TEAS RESPI

Main Function of the respiratory system

Transport oxygen into the blood and remove carbon dioxide from cells.

Why Lungs structure with many alveoli

To maximize surface area for gas exchange (equivalent to half a basketball court).

What Organ system interdependent with the respiratory system

Circulatory system.

Pathway of air from outside to alveoli

Nasal openings → nasal cavity → pharynx → trachea → primary bronchi → bronchioles → alveoli.

What Structure preventing trachea from collapsing

Cartilage rings.

First branches of the trachea

Right and left primary bronchi.

Lobes of the right lung

3 lobes (superior, middle, inferior).

Lobes of the left lung

2 lobes (superior, inferior).

Reason the right lung is larger

The heart sits in the mediastinum, pushing into the left side.

Bronchopulmonary segments

Divisions of each lung, each supplied by its own bronchus and artery.

Alveoli

Thin-walled clusters (like grapes) where gas exchange occurs.

Type I alveolar cells

Cells that form the alveolar wall for gas exchange.

Type II alveolar cells

Cells that release surfactant to reduce surface tension.

Purpose of surfactant

Prevents alveoli from collapsing.

Double membrane protecting the lungs

Pleura.

Function of pleural fluid

Reduces friction during breathing.

Location of the lungs

Thoracic cavity.

Mediastinum

Area between the lungs where the heart sits.

Gas exchange mechanism in the lungs

By diffusion, a passive transport mechanism.

Factors increasing diffusion rate

Greater surface area, higher concentration gradient, shorter diffusion distance.

Direction oxygen moves during gas exchange

From alveoli (high O₂) → capillaries (low O₂).

Direction carbon dioxide moves during gas exchange

From capillaries (high CO₂) → alveoli (low CO₂).

Fate of carbon dioxide after diffusion into alveoli

It is exhaled back into the atmosphere.

Muscles responsible for breathing

Diaphragm and intercostal muscles.

What happens during inhalation

Muscles contract → lung volume ↑ → pressure ↓ → air enters lungs.

What happens during exhalation

Muscles relax → lung volume ↓ → pressure ↑ → air leaves lungs.

Tidal volume

The amount of air inhaled/exhaled in a normal breath.

Residual volume

Air that remains in alveoli after exhalation; prevents lung collapse.

Part of the brain controlling breathing

Medulla oblongata.

How medulla oblongata regulates breathing

Monitors CO₂ levels and blood pH.

Effect of decreased pH on breathing rate

Breathing rate increases to remove CO₂.

Type of blood sent from heart to lungs

Deoxygenated blood (low O₂, high CO₂).

What happens in pulmonary capillaries around alveoli

O₂ diffuses into blood, CO₂ diffuses into alveoli.

Type of blood returning from lungs to heart

Oxygenated blood (high O₂, low CO₂).

Function of systemic circulation with oxygenated blood

Delivers it to body tissues.

Mediastinum

Area between the lungs where the heart sits.

Gas exchange mechanism in the lungs

By diffusion, a passive transport mechanism.

Factors increasing diffusion rate

Greater surface area, higher concentration gradient, shorter diffusion distance.

Direction oxygen moves during gas exchange

From alveoli (high O₂) → capillaries (low O₂).

Direction carbon dioxide moves during gas exchange

From capillaries (high CO₂) → alveoli (low CO₂).

Fate of carbon dioxide after diffusion into alveoli

It is exhaled back into the atmosphere.

Muscles responsible for breathing

Diaphragm and intercostal muscles.

What happens during inhalation

Muscles contract → lung volume ↑ → pressure ↓ → air enters lungs.

What happens during exhalation

Muscles relax → lung volume ↓ → pressure ↑ → air leaves lungs.

Tidal volume

The amount of air inhaled/exhaled in a normal breath.

Residual volume

Air that remains in alveoli after exhalation; prevents lung collapse.

Part of the brain controlling breathing

Medulla oblongata.

How medulla oblongata regulates breathing

Monitors CO₂ levels and blood pH.

Effect of decreased pH on breathing rate

Breathing rate increases to remove CO₂.

Type of blood sent from heart to lungs

Deoxygenated blood (low O₂, high CO₂).

What happens in pulmonary capillaries around alveoli

O₂ diffuses into blood, CO₂ diffuses into alveoli.

Type of blood returning from lungs to heart

Oxygenated blood (high O₂, low CO₂).

Function of systemic circulation with oxygenated blood

Delivers it to body tissues.

Factors increasing diffusion rate

Greater surface area, higher concentration gradient, shorter diffusion distance.

Direction oxygen moves during gas exchange

From alveoli (high O₂) → capillaries (low O₂).

Direction carbon dioxide moves during gas exchange

From capillaries (high CO₂) → alveoli (low CO₂).

Fate of carbon dioxide after diffusion into alveoli

It is exhaled back into the atmosphere.

Muscles responsible for breathing

Diaphragm and intercostal muscles.

What happens during inhalation

Muscles contract → lung volume ↑ → pressure ↓ → air enters lungs.

What happens during exhalation

Muscles relax → lung volume ↓ → pressure ↑ → air leaves lungs.

Tidal volume

The amount of air inhaled/exhaled in a normal breath.

Residual volume

Air that remains in alveoli after exhalation; prevents lung collapse.

Part of the brain controlling breathing

Medulla oblongata.

How medulla oblongata regulates breathing

Monitors CO₂ levels and blood pH.

Effect of decreased pH on breathing rate

Breathing rate increases to remove CO₂.

Type of blood sent from heart to lungs

Deoxygenated blood (low O₂, high CO₂).

What happens in pulmonary capillaries around alveoli

O₂ diffuses into blood, CO₂ diffuses into alveoli.

Type of blood returning from lungs to heart

Oxygenated blood (high O₂, low CO₂).

Function of systemic circulation with oxygenated blood

Delivers it to body tissues.