Respiratory System Flashcards
What are the Functions of the respiratory system? (5)
- To supply oxygen to blood and to remove carbon dioxide from blood
- to regulate the acidity of the extracellular fluids of the body
- temperature control
- elimination of water
- voice production (phonation)
What does the Respiratory consist of? (6)
- Lungs
- Nostrils
- Nasal Cavity
- Pharynx
- Larynx
- Trachea
What are the Nostrils?
The external opening of the air passages
What is the Nasal Cavity?
- It is a cavity in the head that is separated from the mouth by the hard and soft palate.
- It is lined with mucous membrane
What are the functions of the Nasal Cavity? (2)
- To communicate caudally with the Pharynx
2. To warm up the air inspired through the nostrils.
What does the mucous membrane of the caudal part of the nasal cavity contain and what does it do?
It contains the olfactory nerve which mediates one’s sense of smell.
What are the Sinuses?
Air filled cavities from which passages in certain cranial bones open into the nasal cavity.
What sinuses do all farm animals have? (5)
- Maxillary
- Frontal
- Sphenoid
- Palatine
- Lacrimal (cows and sheep)
What is Sinusitis?
An infection of the sinus
How can sinusitis be contracted? (2)
- If the several upper cheek teeth that project into the maxillary sinus become diseased, the sinus may become infected as a result. (common in horses)
- Dehorning mature cattle opens up the frontal sinus which makes it susceptible to infection.
What is the Pharynx?
The common passage for food and air
What are the openings to the pharynx? (5)
- Two from the nasal cavity
- Two from the middle ears
- The mouth
- The larynx
- The esophagus
What are the names of the parts of the pharynx? what do they contain? (3)
- Nasal Part - Nasal Cavity
- Oral Part - Mouth
- Laryngeal Part - Larynx
What is the Larynx?
The voice box
What are the functions of the Larynx? (3)
- Control of inspiration and expiration of air
- Prevents inhalation of foreign objects
- Essential for voice production
What are the five large cartillages that form the basis of the larynx?
- Epiglottis
- Thyroid body
- Thyroid laminae
- Arytenoid
- Cricoid
Which cartilage is located just behind the base of the tongue?
The epiglottis cartilage
Which cartilage makes up the projection from the ventral aspect of the neck?
The body of the thyroid cartilage
Which cartilage is important in swallowing and phonation?
Arytenoid Cartilage
Which cartilage is associated with snoring and roaring (in horses)?
Cricoid cartilage
What is the Trachea?
- A continuation of the larynx.
- Consists of non-collapsible tube formed by series of adjacent cartilage rings which are incomplete dorsally.
The trachea passes caudal as far as the base of the heart where it divides into two what?
Bronchi - one for each lung
Why are lungs sometimes called lights?
They have a specific gravity that is lower than that of water
The lungs completely fill most of the available space in the thoracic cavity. True or False?
True
What is the Hilus of the lung and where is it located?
It is located near the middle of the medial side, where the bronchus, pulmonary artery and nerves enter the lung and pulmonary veins and lymphatics leave.
What are the names of the lobes of the lungs? (3)
- Cranial (Apical)
- Middle (Cardiac)
- Caudal (Diaphragmatic)
What are the components of the Bronchial tree? (7)
- Branches of Bronchi
- Bronchioles
- Intralobular Bronchioles
- Terminal Bronchioles
- Respiratory Bronchioles
- Alveolar Ducts
- Alveolar Sacs containing numerous Alveolus
The alveolar walls are intimately associated with what?
Blood capillaries
What are the characteristics of fetal lungs? (3)
- same consistency as liver
- contain no air
- sink in water
What are the boundaries of the Thorax? (5)
- Cranially by the first pair of ribs, the first thoracic vertebra and the cranial part of the sternum
- Dorsally by the thoracic vertebrae
- Laterally by the ribs
- Ventrally by the sternum
- Caudally by the diaphragm.
What is the Pleura?
a smooth serous membrane that facilitates the movement of lungs within the thorax.
What are the two types of pleura?
- Parietal Pleura
2. Visceral Pleura
Which pleura lines the thorax?
Parietal Pleura
Which pleura covers the lungs?
Visceral Pleura
What is the Mediastinum?
A double layer of pleura that is formed at the junction of the two pleural sacs that surround the two lungs.
What does the respiratory system provide?
an open passage way for the air from the exterior to reach the smallest subdivisions of the lungs.
What is the smallest subdivision of the lungs?
The alveoli
What does external respiration depend on?
the movement of air into and out of the lungs.
How is inspiration achieved?
The enlargement of the thoracic cavity reduces the already negative pressure in the pleural cavity, causing the lungs to enlarge. This results in an inflow of air into the lungs.
What enlarges the thoracic cavity during relatively quiet respiration?
The diaphragm
What is the structure of the diaphragm?
- A dome-shaped structure with convexity directed cranial into the thorax.
- The central portion is tendinous
- The peripheral portion consists of striated muscle (attached to lumbar vertebrae)
Which nerves supply the diaphragm?
The right and left phrenic nerves
What does the contraction of the diaphragm cause?
Forces the abdominal contents caudally thus increasing the length or volume of the thorax.
What other muscles aid inspiration?
The muscles attached to the ribs.
What is Expiration?
The movement of air out of the lungs.
When does expiration result?
Whenever the volume of the thorax is decreased.
Why is expiration passive?
Because of the tendency of elastic structures to return to their normal shape and location.
Which muscles are involved in forceful expiration? Why?
The abdominal muscles are involved because the process requires a considerable amount of muscular effort.
Respiratory movements can be recorded by what? (2)
- Pneumographs
2. Stethographs of plethysmographs
What are the different types of breathing? (3)
- Abdominal
- Costal
- Eupnea
what is Abdominal breathing?
diaphragm contraction (quiet breathing)
What is costal breathing?
Breathing that involves movement of ribs
When is costal breathing required?
occurs when more air is needed
What is Eupnea breathing?
Normal quiet respiration
What is dyspnea?
difficulty breathing
What is apnea?
cessation of respiration
What is hyperpnea?
increased rate of breathing
What is polypnea?
rapid shallow breathing
What is Tidal Volume (TV)?
The volume of air inspired or expired during normal respiration.
When does tidal volume increase?
When one is excited or active.
What is the Inspiratory reserve volume (IRV)?
The amount of air that can be inspired above and beyond that is inspired during a normal quiet inspiration.
What is the Expiratory reserve volume (ERV)?
The amount of air that can be expired following a normal quiet inspiration
What is the Residual volume (RV)?
he amount of air remaining in the lung after a maximal expiratory effort.
What is the total lung capacity (TLC)
The amount of air contained in the lung at the end of maximal inspiration
What is Vital Capacity (VC)?
The maximal amount of air that can be expired after a minimal inspiration
What is the Functional Residual Capacity (FRC)?
The ammount of air remaining in the lungs after a normal expiration
What is the Inspiratory capacity (IC)?
the maximal amount of air that can be inspired after a normal expiration
What is dead space?
space occupied by air at the end of an expiration. Anatomical and physiological.
What is Artificial Respiration?
applied by alternately compressing and releasing the thorax.
When should artificial respiration be started?
as soon as possible after breathing ceases.
How can one rhythmically inflate the lungs during surgery?
Administer oxygen with air given under positive pressure
Exchange of gasses occurs in what?
External and internal respiration
What increases the efficiency of oxygen transport and oxygen exchange in the blood?
The presence of hemoglobin.
Alveolar air is separated from blood in the pulmonary capillaries by a respiratory membrane consisting of: (6)
- Endothelial lining of capillaries
- The capillary basement membrane
- A thin interstitial fluid layer
- The alveolar epithelium
- A layer of alveolar fluid
- an alveolar layer of surfactant
How is oxygen exchanged?
by hemoglobin (erythrocytes)
How is carbon dioxide exchanged?
Mainly as bicarbonate form, some as carbonic acid and about 21% combines with protein amino groups on Hb and is carried as carbamino hemoglobin.
The pressure differences in the lung favor? (2)
- the loading of oxygen onto Hb at the lung alveoli.
2. the unloading of carbon dioxide at the tissue level.
Where are gases absorbed?
Directly into the blood plasma but only a small fraction of the gas is carried in physical solution in the fluid.
How do the thin membranes of the alveolar wall and capillaries facilitate external respiration?
They facilitate the movement of oxygen into the blood and the movement of carbon dioxide into the alveolar air.
What happens during internal respiration?
Oxygen from the blood is diffused to the tissues for cellular oxidation and the resulting carbon dioxide diffuses into the blood.
What is the respiratory system entirely controlled by?
Striated muscle
Is breathing voluntary or involuntary?
The muscles can be conciously controlled (holding ones breath) but normal respiration is almost entirely reflex in nature.
The respiratory mechanism of the brain consists of how many bilateral groups of nerve cells in the brain stem reticular substance
at least 3
What is the Medullary Rhythmic areas?
the respiratory centers
How does the medullary rhythmic area communicate with parts of the body?
Through phrenic nerves
What does the Respiratory Center consist of? (4)
- Pneumotaxic center
- Apneustic center
- Medullary rhythmic area
What are the areas of the Medullary rhythmic area? (2)
- Expiratory area
2. Inspiratory area
How is the inspiration center inhibited?
Stretch receptors in the lung parenchyma visceral pleura and bronchioles. these receptors become stimulated as the lung inflates during respiration causing firing of impulses through the vagus to inhibit the inspiration center.
What are the humoro chemical factors influencing the activity of the respiratory center? (3)
- The level of carbon dioxide in the blood
- H+ ion concentration of the blood
- The oxygen concentration in arterial blood
What is the H+ ion concentration of the blood monitored by?
chemoreceptor cells in the medulla oblongata
How does the inspiratory center recieve impulses as a result of oxygen concentration in arterial blood?
The oxygen concentration stimulates chemoreceptors in the carotid bodies and aortic bodies which in turn send impulses to the inspiratory center.
