pulmonary Circulation

  1.  Pulmonary Arteries from the pulmonary trunk carry deoxygenated blood from the heart

  2.  Pulmonary veins return oxygenated blood to the heart


B.  Systemic Circulation

1.  Cardiac Circulation

     Blood vessels that supply and drain the heart muscle.


2.  Bronchial Circulation O2 for conducting zone

  Bronchial arteries and veins from the systemic flow to the bronchi