Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Gas Exchange > Flashcards

Gas Exchange Flashcards

1
Q

What is the pulmonary circulation?

A

pathway that carries blood through lungs

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

Functions of pulmonary circulation:

A
  • re-oxygenate blood and remove CO2

- exchange metabolic products to and from lungs

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

Pulmonary vessels are ___ flow, ___ pressure, and ____ resistance

A
  • high flow
  • low pressure
  • low resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Arteries in pulmonary vessels have less…

A

smooth muscle than systemic arteries of the same size

  • high compliance needs lower pressure for flow
  • lowers workload of R ventricle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

At rest, what percentage of pulmonary circulation is in the capillaries?

A

15%

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

During exercise, what percentage of pulmonary circulation is in the capillaries?

A

25%

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

Function of alveolar-capillary network:

A

where exchange of gases occurs

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

Layers of respiratory membrane:

A
  • alveolar epithelium: has type 1 cells
  • fused basement membranes: CT
  • capillary endothelium: squamous cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Capillary endothelium has…

A

angiotensin converting enzyme (ACE), which converts angiotensin 1 to angiotensin 2

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

Function of capillary endothelium:

A

inactivates or removes vasoactive substances

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

Exchange of O2 and CO2 is governed by what type of forces?

A

Starling

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

Pulmonary arterial pressure is much lower than…

A

arteries in the systemic system

  • systolic: 25 mmHg
  • diastolic: 10 mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

At rest, what happens to the capillaries at the base and apex of the lung?

A

difference due to gravity

  • base: most capillaries are open and have rapidly flowing blood
  • apex: few capillaries are open and blood flow is slow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

During exercise, distribution of blood flow would be…

A

more uniform due to increased cardiac output and increased pulmonary arterial pressure

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

Function of auxiliary drainage system of the lungs:

A
  • remove excess fluid in ISF

- drains fluid into systemic veins

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

Failure of the auxiliary drainage system results in…

A

pulmonary edema

  • fluid accumulation overcomes removal by lymph system
  • increases diffusion distance
  • decreases exchange of gases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the Va/Q ratio?

A
  • Va: alveolar ventilation
  • Q: flow of blood through capillaries
  • major determinant of normal gas exchange
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Va/Q ratio of a resting, upright individual?

A
  • average: 0.8

- air flow greatest at apex and lowest in base

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

At apex of the lung, there can be a condition called…

A

regional hypoxia: groups of alveoli with low O2

  • higher ventilation and lower perfusion
  • decrease in V and even bigger decrease in Q
  • increase in O2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

At the base of the lung, there can be a condition called…

A

hypoxemia: reduction of O2
- lower ventilation and higher perfusion
- increase in V and even bigger increase in Q
- decrease in O2

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

Pulmonary arterioles control ____ and aids…

A
  • blood flow into capillaries by altering diameter

- aids in balancing perfusion of blood

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

Decreased arterial PO2 produces…

A

hypoxic vasoconstriction

  • resistance to blood flow increases
  • blood flows to areas with lower resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens if all regions of the lungs become hypoxic?

A
  • all arterioles constrict
  • resistance to blood flow increases
  • pulmonary arteriole pressure rises (pulmonary hypertension)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the predominant means for movement of gases?

A

simple diffusion
- moves along their own concentration gradient, which is determined by partial pressure of gas in alveoli and capillary blood

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

What are the pressures of H2O, CO2, and O2 at alveolus?

A
  • pH2O: 47 mmHg
  • pCO2: 40 mmHg
  • pO2: 104 mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the pressures of CO2 and O2 in pulmonary arteries?

A

blood going to lungs

  • pO2: 40 mmHg
  • pCO2: 46 mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the pressures of CO2 and O2 in pulmonary veins?

A

blood leaving lung with oxygenated blood

  • pO2: 100 mmHg
  • pCO2: 40 mmHg
28
Q

O2 gradient diffuses from _____ into ____

A

alveolus into capillary

- from 104 mmHg to 40 mmHg

29
Q

CO2 gradient diffuses from ____ into ____

A

capillary blood into alveolus

- 46 mmHg to 40 mmHg

30
Q

What happens during hyperventilation?

A

increased ventilation by increasing tidal volume and frequency (exercise)

  • increases alveolar pO2
  • decreases pCO2
  • improves gradients for both
31
Q

What happens during hypoventilation?

A

decreased ventilation

  • decreases alveolar pO2
  • increases pCO2
  • decreases gradients for both
32
Q

What is the arterial oxygen pressure?

A

100 mmHg

33
Q

How does O2 get transported in the blood?

A
  • binds to hemoglobin in RBC

- minimal amount of O2 is dissolved in gaseous state in plasma

34
Q

Exchange of gases occur between…

A

blood and tissues

- diffuse through endothelial cells

35
Q

What is the oxyhemoglobin dissociation curve?

A

graph that shows O2 saturation of blood

  • shows how many hemoglobin binding sites are filled with O2
  • dependent on partial arterial pressures of O2 in blood
36
Q

Definition of O2 carrying capacity:

A

max amount of O2 that can be carried by 100mL of blood

37
Q

Definition of O2 content:

A

amount of O2 actually bound to hemoglobin

38
Q

Definition of O2 content/O2 carrying capacity x 100:

A

percent of hemoglobin saturated with O2

39
Q

As pO2 rises, what happens to the % of binding sites on hemoglobin for O2?

A

increases

40
Q

The oxyhemoglobin dissociation curve begins to plateau at _____ and flattens at ____

A
  • plateau: 50 mmHg

- flatten: 70 mmHg

41
Q

What happens when the oxyhemoglobin dissociation curve shifts to the right?

A
  • decreased affinity of hemoglobin for O2

- increased dissociation from hemoglobin

42
Q

What happens when the oxyhemoglobin dissociation curve shifts to the left?

A
  • increased affinity of hemoglobin for O2

- decreased dissociation from hemoglobin

43
Q

What factors affect the oxyhemoglobin dissociation curve?

A
  • pH and CO2
  • temperature
  • 2,3 diphosphoglycerate (DGP)
  • CO
44
Q

How does pH and CO2 affect the oxyhemoglobin dissociation curve?

A
  • decrease in pH shifts it to the right because CO2 generates H+ ions
  • increases in pH when CO2 is released and shifts curve to the left
45
Q

How does temperature affect the oxyhemoglobin dissociation curve?

A
  • increase in temp = curve shifted to the right b/c it facilitates O2 release to tissues
  • decrease in temp = curve shifted to the left b/c O2 release inhibited
46
Q

How does 2,3 DPG affect the oxyhemoglobin dissociation curve?

A

competes directly with O2 at binding site of hemoglobin

- causes right shift

47
Q

How does CO affect the oxyhemoglobin dissociation curve?

A
  • binds to same site as O2
  • has a higher affinity
  • shifts curve to the left
48
Q

CO2 diffuses from…

A

tissue to plasma

- some stay in plasma but mostly into RBC

49
Q

Removal and uptake of CO2 from blood is directly related to…

A

pCO2

50
Q

RBC has what enzyme?

A

carbonic anhydrase, which catalyzes the reaction of CO2 and H2O to make bicarb
- decreases pH of tissues

51
Q

CO2 is predominately transported via…

A

bicarb

52
Q

Structure of erythrocytes (RBC):

A
  • biconcave
  • no nucleus or organelles needed for cell maintenance
  • cytoplasm filled with hemoglobin
53
Q

Function of RBC:

A

carry blood gasses

54
Q

Life cycle of RBCs:

A
  1. created from hematopoietic stem cells in bone marrow (erythropoiesis), which is stimulated by erythropoietin
  2. circulate in blood for 4 months
  3. removed by macrophages in spleen, liver, and marrow
55
Q

Erythropoietin is secreted by…

A

kidneys in response to decreased O2

56
Q

Structure of hemoglobin:

A

4 non-protein heme groups and 4 polypeptide chains (2 alpha and 2 beta chains)

57
Q

What happens to iron at the heme groups?

A

gets reduced to ferrous Fe2+

- that’s the site where O2 binds

58
Q

Where does CO2 bind to on hemoglobin?

A

polypeptide chains

59
Q

Functions of hemoglobin:

A
  • O2 transport (up to 4)
  • CO2 transport
  • H+ transport
60
Q

Hemoglobin in the blood is directly proportionate to…

A

% blood volume occupied by RBC (hematocrit)

61
Q

What is myoglobin?

A

O2 carrying and storage protein in muscle tissues

62
Q

What is anemia and its symptoms?

A
  • abnormally low O2 carrying capacity of the blood
  • shortness of breath
  • physical weakness
63
Q

When do you think anemia occurs in a person?

A
  • decreased number of circulating RBC (hematocrit < 37%)

- abnormal or low hemoglobin

64
Q

Types of anemia caused by decreased number of RBCs:

A
  • megalobastic: decreased folic acid and or cobalamin (vitamin b12)
  • pernicious: autoimmune disease and causes lack of IF (reduces b12 absorption)
  • aplastic: abnormal decrease in production of RBCs
65
Q

Illnesses caused by abnormal hemoglobin:

A
  • sickle cell anemia: glutamine to valine

- thalassemias: defective chains

66
Q

What is methemoglobinemia?

A

alteration in iron state

  • iron converted to ferric (Fe3+) instead of ferrous (Fe2+)
  • causes abnormal hemoglobin levels
67
Q

What is iron deficiency anemia?

A
  • associated with internal blood loss

- comes from inadequate absorption of iron

Physiology (33 decks)

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