Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOL*235 Final Exam > Ch. 23: Respiratory System > Flashcards

Ch. 23: Respiratory System Flashcards

1
Q

Pulmonary ventilation.

A

Inhalation and exhalation of air. Involves exchange of air between atmosphere and alveoli caused by alternating pressure differences created by contraction and relaxation of respiratory muscles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

External/pulmonary respiration.

A

Exchange of gases between alveoli and blood in pulmonary capillaries across the respiratory membrane. Pulmonary capillary blood gains O2 and loses CO2. Converts deoxygenated blood to oxygenated blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Internal/tissue respiration.

A

Exchange of gases between blood in systemic capillaries and tissue cells. Blood loses O2 and gains CO2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cellular respiration.

A

Within cells. The metabolic reactions that consume O2 and give off CO2 during ATP production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Structurally, the respiratory system consists of…

A

The upper respiratory system, and the lower respiratory system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Upper respiratory system.

A

Nose, nasal cavity, pharynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Lower respiratory system.

A

Larynx, trachea, bronchi, lungs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Functionally, the respiratory system consists of…

A

The conducting zone, and the respiratory zone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Conducting zone.

A

Series of interconnecting cavities and tubes outside and within the lungs. Nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles. Filter, warm and moisten air and conduct it to the lungs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Respiratory zone.

A

Tubes and tissues within the lungs where gas exchange occurs. Respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the functions of the respiratory system?

A

Gas exchange, regulates blood pH, contains receptors for smell, filters inspired air, produces vocal sounds, excretes water and heat.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

External nose.

A

Visible. Supporting bony framework and cartilaginous framework covered with muscle and skin. Lined by mucous membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which bones form the bony framework of the nose?

A

Frontal bone, nasal bones, maxillae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which cartilages form the cartilaginous framework of the nose?

A

Septal nasal cartilage (anterior nasal septum), lateral nasal cartilages (inferior to nasal bones), alar cartilages (walls of nostrils). These are all hyaline cartilage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Internal nose.

A

Nasal cavity. Inferior to nasal bone. Superior to oral cavity. Lined with muscle and mucous membrane. Divided into a large inferior respiration region, and a small superior olfactory region.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

External nares.

A

Nostrils. Lead into nasal vestibules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the functions of the internal structures of the external nose?

A

Warming, moistening and filtering incoming air. Detecting olfactory stimuli. Modifying speech vibrations as they pass through the large hollow resonating chambers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Nasal septum.

A

Divides nasal cavity into right and left sides. Anterior part of the nasal septum consists of hyaline cartilage, vomer and perpendicular plate of ethmoid, maxillae and palatine bones.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Anteriorly, the nasal cavity merges with…

A

The external nose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Posteriorly, the nasal cavity communicates with…

A

The pharynx through internal nares.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which ducts open into the nasal cavity and secrete mucus?

A

Paranasal sinus ducts. They also serve as resonating chambers for sound during speaking and singing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which ducts open into the nasal cavity and secrete tears?

A

Nasolacrimal ducts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which bones contain paranasal sinuses?

A

Frontal, sphenoid, ethmoid, maxillae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which bones make up the lateral walls of the internal nose?

A

Ethmoid, maxillae, lacrimal, palatine, inferior nasal conchae bones.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which bones make up the lateral walls of the internal nose?

A

Ethmoid, maxillae, lacrimal, palatine, inferior nasal conchae bones.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which bones form the roof of the internal nose?

A

Ethmoid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which bones form the floor of the internal nose?

A

Palatine bones, and palatine processes of maxillae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Respiratory region of nasal cavity.

A

Lined with ciliated pseudo stratified columnar epithelium with numerous goblet cells. Contains olfactory receptor cells, supporting cells and basal cells which make up the olfactory epithelium (cilia, no goblet cells).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Vestibule.

A

Lined by skin containing coarse hairs that filter dust.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Projections of ____ extend out of each lateral wall of the nasal cavity.

A

Superior, middle and inferior nasal conchae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Nasal conchae.

A

Subdivide each side of the nasal cavity into a series of grovelike air passageways, called superior, middle and inferior nasal meatuses. They increase SA of the internal nose and prevent dehydration by trapping water droplets during exhalation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Pharynx.

A

Funnel-shaped tube that starts at the internal nares and extends to the cricoid cartilage. Posterior to nasal and oral cavities. Superior to larynx. Anterior to cervical vertebrae. Wall is composed of skeletal muscles lined with mucous membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Pharynx functions.

A

Passageway for air and food. Provides a resonating chamber for speech sounds. Contains the tonsils.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Divisions of the pharynx.

A

Nasopharynx, oropharynx, laryngopharynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How are pharynx muscles arranged?

A

Outer circular layer. Inner longitudinal layer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Nasopharynx.

A

Superior. Posterior to nasal cavity. Extends to soft palate. Through the internal nares, the nasopharynx receives air and packages of dust-laden mucus. Lined with ciliated pseudo stratified columnar epithelium. Exchanges small amounts of air with auditory tubes to equalize air pressure between the middle ear and atmosphere. Contains the pharyngeal tonsil (adenoid).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Soft palate.

A

Forms the posterior part of the roof of the mouth. Arch-shaped muscular partition between the nasopharynx and oropharynx. Lined with mucous membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

5 openings in soft palate.

A

2 internal nares, 2 openings that lead to auditory tubes, 1 opening to oropharynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Oropharynx.

A

Intermediate. Posterior to oral cavity. Extends from soft palate to the hyoid bone. Contains the fauces which is the opening from the mouth. Passageway for air, food and drink. Subject to abrasion by food particles so it is lined with nonkeratinized stratified squamous epithelium. Contains the paired palatine and lingual tonsils.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Laryngopharynx.

A

Inferior. Hypopharynx. Begins at hyoid bone. Opens into the esophagus posteriorly, and the larynx anteriorly. Passageway for air, food and drink. Subject to abrasion by food particles so it is lined with nonkeratinized stratified squamous epithelium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Larynx.

A

Short passageway between laryngopharynx and trachea. Extends to cricoid cartilage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Larynx wall is composed of 9 pieces of cartilage.

A

3 occur singly: thyroid cartilage, epiglottis, cricoid cartilage.
3 occur in pairs: arytenoid, cuneiform, corniculate cartilages.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Which of the paired cartilages in the larynx wall are the most important?

A

Arytenoid cartilages, because they influence changes in position and tension of the vocal folds. Triangular pieces of hyaline cartilage located at posterior and superior border of cricoid cartilage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Describe the extrinsic and intrinsic muscles of the larynx.

A

Extrinsic: connect the cartilages to other structures in the throat.
Intrinsic: connect the cartilages to each other, and attach to the rigid cartilages and vocal folds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Laryngeal vestibule.

A

The part of the cavity of the larynx above the vestibular folds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Infraglottic cavity.

A

The part of the cavity of the larynx below the vestibular folds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Adam’s apple.

A

Thyroid cartilage. Consists of 2 fused plates of hyaline cartilage that form the anterior wall of the larynx and give it a triangular shape.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Epiglottis.

A

Large leaf-shaped elastic cartilage covered with epithelium. Closes the larynx during swallowing to direct food and liquid into the esophagus.
Stem: taper inferior portion that is attached to the anterior rim of the thyroid cartilage.
Leaf: unattached and free to move up and down.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What occurs in the larynx and pharynx during swallowing?

A

Elevation of the pharynx widens it to receive the food and drink.
Elevation of the larynx causes the epiglottis to move down and form a lid over the glottis to close it off.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Glottis.

A

Consists of vestibule/vocal folds covered in mucous membrane. The rima glottidis/vestibuli is the space between the vocal folds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Cricoid cartilage.

A

Ring of hyaline cartilage that forms the inferior wall of the larynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Corniculate cartilages.

A

Horn-shaped pieces of elastic cartilage located at the apex of each arytenoid cartilage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the lining of the larynx superior to the vocal folds, and inferior to the vocal folds?

A

Superior: nonkeratinized stratified squamous epithelium.
Inferior: ciliated pseudo stratified columnar epithelium consisting of ciliated columnar cells, goblet cells and basal cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Describe cilia in the upper respiratory tract, and the lower respiratory tract.

A

Upper: cilia move mucus and trapped particles down toward pharynx.
Lower: cilia move mucus and trapped particles up toward pharynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

False vocal cords.

A

Superior vestibular folds. Do not function in voice production. When they are brought together, they function in holding the breath against pressure in the thoracic cavity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

True vocal cords.

A

Inferior vocal folds. The principal structures of voice production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What happens when intrinsic laryngeal muscles contract?

A

Moves rigid cartilages –> pulls elastic ligaments tight –> stretches vocal folds into the airways –> rima glottidis is narrowed. Arytenoid cartilages also pivot and slide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How do the vocal folds produce sound?

A

Air passing through the larynx vibrates the vocal folds and produces sound by setting up sound waves in the column of air in the pharynx, nose and mouth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What causes a variation in pitch?

A

Tension of vocal folds. If vocal folds are pulled taut by muscles, they vibrate rapidly to create a higher pitch.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Contraction of posterior cricoarytenoid muscles moves the…

A

Vocal folds apart to open the rima glottidis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Contraction of lateral cricoarytenoid muscles moves the…

A

Vocal folds together to close the rima glottidis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Whispering.

A

Occurs by closing all but the posterior part of the rima glottidis. Vocal folds do not vibrate. There is no pitch.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Trachea.

A

Anterior to esophagus. Extends from larynx to T5 where it divides into right and left primary bronchi. Tracheal wall consists of mucosa, submucosa, hyaline cartilage and adventitia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Mucosa of trachea consists of…

A

Epithelial layer of ciliated pseudo stratified columnar epithelium, and an underlying layer of lamina propria that contains elastic and reticular fibres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Submucosa of trachea consists of…

A

Areolar connective tissue that contains seromucous glands and their ducts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Describe the horizontal rings of hyaline cartilage in the trachea.

A

16-20 rings are stacked on top of each other connected by dense connective tissue. The open part of each C-shaped ring faces posteriorly toward the esophagus and is spanned by a fibromuscular membrane. Within the fibromuscular membrane are transverse smooth muscle fibres and elastic connective tissue that allow the diameter of the trachea to change during inhalation and exhalation. The solid C-shaped rings provide a semi-rigid support to maintain latency so that the trachea wall does not collapse inward.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Adventitia of trachea consists of…

A

Areolar connective tissue that joins the trachea to surrounding tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Trachea divides into…

A

A right primary bronchus that leads to the right lung.
A left primary bronchus that leads to the left lung.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Which bronchus is more likely to have a lodged aspirated object?

A

Right.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Primary bronchi contain…

A

Incomplete rings of cartilage. Lined by ciliated pseudo stratified columnar epithelium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Carina.

A

Internal ridge. Formed by a posterior and inferior projection of the last tracheal cartilage. Located where the trachea divides into right and left primary bronchi. The mucous membrane of the carina is the most sensitive area of the larynx and trachea for triggering a cough reflex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What does widening and distortion of the carina usually indicate?

A

Carcinoma of the lymph nodes around the region where the trachea divides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

How many lobes do the right and left lungs have?

A

Right: 3
Left: 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Where and what do the primary bronchi divide into?

A

Upon entering the lungs, they divide into lobar/secondary bronchi; one for each lobe.

75
Q

Lobar bronchi.

A

Continue to branch to form segmental/tertiary bronchi that supply the specific bronchopulmonary segments within the lobes.

76
Q

Segmental bronchi.

A

Divide into bronchioles which branch again and again into terminal bronchioles.

77
Q

Terminal bronchioles.

A

Contain club cells which are columnar non-ciliated cells interspersed among epithelial cells. Club cells protect against harmful effects of inhaled toxins and carcinogens, produce surfactant, and function as stem cells which give rise to various cells of the epithelium. Represent the end of the conducting zone of the respiratory system. Beyond the terminal bronchioles, the branches become microscopic and are named respiratory bronchioles or alveolar ducts.

78
Q

Respiratory passages from the trachea to the alveolar ducts contain how many generations of branching?

A

23

79
Q

What are 3 changes that occur as branching becomes more extensive in the bronchial tree?

A

1) Mucous membrane in the bronchial tree changes from ciliated pseudostratified columnar epithelium in the primary bronchi, lobar bronchi, and segmental bronchi to ciliated simple columnar epithelium with some goblet cells in larger bronchioles, to mostly ciliated simple cuboidal epithelial with no goblet cells in smaller bronchioles, to mostly non-conciliated simple cuboidal epithelium in terminal bronchioles.
2) Plates of cartilage gradually replace the incomplete rings of cartilage in primary bronchi, and disappear in distal bronchioles.
3) As the amount of cartilage decreases, the amount of smooth muscle increases. Because there is now no supporting cartilage, muscle spasms can close off the airways = asthma attack.

80
Q

How are the lungs separated from each other?

A

By the heart and other structures of the mediastinum.

81
Q

Parietal pleura of the lung.

A

Superficial layer. Lines the wall of the thoracic cavity.

82
Q

Visceral layer of the lung.

A

Deep layer. Covers the lung surface.

83
Q

Pleural cavity.

A

Between parietal and visceral pleura. Contains small amounts of lubricating pleural fluid secreted by the membranes.

84
Q

The costal surface of the lungs…

A

Lies against the ribs and matches the rounded curvature of the ribs.

85
Q

The mediastinal surface of the lungs…

A

Contains the hilum, through which bronchi, pulmonary blood vessels, lymphatic vessels, and nerves enter and exit.

86
Q

The root of the lung.

A

The bronchi, pulmonary blood vessels, lymphatic vessels and nerves held together by the pleura and connective tissue.

87
Q

Cardiac notch.

A

The left lung contains a medial concavity in which the apex of the heart lies.

88
Q

Compare the sizes of the lungs.

A

The left lung is 10% smaller than the right lung.

89
Q

Describe the shape of the right lung.

A

Thicker, broader, but shorter because the diaphragm is higher on the right side to accommodate the liver.

90
Q

What divide each lung into lobules?

A

Fissures.

91
Q

Oblique fissure.

A

In both lungs. Extends inferiorly and anteriorly.
Left lung: separates superior lobe and inferior lobe.
Right lung: superior part separates superior lobe and inferior lobe, inferior part separates inferior lobe and middle lobe.

92
Q

Horizontal fissure.

A

In right lung only.

93
Q

Each lobe receives its own…

A

Lobar bronchus.
Right main bronchus gives rise to 3 lobar bronchi: superior, middle and inferior.
Left main bronchus gives rise to 2 lobar bronchi: superior, inferior.

94
Q

Lobar bronchi give rise to…

A

Segmental bronchi. There are 10 segmental bronchi in each lung.

95
Q

Bronchopulmonary segment.

A

The portion of lung tissue that each segmental bronchus supplies. Each bronchopulmonary segment has many lobules, and each lobule is wrapped in elastic connective tissue and contains a lymphatic vessel, an arteriole, a venule, and a branch from a terminal bronchiole.

96
Q

Bronchial and pulmonary disorders that are localized in a ____ may be surgically removed without disrupting the surrounding lung tissue.

A

Bronchopulmonary segment.

97
Q

Respiratory bronchioles.

A

Begin the respiratory zone since they have alveoli budding from their walls. As respiratory bronchioles penetrate more deeply into the lungs, the epithelial lining changes from simple cuboidal to simple squamous. These bronchioles also subdivide into alveolar ducts (simple squamous epithelium).

98
Q

Alveolar sac.

A

Terminal duct of an alveolar duct. Composed of alveoli.

99
Q

Type I alveolar cells.

A

More numerous. Simple squamous epithelial cells. Form a continuous lining of alveolar wall. Thin. Main sites of gas exchange. Underlying this layer of cells is an elastic basement membrane.

100
Q

Type II alveolar cells.

A

Less numerous. Septal cells. Found between type I. Rounded or cuboidal epithelial cells with free surface containing microvilli. Secrete alveolar fluid.

101
Q

Alveolar fluid.

A

Keeps the surface between the cells and the air moist.

102
Q

Surfactant.

A

Included in alveolar fluid. A mixture of phospholipids and lipoproteins. Functions to lower the surface tension of alveolar fluid which reduces the tendency of alveoli to collapse.

103
Q

Alveolar macrophages.

A

Present in alveolar walls. Phagocytes that remove fine dust particles and debris from the alveolar spaces. Also fibroblasts that produce reticular and elastic fibres.

104
Q

On the outer surface of the alveoli…

A

The lobule’s arteriole and venule disperse into a network of blood capillaries that consists of a single layer of endothelial cells and basement membrane.

105
Q

Respiratory membrane.

A

Alveolar and capillary walls, blood plasma, and 4 layers.
1) A layer of type I and II alveolar cells and associated alveolar macrophages that constitute the alveolar wall.
2) An epithelial basement membrane underlying the alveolar wall.
3) A capillary basement membrane that is often fused to the epithelial basement membrane.
4) The capillary endothelium.

106
Q

Lungs receive blood from the…

A

Pulmonary arteries and bronchial arteries.
Deoxygenated blood passes through the pulmonary trunk, which divides into a left pulmonary artery that enters the left lung, and a right pulmonary artery that enters the right lung.
Oxygenated blood passes through the aorta, which branches into the bronchial arteries to deliver oxygenated blood to the muscular walls of bronchi and bronchioles.

107
Q

Return of oxygenated blood to the heart from the lungs occurs via…

A

Four pulmonary veins, which drain into the LA.

108
Q

What happens to pulmonary blood vessels in response to hypoxia?

A

They constrict, diverting pulmonary blood from poorly ventilated areas of the lungs to well-ventilated areas of the lungs for more efficient gas exchange.
*In every other area of the body, hypoxia causes vasodilation to increase blood flow.

109
Q

The rate of airflow and the amount of effort needed for breathing are influenced by…

A

Alveolar surface tension, compliance of lungs, airway resistance, and pressure difference.

110
Q

Air moves into the lungs when…

A

The air pressure inside the lungs is less than the air pressure in the atmosphere.

111
Q

Air moves out of the lungs when…

A

The air pressure inside the lungs is greater than the air pressure in the atmosphere.

112
Q

Describe the air pressure just before inhalation?

A

The air pressure inside the lungs is equal to the air pressure of the atmosphere.

113
Q

How do the lungs lower the air pressure inside the lungs?

A

They expand.

114
Q

Boyle’s Law.

A

The pressure and volume of a gas have an inverse relationship.

115
Q

How do the lungs expand?

A

Diaphragm contracts, which flattens this muscle. External intercostals then contract to elevate the ribs.

116
Q

Which nerves innervate the diaphragm?

A

Phrenic nerves.

117
Q

Contraction of the diaphragm is responsible for ___ of air that enters the lungs.

A

75%. The remaining 25% is external intercostals.

118
Q

Intrapleural pressure.

A

The pressure within the pleural cavity. Always a negative pressure lower than the atmospheric pressure. Allows the pleural cavity to function as a vacuum that attaches the visceral pleura to the chest wall.

119
Q

Which muscles are responsible for deep or forced breathing?

A

Accessory muscles. Sternocleidomastoid (elevates sternum), scalene (elevate first 2 ribs), pectoralis minor (elevate 3-5 ribs).

120
Q

Inhalation is a ____ , and exhalation is a ____ .

A

Inhalation: active process.
Exhalation: passive process.

121
Q

How does exhalation occur?

A

It results from elastic recoil of the chest wall and lungs.

122
Q

What are the inwardly directed forces that contribute to elastic recoil?

A

Recoil of elastic fibres that were stretched during inhalation, and the inward pull of surface tension due to the film of intrapleural fluid between the visceral and parietal pleurae.

123
Q

When does exhalation become an active process?

A

Forceful breathing. Muscles of exhalation contract to increase pressure in the abdominal region and thorax.

124
Q

What are the muscles of exhalation?

A

Abdominal and internal intercostals.
Abdominal muscle contraction moves inferior ribs downward and compresses the abdominal viscera.
Internal intercostal contraction pulls ribs inferiorly.

125
Q

When would intrapleural pressure briefly exceed atmospheric pressure?

A

Forced exhalation. Cough.

126
Q

Describe surface tension of alveolar fluid.

A

When liquid surrounds a sphere of air, surface tension produces an inwardly directed force, and this causes alveoli to assume the smallest possible diameter. During breathing, this surface tension must be overcome to expand the lungs.

127
Q

Surface tension accounts for ___ of lung elastic recoil, which decreases the size of alveoli during exhalation.

A

2/3

128
Q

Lung compliance.

A

Related to elasticity and surface tension.
High compliance: lungs and chest wall will expand easily.
Low compliance: lungs and chest wall will resist expansion.

129
Q

Related to compliance, the lungs normally have…

A

High compliance because elastic fibres in lung tissue are easily stretched, and surfactant reduces surface tension.

130
Q

Decreased lung compliance is a common feature of…

A

Pulmonary conditions that scar lung tissue, cause lung tissue to become filled with fluid, produce a deficiency in surfactant, or impede lung expansion.

131
Q

Why would increased lung compliance occur in emphysema?

A

Disintegration of elastic fibres in alveolar walls. Surface area is smaller and pulmonary gas exchange is slowed.

132
Q

Airflow =

A

Pressure different between the alveoli and atmosphere divided by the resistance.

133
Q

As the lungs expand during inhalation, the bronchioles…

A

Enlarge because their walls are pulled outward. Larger-diameter airways have decreased resistance. Airway resistance then increases during exhalation as the diameter of bronchioles decreases.

134
Q

Airway diameter is also regulated by the degree of…

A

Contraction and relaxation of smooth muscle in the walls of the airways. Signals from sympathetic ANS cause relaxation of bronchiolar smooth muscle, resulting in decreased resistance. Signals from parasympathetic ANS cause contraction of bronchiolar smooth muscle, resulting in increased resistance.

135
Q

Eupnea.

A

Normal quiet breathing. Can consist of shallow, deep or combined breathing.

136
Q

Costal breathing.

A

Shallow breathing. Chest breathing. Upward and outward movement of the chest due to contraction of external intercostal muscles.

137
Q

Diaphragmatic breathing.

A

Deep breathing. Abdominal breathing. Outward movement of abdomen due to contraction and descent of diaphragm.

138
Q

Tidal volume.

A

Volume of one breath. 500 mL.
70% of the tidal volume reaches the respiratory zone and participates in external respiration.
30% of the tidal volume remains in conducting airways of nose, pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles.

139
Q

Anatomic dead space.

A

Conducting airways with air that do not undergo respiratory exchange.

140
Q

Inspiratory reserve volume.

A

Additional inhaled air after tidal volume. 3100 mL male. 1900 mL female. Even more air can be inhaled if inhalation follows forced exhalation.

141
Q

Expiratory reserve volume.

A

Additional exhaled air after tidal volume. 1200mL male. 700 mL female.

142
Q

Forced expiratory volume in one second.

A

Volume of air that can be exhaled from the lungs in one second with maximal effort following a maximal inhalation.

143
Q

Residual volume.

A

After expiratory reserve volume is exhaled, considerable air remains in the lungs because the subatmospheric intrapleural pressure keeps the alveoli inflated and some air remains in the noncollapsible airways. 1200mL male. 1100 mL female.

144
Q

Minimal volume.

A

Air remaining after intrapleural pressure rises to equal the atmospheric pressure and forces out some residual volume during thoracic cavity opening. Provides a medical and legal tool for determining whether a baby is born dead or died after birth.

145
Q

Inspiratory capacity.

A

Sum of tidal volume and inspiratory reserve volume.

146
Q

Functional residual capacity.

A

Sum of residual volume and expiratory reserve volume.

147
Q

Vital capacity.

A

Sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume.

148
Q

Total lung capacity.

A

Sum of vital capacity and residual volume.

149
Q

Minute ventilation.

A

Total volume of air inspired and expired each minute. Tidal volume multiplied by respiratory rate. 6000 mL/min.

150
Q

Alveolar ventilation.

A

Volume of air per minute that reaches the respiratory zone. 4200 mL/min.

151
Q

Which laws govern the passive diffusion of oxygen and carbon dioxide?

A

Dalton’s Law and Henry’s Law.

152
Q

Dalton’s Law.

A

Each gas in a mixture of gases exerts its own pressure as if no other gases were present.

153
Q

Partial pressure.

A

The pressure of a specific gas in a mixture of gases.

154
Q

Henry’s Law.

A

The amount of gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility. The higher the partial pressure of a gas over a liquid, and the higher the solubility, the more gas will stay in solution.

155
Q

The rate of pulmonary and systemic gas exchange depends on…

A

1) Partial pressure difference of gases.
2) Surface area available for gas exchange.
3) Diffusion distance.
4) Molecular weight and solubility of gases.

156
Q

Partial pressure difference of gases.

A

Alveolar PO2 must be higher than blood PO2 for O2 to diffuse from alveolar air into blood.

157
Q

How does morphine affect the partial pressure difference of gases?

A

It slows ventilation, decreasing the amount of O2 and CO2 that can be exchanged between alveolar air and blood.

158
Q

High altitude sickness.

A

With increasing altitude, the total atmospheric pressure and PO2 decrease. Inhaled air decreases and O2 diffuses into blood more slowly.

159
Q

Any pulmonary disorder that decreases the functional surface area of the respiratory membranes decreases the…

A

Rate of external respiration.

160
Q

Describe pulmonary edema and diffusion distance.

A

Buildup of interstitial fluid between alveoli slows the rate of gas exchange because it increases diffusion distance.

161
Q

Molecular weight of O2 and CO2.

A

O2 has a lower molecular weight than CO2, but the solubility of CO2 in fluid portions of the respiratory membrane is 24x greater than that of O2, so CO2 actually diffuses faster than O2.

162
Q

___ of inhaled O2 is dissolved in blood plasma, and remaining is bound to hemoglobin in RBCs.

A

1.5%

163
Q

Oxyhemoglobin.

A

Reversible binding of oxygen and hemoglobin.

164
Q

What determines the affinity of Hg for O2?

A

1) Acidity. As acidity increases, the affinity of Hg for O2 decreases, and O2 disassociates more readily from Hg. Bohr effect. When H+ ions bind to amino acids in Hg, they alter its structure to decrease its O2 carrying capacity.
2) Partial pressure of CO2. As PCO2 rises, Hg release more O2. Low blood pH results from high PCO2.
3) Temperature. As temperature rises, more O2 is released from Hg.
4) BPG. Substance found in RBCs. Decreases the affinity of Hg for O2.

165
Q

What determines how much O2 binds to Hg?

A

Partial pressure of O2. The higher the PO2, the more O2 combines with Hg. PO2 is higher in pulmonary capillaries, and low in tissue capillaries.

166
Q

Fetal Hg vs. adult Hg.

A

Fetal Hg has a higher affinity for O2 because it binds BPG less strongly. When PO2 is low, fetal Hg can carry up to 30% more O2 than adult Hg.

167
Q

How is CO2 transported in blood?

A

1) Dissolved CO2. 7% of CO2 is dissolved in blood plasma, diffused into alveolar air, and is exhaled upon reaching the lungs.
2) Carbamino compounds. 23% of CO2 combines with amino groups of amino acids and proteins in blood to form carbamino compounds. In tissue capillaries, PCO2 is high which promotes formation of Hg-CO2. In pulmonary capillaries, PCO2 is low which promotes dissociation of Hg and CO2.
3) Bicarbonate ions. 70% of CO2 is transported in blood plasma as HCO3-.

168
Q

At rest, how much O2 is used each minute by body cells?

A

200 mL

169
Q

Respiratory center.

A

Clusters of neurons located bilaterally in the brainstem. Breathing muscles contract as a result of nerve impulses transmitted from this center, and they relax as a result of absence of nerve impulses.

Medullary respiratory center (DRG, VRG) and pontine respiratory group.

170
Q

Medullary respiratory center.

A

Dorsal respiratory group: During normal breathing, neurons of DRG generate impulses to the diaphragm via phrenic nerves and to the external intercostals via intercostal nerves –> muscles contract –> inhalation. When the DRG becomes inactive after 2 seconds, the diaphragm and external intercostals relax for 3 seconds, allowing the passive recoil of the lungs and thoracic wall.

Ventral respiratory group: Pre-Botzinger complex is a cluster of neurons in VRG that is composed of pacemaker cells that set the basic rhythm of breathing. Pre-Botzinger complex provides input to the DRG to drive the rate at which DRG neurons fire APs. The remaining neurons in the VRG do not participate in normal breathing. It becomes activated when forceful breathing is required. During forceful inhalation, nerve impulses from DRG stimulate diaphragm, external intercostal muscles, and VRG neurons to send impulses to accessory muscles of inhalation. During forceful exhalation, DRG is inactive. VRG neurons involved in forced exhalation send nerve impulses to accessory muscles of exhalation.

171
Q

Accessory muscles of exhalation.

A

Internal intercostals, external oblique, internal oblique, transversus abdominal, rectus abdominis.

172
Q

Pontine respiratory group.

A

PRG neurons are active during inhalation and exhalation. Transmits nerve impulses to DRG. Modifies basic rhythm of breathing generated by VRG.

173
Q

We can voluntarily alter our pattern of breathing because…

A

The cerebral cortex has connections with the respiratory center.

174
Q

The ability to hold your breath is limited by…

A

The buildup of CO2 and H+ in the body. When these increase, the DRG neurons are strongly stimulated.

175
Q

Nerve impulses from ___ and ___ also stimulate the respiratory center, allowing emotional stimuli to alter breathing.

A

Hypothalamus, limbic system.

176
Q

How do chemoreceptors regulate breathing?

A

They monitor levels of CO2, H+ and O2.

177
Q

Central chemoreceptors.

A

In or near the medulla oblongata. Respond to changes in H+ and PCO2 in CSF.

178
Q

Peripheral chemoreceptors.

A

In aortic bodies and carotid bodies. Respond to changes in PO2, H+ and PCO2 in blood.

179
Q

Hypercapnia.

A

PCO2 > 40 mmHg. Central chemoreceptors respond vigorously to the resulting increase in H+. Peripheral chemoreceptors respond to high PCO2, high H+, low O2. Central and peripheral chemoreceptors stimulate DRG to increase rate and depth of breathing.

180
Q

Hyperventilation.

A

Allows inhalation of more O2 and exhalation of more CO2 until PCO2 and H+ levels are lowered to normal.

181
Q

Hypocapnia.

A

PCO2 < 40 mmHg. Chemoreceptors are not stimulated. DRG neurons set their own moderate pace until CO2 accumulates and PCO2 rises to normal.

182
Q

Even before changes in PO2, PCO2, and H+ occur, your rate and depth in breathing increase due to…

A

Proprioceptors when you start to exercise. Nerve impulses from proprioceptors stimulate DRG. Axon collaterals of UMNs that originate in primary motor cortex also feed excitatory impulses into DRG.

183
Q

Hering-Breuer reflex.

A

Inflation reflex. Protective mechanism that prevents excessive inflation of lungs.

When baroreceptors in walls of bronchi and bronchioles become stretched during overinflation of lungs, nerve impulses are sent along vagus nerves to DRG –> inhibit DRG –> diaphragm and external intercostals relax –> further inhalation is stopped –> exhalation begins –> lungs deflate –> stretch receptors are no longer stimulated –> DRG is no longer inhibited –> inhalation begins.

In infants, this reflex functions in normal breathing.
In adults, this reflex is not activated until TD > 1500 mL.

BIOL*235 Final Exam (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions