Respiratory System Flashcards

Cells require oxygen (O2) and produce carbon dioxide (CO2).
Blood carries O2 to cells and removes CO2.
Lungs facilitate O2 intake and CO2 removal via alveoli.
Inhalation: Air enters lungs due to decreased pressure achieved by raising the rib cage and lowering the diaphragm.
Exhalation: Passive process as tissues recoil; forced exhalation involves abdominal and diaphragmatic muscles.
Pleural membrane: Double membrane protecting the lungs with pleural fluid for smooth sliding.

Ventilation: O2 delivery and CO2 expulsion.
Gas exchange: Diffusion of O2 into blood and CO2 out.
Blood pH regulation: Maintaining acid-base levels.
Air preparation: Filtering, warming, humidifying air.
Vocalization: Speech production.
Olfaction: Smell detection.
Protection and defense: Protecting against dehydration, temperature changes, and pathogens.

Palate: Separates nasal and oral cavities; includes hard and soft palates.
- Hard palate: Roof of the mouth and floor of the nasal cavity, formed by palatine and maxillae bones.
- Soft palate: Muscular extension blocking the nasal cavity during swallowing.
Nose: Major entrance/exit, divided into external nose and nasal cavity.
- External nose: Includes root, bridge, dorsum nasi, apex, nostrils (alae), and philtrum.
- Nasal cavity: Separated by the nasal septum, with superior, middle, and inferior nasal conchae to increase surface area, clean, and warm air.

Paranasal sinuses: Air-filled spaces connected to the nasal cavity that lighten the skull and provide voice resonance.
Types: Frontal, maxillary, sphenoidal, and ethmoidal sinuses.
Lining: Mucosa that warms and moistens air.
Epithelium: Pseudostratified ciliated columnar epithelium with goblet cells.
- Cilia: Remove mucus and debris.
Protection: Lysozyme enzyme and defensins provide antibacterial properties.

Pharynx: Tube of skeletal muscle lined with mucous membrane.
Divisions:
- Nasopharynx: Airway with pharyngeal tonsils (adenoids).
- Oropharynx: Air and food passageway with palatine and lingual tonsils.
- Laryngopharynx: Route for ingested material and air; diverges into larynx and esophagus.
Tonsils: Lymphoid tissue that traps and destroys pathogens.

Larynx: Cartilaginous structure connecting pharynx to trachea, regulating air volume.
Cartilages: Thyroid, cricoid, epiglottis, and arytenoid.
Glottis: Contains vestibular folds (false vocal cords) and true vocal cords.
Epiglottis: Flexible cartilage covering trachea opening during swallowing.

Laryngopharynx: Inferior to oropharynx, continuous with esophagus and larynx.
Voice Production: Vocal folds vibrate to produce sound.
- Adduction: Vocal folds brought together.
- Abduction: Vocal folds move apart.
Pitch: Determined by the frequency of vocal fold vibration; influenced by muscle contraction.

Moving the vocal folds together (adduction) and apart (abduction) is achieved by the actions of the intrinsic laryngeal muscles. They act on the arytenoid cartilages, pivoting them on facets located on the upper surface of the cricoid cartilage.

Trachea: Extends from larynx, divides into primary bronchi.
- Structure: C-shaped cartilage rings, trachealis muscle.
- Function: Lined with ciliated mucous membrane to transport mucus out of lungs.
Bronchi: Primary, secondary, and tertiary bronchi; supported by cartilage rings.
Bronchioles: Branch from tertiary bronchi; muscular walls without cartilage.
Carina: Contains nervous tissue that induces coughing.

Respiratory Zone: Site of gas exchange. Includes:
- Respiratory bronchioles
- Alveolar ducts
- Alveoli

Paired organs connected to trachea by bronchi.
Right lung: 3 lobes (superior, middle, inferior).
Left lung: 2 lobes (superior, inferior), cardiac notch.
Bronchopulmonary segments: Divisions of lobes, each with its own tertiary bronchus and artery.
Pulmonary Circulation: Deoxygenated blood to lungs via pulmonary artery.

Pleura: Serous membrane enclosing lungs.
- Visceral pleura: Covers the lungs.
- Parietal pleura: Lines the thoracic wall.
Pleural Cavity: Space between layers, containing pleural fluid.
Function: Lubricates surfaces, maintains lung position, and prevents interference.

Alveolar sac: Cluster of alveoli for gas exchange.
Alveolus: Small sac with elastic walls.
Alveolar pores: Equalize air pressure.
Cell types:
- Type I alveolar cells: Gas exchange.
- Type II alveolar cells: Secrete pulmonary surfactant.
- Alveolar macrophages: Remove debris and pathogens.
Respiratory Membrane: Formed by alveoli and capillary membranes; allows gas exchange.

Breathing: Moving air in and out of lungs.
Mechanisms: Atmospheric pressure ( $P{atm}$ ), intra-alveolar pressure ( $P{alv}$ ), intrapleural pressure ( $P_{ip}$ ).
Inhalation: Air flows in when $P{atm} > P{alv}$ .
Exhalation: Air flows out when $P{alv} > P{atm}$ .
Influences: Lung compliance, surface tension, airway resistance.

Inhalation: Air pressure in the atmosphere is higher than in the lungs.
Exhalation: Lung volume decreases, increasing air pressure in the lungs.
Inspiration: Diaphragm and external intercostal muscles contract, expanding the thoracic cavity.
Expiration: Passive process due to elastic recoil of lungs.

External intercostals: Aid in inspiration.
Internal intercostals: Aid in expiration.
Innermost intercostals: Synergists for internal intercostals.
Respiratory Muscles: Diaphragm, External intercostals, Internal intercostals, and Innermost Intercostals.