Respiratory System

What is ventilation?

Ventilation is the process by which air is moved into (inspiration and out (expiration) of the lungs.

What happens when the diaphragm contracts?

When the diaphragm contracts it flattens to increase the volume of the thoracic cavity.

When will air flow out of the lungs?

When the pressure inside the lungs is higher than the outside.

When will air flow into the lungs?

When the pressure outside the lungs is higher than the pressure inside the lungs.

What is the intercostal muscle?

Intercostal muscles are muscles found between the rubs which are divided into external and internal intercostal muscles.

Why is the trachea lined with a c-shaped cartilage?

1. to hold the trachea open 2. to allow the oesophagus to expand when bolus is swallowed.

Describe the process of inspiration during quiet breathing.

1.a) The intercostal muscles contract moving the ribcage upwards and outwards. b) The diaphragm contracts downwards enlarging the thoracic cavity. 2. Lung volume increases. 3. Air flows from high pressure outside the lungs to the lower pressure inside the lungs.

Describe the process of expiration.

1.a) The intercostal muscles relax moving the ribcage downwards and inwards. b) The diaphragm relaxes upwards decreasing the thoracic cavity. 2. Lung volume decreases. 3. Air flows from high pressure inside the lungs to the lower pressure outside the lungs.

What are alveoli?

Alveoli are tiny air sacs that makes up most of the lung. It is once cell thick and are small and around.

What is the function of the mucous and the cilia?

Mucous: traps dust particles Cilia: beats excess mucous and trapped dust towards the mouth to be expelled or swallowed

What occurs in the conchae?

The air is warmed by the blood in the capillaries.

What are bronchioles? What is it used for and what is it lined with?

The bronchi divides into very small tubes called the bronchioles. It allows air to pass through to the alveoli and it is not lined with anything.

What is the bronchi? What is it used for and what is it lined with?

The bronchi is the lower end of the trachea which is divided into the left and right bronchus. It allows air to pass into the right and left lung. It is lined with cartilage, cilia nad mucous.

What is the diaphragm?

The diaphragm is a dome shaped muscle that separates the thoracic cavity from the abdominal cavity.

What is the pharynx and what is it used for?

The pharynx is a tube that extends from the nasal cavity to the neck, which allows air to pass through to the larynx.

What happens when the diaphragm relaxes?

As the diaphragm relaxes it returns to its dome shape to decrease the size of the thoracic cavity.

What surrounds each alveolus?

Each alveolus is surrounded by a dense network of capillaries which provides a site for gas exchange to occur.

How and why does carbon dioxide move into the blood from the alveoli?

*The blood in the capillaries surrounding the alveolus is brought into the lungs by the pulmonary artery. *The blood in the capillaries around the alveolus is high in carbon dioxide. *The concentration of carbon dioxide in the alveolus is low. *Carbon dioxide diffuse from an area of high concentration in the blood to an area of low concentration in the alveolus.

How and why does oxygen move into the blood from the alveoli?

*The blood in the capillaries surrounding the alveolus is brought into the lungs by the pulmonary artery. *The blood in the capillaries around the alveolus is low in oxygen. *The concentration of oxygen in the alveolus is high. *Oxygen diffuse from an area of high concentration in the alveolus to an area of low concentration in the capillaries.

How are respiratory surfaces suited to their function of gas exchange?

1. Alveoli give the lungs a large internal SA so that large amounts of gases can be exchanged. 2. Each alveoli is supplied with blood vessels so more blood is closer to the air. 3. The membrane of the alveolus is very thin. 4. The lungs are positioned deep inside the body to prevent moisture from escaping because a layer of moisture is needed for the gas to diffuse.

What are the two main functions of the respiratory system?

1. To bring in oxygen for cellular respiration. 2. To remove waste (carbon dioxide made by cellular respiration.

How is the difference in concentration of gases between the alveolus and the capillaries maintained?

1. constant flow of blood - when blood flows through the capillaries it picks up oxygen and loses carbon dioxide 0 it is then replaced by more blood in the capillaries which is low in oxygen and high in carbon dioxide 2. movement of air into and out of our lungs as we breathe - when we breathe in we increase the concentration of oxygen, and when we breathe out we decrease the concentration of carbon dioxide

What are the main functions of the nasal cavity?

1. filters, warms and moistens the air before it enters the lungs 2. contains olfactory receptors 3. acts as a resonating chamber that enhances sound

What can be found inside the lungs?

Bronchi -> Bronchioles -> Alveoli

What does the nasal cavity consist of?

It consists of a left and right chamber which has three projections known as conchae which increases the surface area. It is lined with cilia and mucous.

What happens when the internal external costal muscles contract?

It occurs during heavy breathing - ribcage moves downwards and inwards.

What is the larynx and what is its structure composed of?

The larynx is known as the voice box which are elastic ligaments that vibrates as air passes. it connects the throat with the trachea and it is composed of cartilage and elastic ligaments.

What is the membrane surrounding the lungs called and what is the fluid in between this membrane called?

The lungs is surrounded by a membrane called the pleura membrane. It covers the surface of the lungs and inside the chest. In between the two layers of the membrane is the pleural fluid which holds the lungs against the inside of the cheat walls and allows the lungs to slide along when breathing.

What is inspiration/inhalation?

The process of bringing air into the lungs.

What is expiration/exhalation?

The process of taking air out of the lungs.

What is the function of the ribcage?

The ribcage encloses and protects the lings and provides a point of attachment for the diaphragm.

What happens when the external intercostal muscles contract?

The ribcage moves upwards and outwards.

What is the trachea?

The trachea is a tube that extends down the chest which then divides into two smaller tubes known as the bronchi. It is also lined with a c-shaped cartilage. It is also lined with cilia and mucous.