Lab 13 Flashcards
What is the pathway of electrical activity through the heart?
- Excitations starts at the sinoatrial node and travels through the atria (atria contract)
- Impulse is sent to the atrioventricular valve which relays impulse to the ventricles.
- Impulse sent to the bundle of His which separates into left and right bundles
- The left/right bundles extend to the purkinje fibres where ventricle contraction will occur.
What do P waves, QRS complex, and T waves represent?
P wave - atrial depolarization
QRS complex - ventricular depolarization
T wave - ventricular repolarization
What are the effects of acetylcholine on heart rate and strength of contraction?
Heart rate = decrease
Contraction strength = decrease
What are the effects of epinephrine on heart rate and strength of contraction?
Heart rate = increase
Strength of contraction = increase
What is the difference between systolic and diastolic pressure?
Systolic - the maximum pressure in the arteries during ventricular contraction. (top number)
Diastolic - the minimum pressure in the arteries during ventricular relaxation. (Bottom number)
Why can’t you measure venous blood pressure with a sphygmomanometer?
Because venous blood pressure is much lower than arterial blood pressure.
What is the venous blood pressure formula
Note: d = distance between chalk marks in cm
Formula:
(d-10) (0.78) = venous BP in mmHg
How does the valsalva maneuver affect venous pressure?
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.
What is the pathway of air in the respiratory tract?
Nasal cavity, nasopharynx, oropharynx, laryngopharynx, larynx, trachea, left and right pulmonary bronchi, secondary bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveolar sacs, alveoli
How is ciliated pseudostratified epithelium specialized for the respiratory tract?
- 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.
Atmospheric pressure
Pressure due to the weight of air
Intrapulmonary pressure
Pressure inside the lungs at the alveoli
Intrapleural pressure
Pressure inside the plural cavity
(space between the parietal and visceral pleura)
Tidal volume (TV)
The volume of air inhaled or exhaled in a normal (quiet) breathing cycle.
Average = 500ml for both male and female
Expiratory reserve volume (ERV)
The volume of air that can be forcibly expired after a normal expiration.
Average:
Male = 1200ml
Female = 800ml
