The Respiratory System Flashcards
How do we breath?
Medulla oblongata chemoreceptors detect carbon dioxide changes and adjust rate and depth of breathing.
The human body needs oxygen to release energy from food, this happens within the mitochondria in cells.
Carbon dioxide is the waste product of this process and needs to be removed from the body.
What is metabolism?
Food + Oxygen= Energy (ATP) + Carbon Dioxide + Water + Heat (also lactic acid in anaerobic)
Describe the properties of the lungs
One on each side of the mediastinum (mid thoracic cavity)
Cone shaped with apex, base rests on the diaphragm, costal and medial surfaces
Right lung- 3 lobes, superior, middle and inferior
Left lung- 2 lobes, superior and inferior. Smaller because the heart is to the left of the lung
Each lung is made up of a number of lobules, alveoli and alveolar ducts
What is the pleura?
2 pleural membranes (really a folding of a single membranous sheet) surround the lungs and line the thoracic cavity
Name the layers of the pleural membrane
Parietal pleura (outer) adheres to inner chest wall and diaphragm Visceral pleura (inner) adheres to outer surface Between the layers: fluid filled potential space called the pleural cavity containing pleural fluid
Describe the function of pleural fluid
Reduces friction so membranes slide over each other freely (also causes them to adhere to each other like water between 2 panes of glass)
What is the diaphragm?
A large dome shaped sheet of muscle that separates the thoracic and abdominal cavities
Describe what happens in inspiration and expiration
Diaphragm is the main muscle of inspiration on normal quiet inspiration. When the diaphragm contracts it moves downwards increasing the size of the thoracic cavity. External intercostals can also be used. Situated between ribs, contraction causes ribs to swing outwards and upwards, again increases the size of the thoracic cavity. When thoracic cavity enlarges on inspiration, lungs also expand as they are adhered to chest wall and diaphragm by pleural membranes. If greater inspiration is needed accessory muscles are also used. In expiration, it is a passive process where muscles relax and elastic recoil of the lungs occurs. There is a decrease in volume causing an increase in pressure, pushing air out via diffiusion
Describe active and passive breathing
Expiration is usually passive, if outflow of air to be controlled or forcefully expelled intercostal and abdominal muscles can be used
Inspiration is active, requiring energy and muscle use
What is internal respiration?
The process taking place in the tissues by which gasses are exchanged between the blood and tissue cells. Oxygen moves in CO2 moves out
What is external respiration?
The means by which gasses move between the atmosphere and the body. Oxygen moves from the atmosphere into the bloodstream. Carbon dioxide moves from the blood into the atmosphere.
What is the purpose of accessory muscles in respiration?
Increase the size of the thorax (inspiration) or decrease it further (or with greater control) in expiration
What are the signs of increased work of breathing in children?
Head bobbing Nasal flaring Tracheal tug Shoulder shrugging Sternal recession Intercostal recession Subcostal recession Abdominal breathing
What are the signs of respiratory distress in children?
Snoring Gurgling Stridor Grunting Gasping Wheeze
What are the structures involved in respiration?
Nose Pharynx Larynx Trachea (windpipe) Bronchi (2, one goes to each side) Bronchioles Alveolar ducts- Alveoli Pleural membranes (lung coverings) Muscles of respiration
