Practical Exam 2 PhysioEx

Question 1

What happens if the frog heart is stimulated during the relaxation phase of the contraction cycle?

Answer 1

and extrasystole (extra ventricular contraction) can be created

Question 2

What would prevent the heart from pumping blood properly? (2)

Answer 2

tetanus and wave summation

Question 3

Without what phase, will blood flow from the heart stop? Why?

Answer 3

relaxation; it allows the ventricles to fill with blood

Question 4

the long refractory period of cardiac muscle prevents…(2)

Answer 4

tetanus and wave summation

Question 5

stimulation of the vagus nerve does what to the heart rate?

Answer 5

decreases it

Question 6

how does the vagus nerve conduct signals to the heart?

Answer 6

parasympathetic division of the autonomic nervous system

Question 7

what would happen if the vagus nerve is severed?

Answer 7

the heart rate would increase because it would no longer be slowed by the parasympathetic division

Question 8

what can occur if the vagus nerve is stimulated too much?

Answer 8

vagal escape

Question 9

vagal escape

Answer 9

caused by the sympathetic reflexes or initiation of a rhythm by the Purkinje fibers

Question 10

why is Ringer solution required to maintain heart contractions?

Answer 10

since it contains ions like chloride, sodium, potassium, calcium, and magnesium needed for the cardiac cells to undergo contractions

Question 11

what does a decrease in temperature do to heart rate?

Answer 11

decreases it

Question 12

what does a increase in temperature do to heart rate?

Answer 12

increases it

Question 13

_____ and _____- an adrenergic chemical modifier, increases heart rate similar to sympathetic stimulation

Answer 13

epinephrine, atropine

Question 14

both _____ and _____ are cholinergic chemical modifiers that function similar to acetylcholine- reducing heart rate

Answer 14

pilocarpine, digitalis

Question 15

ions can be _____ and/or _____

Answer 15

chronotropic, inotropic

Question 16

addition of _____ to the ringer solution caused an increase in heart rate

Answer 16

calcium

Question 17

calcium is a _____ chronotropic and ______ inotropic agent

Answer 17

positive, positive

Question 18

what is a way to reduce blood pressure?

Answer 18

using calcium channel blockers that reduce heart contraction force and rate

Question 19

what are calcium ions important for in cardiac muscle cells? (2)

Answer 19

• plateau of the action potential in myocardiocytes
• also used during active muscle contraction

Question 20

addition of _____ and _____ to the ringer solution caused the heart rate to decrease and then become erratic, why?

Answer 20

sodium, potassium
- these are involved in the depolarization and repolarization phases

Question 21

during obstructive diseases such as _____ _____ and ____, the airway radius decreases

Answer 21

chronic bronchitis, asthma

Question 22

what can you measure to tell if someone has chronic bronchitis or asthma?

Answer 22

forced expiratory volume (FEV)

Question 23

what is indicative of an obstructive problem and not a restrictive problem?

Answer 23

as airway radius decreases, there was a corresponding decrease in the FEV

Question 24

people suffering from _____ have lungs that have less elastic recoil

Answer 24

emphysema

Question 25

what causes the residual volume to increase in those with emphysema?

Answer 25

inspiration becomes easier, (greater compliance), expiration requires more muscular effort, leaving more air inside the lungs

Question 26

people suffering from _____ experience greater resistance to inspiration and expiration

Answer 26

asthma

Question 27

what do athma treatments do?

Answer 27

the cause dilation (relaxation of the smooth muscle) of the airways to reduce resistance to airflow

Question 28

what is used to diagnose if a person is suffering from obstructive or restrictive lung disease?

Answer 28

FEV1/FVC ratio

Question 29

what is a normal FEV1/FVC ratio?

Answer 29

80%

Question 30

people suffering from emphysema or acute asthma have _____ respiratory system and have a FEV1/FVC ratio of less than 80%

Answer 30

obstructive

Question 31

the intrapleural pressure is normally _____ than the air pressure within the alveoli

Answer 31

less

Question 32

what happens if the intrapleural pressure and alveolar pressure are equal?

Answer 32

the lung collapses

Question 33

the alveoli are coated in a fluid that does what? (2)

Answer 33

- protect them - promote gas exchange

Question 34

at a gas-liquid boundary, molecules in a fluid tend to..

Answer 34

stick together, creating surface tension

Question 35

what substance is released by septal cells in the alveoli to decrease surface tension there?

Answer 35

surfactant

Question 36

the more surfactant added, the _____ the reduction of surface tension and the _____ the flow rate

Answer 36

greater, greater

Question 37

what happens if surfactant is absent?

Answer 37

this is seen in premature infants, the surface tension in the alveoli would be too high to allow them to fill with air

Question 38

since the pleural cavity exerts _____ pressure than the air pressure inside the alveoli, they remain inflated

Answer 38

less

Question 39

enzymes

Answer 39

mostly proteins that help catalyze chemical reactions

Question 40

what can affect enzyme function? (2)

Answer 40

pH and temperature

Question 41

what could happen if you boil and enzyme?

Answer 41

it might unfold, and upon cooling it might not fold back properly and lose its function, this is seen in tube 1

Question 42

what happens if you freeze an enzyme?

Answer 42

nothing, it will retain its structure and function upon thawing, as seen in tube 2

Question 43

what was IKI used for?

Answer 43

to detect the presence of starch

Question 44

what was Benedict's reagent used for?

Answer 44

to detect the presence of reducing sugars like glucose of maltose

Question 45

what shows that amylase works well at pH 7?

Answer 45

in tube 3, all of the starch hydrolyzed into monosaccharide components (glucose) since the IKI test was negative while the Benedict's test was positive

Question 46

what happened in tubes 7 and 8?

Answer 46

both the IKI and Benedict's tests were positive - they had different pH buffers causing amylase functions to decrease

Question 47

what was tube 5?

Answer 47

it was a control to ensure that the starch did not spontaneously break down into glucose and required the presence of functional amylase to hydrolyze

Question 48

what was tube 6?

Answer 48

it was a control to ensure that the Benedict's test was detecting the presence of reducing sugar, this was maltose

Question 49

what was tube 4?

Answer 49

it was another control, this tube lacked starch so it was to ensure a positive IKI and Benedict's test were due to the presence of starch and its reducing sugar and not because of the presence of the amylase of the buffer

Question 50

cellulose

Answer 50

a polysaccharide that is composed of glucose linked in a different fashion than starch

Question 51

what result from the IKI test would occur if there is cellulose present?

Answer 51

a positive one

Question 52

will amylase break down cellulose? why or why not?

Answer 52

no, it's glucose molecules are linked in a different fashion