Respiratory System Flashcards
What is respiration?
It is the process by which all metabolically active cells in the body are supplied with oxygen and carbon dioxide is removed.
What are the 2 regions of the respiratory system and what do they contain?
The upper respiratory tract that has nose, nasal cavity and pharynx. The lower respiratory tract that has larynx, trachea, bronchi/bronchioles and alveoli.
Which part of the respiratory system passes both food and air?
The pharynx.
What is the floor of the nasal cavity formed with?
The hard and soft palates
What is the pharynx?
Tunnel shaped and extends from nasal cavity to larynx and is about 13cms long. Has 3 sections
What are the 3 parts of the pharynx?
The nasopharynx, oropharynx and Laryngopharynx
What is the function of the nasopharynx?
Upper part, recieves air from nasal cavity
What is the function of the oropharynx?
Middle part, receives air from nasopharynx and food from oral cavity.
What is the function of the Laryngopharanyx?
Lowest part, acts as both respiration and digestion
What are the sinus?
The are openings that lighten the skull and modify sounds. Also lined with mucous membranes that warm and humidify air.
What is the path from the nose to the alveoli?
Air enters the nose, into the nasal cavity, through pharynx, then larynx, then trachea then bronchi then bronchioles and the alveoli
What shape is the lung and what is it surrounded by?
They are cone shaped and surrounded by a double membrane called pleura that protects the lungs
What is the space between the inner and outer pluera layers called?
It is the plueral cavity that contains plueral fluid which lubricates and reduces friction
What separates the lungs?
The mediastinum that contains the heart and major blood vessels
How many lobes does each side of the lung have?
The right lung has 3 lobes and the left has 2 lobes
What are the aveolis and where are they?
They are small pockets or sacs and they sit on the end of the alveolar ducts that are attached to the bronchioles
What does the alveoli do and how?
It allows rapid gas exchange as it is only 1 cell thick
What does the septa cell do?
It produces pulmonary surfactant, reducing the surface tension.
How does the process of inspiration/inhalation work?
Inspiratory muscles contract (diaphragm descends, ribs moves upwards and outwards), thoracic cavity volume increases, lungs stretch and intrapulmonary volume increases, intrapulmonary pressure drops and air flows into lungs down its pressure gradient until intrapulmonary pressure is 0 (equal to atmospheric pressure). It is an active process
How does the process of exhalation work?
Inspiratory muscles relax (diaphragm rises, ribcage descends due to recoil of costal cartilages), Thoracic cavity volume decreases, elastic lungs recoil passively, intrapulmonary volume decreases, intrapulmonary pressure rises and air flows out of lungs down its pressure gradient until pulmonary pressure is 0. It is a passive process
What is the process of external respiration?
Diffusion
What are the factors that affect respiration?
Thickness of membrane (increase by oedema), surface area of the lung (reduced in emphysema) and fluid in tissue.
How does gas pressure travel?
From an area of high concentration to an area of low concentration.
How is carbon dioxide transport assisted?
By carbonic anhydrase
What is alkadosis?
High alkaline in blood. pH over 7.45
What is acidosis?
High acid in blood. pH under 7.35
What are some factors that can cause acidosis?
Renal problems (kidney disease), Metabolic problems (diabetes) and Respiratory problems (asthma)
What is the respiratory centre controlled by?
The pons and the medulla
What are factors that influence depth and rate of respiration?
Local factors (H+, O2, CO2), emotions/cold (hypothalmic manipulation), irritants (reflexes), reflexes (hyperinflation)
Where does the medulla inspiratory area receive input from?
Chemoreceptors, baroreceptors and stretch receptors
What are chemoreceptors sensitive to?
Changes in PO2 and PCO2
What happens to the air at higher altitudes and how does this affect the body?
There is a decrease in o2 and therefore cardiac output increases
What is the respiration rate in adults?
12-18r/min
Define tidal volume
The amount of air moved into or out of the lungs in quiet, relaxed breathing
Define residual volume
The volume of air that remains in the lungs after maximum exhalation
Define inrespiratory reserve volume
The additional amount that can be breathed in by force after a normal inhalation
Define expiratory reserve volume
The additional amount that can be breathed out by force after normal exhalation
Define vital capacity
The volume of air that can be expelled by the lungs by maximum exhalation after maximum inhalation
Define functional residual capacity
The amount of air remaining in the lungs after normal exhalation
Define total lung capacity
The total volume of air that can be contained in the lungs after maximum inhalation
