Respiratory System Flashcards
External Respiration
Exchange of gases between the blood and the lungs.
Internal respiration
Exchange of gases between the blood and cells
8 organs of the respiratory system
- Nose 2. Pharnyx 3. Larynx 4. Trachea 5. Two bronchi 6. Bronchioles 7. Two lungs and the pleura (their covering) 8. Muscles of breathing - intercostal muscles and the diaphragm
Functions of the nose
- Warm the air 2. Filter it (hairs trap larger particles, mucus traps smaller particles and dust) 3. Humidifcation
Pharynx
Extends from the base of the skull to the 6th vertebra. Coated with a mucus membrane lining and is composed of a ciliated columnar epithelium. INSERT PHOTO HERE
Functions of the Pharynx
- Warming and humidifying. 2. Taste 3. Hearing 4. Protection 5. Speech
Larynx
Aka “voice box” Links the pharynx and the trachea. Found at the 3rd-6the vertebrae.
Trachea position
Fund below the larynx and extends downward to the 5th thoracic vertebra where it divides at the carina into the bronchi
Epiglottis
Lead shaped fiobroelastic cartilage, covered with stratified squamous epithelium. Closes off the larynx during swallowing to protect the lungs from accidental inhalation of foreign objects.
Carina
Point where he trachea divides into the right and left bronchi.
Structure of the Trachea
- Outer layer - fibrous and elastic tissues which enclose the cartilage. 2. Middle layer - bands of cartilage and and smooth muscle which wind around the trachea. 3. Ciliated columnar epithelium containing mucus secreting goblet cells
4 Main Parts of the Lungs
- Apex 2. Base 3. Costal Surface 4. Medial surface
Mediastinum
Space between the lungs that is occupied by the heart, great vessels, trachea, right and left bronchi, esophagus, lymph nodes, lymph vessels and nerves.
Divisions of the right and left lung
Right Lung: -Superior, Middle and Inferior Lobes Left Lung: -Superior Lobe -Inferior Lobe
Pleura
Consists of a closed sac of serous membrane which contains a small amount of serous fluid. The lung is pushed into the sac so two layers form, one adheres to the lung, the other to the thoracic cavity.
Visceral Pleura
Adherent to the lung, covers each lobe and passes into the fissures that separate them.
Parietal Pleura
Adherent to the inside of the chest wall and the thoracic surface of the diaphragm.
Describe the breakdown of the bronchi
Bronchioles –> Terminal Bronchioles –> Respiratory Bronchioles –> Alveolar Ducts –> Alveoli Wider passages are called conducting airways because they bring air into the lungs but their walls are too thick to permit gas exchange.
Cartilage in the Lungs
Only present in the larger airways as it is too rigid to allow expansion.
Smooth Muscle in the Lungs
Replaces cartilage in the smaller tubes of the lungs. Allows expansion and contraction.
Epithelial Lining of the Lungs
Ciliated epithelium is gradually replaced with non-ciliated epithelium.
Alveoli
Site of gas exchange within the lungs. Found at the end of the alveolar ducts.
Respiratory membrane
Made up of the alveolar wall and the ` wall which are fused together, site of gas exchange in the lungs (external respiration).
Surfactant
Secreted by septal cells, a phospholipid fluid which prevents the alveoli from drying out. Also reduces surface tension and prevent alveolar walls from collapsing during expiration. Facilitates the initiation of respiration in babies.
Lung defense against infection
The lungs rely on protective cells found in the lung tissue including lymphocytes and plasma cells (which produce anti-bodies) and phagocytes, and alveolar macrophages.
Name the main muscles involved in breathing
Intercostal muscles and the diaphragm.
External intercostal muscle location/function
Found on the top side of the ribs, extend downward and forward, involved in insipration.
Internal intercostal muscle location/function
Found at the back of the ribs, extend downward and backward, used when exhalation becomes active (during exercise). Pull all muscles up toward the first rib which is fixed. Contraction stimulated by the intercostal nerves.
Diaphragm
-floor of the thoracic cavity -roof of the abdominal cavity -starts with a central tendon from which muscle radiate and are attached to lower ribs. On contraction it pulls downward. -supplied by the phrenic nerves -75% of breathing is done by the diaphragm
Elasticity
The ability of the lung to return to its normal shape after each breath.
Compliance
Measure of stretchability of the lungs - ie. effort required to inflate the alveoli. Very little effort required in healthy lungs.
Airway resistance
When increased (during vasoconstriction) more effort is required to inflate the lungs.
Tidal Volume
Amount of air passing into and out of the lungs during each cycle of breathing.
Inspiratory Reserve Volume
Extra volume of air that can be inhaled into the lungs during maximum inspiration.
Inspiratory Capacity
Amount of air that can be inspired with maximum effort.
Functional Residual Capacity
Amount of air remaining in air passages & alveoli at the end of respiration. Prevents alveoli collapse on expiration.
Expiratory Reserve Volume
Largest volume of air which can be expelled from the lungs.
Residual Volume
Volume of air remaining in the lungs after forced expiration (cannot be measured)
Vital capacity (VC)
Maximum volume of air which can be moved into and out of the lungs.
Total Lung Capacity (TLC)
Maximum amount of air the lungs can hold. Normally about liters.
Alveolar ventilation
Volume of air that moves in and out of the alveoli per minute.
Inspiratory Neurones
Set the rate and depth of breathing. Come from the medulla oblongata.
Hypercapnia
Rise in C02 levels in the blood.
Hering-Bruer Reflex
Prevents overinflation of the lungs. Stretch receptors in the lung inhibit respiration when lung capacity reaches its maximum.
macrophage
A large white blood cell, found primarily in the bloodstream and connective tissue, that helps the body fight off infections by ingesting the disease-causing organism. HIV can infect and kill macrophages.
phagocyte
A cell, such as a white blood cell, that engulfs and absorbs waste material, harmful microorganisms, or other foreign bodies in the bloodstream and tissues.
Structures associated with the respiratory system.
The Nose to the Larynx
Nasal Cavity
The Larynx (diagram)
The Trachea and related structures (diagram)
Organs Associated with the Lungs (diagram)
Lobes of the Lungs and Vessels (diagram)
Pleura (diagram)
Lower Respiratory Tract
(Diagram)
Lobes of the lungs
