Respiratory System - Video Notes

Vocabulary-style flashcards covering key terms and definitions from the respiratory system lecture notes.

Primary functions of the respiratory system

Exchange gases (O2 and CO2), produce vocal sounds, sense of smell, and regulate blood pH.

External respiration

Gas exchange between air in the lungs and blood (air → blood).

Internal respiration

Gas exchange between blood and body tissues (blood → tissues).

Respiration

Process of gas exchange between the atmosphere, lungs, and tissues.

Cellular respiration

Cells use oxygen and sugars to produce energy (ATP).

Mitochondrion

Organelle where cellular respiration occurs to generate ATP.

Upper respiratory tract

Nose, nasal cavity, sinuses, and pharynx.

Lower respiratory tract

Larynx, trachea, bronchial tubes, and lungs.

Nose

External structure with nostrils; supported by bones and cartilage; filters large particles.

Nasal cavity

Hollow space behind the nose where air is warmed and moistened.

Nasal septum

Bone that divides the nose into left and right sides.

Nasal concha

Bones (superior, middle, inferior) that divide the nasal cavity and increase surface area.

Mucus membrane

Warm and moisten air; traps particles like dust.

Deviated septum

Septum bends to one side, causing a crooked nose; sometimes repaired surgically.

Paranasal sinuses

Air-filled spaces (maxillary, frontal, ethmoid, sphenoid) that reduce skull weight and voice resonance.

Pharynx

Space behind the oral cavity between the nasal cavity and larynx; includes nasopharynx, oropharynx, laryngopharynx.

Larynx

Enlargement at the top of the trachea that houses vocal cords and contains cartilage.

Thyroid cartilage

Adam’s apple; a main laryngeal cartilage.

Cricoid cartilage

Ring-shaped cartilage of the larynx.

Epiglottic cartilage

Cartilage supporting the epiglottis that prevents food from entering the airway.

False vocal folds

Help close the airway during swallowing; do not produce sound.

True vocal folds

Produce sound; tension changes pitch.

Glottis

Triangular slit between vocal cords; opens for breathing and talking.

Epiglottis

Flap that closes the airway during swallowing to prevent food from entering the trachea.

Trachea

Windpipe; reinforced by cartilage rings; leads to the bronchial tree.

Primary bronchi

Main airways branching from the trachea into each lung.

Secondary (lobar) bronchi

Bronchi that service each lobe of the lungs.

Tertiary (segmental) bronchi

Bronchi that service bronchopulmonary segments.

Bronchioles

Small airways leading to the alveolar ducts and sacs.

Alveoli

Tiny air sacs where gas exchange occurs; connected to capillaries.

Alveolar ducts

Tubes that connect bronchioles to alveolar sacs.

Alveolar sacs

Clusters of alveoli where gas exchange occurs.

Pleura

Two-layered membrane encasing the lungs: visceral and parietal pleura.

Pleural cavity

Space between pleurae containing pleural fluid.

Pulmonary ventilation

Breathing; depends on atmospheric, intra-alveolar, and intrapleural pressures.

Atmospheric pressure

Pressure exerted by the air around us; at sea level 760 mm Hg.

Intra-alveolar (intrapulmonary) pressure

Air pressure inside the alveoli; fluctuates with breathing and equals atmospheric pressure during normal breathing.

Intrapleural pressure

Pressure inside the pleural cavity; normally negative relative to intra-alveolar pressure.

Transpulmonary pressure

Difference between intrapleural and intra-alveolar pressures; determines lung size.

Boyle’s law

At constant temperature, pressure and volume are inversely related: P1V1 = P2V2.

Tidal volume (TV)

Air normally inhaled or exhaled during quiet breathing (~500 mL).

Expiratory reserve volume (ERV)

Extra air that can be exhaled beyond a normal tidal expiration.

Inspiratory reserve volume (IRV)

Extra air that can be inhaled beyond a normal tidal inspiration.

Residual volume (RV)

Air remaining in the lungs after maximal exhale; prevents collapse of alveoli.

Total lung capacity (TLC)

Sum of all lung volumes; total amount of air the lungs can hold.

Vital capacity (VC)

Amount of air that can be moved in and out; sum of TV, IRV, and ERV (excluding RV).

Functional residual capacity (FRC)

Volume remaining after a normal tidal expiration (ERV + RV).

Spirometry

Tests that measure lung volumes and air flow (e.g., FVC, FEV, PEF).

Forced vital capacity (FVC)

Volume of air exhaled after a maximum inhalation.

Ventilatory measures (FEV, FEF 25-75)

FEV: volume exhaled in a specific time; FEF 25–75%: mid-expiratory flow rate.

Respiratory center

Brainstem groups (medulla and pons) that regulate inspiration and expiration.

Dorsal respiratory group (DRG)

Medullary group primarily involved in inspiration.

Ventral respiratory group (VRG)

Medullary group involved in forced expiration and inspiration.

Pneumotaxic area

Pontine center that inhibits inspiration to regulate breathing rate.

Apneustic center

Pontine center that promotes inspiration.

Hyperventilation

Increased breathing rate/depth causing CO2 loss and respiratory alkalosis.

Respiratory membrane

Thin barrier where gas exchange occurs; consists of alveolar and capillary walls.

Hypoxia

Lack of sufficient oxygen in body tissues.

Asphyxia

Severely diminished oxygen supply due to inability to breathe normally (e.g., choking).

Pneumothorax

Collapsed lung due to air in the pleural space.

Pleural effusion

Fluid accumulation in the pleural space.

Cystic fibrosis

Hereditary disease with thick mucus in lungs causing breathing difficulty.

Chronic obstructive pulmonary disease (COPD)

Obstruction of airways, typically due to chronic bronchitis and/or emphysema.

Asthma

Inflammation with bronchospasm and mucus production; bronchial hyperreactivity.

Bronchitis

Inflammation of the airways with mucus production; can be acute or chronic.

Emphysema

Alveolar damage with enlarged air spaces and reduced surface area for gas exchange.

Pneumonia

Infection causing alveoli to fill with fluid or pus.

Tuberculosis

Infectious disease caused by Mycobacterium tuberculosis affecting the lungs.

Influenza

Viral respiratory infection affecting the nose, throat, and lungs.

Rhinovirus

Common cold virus that infects the upper respiratory tract.

Pertussis (Whooping cough)

Bacterial infection causing severe coughing and gasping for breath.

Sleep apnea

Pause or slowing of breathing during sleep.