Chapter 23: Respiratory System (part 1)

Dorsal body cavity

The posterior cavity that contains the brain and spinal cord.

Ventral body cavity

The anterior cavity that contains the thoracic and abdominopelvic cavities.

Cranial cavity

The space inside the skull that houses the brain.

Vertebral canal

The space within the vertebral column that houses the spinal cord.

Thoracic cavity

The chest cavity containing the lungs and mediastinum.

Pleural cavities

The two spaces surrounding the right and left lungs.

Mediastinum

The central region of the thoracic cavity between the lungs.

Abdominopelvic cavity

The cavity containing the abdominal and pelvic organs.

Abdominal cavity

The space containing digestive organs and the spleen.

Pelvic cavity

The space containing the urinary bladder, urethra, rectum and reproductive organs.

Body membranes

Thin sheets of tissue that line cavities and cover and protect organs.

Meninges

Three protective membranes surrounding the brain and spinal cord. (D.A.P.)

Dura mater

The outermost layer of the meninges.

Arachnoid mater

The middle layer of the meninges.

Pia mater

The innermost layer of the meninges.

Mucous membranes

Membranes lining cavities that open to the outside of the body and secrete mucus.

Serous membranes

Membranes lining the ventral body cavity that produce fluid for lubrication.

Parietal membrane

The part of a serous membrane that lines the wall of a body cavity.

Visceral membrane

The part of a serous membrane that covers an organ.

Pericardium

The serous membrane associated with the heart.

Peritoneum

The serous membrane associated with the abdominopelvic cavity.

Pleura

The serous membrane associated with the lungs.

Respiratory system

The system that brings oxygen into the body and removes carbon dioxide.

Upper respiratory tract

Structures extending from the nose through the larynx.

Lower respiratory tract

Structures extending from the trachea through the alveoli.

Ventilation

The movement of air into and out of the lungs.

Respiration

The diffusion of gases across plasma membranes.

Conducting zone

The air passageways that move air but do not perform gas exchange.

Respiratory zone

The air passageways and alveoli where gas exchange occurs.

Pulmonary respiration

The exchange of gases between the alveoli and blood.

Gas transport

The movement of oxygen and carbon dioxide through the blood.

Systemic respiration

The exchange of gases between the blood and body tissues.

Blood pH regulation

The respiratory system's role in controlling blood acidity by changing carbon dioxide levels.

ACE (angiotensin-converting enzyme)

An enzyme involved in regulating blood pressure.

Olfaction

The sense of smell.

Nasal cavity

The space inside the nose that filters, warms and humidifies incoming air.

Nasal vestibule

The area just inside the nostrils.

Hard palate

The bony floor of the nasal cavity.

Nasal septum

The partition that divides the nasal cavity into right and left sides.

Nasal conchae

Bony ridges in the nasal cavity that help direct airflow.

Paranasal sinuses

Air-filled spaces that connect with the nasal cavity and help resonate speech.

Olfactory epithelium

Tissue in the nasal cavity responsible for detecting smells.

Pharynx

The throat, a passageway shared by the respiratory and digestive systems.

Nasopharynx

The upper part of the pharynx behind the nasal cavity.

Oropharynx

The middle part of the pharynx shared by the respiratory and digestive systems.

Laryngopharynx

The lower part of the pharynx that leads toward the esophagus.

Soft palate

The muscular back portion of the roof of the mouth.

Uvula

The small projection extending from the back of the soft palate.

Auditory (Eustachian) tubes

Tubes opening into the nasopharynx that connect to the middle ears.

Larynx

The voice box that connects the pharynx to the trachea and contains structures used for speech.

Thyroid cartilage

The largest cartilage of the larynx, forming the Adam's apple.

Cricoid cartilage

The lowest cartilage of the larynx.

Epiglottis

A flap of cartilage that helps prevent swallowed material from entering the larynx.

Vestibular folds

The false vocal folds located above the true vocal folds.

Vocal folds

The true vocal cords that vibrate to produce sound.

Pseudostratified ciliated columnar epithelium

The lining that traps debris and uses cilia to move mucus toward the pharynx.

Trachea

The airway tube connecting the larynx to the bronchi.

Tracheal cartilage

C-shaped rings of hyaline cartilage that keep the trachea open.

Trachealis muscle

Smooth muscle along the posterior trachea that contracts during coughing.

Goblet cells

Cells that produce mucus to trap debris in the airways.

Cilia

Tiny hairlike structures that move mucus and trapped particles toward the throat.

Carina

Cartilage at the point where the trachea divides into the main bronchi.

Tracheobronchial tree

The branching network of airways extending from the trachea into the lungs.

Primary bronchi

The right and left main airways branching from the trachea.

Lobar (secondary) bronchi

Airways branching from the primary bronchi that supply each lung lobe.

Segmental (tertiary) bronchi

Airways that supply individual bronchopulmonary segments.

Bronchioles

Small airways less than one millimeter in diameter.

Terminal bronchioles

The smallest conducting airways, with no cartilage in their walls.

Bronchodilation

Widening of airways when smooth muscle relaxes, increasing airflow.

Bronchoconstriction

Narrowing of airways when smooth muscle contracts, reducing airflow.

Hilum

The area on the medial surface of the lung where bronchi and blood vessels enter.

Root of the lung

The structures that enter and leave the lung through the hilum.

Apex of the lung

The uppermost part of the lung.

Base of the lung

The lower surface of the lung that rests on the diaphragm.

Lobes of the lungs

The major sections of the lungs; three in the right lung and two in the left.

Fissures

Grooves that separate the lobes of the lungs.

Situs inversus

A condition in which the thoracic and abdominal organs are reversed from their usual positions.

Bronchopulmonary segments

Sections of the lungs supplied by segmental bronchi and separated by connective tissue.

Lobules

Small lung units located beyond the respiratory bronchioles.

Alveoli

Tiny air sacs where gas exchange occurs between air and blood.

Respiratory bronchioles

Small airways branching from terminal bronchioles that contain a few alveoli.

Alveolar ducts

Passages extending from respiratory bronchioles that open into alveoli.

Alveolar sacs

Chambers at the ends of alveolar ducts that connect to multiple alveoli.

Type I pneumocytes

Thin, flat cells covering most of the alveolar surface where gas exchange occurs.

Type II pneumocytes

Secretory cells in the alveoli that produce surfactant.

Pulmonary surfactant

A substance that lowers surface tension and helps prevent alveoli from collapsing after exhalation.

Respiratory distress syndrome (RDS)

A condition in premature infants associated with insufficient surfactant.

Alveolar macrophages

White blood cells that remove debris from the alveoli.

Respiratory membrane

The thin barrier where oxygen enters the blood and carbon dioxide leaves it.

Alveolar epithelium

The thin cell layer forming the wall of an alveolus.

Interstitial space

The thin space between the alveolar and capillary layers of the respiratory membrane.

Capillary endothelium

The thin inner lining of blood capillaries.

Basement membrane

A thin supporting layer beneath the alveolar epithelium and capillary endothelium.