UE 3 Flashcards
(90 cards)
known as the upper airway, warms and filters inspired air so that the lower respiratory tract (the lungs) can accomplish gas exchange or diffusion.
Upper Respiratory Tract
Upper airway structures consist of
the nose; paranasal sinuses; pharynx, tonsils, and adenoids; larynx; and trachea.
performs this function by facilitating life-sustaining processes such as oxygen transport, respiration, ventilation, and gas exchange.
Respiratory system
➔ Oxygen is supplied to, and carbon dioxide is removed from, cells by way of the circulating blood through the thin walls of the capillaries.
➔ Oxygen diffuses from the capillary through the capillary wall to the interstitial fluid.
➔ it diffuses through the membrane of tissue cells, where it is used by mitochondria for cellular respiration.
➔ The movement of carbon dioxide occurs by diffusion in the opposite direction—from cell to blood
Oxygen Transport
The movement of air in and out of the airways continually
replenishes the oxygen and removes the carbon dioxide
from the airways and the lungs. This whole process of gas
exchange between the atmospheric air and the blood and
between the blood and cells of the body is called
Respiration
The goals of respiration are to
provide oxygen to the tissues and to remove carbon dioxide
Respiration is divided into:
● Pulmonary ventilation
● Diffusion
● Transport of oxygen
To achieve these goals of respiration, we should have:
● Efficient respiratory pump
● Efficient heart and circulatory system
● Efficient respiratory control
Mechanisms of Pulmonary Ventilation
Lungs can expand and contract in ways
Gas Transport
Oxygen Transport
Lungs can expand and contract in ways:
- Downward and upward movement of the diaphragm to
lengthen or shorten the chest cavity - Elevation and depression of the ribs to increase and
decrease the anteroposterior diameter of the chest cavity
● Inhaled: oxygen – contract of diaphragm → downward
● Exhaled: carbon dioxide – diaphragm relaxed
oxygen and carbon dioxide carried between the
lungs and body cells by the blood
These gasses can be:
1. Dissolve the blood plasma
2. Chemically combined with other atoms or molecules
present in the blood
Gas Transport
- Loosely binding to the iron present in the protein
hemoglobin in the red blood cells creatinine.
Oxygen transport
➔ requires movement of the walls of the thoracic
cage and of its floor, the diaphragm.
➔ When the chest wall and the diaphragm return to their
previous positions (expiration), the lungs recoil and force
the air out through the bronchi and the trachea.
➔ Inspiration occurs during the first third of the respiratory
cycle; expiration occurs during the latter two-thirds.
Ventilation
Inspiration occurs during
the first third of the respiratory cycle
expiration occurs during
the latter two-thirds.
this phase of respiration normally requires energy
Inspiratory phase
this phase is normally passive, requiring very little energy
Expiratory phase
Physical factors that govern airflow in and out of the lungs
are collectively referred to as
the mechanics of ventilation
Physical factors that govern airflow in and out of the lungs
are collectively referred to as the mechanics of ventilation
and include air pressure variances, resistance to airflow,
and lung compliance
★ During inspiration, diaphragm contract
★ Thoracic Rib cage increases
★ Thorax Pressure decreases
★ After inspiration, the diaphragm recoils
movements of the diaphragm and intercostal muscles enlarge the thoracic cavity and thereby lower the pressure inside the thorax to a level below that of atmospheric pressure. As a result, the air is drawn through the trachea and the bronchi into the alveoli.
Inspiration
the diaphragm relaxes and the lungs recoil, resulting in a decrease in the size of the thoracic cavity. The alveolar pressure then exceeds atmospheric pressure, and air flows from the lungs into the atmosphere.
Expiration
● MEDULLA OBLONGATA and PONS
● CCR- CO2 and hydrogen level s
● PCR- Ph and level of O2 and CO
Brain
● DETERMINES THE CO2
● (INCREASED CO2, DECREASED PH)
● (DECREASED CO2- INCREASED PH)
Lungs
BOTH MAINTAIN THE RATIO OF CARBONIC ACID
Brain and Lungs