4: Why do we breath? Flashcards
Define gaseous exchange
The movement of gases from one place to another, e.g. movement of oxygen out of the alveoli into blood capillaries
Define pleural cavity
Each lung is surrounded by a pleural cavity formed by two serous membranes and containing a small amount of fluid.
Define Alveoli
Small air filled sacs located deep inside the lungs, where gas exchange between the air and blood occurs.
Define cilia
An extension of a cell plasma membrane, which functions to move material over the cell surface. Cilia line the trachea.
Define ventilation
The process of air moving into and out of the lungs.
Define palate
Also known as the roof of the mouth, the hard bony palate is the anterior portion and the soft palate is the posterior portion.
Define pharynx
Also known as the throat, the pharynx is a common pathway for food and air.
Define larynx
A passageway for air located between the pharynx and the trachea. The larynx contains a lot of cartilage to maintain on open airway.
Define epiglottis
Cartilage located at the top of the trachea. The epiglottis tips posteriorly during swallowing to prevent food entering the trachea.
Define trachea
A tubular passageway for air running from the larynx to the lungs. Also known as the windpipe.
Define bronchi
The trachea divides into a left and right bronchi (or primary bronchi) each of which extend into one lung.
Define bronchioles
The bronchi, which extend down into each lung, continue to branch giving rise to bronchioles and finally the terminal bronchioles.
Define respiratory membrane
The location within the lungs that gas exchange takes place. The respiratory membrane consists of the walls of the alveoli and the pulmonary capillaries.
Define diaphragm
A thin skeletal muscle involved in breathing, it separates the thoracic cavity from the abdominopelvic cavity.
Define pleura
A thin cellular sheet (serous membrane) that lines the lungs or the wall of the thoracic cavity.
Define humidfy in respiratory system
The process by which water/moisture is added to the air that enters the body. This happens in the nasal cavity.
Define hilum
The medial surface of the lungs where large blood vessels, lymphatic vessels, nerves and the primary brochi enter and exit.
Define inspiration in respiratory system
The process of air entering the body from the environment and filling up the lungs.
Define expiration in the respiratory system
The process of air exiting the lungs and moving out of the body back into the environment.
What are the 4 processes of respiration?
- ventilation: movement of air into and out of the lungs
- external respiration: gas exchange between the air in the lungs and the blood
- Transportation: of oxygen and CO2 in the blood
- internal respiration: gas exchange between the blood and the tissues.
How is it relate to cellular respiration
Cellular respiration refers to cellular metabolism, it’s not the same, but related as breathing provides oxygen needed in cellular respiration to make ATP from glucose + breathing rids the body of potentially toxic CO2 that is the waste produced during cellular respiration
What are the functions of the repiratory system apart from respiration?
- regulation of blood pH: by changing blood CO2 levels
- production of chemical mediators: lungs produce enzyme called angiotensin-converting enzyme (ACE0, an important component of blood pressure regulation
- voice production: air moving past the vocal folds make sound and speech possible
- olfaction: sensation of smell occurs when airborne molecules are drawn into the nasal cavity
- protection: against microorganisms by preventing them from entering the body and removing them from respiratory surfaces
What are the two ways of classifying the respiratory system?
Structurally and functionally
How is the respiratory system divided structurally?
Into upper respiratory tract (external nose, nasal cavity, pharynx with its associated structures and the larynx) + lower respiratory tract (trachea, bronchi and smaller bronchioles and the lungs)
- note there are alternative definition for this, sometimes the larynx is considered in the lower respiratory tract