Module 2 - Respiratory System

Question 1

What are the three major functions of the respiratory system?

Answer 1

1) Air conduction
2) Air filtration
3) Respiration - exchange of gases

Question 2

What are the three minor functions of the respiratory system?

Answer 2

1) Vocalization
2) Smelling
3) Regulation of body pH

Question 3

Which structures perform the function of conducting air in the respiratory system?

Answer 3

1) The nostrils / Nasal Cavities
2) The mouth/ oral cavity
3) Pharynx (Nasopharyx, Orophayx, Laryngopharynx)
4) Larynx
5) Trachea
6) Bronchi
7) Bronchioles

Question 4

Which structures perform the function of air filtration in the respiratory system?

Answer 4

1) Nostrils: hairs, cilia, and mucus producing goblet cells
2) Trachea and bronchi: cilia and mucus producing goblet cells

Question 5

Which structures perform the function of external respiration in the respiratory system?

Answer 5

1) Respiratory bronchioles
2) Alveolar ducts
3) Alveoli

Question 6

Describe the bronchial tree.

Answer 6

The bronchus is made of two bronchi, which divide into secondary bronchi, then tertiary bronchi, then bronchioles (less than 1 mm in diameter) and finally the alveoli. It is mostly covered in pseudostratified ciliated columnar epithelium, while the bronchioles are covered in simple ciliated cuboidal epithelium.

Question 7

The process of bronchi expanding is called ___________. The process of bronchi becoming smaller is called ___________.

Answer 7

Bronchodilation

Bronchoconstriction

Question 8

Describe the pharynx.

Answer 8

The open structure from the posterior of the nasal cavity (nasal choanae) down to the inferior edge of the cricoid cartilage.

It has three divisions: the nasopharynx, the oropharynx, and the laryngopharynx.

The surface of the nasopharynx is covered by the same pseudostratified columnar epithelium that is found in the bronchia, thrachea, etc. The other two regions of the pharynx, the oropharynx and laryngopharynx, are lined by nonkeratinizing stratified squamous epithelium.

Question 9

Describe the larynx.

Answer 9

Also called the voice box, it begins at the epiglottis, continues through the glottis, and extends down to the inferior edge of the cricoid cartilage. The vocal folds (vocal chords) form the edge of the glottis, and are made of connective tissue covered in nonkeritinized stratified epithelium (mucous membranes). The rest of the larynx is covered in typical pseudostratified columnar ciliated respiratory epithelium.

Question 10

Describe the trachea.

Answer 10

The thrachea is continuous with the larynx, and begins at the inferior edge of the cricoid cartilage. It is held open by c shaped rings of cartilage. The open space in the cartilege allows for expansion of the esophagus, which is posterior to the trachea. It ends where the two bronchi begin. It is lined with pseudostratified ciliated columnar epithelium.

Question 11

What separates the nasal cavity from the mouth?

Answer 11

The hard palette.

Question 12

Describe the structure and function of the soft palette.

Answer 12

The soft palette is in the posterior superior portion of the oral cavity. It elevates and retracts to keep contents of the mouth from entering the nasal cavity when swallowing.

Question 13

Describe the structure and function of the epiglottis.

Answer 13

The epiglottis is a flap of stretchy cartilage. On the superior side it is covered in nonkeritinized stratified squamous epithelium. On the inferior side it is covered in pseudostratified ciliated columnar epithelium. It attaches to the anterior and superior edge of the larynx. Because the air and food passages cross in the oropharynx, the epiglottis covers the larynx when we swallow to keep us from breathing food.

Question 14

Describe the structure and function of the nasal cavity.

Answer 14

It begins at the nostrils. Just posterior to the intrance is the vestibule, where the stratified squamous epithelium is covered in thick hairs to serve as a coarse filter. The vestibule is divided by the septum and bordered laterally by the superior, middle, and inferior conchae. These have a large concentration of capillaries, and serve to increase the surface area of the skin and also to create turbulence in the air. This give the air more exposure to the warmth and moisture provided by the large blood supply. It ends at the choanae, or the openings to the nasopharnx.

Question 15

In regards to where they occur (not the presence of oxygen), what are the two types of respiration, and where do they occur?

Answer 15

Internal and external.

Internal occurs in the cells.

External respiration occurs in the bronchioles, alveolar ducts, and alveolar sacs (alveoli).

Question 16

What is histology?

Answer 16

The study of the structure of cells.

Question 17

Most of the respiratory tract is covered in ______, _______, _______ epithelium. What do these terms mean?

Answer 17

pseudostratified, ciliated, columnar epithelium

Pseudostratified means it looks like it’s layerd, when really the cells are just of differing heights.

Ciliated means the cells have projections that look like hairs and which move in waves to push along material on the cell’s surface.

Columnar means column shaped.

Question 18

Describe stratified squamous epithelium.

Answer 18

The stratified squamous epithelium is layers (stratified) of thisn (squamous) skin cells. They start out as cuboidal cells. As new cells develop beneath, the cuboidal cells become the next layer of cells and begin to flatten out.

Question 19

What kind of epithelium lines bronchioles?

Answer 19

The epithelium is ciliated cuboidal epithelium and contains some secretory cells called clara cells.

Question 20

Describe the nasopharynx.

Answer 20

The upper portion of the pharynx, it is continuous and posterior to the nasal cavity. It continues down to the soft palette anteriorly, and is continuous to the oropharynx posteriorly. It contains the adenoids and the eustachian tubes.

Question 21

Describe the oropharynx.

Answer 21

The oropharynx is the middle portion of the pharynx. It lies inferior to the nasopharynx, posterior to the oral cavity, and superior to the epiglottis.

Question 22

Describe the layngopharynx.

Answer 22

Where the pharynx, larynx and esophagus meet. It begins at the superior edge of the epiglottis, and continues to the inferior edge of the cricoid cartilage.

Question 23

List the cartilage that exist singly in the larynx.

Answer 23

Thyroid

Cricoid

Epiglottis

Question 24

List the cartilage that exists in pairs in the larynx.

Answer 24

Corniculate

Cuniform

Arytenoid

Question 25

What is the trachealis?

Answer 25

The trachealis is smooth muscle that crosses the posterior side of the c-shaped rings of cartilage in the trachea. It tightens and constricts the trachea, making our cough more forceful.

Question 26

Describe the structure and function of alveoli.

Answer 26

Alveolar sacs are clusters of alevoli. Alveolar ducts bring air from the bronchioles into the alveoli. The alveoli are small globes of very thin skin at the end of the bronchioles. This is where gas exchange happens.

Question 27

Describe the structure and function of the pulmonary serosa.

Answer 27

The pulmonary serosa is made of visceral plurae, which surrounds the lungs, and peritoneal plurae, which lines the cavity. Between them is the pleural cavity, which is lubricated with serous fluid. This lining helps keep the lung inflated, because in order for the lung to collapse it would need to pull against the vaccum formed between these two membranes. If the serosa become inflammed they begin to rub together in a painful manner. Inflammation of the pleural serosa is called pleursy.

Question 28

How many lobes does each lung have? What are they called?

Answer 28

The right lung has three lobes, the superior, the middle and the inferior. The heart and stomach take up room on the left side, so the left lung only has two lobes, the superior and inferior.

The Superior and Middle lobes of the right lung are separated at the horizontal fissure, and the middle and inferior lobes are separated by the oblique fissure.

The superior and inferior lobes of the left lung are separated by the oblique fissure.

Question 29

In ___________ respiration, the difference in concentration of ____ in the blood and ____ in the air in the alveoli drives the __________ of the gases between the blood and the air.

Answer 29

External, CO₂, O₂ , diffusion

Question 30

What are the three kinds of cell present in alveoli.

Answer 30

1) Type I pneumocytes make up 95% of the the alveolar surface area. They are simple squamous epithelium cells. They have a junction with the capillaries and are one layer thick to allow for gas exchange.
2) Type II pneumocytes are sprinkled throughout the type I cells. They secrete pulmonary surfactant, a lipoprotein that covers the luminal (lining) surface to keep the alveoli from collapsing. They also replace damaged Type I cells, if needed. They take up 5% of the surface area, but 60% of the total number of cells.
3) Macrophages phagocytize any foreign cells or debris, then make their way up the bronchial tree by riding on the cilia to the epiglottis, where they are either coughed out or swallowed.

Question 31

Breathing in is called ________.

Breathing out is called ________.

Answer 31

Inspiration (inhalation)

Expiration (exhalation)

Question 32

Four ______ groups and four ________________ combine to create hemoglobin. Hemoglobin combines with ______________ to create _______________. There are ____________ of molecules of hemoglobin in one red blood cell.

Answer 32

heme groups, polypepetide chains, oxygen, oxyhemoglobin, millions

Question 33

In ____________ respiration, the high concentration of _________ in the blood and ___________ in the cells drives ____________ of these gases into/out of the cells.

Answer 33

Internal, oxygen, carbon dioxide, diffusion

Question 34

In what form does CO2 exist in the body?

Answer 34

Carbon dioxide can exist as a dissolved gas, it can attach to hemoglobin, and it can form carbonic acid (H₂CO₃) but mostly it exists as a bicarbonate ion (HCO₃^-1).

Question 35

What is the main function of oxygen in the body?

Answer 35

It is used in the cells to make ATP.

Question 36

What three conditions must be met for gas exchange in the alveoli to occur?

Answer 36

1) The alveoli must be moist. The body uses water and surfactant to keep the alveoli from drying out.
2) The epithelium needs to be thin. It is a single cell thick.
3) There needs to be a large surface area. Our lungs have 50 x the surface area of our skin.

Question 37

What is “residual volume” and what is its purpose?

Answer 37

Residual volume is the air left in the lungs after exhalation.

It preserves moisture and maintains open space.

Question 38

Answer 38

IRV - Inspiratory Reserve Volume

TV - Tidal Volume

VC - Vital Capacity

ERV - Expiratory Reserve Volume

RV - Residual Volume

FRC - Functional Residual Capacity

TLC - Total Lung Capacity

Question 39

Answer 39

Question 40

What are the three interdependant aspects of the gas phase of matter, and three laws of gasses that are applicable to the process of respiration?

Answer 40

Pressure, temperature, volume

Boyle’s Law says that at a given temperature there is an inverse relationship between the volume and the pressure.

Charle’s Law says that a given pressure, there is a direct relationship between temperature and volume.

Dalton’s Law says that the total pressure of a mixture of gases is the sum of the pressure of each one. That is, the pressure of each gas is independent.

Question 41

How does Boyle’s law pertain to respiration?

Answer 41

A change in lung volume wil draw in air, because expanding lung volume reduces the pressure in side the lungs relating to the outside and the air rushes in.

Question 42

How does Charles’ Law pertain to respiration?

Answer 42

The temperature of air affects how much room it takes up. In the winter you take shallower breaths, because the air will expand in your nasal cavity as it warms up. In the summer you just have to take deeper breaths.

Question 43

How does Dalton’s Law pertain to the process of respiration?

Answer 43

Air is a solution of different gases. The concentration of O₂ is higher in the air than in our blood, so it will enter even though the blood may be high in CO₂. The presence of CO₂ doesn’t inhibit the diffusion of O₂, because their partial pressures are independent.

Question 44

Define the respiratory rate, and give typical values for adults and children.

Answer 44

The respiratory rate is the number of breaths per minute.

Adults typically have 12-15

Children have 18-20.

Question 45

Define the Respiratory Minute Volume.

Answer 45

The respiratory minute volume is how much air gets moved through the lungs in one minute.

RMV = TV * RR

tidal volume * respiratory rate

ex: 12 breaths/minute * 500 ml

= 6000 ml/min (This is a typical value)

Question 46

What is emphysema?

Answer 46

Emphysema is the loss of alveoli, and thus alveolar ventilation. Usually caused by smoking.

Question 47

What parts of the brain control external respiration?

Answer 47

The cerebral cortex controls voluntary respiration.

The medula oblongata controls involuntary respiration. It coordinates the movements that cause you to inspire and expire, as well as sneezing and coughing.

The pons controls how fast you breathe.

Both the pons and the medula oblongata possesses chemoreceptors that monitor the oxygen and carbon dioxide levels in the blood.

Question 48

What is cystic fibrosis?

Answer 48

Cystic fibrosis is a progressive genetic disease that affect a cell’s chloride channels. As a result, mucus producing cells in the lungs, skin and pancreas aren’t able to function properly. The most notable symptom is thickened mucus in the lungs, which leads to chronic pulmonary infections. Very salty sweat and problems digesting fats are also symptoms. Respiratory failure is the leading cause of death in people with CF.

Question 49

What is pulmonary edema?

Answer 49

Pulmonary edema is fluid build-up in the lungs. Upon auscultation you can hear pops and crackles as the alveoli pop open.

Question 50

What is Pleursy?

Answer 50

Pleursy is fluid and inflammation in the pleural cavity. It is very painful.