Edema and Exercise Physiology Flashcards
Edema is an abnormal accumulation of ____fluid in the ________ ______ of tissues.
Extracellular
Interstitial spaces
Fill in the blanks
Which one is the major force? What prevents fluid from accumulating when everything is working as it should?
Red: Hydrostatic (MAJOR force)
Blue: Plasma colloid osmotic/oncotic
Fluid accumulation is prevented by lymphatic drainage
What 2 questions do you ask yourself to determine whether edema is present?
- Do we have visible enlargement?
- Does it pit? (Pitting = Edema)
What is an example of a breed of horse is bred to be an endurance horse? What about a sprinter?
Thoroughbred, Arabian (endurance)
Quarterhorse (sprinter)
How is the athletic prowess of mammals evaluated? What is this in a fit racehorse?
O2 comsumption (VO2 max)
160 ml/kg/min
What are the 3 major pathways for energy supply to muscles?
Creatine phosphate pathway
Anaerobic glycolysis
Aerobic glycolysis and fat oxidation
How does the maximum heart rate of cows and horses compare? What about cardiac output? How do the lungs of these species compare?
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
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.
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.
Horses have higher intramuscular ______ than other species.
Glycogen
________ (process) breaks down glucose to generate _____ and _____ in the cytoplasm. It generates _____ (small/large) amounts of ______ rapidly and inefficiently.
ANAEROBIC GLYCOLYSIS breaks down glucose to generate LACTATE and ATP in the cytoplasm. It generates SMALL amounts of ATP rapidly and inefficiently.
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?
Aerobic pathway
Endurance horses
High fat diets
Does training a horse anaerobically or aerobically (potentially) confer an improved output?
Aerobically
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”.
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”.
Is more fat used up at submaximal (30% VO2max) or maximal (60% VO2max) exercise intensity?
Submaximal
What types of muscle fiber are most related to stance? Which limbs have more of these fibers?
Type 1
Front limbs
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?
IIA
IIX
IIAX
How does a horse increase the oxygen carrying capacity of their blood temporarily?
Splenic contraction
Training a horse increases it’s baseline _____ to a maximum of +____%.
PCV
50
What happens if a horses PCV is increased too much?
Blood becomes overly viscous (sludgy)
What is the baseline heart rate of a fit horse? At maximum intensity, how much can the rate increase?
25 bpm
10 times (220-250 bpm)
What occurs when increasing the negative air pressure within the thorax during inspiration?
Cardiac output increases because SV is increased due to increased venous return.
What can manifest if diastole is shortened to increase stroke volume, caused by decreased myocardial perfusion?
Arrythmias
What is the limiting factor for maximal exercise?
Respiratory capacity
What occurs in racehorses because their respiratory system cannot keep up during maximal exercise?
Exercise Induced Pulmonary hemorrhage (EIPH)
At moderate to high speed, the respiration rate of a horse is linked with _____ frequency. What is the max rate?
Stride
130 per min (breaths and stides)
Why are racehorses running at maximum intensity hypoxemic?
Diffusion limitation- RBCs are zipping through the capillaries too quickly to fully saturate with oxygen
What muscle fibers deplete first in endurance horses? Racehorses? What else causes muscle fatigue in horses?
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).
What are some causes of poor performance in horses?
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
What are the two types of standard exercise tests that utilize a treadmill?
Incremental exercise test
Run to fatigue test
How is lactate used to to assess athletic ability?
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
How is performance potential assessed?
-
Heart sizes
Heart score
ECG evaluation
(Bigger=better) -
Muscle biopsy
Look for inherited abnormalities and muscle composition - Inter-mandibular width (More narrow= more resistance to airflow= poorer potential)
- Treadmill testing
(Note: Do not underestimate “Will to Win”, can’t really predict that)
How is the lower respiratory tract evaulated?
Bronchialveolar lavage
(Looking for signs of inflammation- i.e. cell population showing some or all of the followng: NO>5%, EO>1%, MC>2%)
The presence of what in a BAL is supporting of a diagnosis of EIPH?
Hemosiderophages
