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Respiration • Cardiopulmonary system • Respiratory and conducting divisions • Three processes 1. Breathing 2. Exchange of gases 3. Use of oxygen

Respiratory System Part 1: Respiratory Anatomy

Respiration • Pulmonary ventilation (breathing): movement of air into and out of the lungs • External respiration: O2 and CO2 exchange between the lungs and the blood • Transport: O2 and CO2 in the blood • Internal respiration: O2 and CO2 exchange between systemic blood vessels and tissues

Functional Anatomy • Structures – Nose – Pharynx – Larynx – Trachea – Lungs – Bronchial tree – Pleurae

Respiratory system

Circulatory system

Nose • Functions Nasal cavity Nostril

– – – – –

Oral cavity Pharynx

Larynx

Trachea Carina of trachea Right main (primary) bronchus Right lung

Left main (primary) bronchus

Provides an airway for respiration Moistens and warms entering air Filters and cleans inspired air Resonating chamber for speech Olfactory receptors

Left lung Diaphragm

Figure 22.1

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Frontal bone Epicranius, frontal belly

Nasal bone Septal cartilage

Root and bridge of nose

Maxillary bone (frontal process) Lateral process of septal cartilage

Dorsum nasi Ala of nose

Minor alar cartilages Dense fibrous connective tissue

Apex of nose Naris (nostril)

Major alar cartilages

Philtrum

(b) External skeletal framework Figure 22.2a

Cribriform plate of ethmoid bone Sphenoid sinus

Figure 22.2b

Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Nostril

Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Oropharynx Palatine tonsil Isthmus of the fauces

Hard palate Soft palate Tongue Lingual tonsil

Laryngopharynx

Esophagus

Trachea (c) Illustration

Larynx Epiglottis Vestibular fold Thyroid cartilage Vocal fold Cricoid cartilage Thyroid gland

Hyoid bone

Figure 22.3c

Pharynx • “Throat” • Between internal nares and larynx Transports air • Three regions

Pharynx Nasopharynx

1. Nasopharynx 2. Oropharynx 3. Laryngopharynx

Oropharynx Laryngopharynx

Transports air, liquids and solids

(b) Regions of the pharynx

Figure 22.3b

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Thought Questions

Larynx

1. Name 2 functions of the nasal cavity. 2. Which pharyngeal region(s) would you expect to find stratified squamous epithelium and why?

• Cartilage framework – Glottis – Epiglottis

• Functions 1. Provides a patent airway 2. Routes air and food into proper channels 3. Sound production

Body of hyoid bone

Epiglottis

Epiglottis

Thyrohyoid membrane

Thyrohyoid membrane

Body of hyoid bone Thyrohyoid membrane

Cuneiform cartilage Corniculate cartilage Arytenoid cartilage

Thyroid cartilage Laryngeal prominence (Adam’s apple)

Arytenoid muscles

Cricothyroid ligament

Vocal fold (true vocal cord)

Cricoid cartilage

Cricoid cartilage

Fatty pad Vestibular fold (false vocal cord) Thyroid cartilage

Cricothyroid ligament Cricotracheal ligament

Cricotracheal ligament Tracheal cartilages

Tracheal cartilages (b) Sagittal view; anterior surface to the right

(a) Anterior superficial view Figure 22.4a

Figure 22.4b

Sound Production • Vocal folds

Base of tongue Epiglottis

– Sound = vibration of folds

Vestibular fold (false vocal cord) Vocal fold (true vocal cord)

• Pitch – Tension of the vocal cords

Glottis

• Loudness

Inner lining of trachea Cuneiform cartilage

– Air pressure

Corniculate cartilage (a) Vocal folds in closed position; closed glottis

(b) Vocal folds in open position; open glottis

Figure 22.5

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Sound Production

Trachea

• 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

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

• Smooth muscle and connective tissue –C-shaped cartilage rings

Lungs

Posterior

• Left Mucosa Esophagus

– 2 lobes

• Right

Submucosa

Trachealis muscle

Seromucous gland in submucosa

Lumen of trachea

– 3 lobes

Hyaline cartilage Adventitia Anterior (a) Cross section of the trachea and esophagus Figure 22.6a

Trachea Thymus

Lung

Intercostal muscle Rib Parietal pleura Pleural cavity Visceral pleura

Lungs and Bronchial Tree Trachea

Middle lobe of right lung

Superior lobe of left lung Left main (primary) bronchus Lobar (secondary) bronchus Segmental (tertiary) bronchus

Inferior lobe of right lung

Inferior lobe of left lung

Apex of lung Right superior lobe Horizontal fissure Heart (in mediastinum) Right middle lobe Oblique fissure Right inferior lobe Diaphragm Base of lung

Superior lobe of right lung

Left superior lobe Oblique fissure Left inferior lobe

Cardiac notch

(a) Anterior view. The lungs flank mediastinal structures laterally. Figure 22.10a

Figure 22.7

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Bronchial Tree

Bronchial Tree

• Trachea

Trachea

– Primary bronchi

Primary bronchi

• Right bronchus

Secondary bronchi

– Shorter – Branches into 3 secondary bronchi

Tertiary bronchi

• Left bronchus

Bronchioles

– Branches into 2 secondary bronchi

Terminal bronchioles Respiratory bronchioles

Respiratory zone (10%)

Alveoli

(90%)

Alveoli • Gas exchange • Large surface area + small diameter = high surface tension – Pulmonary surfactant – Infant respiratory distress syndrome

Respiratory bronchiole Alveolar duct

Alveoli Alveolar duct Respiratory bronchioles Terminal bronchiole

Alveolar pores

Alveolar duct Alveolar sac

Alveoli Alveolar sac

(a)

(b)

Squamous epithelium with an elastic membrane

Figure 22.8a

Figure 22.8b

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Terminal bronchiole

Red blood cell

Respiratory bronchiole Nucleus of type I (squamous epithelial) cell Alveolar pores Capillary O2 Type I cell CO2 of alveolar wall Alveolus Macrophage Endothelial cell nucleus

Smooth muscle Alveolus

Elastic fibers

Capillary

Alveolar epithelium Fused basement membranes of the Respiratory alveolar epithelium membrane Red blood cell and the capillary in capillary endothelium Alveoli (gas-filled Type II (surfactantCapillary secreting) cell air spaces) endothelium (c) Detailed anatomy of the respiratory membrane

Alveolus

Capillaries

(a) Diagrammatic view of capillary-alveoli relationships Figure 22.9a

Figure 22.9c

Pleurae

Pleurae

• Thin, double-layered serosa

• Three functions

– Parietal pleura

1. 2. 3. 4.

• Thoracic wall and superior face of diaphragm

– Visceral pleura • External lung surface

• Pleural fluid – Lubrication

Parietal Pleura

Reduction of friction Pressure gradient Compartmentalization (Also cushioning and protection)

Visceral Pleura

Pleural Cavity

Fill in the blanks External nares Vertebra Right lung Parietal pleura Visceral pleura Pleural cavity Pericardial membranes Sternum

Posterior

Esophagus (in mediastinum) Root of lung at hilum • Left main bronchus • Left pulmonary artery • Left pulmonary vein Left lung Thoracic wall Pulmonary trunk Heart (in mediastinum) Anterior mediastinum

___2___ secondary bronchi ___5____ _____6_______

Anterior (c) Transverse section through the thorax, viewed from above. Lungs, pleural membranes, and major organs in the mediastinum are shown.

nasal cavity trachea

___1___ ____3____

__4__ bronchi terminal bronchioles Respiratory zone ___7___

Word bank: respiratory bronchioles, larynx, tertiary, alveoli, bronchioles, primary bronchi, pharynx

Figure 22.10c

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