Unit 2.2 Flashcards
List the principal structures of the
ventilatory system.
Nose, mouth, pharynx, larynx, trachea,
bronchi, bronchioles, lungs, and
alveoli
Outline the functions of the conducting
airways
Nose: humidifies the air and filters particles due to hair and mucus
Pharynx: Swallowing, Regulation of Airflow, sound
Larynx: Respiration, epiglottis prevent food entering airway
Trachea: lined with mucus and ciliated cells, pushes foreign particles back towards larynx where swallowed
Pulmonary Ventilation -
Pulmonary Ventilation - movement of air in and out of the lungs
Total Lung Capacity (TLC)
- the amount of air in the lungs after a maximal inspiration
Vital Capacity (VC)
the amount of air that can be exhaled after a maximal inhalation
Tidal Volume (TV)
the amount of air an individual can inhale or exhale during normal quiet
breathing (7-8% of total lung capacity)
Expiratory Reserve Volume (ERV) -
- the amount of air an individual can exhale beyond a tidal
expiration (20% of total lung capacity)
Inspiratory Reserve Volume (IRV)
the amount of air that an individual can inhale above a
tidal inspiration (60% of the total lung capacity)
Residual Volume (RV)
the amount of air remaining in the lungs after a maximal exhalation
(makes up 20% of the total capacity)
Explain the mechanics of ventilation in the human lungs
Inhalation
- Diaphragm contracts and lowers
Accessory muscle: sternocleidomastoid lifts sternum and scalene and pectoralis minor help lift ribs - External intercostal muscles contract
- This causes the rib cage to move upwards and outwards
- The volume of the chest cavity increases
- The pressure inside the lungs drops below atmospheric pressure
- Air rushes into the lungs
Explain the mechanics of ventilation in the human lungs
Exhalation
The diaphragm relaxes and turns to a dome shape
- Internal intercostal muscles contract
And abdominal muscles push diaphragm back up
- This causes the rib cage to move downwards and inwards
- The volume of the chest cavity decreases
- The pressure inside the lungs increases above atmospheric pressure
- Air is forced out of the lungs and into the atmosphere
Describe the nervous and chemical control of ventilation during exercise.
When we exercise, the medulla receives messages from a number of senses around the body, which can cause an increase in ventilation (faster and deeper breathing):
Ventilation increases as a direct result of increases in blood acidity levels due to
increases in carbon dioxide content in the blood, which is detected by the respiratory
center
↳ this results in an increase in the rate and depth of ventilation
Stretch receptors in the lungs - tell the medulla that the lungs are getting over stretched
Proprioceptors (Movement sensors) – in the tendons and muscles sense contraction of skeletal muscle
Chemoreceptors– Sense concentration changes of oxygen and carbon dioxide in the blood.
Outline the role of hemoglobin in oxygen transport
98.5% of oxygen in the blood is transported by hemoglobin as oxyhemoglobin within red
blood cells
Explain the process of gaseous exchange at the alveoli
Gas exchange of oxygen and carbon dioxide takes place in the alveoli
1. Oxygen from the inhaled air diffuses through the walls of the alveoli and into the capillaries to the red blood cells
2. The red blood cells carry the oxygen to the body (oxygenated)
3. Carbon dioxide which is produced by the body return to the lungs in the red blood cells (deoxygenated)
4. The carbon dioxide then diffuses across the capillary and the alveolar walls into the air so that it can be removed from the body via expiration
Gaseous Exchange
the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. It occurs in the lungs between the alveoli and the capillaries which are located around the walls of the alveoli
