chaper 9 bio

Trachea

Function: air flow into the lungs

Pathway to O2 & CO2: Oxygen follows a downward pathway to the lungs, while carbon dioxide follows the same path upward to be exhaled

Where it can be found: lower neck/upper chest

Pharynx

Function: a shared pathway for respiration and digestion

Pathway of O2 & CO2: During inhalation, oxygen-rich air travels through the pharynx on its way to the lungs, and during exhalation CO2 travels through the pharynx and out

Found in: middle of the neck

Bronchiolel

Function: deliver O2 to the alevoli and remove CO2 during exhalation

Pathway to O2 and CO2: Air travels down the bronchioles to the alveoli, where O₂ diffuses into the blood and CO₂ to be exhaled

Found in: lungs

Bronchus

Function: conducting air, warming and humidifying it, protecting the lungs through mucus trapping, and regulating airflow

Pathway to O2 and CO2: Air moves through the bronchi → bronchioles → alveoli, where O₂ enters the blood and CO₂ is released to be breathed out

Found in: lungs

Nasal cavity

Function: The nasal cavity filters, warms, and humidifies incoming air before it travels to the lungs

Pathway to O2 & CO2: Air enters the nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli, where O₂ passes into the blood and CO₂ goes back out

Found in: nose/mouth

Pleural membrane

Function: reduces friction and maintains pressure so the lungs can expand and contract smoothly during breathing

Pathway to O2 & CO2: O₂ passes through the pleural membrane-enclosed lungs down to the alveoli where it enters the blood, while CO₂ travels the reverse path from the blood to be exhaled

Found in: thoracic(chest)

Epiligottis

Function: covers the airway during swallowing to prevent food and liquid from entering the lungs

Pathway to O2 & CO2: Air passes through the epiglottis → larynx → trachea → bronchi → bronchioles → alveoli, where O₂ enters the blood and CO₂ goes back out

Found in: throat

Glottis

Function: controls airflow in and out of the lungs and produces sound by vibrating as air passes through it

Pathway to O2 & CO2: Air passes through the glottis → trachea → bronchi → bronchioles → alveoli, where O₂ enters the blood and CO₂ is expelled back out

Found in; throat

Alveoli

Function: O₂ diffuses from inhaled air into the blood and CO₂ diffuses from the blood to be exhaled

Pathway to O2 & CO2: Air travels from the nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → directly into the alveoli, where O₂ enters the blood and CO₂ is released back out

Found in: lungs

Advantages/disadvantages of mouth breathing vs breathing through your nasal cavity

Mouth Advantages: faster airflow,

Mouth Disadvantages: dry mouth/bad breath

Nasal advantages: filters air

Nasal disadvantages: limited airflow when congested

Vital capacity

The maximum amount of air you can exhale after taking the deepest breath possible

Tidal volume

The amount of air inhaled or exhaled in one normal, relaxed breath

Expiratory reserve volume

The extra air you can forcefully exhale after a normal exhale

Inspiratory reserve volume

The extra air you can forcefully inhale after a normal inhale

Residual volume

The air that always remains in the lungs after the most forceful exhale

Total lung capacity

The total amount of air the lungs can hold at maximum inflation (vital capacity + residual volume)

Internal respiration

The exchange of O₂ and CO₂ between the blood and the body’s tissues at the cellular level

Describe how pressure affects inhalation and exhalation

When the diaphragm contracts it lowers lung pressure pulling air in, and when it relaxes it raises lung pressure pushing air out, as air always flows from high to low pressure

What happens in your diaphragm for inhalation and exhalation

Inhalation: The diaphragm contracts and flattens downward, increasing lung volume and pulling air in

Exhalation: The diaphragm relaxes and domes upward, decreasing lung volume and pushing air out.​​​​​​

What your intercostal muscles do for inhalation and exhalation

Inhalation: The external intercostal muscles contract, lifting the ribs up and outward, expanding the chest cavity to allow air in.

Exhalation: The internal intercostal muscles contract, pulling the ribs down and inward, compressing the chest cavity to push air out.​​​​​​​​​​​​​​​​

Process of exhalation in full, what structures in your chest cavity does it go through, what does it look like?

The diaphragm relaxes, ribs pull inward, lung pressure rises, and CO2 rich air is pushed from the alveoli up through the bronchioles → bronchi → trachea → out through the nose or mouth

process of inhalation in full, what structures in your chest cavity does it go through, what does it look like?

The diaphragm flattens, ribs lift, pressure drops, and air rushes in through the nose → trachea → bronchi → bronchioles → alveoli