PULMONARY CIRCUIT DURING EXERCISE

Question 1

PULMONARY CIRCUIT

Answer 1

• during exercise

Question 2

blood flow (CO)

Answer 2

• LARGE INCREASE

Question 3

pulmonary arterial pressure

Answer 3

• SLIGHT INCREASE

- mostly NORMAL

Question 4

pulmonary vascular resistance

Answer 4

• LARGE DECREASE

- flow is inverse to resistance

Question 5

pulmonary blood volume

Answer 5

• INCREASE

- due to increase in CO

Question 6

number of perfused capillaries

Answer 6

• INCREASE
• for better exchange in the lung
• increase Oxygenation

Question 7

capillary surface area

Answer 7

• INCREASE, which means INCREASED rate of gas exchange

Question 8

smoker

Answer 8

• pulmonary hypertension

- increase lung marking in the X-ray

Question 9

systemic circuit ARTERIAL SYSTEM

Answer 9

• PO2 NO CHANGE, fully saturated
• PCO2 no change, increase ventilation proportional to increase metabolism
• pH no change, or decrease due to production of lactic acid, extreme exercise decrease pH due excessive production of lactic acid causing muscle cramps extracellular to intracellular, electrolyte shift
• MAP slight increase
• body temp. slight increase
• blood flow LARGE INCREASE
• vascular resistance (TPR) LARGE DECREASE due to release of lactic acid, due to dilation of skeletal muscle beds

Question 10

systemic circuit VENOUS SYSTEM

Answer 10

• PO2 DECREASE, due to increase extraction

- PCO2 INCREASE, due to metabolism

Question 11

during exercise

Answer 11

• INCREASE SYSTOLIC PRESSURE
• DECREASE DIASTOLIC PRESSURE
  = MEAN PRESSURE SAME

Question 12

exercising muscle

Answer 12

• blood flow INCREASE
• vascular resistance DECREASE due to release in lactic acid
• capillary pressure INCREASE due to increase in flow
• capillary filtration INCREASE, due to increase hydrostatic pressure
• lymph flow INCREASE
• venous PO2 DECREASE and can reach extremely LOW levels
• extraction of oxygen INCREASE

Question 13

Cutaneous blood flow

Answer 13

• initially DECREASE, then INCREASE to dissipate heat

Question 14

Coronary blood flow

Answer 14

• INCREASE due to INCREASE IN VOLUME WORK of the heart

- due to increase in ADENOSINE

Question 15

cerebral blood flow

Answer 15

• no change due to unchanged arterial CO2

Question 16

renal blood flow

Answer 16

• decrease in the splanchnic circuit

Question 17

heart

Answer 17

• increase volume work
• increase HR, increase metabolism, increase production of ADENOSINE, causing increase in coronary flow
• preload normal in light and moderate exercise
• preload increase in heavy exercise

Question 18

regular exercise

Answer 18

• increase maximal O2 consumption
• increase ability to deliver O2 to active muscle by increasing CO
• increase coronary flow, increase adenosine
• low HR but > SV
• increase SV 35%
• HR normal same as untrained individuals
• increases # of arterioles, w/c decreases minimal resistance during exercise
• increase capillary density, w/c increases surface area and decreases diffusion distance
• increase # of oxidative enzymes in the mitochondria due to INCREASE IN ELECTRON TRANSPORT CHAIN, increase metabolism causing weight control