Lab # 5The Respiratory System 1

Functions of Respiratory System

1- O2 and CO2 exchange between blood and air

2- Speech and other vocalizations (laughing, crying)

3- It provides the sense of smell

4- It helps to control the pH of body fluids by eliminating CO2

5- It helps to regulate blood pressure by synthesis of a vaso-constrictor called angiotensin II

6- Breathing creates pressure gradients between thorax and abdomen that promote the flow of lymph and venous blood

7- Breath-holding helps expel abdominal contents during urination, defecation, and childbirth

Principal Organs of the Respiratory System

Trachea

Nose

Pharynx

Larynx

Lungs

Bronchi

The Nasal Cavity

Nasal conchae:

Meatuses:

Superior Middle

Inferior

SuperiorMiddleInferior

Vestibule

Functions of the nose1- It warms, cleanses, and humidifies inhaled air

2- It detects odors in the airstream

3- It serves as a resonating chamber that amplifies the voice

Posterior nasal

aperture

The respiratory epithelium lines the rest of nasal cavity except vestibule. It is a ciliated pseudostratified columnar epithelium with goblet cells

Nasopharynx

Oropharynx

Laryngopharynx

Pharyngeal tonsil

Auditory tube

Palatine tonsil

(posterior to nasal apertures and above soft palate)

(space between soft palate and epiglottis)

(from the epiglottis to the cricoid cartilage)

The Pharynx

The Larynx

(a) Anterior (b) Posterior (c) Median

It is a cartilaginous chamber about 4 cm (1.5 in.)

Functions: 1- To keep food and drink out of the airway2- Production of sound (phonation)

Hyoid bone

Thyroid cartilage

Arytenoid cartilage

Cricoid cartilage

EpiglottisEpiglottis

Hyoid bone

Thyroid cartilage

Vestibular fold

Vocal cord

Arytenoid cartilage

Cricoid cartilage

Tracheal cartilage

Corniculate cartilage

It closes the airway during swallowing

Trachea

Epiglottic cartilage

Median

Vestibular foldThey play no role in speech but close the larynx during swallowing

Vocal cord

They produce sound when air passes between them

(from the thyroid cartilage to the arytenoid cartilage)

The Larynx

The TracheaThe trachea (windpipe) is a rigid tube about 12 cm (4.5 in.) long and 2.5 cm (1 in.) in diameter. It is found anterior to the esophagus and it is supported by 16 to 20 C-shaped rings of hyaline cartilage, which reinforces the trachea and keeps it from collapsing when you inhale Trachea

Ciliated pseudostratified columnar epithelium with goblets cells

Mucociliary escalator

Mucous gland

Ciliated cell Goblet cell

Mucus

It is a mechanism that moves debris-laden mucus to the pharynx to be swallowed

Ciliated pseudostratified columnar epithelium with goblets cells

The LungsThey are conical organs with a broad, concave base, resting on the diaphragm, and a blunt peak called the apex projecting slightly above the clavicle

Apex of lung

Base of lung

Oblique fissure

Horizontal fissure

Oblique fissure

Superior lobe

Middle lobe

Inferior lobe

Superior lobe

Inferior lobe

Costal surface

Mediastinal surface

Diaphragmatic surface

Larynx

Trachea

Carina

Thyroidcartilage

Cricoidcartilage

Main bronchi (primary)

Superior lobarbronchus

Middle lobarbronchus

Inferior lobarbronchus

Superior lobar bronchus (secondary)

Inferior lobar bronchus (secondary)

Segmental bronchi(10 on right)

Segmental bronchi (tertiary)(8 on left)

Bronchopulmonary segment: It is a functionally independent unit of the lung tissue

Bronchial TreeAll bronchi are lined with ciliated pseudostratified columnar epithelium

The lamina propria has an abundance of mucous glands and lymphocyte nodules (bronchus-associated lymphoid tissue, BALT) positioned to intercept inhaled pathogens

Main bronchus

Lobar bronchus

Segmental bronchus

Bronchiole

(lung)

(lobe)

(segment)

(pulmonary lobule)

(final branches of conducting division)

Terminal bronchioles

Conducting Division of Respiratory System

1- Nostrils

It consists of those passages that serve only for airflow:

2- Nasal cavity3- Pharynx4- Larynx5- Trachea6- Main (primary) bronchi (lungs)7- Lobar (secondary) bronchi (lobes)8- Segmental (tertiary) bronchi (segments)9- Bronchioles (lobules)10- Terminal bronchioles (the final branches)

Bronchioles and terminal bronchioles lack of supportive cartilages)

Respiratory Division of Respiratory System

1- Respiratory bronchioles 2- Alveolar duct

It consists of those structures that participate in gas exchange

3- Atrium4- Alveoli

Bronchiole

Terminal bronchioles

Respiratory bronchioles

Openings of alveolar ducts

Every respiratory bronchiole divides into 2 to 10 alveolar ducts, which end in the alveolar sac

Alveolar sac

Alveoli

Pulmonary arteriole

Pulmonary venule

The Respiratory Membrane

Squamous alveolar cell

Capillary endothelial

cell

Respiratory membrane

Shared basement membrane

O2

CO2

CO2

CO2

CO2

CO2

O2

O2

O2

O2

O2

Nasal cavity

Nasopharynx

Trachea

Bronchi

Bronchioles

Terminal bronchioles

Alveoli

Oropharynx

Laringopharynx

Ciliated pseudostratified columnar epithelium

Stratified squamous epithelium

Stratified squamous epithelium

Larynx (superior part) Stratified squamous epithelium

Larynx (inferior part)

Ciliated pseudostratified columnar epithelium

Ciliated pseudostratified columnar epithelium

Ciliated pseudostratified columnar epithelium

Ciliated pseudostratified columnar epithelium

Ciliated simple columnar epithelium

Simple cuboidal epithelium

Simple squamous epithelium (with 5% of round or cuboidal cells (type II alveolar cells)

Epithelium Type Changes in the Respiratory System

The Respiratory Muscles