Zool 241 final Flashcards

1
Q

Diving Duration Frequency

A

It’s energetically costly and painful to dive for a long period of time. It must be worth the cost!

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2
Q

Hemoglobin

A

Heme: an organic ring containing an iron molecule, which can bind to O2 Within red blood cells (RBC)

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3
Q

Hemoglobin-O2 Equilibrium Curve

A

P50 is like Km for enzymes! It shows binding affinity for O2

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4
Q

Diving in mamals aerobic or anaerobic

A

Dive is aerobic because lactic acid is constant. After the dive, lactic acid washout- deal with consequences of being underwater

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5
Q

Spike in lactic acid

A

Spike in lactic acid after dive- EPOC, INCURRING AN OXYGEN DEBT DUING DIVE AND DEAL WITH REPRUCCUSSIONS AFTER dive.

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6
Q

Bradycardia

A

A near instantaneous reduction in HR (bradycardia)

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7
Q

Grey seal HR on land

A

119beats/min

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8
Q

Why is this drop in heart rate important?

A

minimize use of oxygen, metabolic rate, not wasting energy transferring blood throughout the body -Oxygen is restricted to where its needed most -BRAIN oxygen is not restricted during dive. CANNOT CUT OFF OXYGEN AND ENERGY SUPPLIES. Chronic tissue damage occurs very fast, have to keep glucose in the brain - Others not as crucial, have some oxygen to keep them alive - Only need brain and muscles for movement - Lungs not as necessary- collapse of lungs further restrict amount of oxygen

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9
Q

Why not storing oxygen in the lungs?

A

For humans, we have to transport oxygen to the muscles which takes a faster heart rate. Diving ANIMALS already store oxygen in muscles and blood, so can keep bradycardia and dive longer

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10
Q

Myoglobin

A

P50 is lower than hemoglobin System has to be severely oxygen derived before myoglobin releases oxygen Constant, supplies at a moderate rate, supply of oxygen- beneficial for hypoxic environment Diving have lots of myoglobin- store a lot of oxygen in muscle, have lower heart rate

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11
Q

Spleen stores…

A

storage sites for RBC

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12
Q

Spleen acts as a ____ ______.

A

Acting as scuba tanks, provide more oxygenated blood to diving animals

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13
Q

relationship between norepinephrine and spleen thickness

A

-More time spent in the water- more norepinephrine- reduces spleen thickness (inverse relationship)

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14
Q

Why don’t you just store all RBC in the blood?

A

-You would need a faster heart rate -If all RBC in blood, Viscosity of blood will increase, more energy required to move blood around, cannot be bradycardia -So store RBC in the spleen, transports blood more efficiently

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15
Q

Preventing the bends in diving mammals

A

-When you resurface quickly, pressure goes down suddenly, components of nitrogen will bubble in your blood Diving mammals: They allow lungs to collapse, air is trapped in trachea, bronchus and bronchioles -Prevents oxygen from forcibly mixing with blood, slows buildup of pressure, helps prevent the bends.

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16
Q

Antioxidant radicals when resurfacing

A

Diving increase radicals after resurfacing -By-product of aerobic metabolism during EPOC for diving animals -Radicals will increase in this process -Enzymes to the rescue: antioxidant enzymes help with these problems so they can dive deeper

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17
Q

Solution to antioxidant radicals

A
  • Enzymes to the rescue: antioxidant enzymes help with these problems so they can dive deeper
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18
Q

Why dive deeper?

A

More access to food Less predators in deeper water

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19
Q

Myoglobin found in what tissue

A

muscle tissue

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20
Q

Myoglobin in diving mammals is a ___ relationship whereas in humans, it is _____ more dive duration- ____ myoglobin concentration

A

linear hyperbolic

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21
Q

Peripheral vasoconstriction _____ oxygen transport, causing muscle tissue to become ______ thus decreasing P50 of oxygen in the muscle, then

A

decreases hypoxic Mb will give up bound oxygen supplying the muscle oxygen for aerobic metabolism

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22
Q

Myoglobin has ____ oxygen affinity comapred to hemoglobin, THUS HOLDS _____ to oxygen until it reaches ____-

A

higher affinity to oxygen compared to hemoglobin hold on to oxygen tightly until it reaches hypoxia

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23
Q

what are the 4 response causes of diving?

A

bradycardia(decreased heart rate) Apnea Peripheral vasoconstriction Lactic acid washout

24
Q

Peripheral vasoconstriction definition and maintains flood flow to 3 areas

A

during diving, there is a large decrease in blood flow to peripheral tissues ****maintains blood flow to heart brain and adrenals

25
Q

bradycardia is ___ of resting heart rate

A

1/10 or 10%

26
Q

Lactic acid increases upon submergence - forced dive

A

Dives were first considered to be anaerobic- evidence was a lactic acid washout but NO Only forced dives had lactate washout Forced submergence- stress response, primitive response to asphyxiation

27
Q

ADL stands for ____ ____ _____ and Definition

A

Aerobic Dive Limit Maximum breath-hold that is possible without any increase in blood lactate during or after a dive indicating aerobic metabolism

28
Q

Voluntary dives

A

majority of voluntary dives in seals are entirely aerobic, did not generate lactate

29
Q

Dives exceed ADL, (long dives)

A

they performed anerobic metabolism and started to generate lactate features: -longer between dive recovery times -lactate washout

30
Q

Dives within ADL are advantageous

A

because they minimize time of recovery maximize foraging time

31
Q

Voluntary Dives

A

Dive response is less pronounced most dives are within the ADL Organs continue to function physiological homeostasis is maintained

32
Q

Why is Hypometabolism in dives that exceed ADL lower than expected?

A
  • suppression of metabolism to limit lactate production
33
Q

Hypothermia in diving penguins and diving seals why?

A

certain body regions are intentionally cooled during a dive decrease oxygen demand by decreasing temperature

34
Q

Summary Forced versus Voluntary Dives

A

-Bradycardia was not as pronounced in voluntary dives -Peripheral vasoconstriction was present in both forced and voluntary dives -Lactic acid washout was present in forced dives but only present in voluntary dives that surpassed the ADL

35
Q

Physiological Challenges of Diving

A

-Temperature -Hypoxia -Build-up of metabolic wastes -Increased pressure at depth -Increased solubility of gases -Isolation from oxygen source due to breath-hold

36
Q

RETIA MIRABILIA- cardiovascular adjustments

A
  • a system of closely-aligned blood vessels that allow the animal to trap oxygen via countercurrent exchange Bradycardia and peripheral vasoconstriction together result in significant decrease in blood tissue to the tissues
37
Q

Diving mammals store most of oxygen in ___ and ___

A

blood and muscle, very little in respiratory (lungs)

38
Q

myglobin desaturation, a ____ not a ____. Thus, it _____ releases oxygen from muscle stores

A

linear not a hyperbolic desaturation slowly

39
Q

Myglobin as a ____ store Greater myglobin concentration is associated with ____ aerobic capacity

A

energy supplying the diving animal with a source of fuel for aerobic metabolism increases dive duration - greater

40
Q

Epaxial muscles of the harbor seal

A

Type I (slow twich oxidative lipds for ATP production) and Type IIa (fast twich oxidative but with enhanced anaerobic) DIVING MAMMALS lost Type IIB (fast twich glycolytic- glucose for anaerobic ATP)

41
Q

Swimming Behavior

A
  • During deep dives seals sink rather than propel themselves downwards (up to 90% of the time they are gliding rather than actively swimming)
42
Q

Why diving mammals sink during diving?

A

-This has a clear advantage in terms of energetic costs and conservation of oxygen -This behaviour is more prevalent during times where the animal has smaller fat deposits, and is therefore less buoyant

43
Q

Hematocrit

A

ratio of volume of RBC to total volume of blood increases viscosity of blood

44
Q

Norepinephrine Epinephrine

A

drops heart rate, increases vasoconstruction increases heart rate decreases vasoconstruction During dive, norepinephrine happens

45
Q

catecholamine regulation

A

regulates HR and vasoconstriction

46
Q

Bajou indigenous people and hematocrit

A

optimize blood O2 store higher hematocrit

47
Q

Habour seal vs Dog capillary density

A

harbour seal- 60% reduction in capillary density

48
Q

Oxygen concentration and Lactic acid concentration in muscle and blood

A

Notice that within the first 5-10 minutes, all of the O2 in the muscles were used up, while we see arterial blood O2 is still high and only is low after 20 or so minutes Once muscle O2 are used up, they undergo anaerobic metabolism producing lactic acid

49
Q

•Why does arterial blood oxygen content decrease more gradually?

A

Because muscle not perfused with blood, O2 can’t move from blood to muscle, instead muscles use up O2 within itself and it’s drained quickly.

50
Q

•what is ADL?

A

longest time one can dive without running out of O2 (aka. when blood [lactate] increases)

51
Q

•Why does [lactic acid] stay low in the blood?

A

Because blood moves to only to a few places (brain, heart, lung), arterial blood PO2 drops much slowly and lactic acid build ups is a lot slower

52
Q

What happens to lactate after a dive?

A

Vasoconstriction stops when dive is completed, and lactate within muscle release into blood to become metabolized once they resurface following concentration gradient (so initially there is a rise in lactate in blood while lactate in skeletal muscle decreases).

53
Q

what happens in alveoli collapse?

A
  • Air is pushed into non-respiratory bronchioles, bronchi and trachea
  • Gas exchange between lungs and blood can’t occur
  • Good because minimizes O2 depletion and N2 can’t enter blood (prevents bends)

Recall air is mainly made up of N2 and causes bends during diving

54
Q

Insulation

A
55
Q

Lateral rete mirabele

A

as venous blood goes outward from red swimming muscle, it loses heat to the close arterial blood, which carries heat back into the red swimming muscles.

***red muscles produce heat in tuna