Brainscape's Knowledge GenomeTM

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


See full index

Human Physiology > Pulmonary/Respiratory > Flashcards

Pulmonary/Respiratory Flashcards

1
Q

Functions of the lungs

A
  1. gas exchange
  2. regulation of H+ concentration (controls blood + body fluid pH)
  3. partial or complete removal of neurotransmitters and paracrine agents from the blood stream (endothelial cells of the pulmonary capillaries)
  4. production and secretion of substances into the blood (i.e. histamine, angiotensin II)
  5. acts as a sieve that traps and dissolves small blood clots
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the two circulations of the pulmonary system

A
  1. Pulmonary circulation
  2. bronchial circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe the gas exchange in pulmonary circulation and where it occurs/how blood gets there

A
  • > high compliance (stretch), low resistance(R) system
  • > carries deoxygenated blood from the right ventricle to the pulmonary trunk, to the pulmonary arteries and then to the gas exhanging units of the lungs
  • > after gas exchange has occured, the re-oxygenated blood will enter into the pulmonary veins and drain into the left atrium and from there to the left ventricle where it is distributed
  • > as this oxygenated blood travels through the aorta, some is diverted into the right and left bronchial arteries which is the start of the bronchial circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

results of alveolar hypoxia

A

alveolar hypoxia results in pulmonary vasocontriction to shunt blood from poorly ventilated areas of the lungs to better ventilated areas (diverting blood to better-oxygenated lung segments)

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

describe the gas exchange/blood movement of bronchial circulation

A
  • > originates from branches off the aorta
  • > supplies the supporting tissues, connective tissue, septa, large and small bronchi from the trachea to the terminal bronchioles wth oxygenated blood
  • > after supplying the supporting tissues, bronchial venous blood drains directly into the pulmonary veins (LH) diluting the oxygenated blood (slightly less O2ed blood mixes with more O2 blood from PV ) that has just passed through the pulmonary capillaries (=physiological shunt)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

results of hypoxia in bronchial circulation

A

vasodilation

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

Explain how gas exhange works

A

O2 absorption and CO2 excretion occurs in the gas-exchanging units = alveolus

  • > gases diffuse across the membrane of the alveolus and the pulmonary capillaries through a thin fluid layer containing: surfactant, plasma and connective tissue
  • > air enters through trachea, down bronchi and connecting bronchioles and eventually to the respiratory bronchioles and alveolar ducts and into the alveoli where gas exchange occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

where is CO2 produced

A

CO2 is produced in the cells/tissues during metabolism (i.e. at rest, 200ml can be produced per min)

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

Explain the three pathways of CO2 in the body

A
  1. 10% of CO2 that diffuses from the tissues into the capillaries dissolves in the plasma
  2. 30% reacts with hemoglobin (Hb) within the RBC’s to become Hb-CO2 (carbaminnohemoglobin)
  3. 60% is converted into bicarbonate (HCO3) and H within the RBC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how is the CO2 that enters the RBC converted into HCO3 and what happens when it is formed

A

carbonic anhydrase converts CO2 to carbonic acid (H2CO2) and then converts it to HCO3 and H+

  • > once HCO3 is formed, it moves out of the RBC into the plasma in exchange for Cl-
  • > the H+ ions bind (most of them) to Hb to become HHb (reduced hemoglobin) which plays a role in preventing acidosis (inc. H in plasma, lower pH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what occurs if there is a decrease in free H+ in the plasma

A

this results in increased pH, decreased body acidity (alkalosis)

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

Explain CO2 movement from the bloodstream to the alveolus

A
  1. CO2 dissolved in plasma diffuses into alveoli (accross concentration gradient)
  2. as CO2 leaves the blood, CO2 concentrations in the blood decrease
    - > this triggers more CO2 to be released from hemoglobin and diffuse into the blood
    - > H becomes more available as HHb also releases H, this H will be donated to plasma HCO3 forming H2CO3 and eventually H2O + CO2
    - > CO2 formed from this method will diffuse into the alveoli for gas exchange
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Explain O2 movement from alveoli to bloodstream

A
  • > high concentrations of O2 in the alveoli and low concentrations in the blood allows the O2 to diffuse out of the alveoli and into the bloodstream (across the conc. grad)
  • > oxygen molecules bind to the iron-containing heme groups in hemoglobin (there are 4 heme groups in each HB molecule so 4x oxygen mol)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

percentage of O2 that is insoluble in blood vs percent of O2 carried off by Hb

A

insoluble

1.5%

carried by Hb

98.5%

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

hemoglobin saturation

A

percentage of hemoglobin binding sites in the bloodstream occupied by oxygen.

(amount of O2 on Hb)/(maximum possible amount) x 100

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

hemoglobin saturation is dependant on __________

A
  1. blood PO2 (partial pressure of O2 in the blood)
  2. amount of hemoglobin (Hb) in each L of blood
17
Q

what happens when we increase PO2 from 10-60mmHg

A

the rate at which oxygen combines with Hb increases very rapidly as PO2 increases from 10-60mmHg such that at a PO2 of 60mmHg, 90% of the Hb is combined with O2

  • > further increases of PO2 above 60mmHg (to 100mmHg) results in very little saturation(go from 90- around100); so if saturation levels drop from normal 100mmHg you still retain 90% of your blood O2 saturation
18
Q

other factors that will influence saturation of Hb with oxygen

A
  • > 2,3-biosphosphoglycerate (BPG) concentrations
  • > temperature
  • > [H+]/acidity
19
Q

explain how BPG concentration affects Hb’s oxygen saturation

A

BPG is produced by the erythrocytes as a result of anaerobic glycolysis and increases in low oxygen situations.

  • > increasing concentrations of BPG will decrease the affinity of Hb for oxygen = increasing the ability to offload oxygen to the tissues
20
Q

explain how temperature influences the saturation of Hb with oxygen

A
  • > as blood/body temp drops, affinity of Hb for oxygen increases (oxygen bound tighter to hemoglobin)
  • > as temperatures increases, affinity of Hb for oxygen decreases
21
Q

explain how [H+] /acidity influences the saturation of Hb with oxygen

A
  • > as acidity increases, affinity of Hb for oxygen decreases
22
Q

Explain how O2 goes from the bloodstream to the cells/tissues

A
  • > plasma oxygen concentration will be higher than peripheral tissue concentrations so here easy diffusion of oxygen from the blood into the tissues
  • > initialy, dissolved oxygen will diffuse out of the blood into the tissues then oxygen bound to hemoglobin will dissociate and diffusefrom the plasma into the tissues
23
Q

why does O2 consumption by tissues/cells increase during exercise

A
  1. because O2 is used up by the tissues, more can dissociate from Hb in the capillaries and diffuse across the conc. grad.
  2. more O2 is delivered to the tissues by increased bloow flow

Human Physiology (9 decks)

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