What physiological systems are involved in

make the exercising horse and athlete?

EXERCISE PHYSIOLOGY

RESPIRATORY SYSTEM• Function - Exchange oxygen and carbon dioxide

• Oxygen is used for tissues

• Carbon dioxide is released by those tissues

• Air passes through the trachea to bronchi

• Alveoli

• Functional units where gas exchange occurs

• During inspiration

• Diaphragm and intercostal muscles expand the chest, allowing air to flow in

• The amount of air inspired or expired during a normal breath is referred to as

• Tidal Volume

RESPIRATORY SYSTEM• During exercise, tissues needs for oxygen increases

• Minute volume must increase

• From about 150 L/min to 1500 L/min (during fast gallop)

• At a gallop, respiration rate and stride rate are coupled in a 1:1 ratio

• Expiration occurring when from limbs make ground contact

RESPIRATORY DISORDERS• EIPH

• Exercise Induced Pulmonary Hemorrhage

• Presence of blood in the respiratory tract after exercise

• Referred to as “bleeders”

• Laryngeal Hemiplegia

• Dysfunctional larynx due to nerve damage

• Can be treated surgically

• COPD

• Chronic Obstructive Pulmonary Disease

• Commonly called “heaves”

• Inflammation of the bronchioles

• Caused by moldy hay or straw

CARDIOVASCULAR SYSTEM• Consists of blood, a series of tubes (blood vessels) through which the blood flows, and a

heart which creates the flow of blood

• Blood is composed of

• Red Blood Cells

• Erythrocytes

• White Blood Cells

• Leukocytes

• Platelets

• Cellular elements are called plasma

• Adult horse (1000lbs) contains approx 50 L (13.2 gal) of blood

CARDIOVASCULAR SYSTEM• Cardiac Output (CO)

• Measure of how much blood the heart can pump per minute

• Product of heart rate (HR) times stroke volume (SV)

• HR: 25 – 45 Beats/min

• Average around 32 – 35

• Max 220 – 250 beats/min

MUSCULAR SYSTEM• 3 Categories

• Smooth

• Involuntary & automatic contractions

• Cardiac

• Involuntary & automatic contractions

• Skeletal

• Voluntary & functions in movement of the horse

MUSCULAR SYSTEM• Skeletal Muscle

• Striated in design

• Composed of numerous muscle bundles

• Which make up muscle fibers

• Contain several hundred to several thousand contractile filaments

• Responsible for muscle contraction

MUSCLE FIBERS• Type I

• Slow-contracting fibers

• Low ability to oxidize glucose or glycogen rapidly

• Fatigue resistant

• Utilize fuels in the presence of oxygen

• Long term use

• Nonstrenuous work

• Provide endurance

MUSCLE FIBERS• Type II

• Fast contracting fibers

• Fatigue more quickly

• High glycolytic activity (use glycogen as energy)

• Classified as

• Type IIA

• Type IIB

• Type IIC

• According to myosin structure