Edema and Exercise Physiology

Question 1

Edema is an abnormal accumulation of ____fluid in the ________ ______ of tissues.

Answer 1

Extracellular

Interstitial spaces

Question 2

Fill in the blanks

Which one is the major force? What prevents fluid from accumulating when everything is working as it should?

Answer 2

Red: Hydrostatic (MAJOR force)

Blue: Plasma colloid osmotic/oncotic

Fluid accumulation is prevented by lymphatic drainage

Question 3

What 2 questions do you ask yourself to determine whether edema is present?

Answer 3

1. Do we have visible enlargement?
2. Does it pit? (Pitting = Edema)

Question 4

What is an example of a breed of horse is bred to be an endurance horse? What about a sprinter?

Answer 4

Thoroughbred, Arabian (endurance)

Quarterhorse (sprinter)

Question 5

How is the athletic prowess of mammals evaluated? What is this in a fit racehorse?

Answer 5

O2 comsumption (VO2 max)

160 ml/kg/min

Question 6

What are the 3 major pathways for energy supply to muscles?

Answer 6

Creatine phosphate pathway

Anaerobic glycolysis

Aerobic glycolysis and fat oxidation

Question 7

How does the maximum heart rate of cows and horses compare? What about cardiac output? How do the lungs of these species compare?

Answer 7

Similar max HR

Horses have a heart CO and SV than cows

Horse lungs are twice the size and 1.6 times the surface area of cow lungs

Question 8

The aerobic pathway involves the ____ ________ of FFAs mobilized frrom adipose tissue and stored in muscle. It produces 3 times ______(more/less) ATP than the other pathways at a much ______(slower/faster) rate.

Answer 8

The aerobic pathway involves the BETA OXIDATION of FFAs mobilized frrom adipose tissue and stored in muscle. It produces 3 times MORE ATP than the other pathways at a much SLOWER rate.

Question 9

Horses have higher intramuscular ______ than other species.

Answer 9

Glycogen

Question 10

________ (process) breaks down glucose to generate _____ and _____ in the cytoplasm. It generates _____ (small/large) amounts of ______ rapidly and inefficiently.

Answer 10

ANAEROBIC GLYCOLYSIS breaks down glucose to generate LACTATE and ATP in the cytoplasm. It generates SMALL amounts of ATP rapidly and inefficiently.

Question 11

Which pathways is most fully engaged when the horse is working at sub-maximal capacity? What type of horse relies most heavily on this pathway? What diets are best for these horses?

Answer 11

Aerobic pathway

Endurance horses

High fat diets

Question 12

Does training a horse anaerobically or aerobically (potentially) confer an improved output?

Answer 12

Aerobically

Question 13

The ______ pathway generates tremendous amounts of ATP however it is only sustained for a few sections. In these initial seconds of exersize, the ________ pathway “comes up to speed”.

Answer 13

The PHOSPHOCREATINE pathway generates tremendous amounts of ATP however it is only sustained for a few sections. In these initial seconds of exersize, the ANAEROBIC pathway “comes up to speed”.

Question 14

Is more fat used up at submaximal (30% VO2max) or maximal (60% VO2max) exercise intensity?

Answer 14

Submaximal

Question 15

What types of muscle fiber are most related to stance? Which limbs have more of these fibers?

Answer 15

Type 1

Front limbs

Question 16

Which types of fibers are fast oxidative glycolytc fibers that sustain high power for prolonged periods?

What fibers are 3 times faster than those described above and are adapte for high power output for a limited duration?

What is the intermediate fiber between the two describes above called?

Answer 16

IIA

IIX

IIAX

Question 17

How does a horse increase the oxygen carrying capacity of their blood temporarily?

Answer 17

Splenic contraction

Question 18

Training a horse increases it’s baseline _____ to a maximum of +____%.

Answer 18

PCV

50

Question 19

What happens if a horses PCV is increased too much?

Answer 19

Blood becomes overly viscous (sludgy)

Question 20

What is the baseline heart rate of a fit horse? At maximum intensity, how much can the rate increase?

Answer 20

25 bpm

10 times (220-250 bpm)

Question 21

What occurs when increasing the negative air pressure within the thorax during inspiration?

Answer 21

Cardiac output increases because SV is increased due to increased venous return.

Question 22

What can manifest if diastole is shortened to increase stroke volume, caused by decreased myocardial perfusion?

Answer 22

Arrythmias

Question 23

What is the limiting factor for maximal exercise?

Answer 23

Respiratory capacity

Question 24

What occurs in racehorses because their respiratory system cannot keep up during maximal exercise?

Answer 24

Exercise Induced Pulmonary hemorrhage (EIPH)

Question 25

At moderate to high speed, the respiration rate of a horse is linked with _____ frequency. What is the max rate?

Answer 25

Stride 130 per min (breaths and stides)

Question 26

Why are racehorses running at maximum intensity hypoxemic?

Answer 26

Diffusion limitation- RBCs are zipping through the capillaries too quickly to fully saturate with oxygen

Question 27

What muscle fibers deplete first in endurance horses? Racehorses? What else causes muscle fatigue in horses?

Answer 27

Type 1 (then type II) Type IIX fibers **Significant acidemia** caused by high lactate production impairs **ATP-producing pathways** and causes **heat stress (internal hyperthermia in combination with humidity).**

Question 28

What are some causes of poor performance in horses?

Answer 28

**_Musculoskeletal_** * Clinical rhabdomyolysis ('Tying up'/ Monday Morning Disease) * Subclinical myopathies * **Lameness (#1 CAUSE OF POOR PERFORMANCE/Excerisize intolerance)** _Respiratory_ (**Second most common**) * **Dynamic airway obstructions** * Displaced dorsal soft palate (DDSP) * Dynamic pharyngeal collapse * Laryngeal hemiplasia * Nasal collapse _Cardiac_ (**3rd most common)** * Arrythmias * Exercise induced myocardial dysfunction _Other_ * Diaphragmatic flutters * Anhydrosis * Jugular vein thrombosis * Mediastinal lymphosarcoma

Question 29

What are the two types of standard exercise tests that utilize a treadmill?

Answer 29

Incremental exercise test Run to fatigue test

Question 30

How is lactate used to to assess athletic ability?

Answer 30

It reveals the animals **anaerobic capability** Measure speed at which lactate reached 4mmol/L Or measure amximum lactate level they can reach before fatigueing Can be used to monitor how fitness is improving due to training

Question 31

How is performance potential assessed?

Answer 31

1. **Heart sizes** Heart score ECG evaluation (Bigger=better) 2. **Muscle biopsy** Look for inherited abnormalities and muscle composition 3. **Inter-mandibular width** (More narrow= more resistance to airflow= poorer potential) 4. Treadmill testing (***Note: Do not underestimate "Will to Win", can't really predict that)***

Question 32

How is the lower respiratory tract evaulated?

Answer 32

**Bronchialveolar lavage** ## Footnote (Looking for signs of inflammation- i.e. cell population showing some or all of the followng: **NO\>5%, EO\>1%, MC\>2%**)

Question 33

The presence of what in a BAL is supporting of a diagnosis of EIPH?

Answer 33

Hemosiderophages