Week 2 - Respiratory Sytem Flashcards
(105 cards)
1
Q
What is the function of the nose?
A
The nostrils provide entrance to the nasal cavity; internal hairs begin to filter incoming air
Location: Part of face centred above the mouth, in and below spaces between eyes
2
Q
What is the function of the nasal cavity?
A
Conducts air to the pharynx: mucous lining filters warms and moistens incoming air.
Location: Hollow space behind nose
3
Q
What is the function of the Paranasal Sinuses?
A
Reduce the weight of the skull; serve as resonant chambers
Location: Hollow spaces in certain skull bones
4
Q
What is the function of the Pharynx?
A
The passageway for air moving from the nasal cavity to the Larynx and for food moving from oral cavity to esophagus.
Location: Space behind the oral cavity, the nasal cavity, and epiglottis.
5
Q
What is the function of the Larynx?
A
The passageway for air; prevents foreign objects from entering the trachea; houses the vocal cords.
Location: Enlargement at top of Trachea
6
Q
What is the function of the trachea?
A
The passageway for air; mucous lining, continues to filter particles from incoming air
Location: Flexible tube that connects the Larynx with bronchial tree
Description: Flexible cylindrical tube (windpipe)
7
Q
What is the function of the Bronchial Tree?
A
Conducts air from Trachea to Alveoli; mucous lining continues to filter particles from incoming air.
Location: Branched tubes that lead from Trachea to Alveoli
8
Q
What is the function of the Lungs?
A
Contain air passages, alveoli, blood vessels, connective tissues, lymphatic vessels, and nerves.
Location: Soft, cone-shaped organs that occupy a large portion of the thoracic cavity.
9
Q
What does the upper respiratory tract contain?
A
Includes the nose, nasal cavity, paranasal sinuses, pharynx and larynx.
10
Q
What does the lower respiratory tract contain?
A
Includes the trachea, bronchial tree, and lungs
11
Q
What is the nasal septum?
A
The Midline wall of bone and cartilage that separates the nasal cavity into right and left parts.
12
Q
What are the nasal conchae and its function?
A
Any of the shelf-like bones or bony processes extending medially from the wall of the nasal cavity; also called a turbinate bone.
Supports the mucous membrane that lines the nasal cavity.
Helps increase the mucous membrane’s surface area.
13
Q
What does the mucous membrane in the nasal cavity contain?
A
pseudostratified ciliated epithelium that is rich in mucus-secreting goblet cells.
Also includes an extensive network of blood vessels.
14
Q
What are the functions of the mucous membrane that lines the nasal cavity?
A
The mucous membrane is pseudostratified ciliated epithelium. There are many blood vessels in this area. The epithelial layer and blood warm, moisten, and filter incoming air. Mucus traps dust and pathogens, and cilia move the mucus to the Pharynx to be swallowed. Trapped microorganisms are destroyed in the stomach.
15
Q
What is the Larynx composed of?
A
A framework of muscles and cartilages bound by elastic tissue. The largest cartilage is the Thyroid.
16
Q
What is inside the Larynx?
A
Two pairs of horizontal vocal folds, composed of muscle tissue and connective tissue with a covering of mucous membranes.
Upper folds are called false vocal cords because they do not produce sound.
The muscle fibers within these folds help close the airway during swallowing.
17
Q
What do the lower folds of the Larynx do?
A
They are the true vocal cords. They are made up of muscle fibers and strong, elastic connective tissue.
18
Q
What lines the inner trachea walls?
A
A ciliated mucous membrane with many goblet cells
19
Q
What is internal respiration?
A
Gas exchange between blood and tissue
20
Q
What is ventilation?
A
Movement of air into and out of the lungs
21
Q
What is cellular respiration?
A
The use of Oxygen for metabolic reactions within cells
22
Q
What are the correct steps of inspiration, starting from the nose?
A
- Nasal Cavity
- Nasopharynx
- Oropharynx
- Laryngopharynx
- Larynx
23
Q
What are the bony processes that curl out from the lateral walls of the nasal cavities, serving to stir up the air as it is inhaled?
A
Conchae
24
Q
Describe what the Bronchial Tree consists of…
A
Consists of branched airways leading from the Trachea to the microscopic air sacs in the lungs.
1. Its branches begin with the right and left main (primary) bronchi.
2. Each bronchus enters its respective lung.
3. Each main bronchus divides into LOBAR (secondary) Bronchi and then into increasingly finer tubes.
4.
25
Describe what the Bronchial Tree consists of...
Consists of branched airways leading from the Trachea to the microscopic air sacs in the lungs.
1. Its branches begin with the right and left main (primary) bronchi.
2. Each bronchus enters its respective lung.
3. Each main bronchus divides into LOBAR (secondary) Bronchi and then into increasingly finer tubes.
4. Among these smaller tubes are bronchioles that continue to branch, giving rise to terminal bronchioles,, respiratory bronchioles and very thin tubes called Alveolar Ducts.
5. The Alveolar Ducts lead to Alveolar sacs.
6. Alveolar sacs are composed of microscopic air sacs called Alveoli, which lie within capillary networks.
7. The Alveoli are sites of gas exchange between the inhaled air and bloodstream.
26
What do the mucous membranes of the Bronchial tree do?
They continue to filter incoming air, and the many branches of the tree distribute the air to alveoli throughout the lungs.
27
What does the Alveoli do?
Provide a large surface area of thin squamous epithelial cells through which gases are easily exchanged.
Oxygen diffuses from the alveoli into the blood in nearby capillaries, and co2 diffuses from the blood into the alveoli.
28
What is the function of the cartilaginous rings in the tracheal wall?
The rings of the Trachea prevent the collapse of the trachea and blockage of the airway leading to the lungs.
29
What is the difference between the right and left lung?
- The right lung is larger
- The right lung is divided into 3 lobes and the left is divided into 2 lobes
-
30
What is the Visceral Pleura?
Serous membrane that covers the surface of each lung.
31
What is the Parietal Pleura?
Serous membrane that covers the inner surface of the thoracic cavity wall.
It borders part of the mediastinum and lines the inner wall of the thoracic cavity and the superior surface of the diaphragm.
32
What is the Pleural cavity?
Potential space between the visceral and parietal pleural membranes.
33
What happens if there is a puncture in the thoracic wall of the lungs?
It will admit atmospheric air into the pleural cavity and creates a real space between the membranes.
This condition, called PNEUMOTHORAX, may collapse the lung on the affected side because of the lung's elasticity.
34
What is a collapsed lung called?
Atelectasis
35
What is atmospheric pressure?
Pressure exerted by the weight of air surrounding the earth, equivalent at sea level to the weight of a column of Mercury 760 milliliters high.
36
Describe the events of Inspiration...
1. Nerve impulses from the phrenic nerves stimulate the diaphragm to contract downward.
2. This increases the volume inside the thoracic cavity and decreases the pressure of the gases inside the lung.
3. When the pressure drops to a level slightly below atmospheric pressure, air rushes into the air passages and reaches the alveoli.
4. Once in the Alveoli, oxygen diffuses into the alveolar capillaries.
37
How does the expansion of the chest wall expand the lungs during inspiration?
1. The diaphragm contracts downwards, and the external intercostal muscles cause the wall of the thoracic cavity to move outward and upward.
2. The parietal pleura moves along with the thoracic wall as it expands
3. Since the parietal pleura is held against the visceral pleura by the serous fluid between them, the layers of the pleural membrane move together.
4. The visceral pleura is attached to the outer surface of the lungs.
5. Therefore, when the thoracic cavity expands, and both layers of the pleura expand with it, the lungs expand too.
38
What is surface tension?
Force due to the attraction of water molecules that makes it difficult to inflate the alveoli of the lungs.
39
What forces cause normal expiration?
1. Forces involved in normal expiration are derived from elastic recoil of the tissues that stretched during inspiration and from surface tension in the alveoli.
2. During expiration, when the diaphragm and external intercostal muscles are no longer being stimulated to contract, they snap back to their relaxed positions.
3. The stretched elastic tissues of the lungs also return to their original positions.
4. As elastic recoils, surface tension increases in the alveoli, decreasing their diameter.
5. These events increase the pressure inside the alveoli to a level slightly higher than that of atmospheric pressure.
6. Air now rushes passively out of the lungs and air passages.
40
What is Spirometry?
A procedure that measures air volumes.
41
What is tidal volume?
The volume of air entering and leaving the lungs in a respiratory cycle.
42
What is the normal amount of air that enters the lungs in a respiratory cycle?
500 mL.
43
What is a resting tidal volume?
The volume of air that has moved in, then out, of the lungs in the respiratory cycle at rest.
44
What is the volume and description of the Inspiratory reserve Volume (IRV)?
Volume: 3,000mL
Description: Maximal volume of air that can be inhaled at the end of a resting inspiration.
45
What is the volume and description of the Expiratory reserve volume (ERV)?
Volume: 1,100mL
Description: Maximal volume of air that can be exhaled at the end of a resting expiration.
46
What is the volume and description of the Residual Volume (RV)?
Volume: 1,200mL
Description: Volume of air that remains in the lungs even after a maximal expiration.
47
What is the volume and description of the Vital Capacity (VC)?
Volume: 4,600mL
Description: Maximum volume of air that can be exhaled after taking the deepest breath possible
VC= TV+IRV+ERV.
48
What is the volume and description of the Inspiratory capacity (IC)?
Volume: 3,500mL
Description: Maximum volume of air that can be inhaled following exhalation of resting tidal volume.
IC= TV+IRV
49
What is the respiratory membrane?
Layers including a capillary wall, an alveolar wall, and their basement membranes through which blood and inspired air exchange gases.
50
What is the Alveoli?
Microscopic cavities that resemble a cluster of grapes at the end of the alveolar ducts.
Each Alveolus consists of a tiny space within a thin wall that separates it from adjacent alveoli.
51
Which force moves Oxygen and carbon dioxide across the respiratory membrane?
The partial pressure of oxygen (o2) or the Po2, is higher in the alveoli than in the alveolar capillaries. So, oxygen diffuses from the alveoli into the capillaries.
For carbon dioxide, the Pco2 is higher in the alveolar capillaries than in the alveoli, so CO2 diffuses from the capillaries into the alveoli.
52
What is Diffusion?
Is the tendency of molecules or ions in a liquid solution or air to move from regions of higher concentration to regions of lower concentration.
It occurs because molecules and ions are always in constant motion.
53
What is Partial Pressure?
The amount of pressure each gas contributes to the total pressure of the gas (in a mixture of gases).
54
Indicate three factors that increase the diffusion of gases across the respiratory membrane.
1. Greater Partial Pressure Gradient
2. Thinner Membrane
3. Increased surface area of the membrane
55
What are the walls of the Alveoli primarily made up of?
Simple Squamous Epithelium
56
When does Diffusion occur until?
Equilibrium is reached.
57
What amount of partial pressure in atmospheric air is equivalent to the amount of oxygen?
160mm Hg
58
By what method is almost 98% of the oxygen in the blood carried?
Bound to the iron portion of the Hemoglobin molecules in the red blood cells.
59
List the two methods by which oxygen is transported in the blood.
Dissolved directly in the plasma
| Bound to the iron of the hemoglobin molecules in red blood cells.
60
How many oxygen molecules can Hemoglobin molecules bind?
4
61
As blood leaves the lungs, hemoglobin is _____% saturated with oxygen. As blood leaves the tissue capillaries, the hemoglobin is _____% saturated.
100%:75%
62
What does the term 'Hypoxia' refer to?
A deficiency of oxygen reaching the tissues
63
List three ways that blood transports carbon dioxide.
as bicarbonate ions
as carbaminohemoglobin
as a dissolved gas
64
What is the volume and description of the functional residual capacity (FRC)?
Volume: 2,300mL
Description: Volume of air that remains in the lungs following exhalation of resting tidal volume:
FRC= ERV+RV
65
What is the volume and description of the total lung capacity (TLC)?
Volume: 5,800 mL
Description: Total volume of air that the lungs can hold:
TLC= VC+RV
66
Where are the respiratory areas?
Brainstem, scattered throughout the Medulla Oblongata and pons.
67
Where are the ventral respiratory group (VSR) and the dorsal respiratory group (DRG) located?
The Medullary Respiratory Centre
68
What are the characteristics of the ventral respiratory group?
Located in the Medullary Respiratory Centre
| Controls the basic rhythm of breathing
69
What is the role of the dorsal respiratory group in control of respiration?
Stimulates the inspiratory muscles
70
What is the foetal development of the respiratory system (in stages)?
26 Days: Lower resp system begins to develop until separation from the foregut is achieved
week 5: Lung buds form and begin to differentiate into bronchi
week 7-10: Development of Larynx
Week 5-16: Airway branches are formed
Week 13-25: Canalicular period. Bronchi enlarge and lung tissue becomes highly vascular
Week 26-28: Lungs are capable of gas exchange. Type 2 Alveolar (septal cells) cells secrete surfactant.
Week 24-Birth: Capillary network proliferates around the alveoli. 8-10% of cardiac output flows through lungs.
71
During Inspiration, what is the correct order of airway structures that air would flow through?
Starting from the intralobular bronchiole.
1. Intralobular bronchiole
2. Terminal bronchiole
3. Alveolar duct
4. Alveolar sac
5. Alveolus
72
epithelium, located in the respiratory tract, is equipped with what type of structure(s) on its free surface?
Cilia
73
What do the Bronchioles do?
The contract and is used to control airflow into the areas of the lung if/they serve (s).
74
What is the role of Surfactant?
To reduce surface tension within the fluid lining the alveoli.
75
Which segment of the respiratory tract, functions as a passageway for both food and air?
The Pharynx
76
What is the effect of bronchoconstriction on airflow in the lungs?
It decreases airflow.
This is due to the changes in the diameter of the bronchioles. It can also shift the areas of the lungs that are ventilated.
77
Describe air pressures at the end of expiration (the pause between breaths).
Air pressure inside and outside of the lungs are equal.
78
What occurs during Inspiration?
1. The respiratory centre sends an impulse via the phrenic nerves.
2. The diaphragm contracts and moves downwards
3. The volume of the thoracic cavity increases
4. The pressure in the alveoli decreases to 759mmHg
5. Atmospheric pressure is greater than the alveolar pressure
6. Air moves into the lungs.
79
What do the external intercostal muscles do?
External intercostal muscles – elevates the ribs and sternum, extending the anterior/posterior dimension of the thoracic cavity.
80
What is the result of inspiration?
An increase in the volume of the thoracic cavity.
| As the lungs are held against the inner thoracic wall by the pleural seal, they also undergo an increase in volume.
81
How does the expansion of the chest wall expand the lungs during inspiration?
During inspiration, the diaphragm contracts downward, and the external intercostal muscles cause the wall of the thoracic cavity to move upward and outward.
The Parietal Pleura moves along the Thoracic wall as it expands.
Since the parietal pleura is held against the visceral pleura by the serous fluid between them, the layers of the pleural membrane move together.
The visceral pleura is attached to the outer surface of the lungs. Therefore, when the thoracic cavity expands, and both layers of the pleura expand with it, the lungs expand too.
82
What occurs during normal expiration?
1. The forces involved during normal expiration are derived from elastic recoil of the tissues that stretched during inspiration and from surface tension in the alveoli.
2. When the diaphragm and external intercostal muscles are no longer being stimulated to contract, they snap back to their relaxed position.
3. The stretched elastic tissues of the lungs also return to their original positions.
4. As elastic recoil occurs, surface tension increases in the alveoli, decreasing their diameter.
5. These events increase the pressure inside the Alveoli to a level slightly higher than that of the atmospheric pressure.
6. Air now rushes passively out of the lungs and air passages.
83
what is surface tension?
Force due to the attraction of water molecules that makes it difficult to inflate the alveoli of the lungs.
84
What happens if a person needs to exhale more than normal?
```
The internal (expiratory) intercostal muscles can contract. The muscles pull the ribs and sternum downward and inward, increasing the air pressure in the lungs to force more air out.
Additionally, the abdominal wall muscles such as the external and internal obliques, transverse abdominis, and rectus abdominis, can squeeze the abdominal organs inward.
In this way, the abdominal wall muscles can increase pressure in the abdominal cavity and force the diaphragm still higher against the lungs.
These actions force additional air out of the lungs.
```
85
What is inflation reflex?
It is a response that protects the lungs from overinflation during forced inspiration.
When stretch receptors in the pleura, bronchioles, and alveoli are stimulated by stretching of the tissues of the lungs, they send impulses to the respiratory areas.
In response, the duration of each inspiratory movement is shortened. This stops the lungs from overinflating.
86
What factors affect breathing?
Changes in body fluid chemistry, the degree to which lung tissues stretch, a person's emotional state, and the level of physical activity.
87
How are levels of CO2 detected in the blood?
Chemoreceptors in the ventral part of the Medulla oblongata sense changes in the cerebrospinal fluid (CSF) levels of carbon dioxide.
88
What happens if co2 levels rise in the blood?
Chemoreceptors signal the respiratory areas, and respiratory rate and tidal volume increase.
High levels of co2 in the blood result in a decrease in pH.
This also stimulates the aortic bodies to also send signals to the respiratory center in the medulla.
These 2 pathways, both based upon co2 levels, increase ventilation and create a negative feedback loop. This keeps the breathing rate normal.
89
What happens if there are low oxygen blood levels found?
Peripheral chemoreceptors in specialized structures called carotid bodies and aortic bodies sense change in blood oxygen levels.
Peripheral chemoreceptors are in the wall of certain large arteries in the neck and thorax (the carotid artery and aorta).
When decrease blood oxygen stimulates these peripheral receptors, they send impulses to the respiratory centre, and breathing rate and tidal volume rise.
Blood o2 levels must be about 50% of normal to trigger this mechanism.
90
What happens if breathing stops?
Blood levels of carbon dioxide rise and oxygen levels fall. These changes stimulate chemoreceptors, and soon the urge to inhale overpowers the desire to hold the breath.
91
How does Hyperventilation affect breathing?
It lowers the blood carbon dioxide level below normal.
Following Hyperventilation, it takes longer for carbon dioxide to rise to the level that stimulates the respiratory areas.
92
What is Hyperventilation?
Deep and rapid breathing that lowers the blood Co2 levels.
93
What is Oxyhemoglobin?
A compound formed by oxygen binding to hemoglobin in alveolar capillaries.
94
what is the normal Alveola Po2 ?
104mm Hg.
95
How is oxygen transported from the lungs to the cells?
98% of the oxygen chemically binds to hemoglobin in red blood cells, and the other 2% dissolves in the blood plasma.
The circulating blood transports the o2 to the body cells.
96
When blood enters the systemic capillaries, how much Po2 does it contain?
95mm Hg.
This can be caused by...
- some oxygen-poor systemic venous blood draining the bronchi and bronchioles mixing with pulmonary venous blood before returning to the heart.
This results in Po2 of the left atrial, left ventricular and systemic arterial blood drop to 95mm Hg.
97
what stimulates blood to release oxygen to the tissues?
- Low Po2 in the tissue and body cells, high blood level of CO2, high blood acidity (low blood pH), high blood temperature .
98
Describe 3 forms in which blood can transport co2 from the cells to the lungs.
- bicarbonate ions
- chemically bound to hemoglobin
- dissolved in the blood plasma.
- majority is transported as bicarbonate ions.
99
How can haemoglobin carry oxygen and carbon dioxide at the same time?
they have different binding sites on the haemoglobin molecules.
oxygen binds to iron atoms in the heme group
co2 binds to the amino groups in the globin portions of the hemoglobin molecules.
100
how is co2 released from the blood into the lungs?
1. co2 diffuses across the respiratory membrane from the alveolar capillaries into the alveoli. This is because its concentration and partial pressure are higher in the capillaries than in the alveoli.
2. Dissolved co2 easily diffuses across the membrane
3. Carbaminohemoglobin decomposes in the alveolar capillaries, releasing the CO2, which then leaves the red blood cells and diffuses in the alveoli.
4. At the alveolar capillaries, bicarbonate ions enter the red blood cells, and combine with the hydrogen ions that have been bound to hemoglobin, to form carbonic acid, H2CO3.
5. The carbonic acid then dissociates into CO2 and H20, and the Co2 diffuses into the alveoli across the respiratory membrane.
101
Which respiratory control center influences the rhythm of breathing by limiting inspiration?
Pontine respiratory group
102
The medullary respiratory center is composed of what two areas?
Ventral and Dorsal
103
What are three functions of the chemosensitive areas (central chemoreceptors) in the medulla oblongata?
detect changes in levels of hydrogen ions
detect changes in levels of carbon dioxide
detect changes in the cerebrospinal fluid
104
The medullary respiratory center is composed of what two areas?
Ventral respiratory group
| Dorsal respiratory group
105
List four characteristics of the dorsal respiratory group (DRG).
Located in the medulla oblongata
Integrates sensory information about the respiratory system
Modifies function of ventral respiratory group
Stimulates the diaphragm
