Lab 13

Question 1

What is the pathway of electrical activity through the heart?

Answer 1

1. Excitations starts at the sinoatrial node and travels through the atria (atria contract)
2. Impulse is sent to the atrioventricular valve which relays impulse to the ventricles.
3. Impulse sent to the bundle of His which separates into left and right bundles
4. The left/right bundles extend to the purkinje fibres where ventricle contraction will occur.

Question 2

What do P waves, QRS complex, and T waves represent?

Answer 2

P wave - atrial depolarization

QRS complex - ventricular depolarization

T wave - ventricular repolarization

Question 3

What are the effects of acetylcholine on heart rate and strength of contraction?

Answer 3

Heart rate = decrease

Contraction strength = decrease

Question 4

What are the effects of epinephrine on heart rate and strength of contraction?

Answer 4

Heart rate = increase

Strength of contraction = increase

Question 5

What is the difference between systolic and diastolic pressure?

Answer 5

Systolic - the maximum pressure in the arteries during ventricular contraction. (top number)

Diastolic - the minimum pressure in the arteries during ventricular relaxation. (Bottom number)

Question 6

Why can’t you measure venous blood pressure with a sphygmomanometer?

Answer 6

Because venous blood pressure is much lower than arterial blood pressure.

Question 7

What is the venous blood pressure formula

Answer 7

Note: d = distance between chalk marks in cm

Formula:
(d-10) (0.78) = venous BP in mmHg

Question 8

How does the valsalva maneuver affect venous pressure?

Answer 8

This maneuver will cause the glottis to close and make an increase in thoracic pressure.

It will then cause an increase in venous pressure due to a decrease in venous return.

Question 9

What is the pathway of air in the respiratory tract?

Answer 9

Nasal cavity, nasopharynx, oropharynx, laryngopharynx, larynx, trachea, left and right pulmonary bronchi, secondary bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveolar sacs, alveoli

Question 10

How is ciliated pseudostratified epithelium specialized for the respiratory tract?

Answer 10

• contains goblet cells which secret mucus to trap dust and foreign particles.
• contains cilia which expel the mucus with trapped dust and particles out of the lungs.

Question 11

Atmospheric pressure

Answer 11

Pressure due to the weight of air

Question 12

Intrapulmonary pressure

Answer 12

Pressure inside the lungs at the alveoli

Question 13

Intrapleural pressure

Answer 13

Pressure inside the plural cavity
(space between the parietal and visceral pleura)

Question 14

Tidal volume (TV)

Answer 14

The volume of air inhaled or exhaled in a normal (quiet) breathing cycle.

Average = 500ml for both male and female

Question 15

Expiratory reserve volume (ERV)

Answer 15

The volume of air that can be forcibly expired after a normal expiration.

Average:
Male = 1200ml
Female = 800ml

Question 16

Vital capacity (VC)

Answer 16

The maximum amount of air that can be moved into and out of the lungs from a maximal inspiration to a maximal expiration.

Average:
Male = 4800ml
Female = 3400ml

Question 17

Inspiration reserve volume (IRV)

Answer 17

The amount of air that can be forcibly inhaled after a normal inspiration.

Average:
Male = 3100ml
Female = 2100ml

Question 18

Muscles involved in quiet inspiration

Answer 18

• diaphragm
• intercostal muscles

Question 19

Muscles in evolved in forced inspiration

Answer 19

• sternocleidomastoid
• pectoralis minor
• scalene

Question 20

Muscles involved in forced expiration

Answer 20

• abdominal muscles
• internal intercostals

Question 21

What is the formula for Spirograph calculations?

Answer 21

IRV = VC - (ERV + TV)