OIA1004 (TERMS) RESPIRATORY SYSTEM I

Upper respiratory system

The part of the respiratory system that includes structures from the nose to the larynx.

Lower respiratory system

The part of the respiratory system that includes structures after the larynx.

Gas exchanges

The process of oxygen intake and carbon dioxide removal through exhalation.

Inhalation / inspiration

The act of taking air into the lungs.

Exhalation / expiration

The act of expelling air from the lungs.

Delivery of gases to body cells

The process of transporting oxygen to cells and removing carbon dioxide.

Gas conditioning

The process by which passageways to the lungs purify, warm, and humidify incoming air.

Regulation of blood pH

The respiratory system helps regulate blood pH by controlling the amount of carbon dioxide.

Sound production

The larynx, nasal cavity, paranasal sinuses, teeth, lips, and tongue work together to produce sound.

Olfactory sensation

The special sensory function of the nose that provides the sense of smell.

Conducting zone

A series of interconnecting cavities and tubes that filter, warm, and moisten air and conduct it into the lungs.

Respiratory zone

Tubes and tissues within the lungs where gas exchange occurs.

External nose

The visible part of the nose on the face, supported by bone and hyaline cartilage.

Root of the nose

The area between the eyebrows.

Apex of the nose

The tip of the nose.

Bridge of the nose

The bony framework of the nose formed by nasal bones.

External naris

Nostril; external opening into nasal cavity

Nasal cavity

Divided by a midline nasal septum, formed anteriorly by septal cartilage & posteriorly by vomer bone and perpendicular plate of ethmoid bone.

Internal nares

Openings through which the nasal cavity is continuous posteriorly with the pharynx.

Nasal vestibule

The front part of the nasal cavity that contains hairs for air filtration.

Superior olfactory region

Part of the nasal cavity responsible for the sense of smell.

Inferior respiratory region

Part of the nasal cavity involved in respiration.

Pseudostratified ciliated columnar epithelium

Type of epithelium found in the nasal cavity with numerous goblet cells.

Nasal conchae

Structures that create groovelike passageways called nasal meatus, increasing surface area and preventing dehydration.

Paranasal Sinuses

Cavities in certain bones lined with mucous membranes, including frontal, sphenoid, ethmoid & maxillary bones.

Functions of the Nose

Provides an airway for respiration, warms, moistens and filters incoming air, serves as a resonating chamber for speech, and houses the olfactory receptors.

Pharynx

Throat; starts at internal naris & extends to cricoid cartilage of larynx, composed of skeletal muscles & lined with a mucous membrane.

Deglutition

The process of swallowing assisted by contraction of skeletal muscles in the pharynx.

Nasopharynx

Superior portion of the pharynx from nasal cavity to soft palate; serves as a respiratory pathway only.

Oropharynx

Intermediate portion of the pharynx from soft palate to hyoid bone; serves as both respiratory & digestive pathway.

Laryngopharynx

Inferior portion of the pharynx that opens into the esophagus and larynx; serves as both respiratory & digestive pathway.

Larynx

Voice box found in the anterior neck (C4-C6 vertebrae) connecting the laryngopharynx with the trachea.

Cavity of larynx

Space extending from the tip of the epiglottis to the inferior border of the cricoid cartilage.

Laryngeal skeleton

Consists of 9 cartilages, including 3 single cartilages and 3 paired cartilages.

Cricoid cartilage

A cartilage in the larynx that becomes larger during puberty due to hormonal changes.

Epiglottis

Elastic cartilage that extends from posterior of tongue to thyroid cartilage.

Glottis

A pair of vocal folds (mucous membrane) + rima glottidis (medial opening between them).

Lining of larynx (superior to vocal folds)

Stratified squamous epithelium.

Lining of larynx (inferior to vocal folds)

Pseudostratified ciliated columnar epithelium.

Functions of the larynx

Provide patent (open) airway, a switching mechanism to route air & food into proper channels, and houses vocal folds for voice production.

Speech

Involves intermittent release of expired air & opening and closing of the glottis.

Intrinsic laryngeal muscles

Influence the length of the true vocal cords & size of glottis.

Pitch of sound

Related to the tension in vocal folds.

Loudness of voice

Depends on the pressure of air forced across vocal cords.

Trachea

Windpipe that extends from larynx to superior border of T5 and divides into right and left primary bronchi.

Layers of tracheal wall

1. Mucosa: pseudostratified ciliated columnar epithelium; 2. Submucosa: areolar connective tissue that contains seromucous glands; 3. Hyaline cartilage: C shaped rings cartilage providing semi-rigid support; 4. Adventitia: areolar connective tissue.

Right primary bronchus

More vertical, shorter, and wider than the left primary bronchus.

Carina

Internal ridge where trachea divides into right and left primary bronchi.

Mucosa of primary bronchi

Highly sensitive to irritants, triggering a cough reflex.

Structural changes in bronchi

Mucous membrane changes from pseudostratified ciliated columnar epithelium to ciliated simple columnar epithelium with/without goblet cells, then to nonciliated simple cuboidal epithelium in terminal bronchioles.

Goblet cells

Produce mucus to trap particles.

Cilia

Move the mucus toward pharynx for removal.

Cartilage in bronchi

Plates of cartilage gradually replace the rings & disappear in the distal bronchioles.

Smooth muscle in bronchi

Helps to maintain patency; muscle spasms can close the airways (asthma attack).

Sympathetic nervous system

Causes relaxation of bronchiolar smooth muscle.

Lung anatomy

Paired cone-shaped organs in the thoracic cavity, separated by the heart and other structures in the mediastinum.

Pleural membrane

Each lung is enclosed by a double-layered pleural membrane consisting of parietal pleura (superficial layer) and visceral pleura (deep layer).

Pleural cavity

Space between the layers of pleural membrane.

Pleural fluid

Reduces friction & produces surface tension (stick together).

Apex

Narrow superior tip of lung

Base

Inferior surface of lung that rests on the diaphragm

Hilum

Region where blood vessels & nerves enter and exit lungs

Cardiac notch

Concavity that the heart lies

Left lung

10% smaller than right lung

Pulmonary artery

Deoxygenated blood

Bronchial arteries

Oxygenated blood to perfuse muscular walls of bronchi and bronchioles

Right lung

3 lobes (superior, middle, inferior)

Left lung

2 lobes (superior, inferior)

Fissures

One or two fissures divide each lung into lobes

Oblique fissure

One of the fissures dividing the lung lobes

Horizontal fissure

One of the fissures dividing the lung lobes

Secondary (lobar) bronchus

Each lobe receives its own secondary bronchus that branches into tertiary (segmental) bronchi

Bronchopulmonary segment

Segment of lung tissue that is supplied with tertiary bronchus

Lobules

Small compartments wrapped in elastic connective tissue containing a lymphatic vessel, arteriole, venule & branch from terminal bronchiole

Terminal bronchioles

Branch into respiratory bronchioles which divide into alveolar ducts

Alveoli

Cup-shaped outpouching lined by simple squamous epithelium

Alveolar sac

Consists of 2 or more alveoli sharing a common opening

Type I alveolar cells

Simple squamous epithelial cells that form nearly continuous lining of alveolar wall and are the main site of gas exchange

Type II alveolar cells

Cuboidal epithelial cells that secrete alveolar fluid and surfactant, found between type I alveolar cells

Alveolar macrophages

Dust cells that remove fine dust particles

Respiratory membrane

Very thin (0.5 μm) structure allowing rapid diffusion of gases, consisting of alveolar wall, epithelial basement membrane, capillary basement membrane, and capillary endothelium

Nose

Functions as a passageway for air and food, provides a resonating chamber for speech sounds, and houses the tonsils

Pharynx

Connects the laryngopharynx with the trachea; houses the vocal cords

Larynx

Functions in voice production

Pleura

Serous membrane that surrounds the lungs

Type I alveolar cells

Simple squamous epithelial cells that form a continuous lining of the alveolar wall; sites of gas exchange

Type II alveolar cells

Secrete alveolar fluid and surfactant

Epiglottis

Prevents food or fluid from entering the airways