H&SC-Unit 4-Cardiovascular Systems

Alveoli

Tiny air sacs in the lungs which increase the lungs surface area, they are surrounded by capillaries, and they are were oxygen uptake takes places and where carbon dioxide is removed from the blood.

Trachea

A membranous tube that connects the larynx to the bronchi and is what delivers air to and from the lungs, its opening is protected by a flap called the epiglottis and it closes when you swallow.

Larynx

Hollow muscular organ forming an air passage to the lungs and holds the vocal cords.

Bronchi

Two large tubes that are the extension of the trachea and form the main pathway into the lungs. 

Intercostal muscles

muscles located between and attached to the ribs they are part of the respiratory system and facilitate the breathing process, there are internal and external intercostal muscles. 

Diaphragm

a muscle located at the bottom of the lungs that separates the chest from the abdomen and is central to the respiratory system. 

Pleural membrane

a double membrane which lines the lungs and the inside of the ribcage, and the space between the two membranes contains a fluid secreted by the pleural membranes allowing the lungs to move smoothly during respiration. (One is attached to the lungs, and one is attached to the diaphragm and the ribcage)

Bronchioles

smaller branching off-tubes from the bronchi

Pleural fluid

found in between the pleural membrane and causes the pleural membranes to stick together. 

Explain the process when inspiration takes place

During inspiration, the external intercostal muscle contract and the internal intercostal muscles relax, this causes the ribcage to raise upwards. The diaphragm contracts and flattens, this causes the volume in the thorax to increase, thus the lowering the pressure, the difference between the pressure in the thorax and the atmosphere creates a gradient, this causes air to be forced into the lungs. 

Explain the process when inspiration takes place

During expiration, the internal intercostal muscles contract and the external intercostal muscles relax, this causes the ribcage to move downwards and inwards, The diaphragm relaxes and raises upwards, this causes the volume in the thorax to decrease, thus lowering the pressure, the difference between pressure in the thorax and the atmosphere creates a gradient, this causes air to be forced out of the lungs.