Respiratory System Lecture Notes

Vocabulary flashcards covering the mechanics of the respiratory system, gas exchange processes, transport of oxygen and carbon dioxide, and related medical conditions like Cystic Fibrosis and Emphysema.

Respiratory System Function

Allows animals to move oxygen (for cellular respiration) into body tissues and remove carbon dioxide (waste product of cellular respiration) from cells.

Why do we breathe?

Air in the alveoli must be exchanged in order to give oxygen to your lungs and carry carbon dioxide AWAY from your lungs

Cellular Respiration Equation

$$Glucose + Oxygen \rightarrow carbon dioxide + energy + water$$

Spiracles

Specialized structures used for gas exchange in terrestrial insects.

Inspiration (Inhalation)

The phase of breathing where the diaphragm and intercostal muscles contract, causing the volume in the lungs to increase and pressure to decrease.

Exhalation

The phase of breathing where muscles relax, the diaphragm domes upward, lung volume decreases, and pressure increases.

Alveoli

Moist, thin-walled pockets that serve as the primary site of gas exchange in mammals.

Alveolar Oily Surface

A coating that prevents the alveolar wall from collapsing and sticking together.

Hemoglobin

A protein that binds to $O_2$ for transport in the bloodstream and also attaches to extra $H^+$ to lower blood acidity.

Oxygen Transport

Oxygen diffuses through lung capillary wall

Carried to tissues bound to hemoglobin

Diffuse through tissue capillary walls

CO2 Transport Percentages

7% dissolved in blood, 20% bound to hemoglobin, and 70% dissolved in plasma via the Bicarbonate Buffer System.

Bicarbonate Buffer System

A process where $CO_2$ reacts with water to form carbonic acid, which ionizes into bicarbonate ions and protons ($H^+$).

Nicotine

A toxic chemical in inhaled smoke that paralyzes the cilia that normally clean the lungs.

Emphysema

A condition, often caused by smoking, where the alveoli become dry, brittle, and eventually rupture.

Cystic Fibrosis (CF)

An inherited disorder caused by a mutation of the CFTR gene, leading to salt imbalance and thick, sticky lung mucus.

CFTR gene

The gene that controls salt balance in the lungs by regulating the amount of chloride ions across the cell membrane.

Air Pressure Rule

Air will always move from an area of high pressure to an area of low pressure.

Diaphragm

A thin spherical muscle located in the chest cavity responsible for most of the pressure changes in the lungs.

Inspiration

Diaphragm contracts and moves downward

Intercostal muscles expand the rib cage up and out

Volume in lungs increases

Pressure in lungs decreases

Air flows out

Exhalation

The diaphragm relaxes and moves up

Intercostal muscles move the ribcage down and in

Volume in lungs decreases

Pressure increases

Air rushes in

Intercostal muscles

Muscles located between the ribs that expand the ribcage upwards and outwards during inspiration.

Pleural Membranes

Membranes that cover the lungs and inner walls of the chest cavity, containing a thin layer of liquid to allow free movement and keep lungs attached.

Pneumothorax

A collapsed lung caused by breaking the pleural membrane and letting air into the pleural space.