Midterm 1 Review

Question 1

Events in Pacemaker Potential

Answer 1

• Slow depolarization
• Threshold
• Rapid depolarization
• Action Potential
• Repolarization

Question 2

Slow Depolarization of SA Node

What happens to permeability and movement of each ion

Answer 2

• K permeability decreases
• Na permeability increases
• Slow Na influx
• Midway through Ca channels briefly open

Question 3

Rapid Depolarization of SA Node

Answer 3

• L-type Ca channels open
• Lots of Ca moves in

Question 4

Rpolarization of SA Node

Answer 4

• L-type Ca channels close
• K rectifier channels open
• K moves out

Question 5

Average BPM of Autorhythmic Cells

Answer 5

• SA Node 70 bpm
• AV Node 40 bpm
• Purkinje fibers 20 bpm
• Purkinje fibers occasionally make extrasystoles
• AV node and purkinje fibers are depolarized by SA node before they can do it for themsellves except during extrasystole

Question 6

Action Potential Events in Myocardial Contractile Cells

Answer 6

• Depolarization
• Plateau
• Repolarization

Question 7

Depolarization of Contractile Cells

Answer 7

• Na in

Question 8

Plateau of Contractile Cells

Answer 8

• Ca moves in and keeps the cell depolarized to make sure the atria empty fully before the ventricles contract, also prevents tetanus

Question 9

Repolarization of Contractile Cells

Answer 9

• K out

Question 10

End Systolic Volume

Answer 10

• Amount of blood left at the end of systole after the heart has contracted
• Empty heart

Question 11

End Diastolic Volume

Answer 11

• Amount of blood at the end of diastole before the heart contracts
• Full heart

Question 12

Effects of Exercise on the Heart

Epi, HR, Contractility, SV, Venous return, CO, filling time, coronary ar

Answer 12

• Increase in Epinephrine, which increases heartrate, contractility, venous return, and stroke volume
• Cardiac output increases up to 5x to 25L/min
• Filling time decreases
• Coronary Arteries dilate so the heart muscle gets adequate blood flow

Question 13

Effects of Fitness on the Heart

Answer 13

• Bigger heart
• Decreased resting heartrate
• Bigger coronary arteries
• More collateral blood vessels (decreased risk of ischemia)
• Cardiac Remodelling

Question 14

Cardiac Remodelling

Answer 14

• Increase in ventricle space
• Pathological: Fibrosis, muscle death and thinning, due to high BP, heart failure, or infarct
• Physiological: Thicker muscle, no dysfunction, consequence of training or pregnancy

Question 15

Capillary Fluid Exchange

Hydrostatic pressure, Osmotic pressure,

Answer 15

• Hydrostatic = blood pressure, moves fluid into tissue
• Osmotic net pressure = cell pressure, moves fluid back into capillaries

Question 16

Blood Presure Hormones

Answer 16

• Renin-Angiotensin system
• Angiotensin causes vasoconstriction
• Renin causes angiotensin II production, which increases ADH and Aldosterone
• ADH increases water reabsorption
• Aldosterone increases Na reabsorbtion

Question 17

Chemoreceptors

Answer 17

• Peripheral in aortic arch and carotid sinuses, detect increase in H+ and CO2, sometimes very low O2
• Central in medulla, monitor CSF for high H only because CO2 does not cross blood brain barrier

Question 18

CO2 Transportation

Answer 18

• Little dissolves in Plasma, some carried on HB, most transported as bicarbonate
• CO2 + HB -> HbCO2
• CO2 + H2O -> H2CO3 -> HCO3- + H+
• Chloride shift pushes HCO3- out of the cell while drawing Cl in to alance it & vice versa

Question 19

Acidosis

Answer 19

• Hindered ventilation
• CO2 buildup
• H+ buildup
• pH will drop
• Kidneys pee out extra H+
• Breathing rate corrects for metabolic acidosis

Question 20

Alkalosis

Answer 20

• Hyperventilation
• CO2 lost but not replaced with O2
• No reflex to breathe slowly
• Loss of H+
• Body becomes alkalotic
• Kidney corrects for respiratork Alkalosis, breathing rate corrects for metabolic alkalosis

Question 21

Layers of the Heart Wall

Answer 21

• Epicardim on the outside
• Myocardium muscle layer
• Endocardium inside

Question 22

Single Cartilages of the Larynx

Answer 22

• Epiglottis
• Thyroid (big anterior cartilage, adam’s apple)
• Cricoid (ring under thyroid cartilage)

Question 23

Arytenoid Cartilages of the Larynx

Answer 23

• Influence the positions and tensions of the vocal cords

Question 24

Lung Hilus

Answer 24

• Where bronchi, blood vessels, nerves enter and exit

Question 25

How Many Lobes in Each Lung

Answer 25

- Right lung has three lobes - Left lung has 2 - Each lung has a oblique fissure - Right lung has horizontal fissure

Question 26

Respiratory Cell Types

Answer 26

- Type I cell: simple squamous epithelium - Type II cell: Surfactant secreting cell - Macrophages present

Question 27

Respiratory Brain Centers

Answer 27

- Pre-Botzinger complex generates resp rhythm - Apneustic center overrides for longer breaths - Pneumotaxic center overrides apneustic center when breath has been held for too long

Question 28

Hering-Breuer Reflex

Answer 28

- Stretch receptors prevent overinflation

Question 29

Surfactant

Answer 29

- Decreases alveolar fluid surface tension to prevent alveolar collapse - Premature infants have little surfactant so they have respiratory distress

Question 30

Lung Compliance

Answer 30

- Expandability of the lungs - Change in volume in response to a given change in pressure - Effort required to distend the lungs - Usually pretty high because the lungs have lots of elastin and surfactant - Diminished by nonelastic scar tissue, reduced surfactant, decreased thoracic cage flexibility

Question 31

Lung Recoil

Answer 31

- How the lungs rebound after being stretched - Depends on collaged in lung tissue ad alveolar surface tension - This is why some surface tension is a good thing