HUBS1406 Lecture Notes - Lecture 9: Simple Squamous Epithelium, Obstructive Lung Disease, Gas Exchange

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harlequinhorse931

12 Oct 2018

School

University of Newcastle

Department

Human Biosciences

Course

HUBS1406

Professor

Evans

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Document Summary

A gas exchange membrane (the lung tissue itself). This needs to be very thin, and have a huge surface area for diffusion of gases into and out of the bloodstream. A system of tubes (airways) to bring the gas in contact with the gas exchange membrane. A system of bellows (the chest wall and the muscles of respiration) that changes the gas regularly, so that exchange continues and doesn"t just stop. Alveoli are the air sacs" in lungs which maintain concentration gradient of o2 and co2. Simple squamous epithelium layer is thin= fast diffusion. Alveoli: macrophages + surfactant secreting cell (type ii cell). Cartilage provides structural integrity to keep the airways open. Braces open rings of cartilage which decrease in the bronchioles. Bronchi have cartilage ranging from the rings down to the plate, structural integrity, keeping it open: bronchioles have the ability to constrict and dilate and modulate airflow.

Related Questions

True of False: Freshwater environments have a higher concentration of oxygen than saltwater environments.

QUESTION 2 If the difference in partial pressure of gas on either side of the barrier to diffusion is 0, which of these events will occur?

The area for gas exchange will increase to accommodate this similarity.

The constant for diffusion will decrease.

The rate of diffusion will be 0.

The distance thickness of the barrier to diffusion will also be 0.

QUESTION 3 On the x-axis of the oxygenâhemoglobin equilibrium curve is the partial pressure of oxygen in tissues. Which type of blood is most likely to be represented by the right-hand side of the axis? (Hint: the oxygen-hemoglobin equilibrium curve is figure 45.14 in your book on pg 913)

blood found in the left ventricle

blood found in the right atrium

blood found in the superior vena cava

blood found in the inferior vena cava

QUESTION 4 Which of these is an example of pulmonary circulation?

Blood is pumped from the right ventricle to the lungs.

Blood is pumped from the left ventricle to the aorta.

Blood is pumped from the aorta to the cardiac vein.

Blood is pumped from the inferior vena cava to the right atrium.

QUESTION 5 O2 will diffuse from blood to tissue faster in response to which of the following conditions?

an increase in the PO2 of the tissue

a decrease in the PO2 of the tissue

an increase in the thickness of the capillary wall

a decrease in the surface area of the capillary

QUESTION 6 Which of the following promotes oxygen release from hemoglobin?

a decrease in temperature

a decrease in carbon dioxide levels

a decrease in pH

a decrease in carbonic anhydrase

QUESTION 7 How does the medulla oblongata sense the amount of carbon dioxide in the blood?

A. Carbonic anhydrase produced by cells performing cellular respiration is exported and travels though the blood, and binds to a receptor on the medullary respiratory center, which causes a signal amplification resulting in a change in gene expression which results in the production of proteins that will cause the diaphragm to contract

B. CO2 produced by cells performing cellular respiration reacts with blood plasma for form an acid, which increases the pH of the blood, which causes the medullary respiratory center to contract the diaphragm

C. CO2 produced by cells performing cellular respiration reacts with blood plasma for form an acid, which decreases the pH of the blood, which causes the medullary respiratory center to contract the diaphragm

D. A and B

E. A and C

QUESTION 8 Which of the following parts of the lung are considered "dead space"? A. The alveoli B. The trachea C. The bronchi D. B and C E. All of the above

QUESTION 9 Which of the following blood vessels have the thinnest walls?

arteries

arterioles

capillaries

venules

veins

QUESTION 10 How does the interstitial fluid return to the bloodstream?

A. Interstitial fluid flows into the capillary where the osmotic pressure driving fluid into the bloodstream is greater than the blood pressure driving fluid out of the blood

B. Interstitial fluid flows into the capillary where the blood pressure driving fluid into the bloodstream is greater than the osmotic pressure driving fluid out of the blood

C. Interstitial fluid leaves the tissue via lymphatic ducts and travels through the lymphatic system, which returns the fluid to the veins. D. A and C

E. B and C

QUESTION 11 True or False: When an electrocardiogram (EKG or ECG) shows a flat line (aka asystole), medical personnel will restart the heart using a defibrillator.

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1. Which of the following are considered blood vessels within the cardiovascular system? (Select all that apply.)

Veins

Arteries \

Epithelial tissue

Capillaries

Epidermis

2. The middle muscle layer found in the walls of the heart is the __________.

Myocardium

Epicardium

Endocardium

Aorta

3. Blood is transported throughout the body via ___________.

Veins
Arteries

Capillaries

All of the above

4. The right atrium receives blood from all parts of the body except the ______________.

Abdominal cavity

Lungs

Dorsal cavity

Cranium

5. Blood carries which of the following?

Oxygen and cellular waste

Oxygen, nutrients, hormones, enzymes, and cellular waste

Nutrients, hormones, enzymes

Oxygen, nutrients, enzymes

6. Vocal chords are found in the ____________.

Bronchus

Trachea

Larynx and Pharynx

Nasal cavity

7. The trachea is mostly lined by ________________.

Alveoli

Ciliated

mucous membrane

Lung capillaries
Vocal chords

8. Excess CO2 from the body is __________________.

Stored in the pancreas

Digested by cells

Excreted by the respiration process

Used to make ATP

9. CO2 from the body is released into the lungs via _________________.

Ciliated mucous membrane

Alveolar air

Nasal cavity

Bronchial tree

10. The principal function(s) of gas exchange is ____________________.

To supply cells with oxygen

To remove CO2 from the body

Both A and B

Neither of the above

One of the most common chronic conditions affecting the respiratory system is asthma. Asthma is a condition characterized by inflammation of the airways. When an asthma attack is triggered, the airways become even more inflamed and can restrict breathing. Common symptoms during an asthma attacks include coughing, wheezing, tightness in the chest and shortness of breath. Severe asthma attacks can be fatal. People with a family history of asthma are more likely to have the condition. While there is no cure for asthma, proper medical care and a management plan can help to maintain quality of life for people living with asthma. There are different types of asthma, each with their own triggers and management plans. Type Description Exercise-induced Bronchoconstriction (EIB), or Exercise-induced Asthma (EIA) Some people only experience asthma symptoms during exercise. Exercise-induced asthma causes the narrowing of airways during exercise, which restricts the flow of air to and from the lungs. Cold, dry air tends to exacerbate symptoms, while warm, humid air may reduce symptoms. People with exercise-induced asthma should work with their doctor to create a management plan that still allows them to exercise while keeping their symptoms under control. Allergic Asthma Allergic asthma is the most common form of asthma. It is triggered by inhaling allergen particulates, such as dust mites, pollen, pet dander, or mold. The bodyâs reaction to the allergens causes inflammation that results in coughing, wheezing, and other symptoms of asthma. Occupational Asthma Occupational asthma is caused by the frequent inhalation (breathing) of gases, fumes, dust, or other harmful substances in the workplace. Employees working in the chemical or petroleum industries are frequently exposed to chemicals such as Sulphur dioxide or hydrochloric acid, and may develop occupational asthma after prolonged exposure. Childhood Asthma Childhood asthma is usually developed before age 5. It is a condition that affects millions of children. It is vital that childhood asthma is properly controlled to prevent damage to the developing lungs Risk factors: â¢ Allergies â¢ Family history â¢ Frequent respiratory infections â¢ Low birth-weight â¢ Second-hand smoke â¢ Residing in a low-income, urban environment

Asthma symptoms that are triggered by exposure to pollen, pet dander, mold, or dust mites is indicative of which of the following types of asthma:

Occupational asthma

Childhood asthma

Allergic asthma

Exercise-induced asthma

aquamarinecaribou889

Background

Almost all animal and plant cells require oxygen and give off carbon dioxide. This is called gas exchange and it occurs by passive diffusion. Some animals do all or most of their gas exchange across their skin (for example amphibians) but they have very low metabolisms and use very little oxygen and get rid of very little carbon dioxide.

On the other hand humans (and other mammals) have very high metabolic requirements and we canât rely on gas exchange over the limited 1.5 to 2.0 square meters of our skin to get enough oxygen in and carbon dioxide out fast enough. Our gas exchange takes place across a very thin membrane in the Alveoli of the lung and the gas exchange surface in humans is estimated to be between 50 and 100 square meters, or between 25 and 67 times our skin surface area.

Our lungs provide a huge surface for gas exchange but they are a dead-end system. Once the oxygen in the lungs is used up it needs to be replenished and carbon dioxide builds up in the air spaces in the lungs and needs to get out. This is where the diaphragm and a few of the skeletal muscles become important. In its relaxed state the diaphragm is at its longest and the space in the thoracic cavity (and the lungs) is small. When the diaphragm contracts it shortens, which increases the volume of the thoracic cavity (and the lungs). The increase in size means the pressure is lower in the lungs than outside so air comes into the lungs (inhalation). As the diaphragm relaxes, the lungs decrease in size enough that the pressure inside the lungs is higher than the external air pressure so air comes out (exhalation).

Introduction

In this lab you will be building a model of a lung and experimenting with different ways to breath.

Supplies:

In the Lab Kit

One round 9" balloon (one lung, we donât need two for this)
medium-sized plastic bag large enough to fit over bottom end of bottle (diaphragm)
medium-size, thin rubber band

You supply

plastic 2-liter soda bottle with bottom cut off (thoracic cavity)

Tape (optional)

Directions:

1. Insert the balloon through the open bottom of a modified 2-liter soda bottle and up over the neck of the bottle. Pull the end of the balloon over the edges of the neck of the bottle. The balloon is held open by the neck of the bottle.

2. Place the plastic bag over the bottom (open) end of the 2-liter bottle and use the rubber band to hold it in place. This will serve as the diaphragm. To inflate the lung, blow into the balloon just before you fasten the rubber band. You can also wrap tape over the edges of the plastic bag to minimize air leaks

3. Grasp the bottom of the plastic bag and pull it down and push it up. Watch as the "lungs" (the balloon) expand and contract as you do this. The balloon has to change size because the air space between the balloon and bottle must remain constant. (Well, it would if the seal around the plastic bag and bottle were perfect).

You may block the "trachea" (the neck of the bottle) so that the air supply is cut off and watch as nothing happens when the "diaphragm" is pushed in and out.

This model isnât perfect. None of the joints are air tight as they would be in a real thoracic cavity. Pull the âdiaphragm down and watch the lungs expand . If you hold it in place, the lungs will collapse again over time. This is because of leaks and is not how real lungs work. Pushing the diaphragm in and pulling it out over and over does give you an idea of how lungs work. As the diaphragm tightens, contracts (pull down on the plastic bag) the lungs fill with air. As the diaphragm relaxes (push up on the plastic bag) air is expelled from the lungs .

There are several different ways we breath, i.e. expand our thoracic cavity so that our lungs can expand. You have just made a demonstration model of the diaphragm at work. You can also use your rib cage to expand and contract so that you can inhale and exhale. There are muscles between and around your ribcage which you can use to change the size of your thoracic cavity.

This is approximately what your model of a lung will look like.

Answer the questions on the Report Page

Report Page Name

1. Put a hand on your lower ribcage and try moving your ribs out and in. Does air also move in and out?

2. Someone with an upper back or neck injury may not have the options of using diaphragm or ribs to breath. They can learn to use the clavicle and the muscles attached to expand their thoracic cavity a small amount and breathe independently for short periods of time. Put your hand on you clavicle and try to raise and lower just that bone without using your diaphragm or your ribs. It isnât easy but you should be able to get a little air into and out of your lungs this way. How effective do you think this way of breathing is?

3. When you take a really deep breath you use all these muscle groups to help. Take a really deep breath and notice that your ribs expand, your lower abdomen comes out (a sign that the diaphragm has contracted) and your shoulders lift a little (the upper chest and clavicle are working). Now take a relaxed breath. Only your abdomen should go in and out. The movement of your abdomen is a result of the contracting diaphragm pushing on the contents of your âgutâ which forces your abdomen to push out.

Do you breath in or out when your diaphragm contracts?\

4. If a hole were poked in your thoracic wall (the wall of the pop bottle â the hole should be at least the diameter of a pencil)

a. what would happen when you tried to breath? (This is a pneumothorax).

b. Is the space between the balloon and plastic bottle still required to remain constant?

5. Would it be possible to live with a paralyzed diaphragm? Explain your answer.

fuchsiamuskrat152

HUBS1406 Lecture Notes - Lecture 9: Simple Squamous Epithelium, Obstructive Lung Disease, Gas Exchange

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