exam 2 lecture

Question 1

What is the primary function of bone marrow in the immune system?

Answer 1

Production and maturation of B-cells.

Question 2

Which organ is primarily responsible for storing and activating B-cells?

Answer 2

spleen

Question 3

What are the five cardinal signs of inflammation?

Answer 3

Heat, Swelling, Pain, Redness, Loss of Function.

Question 4

Which cells are primarily responsible for phagocytizing pathogens and presenting antigens?

Answer 4

Macrophages.

Question 5

Which type of immunity is specific, adaptive, and slower to respond to pathogens?

Answer 5

Adaptive immunity.

(Adaptive immunity is a specific, slower response that involves B-cells and T-cells, targeting non-self pathogens with precision. It contrasts with the faster, non-specific innate immune response​)

Question 6

What is the function of cytotoxic T-cells (CD8+)?

Answer 6

Directly eliminating virally infected cells.

(by injecting toxic chemicals that induce apoptosis)

Question 7

What is the role of Helper T-cells (CD4+)?

Answer 7

Secreting lymphokines to recruit other immune cells.

Question 8

Which cells are responsible for producing antibodies?

Answer 8

Plasma cells

Question 9

What is the main difference between acute and chronic inflammation?

Answer 9

Acute inflammation is fast and localized, while chronic inflammation is slower and can be systemic.

Question 10

What is the function of suppressor T-cells?

Answer 10

Reducing the intensity of the immune response.

Question 11

Which process ensures that only T-cells that can respond to antigens presented on MHC proteins mature?

Answer 11

positive selection

Question 12

What is the purpose of clonal selection in B-cells?

Answer 12

to ensure high specificity for non-self antigens.

(Clonal selection is the process by which only B-cells that have high affinity for non-self antigens are selected for activation, ensuring that the immune response is highly specific to pathogens​()

Question 13

Which type of immunity involves the direct transfer of antibodies from one individual to another?

Answer 13

passive immunity

(antibodies are transferred from one individual to another, such as through maternal antibodies passed to a baby or through antibody injections. It is temporary because no plasma cells are transferred)

Question 14

What do non-enzymatic antioxidants like Vitamin C and E do for the immune system?

Answer 14

Reduce reactive oxygen species (ROS) and inflammation.

( Vitamin C and E help to neutralize reactive oxygen species (ROS), which are harmful free radicals that can damage cells, thereby reducing inflammation and supporting the immune system)

Question 15

What are the two main types of respiration?

Answer 15

External and Internal

Question 16

What is the main function of the conducting zone in the respiratory system?

Answer 16

conducts air from the larynx to the lungs

(It does not participate in gas exchange (respiratory zone) because its walls are too thick. Instead, its primary role is to provide a pathway for air​)

Question 17

Which cells in the conducting zone secrete mucus to trap foreign particles?

Answer 17

goblet cells

(conducting zone secrete mucus, which traps foreign particles from inhaled air. This mucus is then propelled out of the respiratory tract by ciliated cells​)

Question 18

Which structure prevents food from entering the respiratory tract during swallowing?

Answer 18

Epiglottis

(epiglottis covers the larynx during swallowing to prevent food from entering the respiratory tract. This ensures that food is directed toward the esophagus instead​)

Question 19

What is the primary site of gas exchange in the lungs?

Answer 19

Alveoli

(The alveoli are the primary structures where gas exchange occurs in the lungs. They are thin-walled and surrounded by capillaries, allowing oxygen and carbon dioxide to diffuse across the respiratory membrane)

Question 20

Which law explains the relationship between pressure and volume during breathing? - (inverse relation)

Answer 20

boyles law

Question 21

What happens to the intrapleural pressure during inspiration?

Answer 21

decreases

( During inspiration, the chest wall expands, and the lungs are pulled outward, which causes the intrapleural pressure to become more negative)

Question 22

What is the clinical significance of pneumothorax?

Answer 22

It causes the lung to collapse.

( air enters the pleural space, causing the separation of the chest wall and lung. This leads to the lung collapsing because the negative pressure that keeps the lung expanded is lost)

Question 23

Which muscles are involved in breathing and expanding the chest wall?

Answer 23

Diaphragm and external intercostals.

Question 24

What role does the pleural fluid play in the respiratory system?

Answer 24

Allows the pleura to slide easily during breathing

(located in the intrapleural space, allows the pleurae (visceral and parietal layers) to slide effortlessly against each other during ventilation. This ensures smooth movement of the lungs during inspiration and expiration)

Question 25

What type of epithelial cells are found in the alveoli and are involved in gas exchange?

Answer 25

Type I alveolar cells

(primary cells involved in gas exchange in the alveoli. They are thin, allowing for efficient diffusion of oxygen and carbon dioxide between the air in the alveoli and the blood in the surrounding capillaries)

Question 26

What is the function of Type II alveolar cells?

Answer 26

They secrete surfactant to reduce surface tension.

(secrete surfactant, which reduces surface tension in the alveoli. This prevents the alveoli from collapsing, ensuring they remain open for gas exchange​)

Question 27

What happens to the volume of the alveoli during inspiration?

Answer 27

it increases

(During inspiration, the alveoli expand as the lungs increase in volume. This causes a decrease in intra-alveolar pressure, allowing air to flow into the lungs according to Boyle’s Law​)

Question 27

How does tobacco smoke affect the mucus escalator in the respiratory system?

Answer 27

It paralyzes the cilia, stopping the mucus escalator.

Question 28

Which muscles are primarily responsible for increasing the volume of the thoracic cavity during inspiration?

Answer 28

Diaphragm and external intercostals.

Question 29

What is lung compliance, and why is it important?

Answer 29

It refers to the increase in lung volume for a given effort and determines the ease of breathing.

(Lung compliance refers to how much the lung volume increases for a given amount of effort. High compliance means the lungs expand easily, while low compliance makes breathing more difficult. Lung compliance is affected by lung elasticity and surface tension)

Question 30

What role does pulmonary surfactant play in the lungs?

Answer 30

It decreases surface tension in the alveoli to prevent collapse.

(Pulmonary surfactant, produced by Type II alveolar cells, reduces surface tension in the alveoli. This helps keep the alveoli open and prevents them from collapsing, especially during exhalation)

Question 31

What effect does airway resistance have on pulmonary ventilation?

Answer 31

It limits airflow, making it harder to breathe.

(. Higher resistance, often due to the contraction of smooth muscle in the bronchioles, makes it harder to move air in and out of the lungs​)

Question 32

What is tidal volume?

Answer 32

The volume of air moved in and out during a normal breath.

Question 33

What is the condition called when air is trapped in the lungs due to the destruction of alveolar walls, reducing oxygen exchange?

Answer 33

Emphysema

( exposure to toxins such as tobacco smoke, leads to the destruction of alveoli and the surrounding tissue. This reduces the lung’s ability to exchange oxygen and traps air in the lungs)

Question 34

What is alveolar ventilation, and how does it differ from minute ventilation?

Answer 34

Alveolar ventilation is the volume of air reaching the alveoli, while minute ventilation is the total volume of air entering the lungs per minute.

Question 35

During exercise, which of the following is a more efficient way to increase alveolar ventilation?

Answer 35

Increasing tidal volume.

(it brings more fresh air to the alveoli, whereas simply increasing the respiration rate brings more air but also more dead space air​)

Question 36

What is the respiratory quotient (RQ) at rest, and what does it represent?

Answer 36

0.8, representing the ratio of CO₂ produced to O₂ used.

( The respiratory quotient (RQ) is the ratio of the volume of CO₂ produced to the volume of O₂ used during metabolism. At rest, the typical RQ is 0.8, meaning that 80% as much CO₂ is produced as O₂ is used)

Question 37

Which factors decrease hemoglobin’s affinity for oxygen, making it easier to release oxygen to tissues?

Answer 37

Increased temperature, decreased pH, and high CO₂.

Question 38

What is the main way carbon dioxide is transported in the blood?

Answer 38

As bicarbonate in the plasma.

Question 39

What happens to the bicarbonate in red blood cells when blood reaches the lungs?

Answer 39

It is converted back into CO₂ and expelled.

(When blood reaches the lungs, bicarbonate is converted back into carbon dioxide (CO₂) inside the red blood cells. The CO₂ then diffuses into the alveoli and is expelled during exhalation​)

Question 40

Diaphragm

Answer 40

contraction pulls the
diaphragm down

Question 41

External intercostals

Answer 41

contraction pulls ribs
up and out

Question 42

passive expiration:

Answer 42

No muscle contraction
Relaxation of the diaphragm
and external intercostals

Question 43

active expiration

Answer 43

Internal intercostals and
abdominal muscles:
contraction pulls ribs down and in
volume of the chest cavity decreases
volume of the alveoli decreases
volume down à pressure up
(Boyle’s law)
air goes down the pressure gradient

Question 44

Lung compliance depends on:

Answer 44

the elasticity of the lungs

the surface tension of the fluid lining
the alveoli

Question 45

pulmonary surfactant also…

Answer 45

pulmonary surfactant forms a film on the inner surface of the alveoli

Question 46

Airway resistance

Answer 46

Does the cross-sectional area of the airway
increase or decrease from the big larynx to the
the teeny tiny bronchioles?

INCREASES

• A big factor is contraction of the smooth muscle
  in the walls of the bronchioles

Question 47

spirometer

Answer 47

measure volumes of inspired and expired air

Used to
* diagnose disorders
* to measure severity of disorders
* to measure effectiveness
of different treatments

Question 47

Inspired reserve volume and Expired reserve volume

Answer 47

the extra you can squeeze in when you really try

expired: the extra you can squeeze out
when you really try

Question 48

Pneumonia

Answer 48

Alveolar inflammation and abnormal alveolar filling with fluid

Question 49

respiratory membrane

Answer 49

1) Alveolar epithelial cells
2) Capillary endothelial cells
3) Fused basement membranes

Question 50

Concentration gradients
for O2 and CO2 are affected
by

Answer 50

their partial pressures and
their solubilities

Question 51

When O2 is bound to hemoglobin, it does NOT what:

Answer 51

it does not contribute to the partial pressure of O2 in the blood, so more
O2 can move from the alveoli to the blood .

Question 52

Hemoglobin binds O2 reversibly

Answer 52

Binding must be tight enough to pick up lots of O2 in the lungs, but
not so tightly that it can’t release O2 in the tissues

Question 53

Hemoglobin-oxygen
dissociation curve
is not linear AND

Answer 53

Note that there is normally a big reserve of
O2 that can be used by local tissues experiencing high metabolic rates

Question 54

Factors that decrease binding affinity shift the curve to the right

Answer 54

(Higher partial pressure is required to
achieve the same degree of saturation)

Question 55

Factors that increase binding
affinity shift the curve to
the left

Answer 55

Lower partial pressure is required
to achieve the same degree of
saturation