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Respiratory System

Part 1: Respiratory Anatomy

Respiration

• Cardiopulmonary system

• Respiratory and conducting divisions

• Three processes

1. Breathing

2. Exchange of gases

3. Use of oxygen

Respiration

• Pulmonary ventilation (breathing):movement of air into and outof the lungs

• External respiration: O2 and CO2exchange between the lungsand the blood

• Transport: O2 and CO2in the blood

• Internal respiration: O2 and CO2exchange between systemic bloodvessels and tissues

Respiratory

system

Circulatory

system

Functional Anatomy

• Structures

– Nose

– Pharynx

– Larynx

– Trachea

– Lungs

– Bronchial tree

– Pleurae

Figure 22.1

Nasal cavity

Nostril

Oral cavity

Pharynx

Larynx

Trachea

Carina of

trachea

Left main

(primary)

bronchus

Right main

(primary)

bronchus

Right lung

Left lung

Diaphragm

Nose

• Functions

– Provides an airway for respiration

– Moistens and warms entering air

– Filters and cleans inspired air

– Resonating chamber for speech

– Olfactory receptors

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Figure 22.2a

Epicranius,

frontal belly

Ala of nose

Root and

bridge of

nose

Dorsum nasi

Apex of nose

Philtrum

Naris (nostril)

Figure 22.2b

Frontal bone

Nasal bone

Septal cartilage

Maxillary bone

(frontal process)

Lateral process of

septal cartilage

Minor alar cartilages

Major alar

cartilages

Dense fibrous

connective tissue

(b) External skeletal framework

Figure 22.3c

Sphenoid sinusFrontal sinus

Nasal meatuses

(superior, middle,

and inferior)

Nasopharynx

Uvula

Palatine tonsil

Isthmus of the

fauces

Posterior nasal

aperture

Opening of

pharyngotympanic

tube

Pharyngeal tonsil

Oropharynx

Laryngopharynx

Vocal fold

Esophagus

(c) Illustration

Nasal conchae

(superior, middle

and inferior)

Nasal vestibule

Nostril

Nasal cavity

Hard palate

Soft palate

Tongue

Lingual tonsil

Epiglottis

Hyoid boneLarynx

Thyroid cartilage

Vestibular fold

Cricoid cartilage

Thyroid glandTrachea

Cribriform plate

of ethmoid bone

Figure 22.3b

Pharynx

Nasopharynx

Oropharynx

Laryngopharynx

(b) Regions of the pharynx

Pharynx

• “Throat”

• Between internal nares and larynx

• Three regions

1. Nasopharynx

2. Oropharynx

3. Laryngopharynx

Transports air

Transports air,

liquids and solids

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Thought Questions

1. Name 2 functions of the nasal cavity.

2. Which pharyngeal region(s) would you

expect to find stratified squamous epithelium

and why?

Larynx

• Cartilage framework

– Glottis

– Epiglottis

• Functions

1. Provides a patent airway

2. Routes air and food into proper channels

3. Sound production

Figure 22.4a

Body of hyoid bone

Epiglottis

Cricoid cartilage

Tracheal cartilages

Thyroid cartilage

Laryngeal prominence

(Adam’s apple)

Cricothyroid ligament

Cricotracheal ligament

(a) Anterior superficial view

Thyrohyoid

membrane

Figure 22.4b

Epiglottis

Body of hyoid bone

Thyrohyoid membrane

Vestibular fold

(false vocal cord)

Vocal fold

(true vocal cord)

Cricothyroid ligament

Cricotracheal ligament

Fatty pad

Thyroid cartilage

Cuneiform cartilage

Corniculate cartilage

Arytenoid cartilage

Cricoid cartilage

Tracheal cartilages

Arytenoid muscles

(b) Sagittal view; anterior surface to the right

Thyrohyoid

membrane

Figure 22.5

(a) Vocal folds in closed position;

closed glottis

(b) Vocal folds in open position;

open glottis

Base of tongue

Epiglottis

Vestibular fold

(false vocal cord)

Vocal fold

(true vocal cord)

Glottis

Inner lining of trachea

Cuneiform cartilage

Corniculate cartilage

Sound Production

• Vocal folds

– Sound = vibration of folds

• Pitch

– Tension of the vocal cords

• Loudness

– Air pressure

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Sound Production

• Chambers of pharynx, oral, nasal and sinus cavities amplify and enhance sound quality

• Sound is “shaped” into language by muscles of the pharynx, tongue, soft palate and lips

Trachea

• Windpipe

–From the larynx into the mediastinum (membranous partition between the lungs)

• Smooth muscle and connective tissue

–C-shaped cartilage rings

Figure 22.6a

(a) Cross section of the trachea and esophagus

Hyaline cartilage

Submucosa

Mucosa

Seromucous gland

in submucosa

Posterior

Lumen of

trachea

Anterior

Esophagus

Trachealis

muscle

Adventitia

Lungs

• Left

– 2 lobes

• Right

– 3 lobes

Figure 22.10a

Trachea

Apex of lung

Thymus

Right superior lobe

Horizontal fissure

Right middle lobe

Oblique fissure

Right inferior lobe

Heart

(in mediastinum)

Diaphragm

Base of lung

Left

superior lobe

Cardiac notch

Oblique

fissure

Left inferior

lobe

Lung Pleural cavityParietal pleura

Rib

Intercostal

muscle

Visceral pleura

(a) Anterior view. The lungs flank mediastinal structures laterally.

Figure 22.7

Trachea

Superior lobe

of right lung

Middle lobe

of right lung

Inferior lobe

of right lung

Superior lobe

of left lung

Left main

(primary)

bronchus

Lobar

(secondary)

bronchus

Segmental

(tertiary)

bronchus

Inferior lobe

of left lung

Lungs and Bronchial Tree

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Bronchial Tree

• Trachea

– Primary bronchi

• Right bronchus

– Shorter

– Branches into 3 secondary bronchi

• Left bronchus

– Branches into 2 secondary bronchi

Bronchial Tree

Trachea

Primary bronchi

Secondary bronchi

Tertiary bronchi

Bronchioles

Terminal bronchioles

Respiratory bronchioles

Alveoli

Respiratory zone

(10%)

(90%)

Alveoli

• Gas exchange

• Large surface area + small diameter = high

surface tension

– Pulmonary surfactant

– Infant respiratory distress syndrome

Figure 22.8a

(a)

Alveolar duct

Alveolar ductAlveoli

Alveolar

sac

Respiratory

bronchioles

Terminal

bronchiole

Figure 22.8b

(b)

Alveolar

pores

Alveolar

duct

Respiratory

bronchiole

Alveoli

Alveolar

sac

Squamous epithelium with an elastic membrane

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Figure 22.9a

Elastic

fibers

(a) Diagrammatic view of capillary-alveoli relationships

Smooth

muscle

Alveolus

Capillaries

Terminal bronchiole

Respiratory bronchiole

Figure 22.9c

Capillary

Type II (surfactant-

secreting) cell

Type I cell

of alveolar wall

Endothelial cell nucleus

Macrophage

Alveoli (gas-filled

air spaces)

Red blood cell

in capillary

Alveolar pores

Capillary

endothelium

Fused basement

membranes of the

alveolar epithelium

and the capillary

endothelium

Alveolar

epithelium

Respiratory

membrane

Red blood

cell

O2

Alveolus

CO2

Capillary

Alveolus

Nucleus of type I

(squamous

epithelial) cell

(c) Detailed anatomy of the respiratory membrane

Pleurae

• Thin, double-layered serosa

– Parietal pleura

• Thoracic wall and superior face of diaphragm

– Visceral pleura

• External lung surface

• Pleural fluid

– Lubrication

Pleural Cavity

Visceral Pleura

Parietal Pleura

Pleurae

• Three functions

1. Reduction of friction

2. Pressure gradient

3. Compartmentalization

4. (Also cushioning and protection)

Figure 22.10c

Esophagus

(in mediastinum)

Right lung

Parietal

pleura

Visceral

pleura

Pleural

cavity

Pericardial

membranes

Sternum

Anterior

Posterior

Root of lungat hilum

Left lung

Thoracic wall

Pulmonary trunk

Heart (in mediastinum)

Anterior mediastinum

(c) Transverse section through the thorax, viewed from above. Lungs,

pleural membranes, and major organs in the mediastinum are shown.

• Left main bronchus

• Left pulmonary artery

• Left pulmonary vein

Vertebra

Fill in the blanks

External nares nasal cavity ___1___

___2___ trachea ____3____

secondary bronchi __4__ bronchi

___5____ terminal bronchioles

_____6_______ ___7___Word bank: respiratory bronchioles, larynx, tertiary, alveoli, bronchioles, primary bronchi, pharynx

Respiratory zone