Notes On Oxygen Consumption

Submitted By haleighnichole
Words: 519
Pages: 3

10/19 Notes
4. Recovery
a) Excessive post exercise oxygen consumption (EPOC)
1. Oxygen reserves of myoglobin (oxygen storage molecule in muscle)
2. Lactic acid build up
3. Glycogen stores
4. ATP and creatine phosphate
b) Heat production
-only 40% of energy is used, the rest is lost as heat
-sweat and heat radiation diffuse excess heat
E. Strains, Tears, and Sprains
1. Strain-the muscle is over stretched and may be torn. Also called a “pulled muscle.” Inflammation of muscle can cause joints to be immobilized.
2. Tear- a tear can occur on the cartilage, muscle tendons, or ligament and also causes inflammation.
3. Sprain- the reinforcing ligaments of a joint are strained or torn. Healing takes longer because ligaments are poorly vascularized.

I. Smooth Muscle
A. Structure
-spindle shaped cells of various sizes
-only have endomysium which contain blood muscle and nerves
-generally arranged in 2 layers
1. Longitudinal- fibers run parallel and constrict the organ and cause dilation
2. circular- fibers run around the circumference and cause constriction of the lumen and elongation
-Peristalsis- is the alteration of circular and longitudinal contraction that moves substances through the lumen (intestines, uterus, bladder) EX: Chinese finger trap
B. Microstructure
-Varicosities-bulbous swellings of the autonomic nerve fibers
-Caveolae-extensions of sarcolemma
-actin/myosin in diagonal pattern (no sarcomere)
-calmodulin instead of troponin for calcium binding
-dense bodies-intermediate filaments act as an anchor
-less sarcoplasmic reticulum
-Myosin kinase-(phosphorylates the myosin)
C. Contraction
1. Varicosities release a neurotransmitter across diffuse neuromuscular junction (synaptic cleft)
2. AP is generated across muscle fibers to initiate synchronized contraction
3. VR channels open, Ca++ flows into cytosol from extracellular fluid or SR
4. Ca++ binds to calmodulin (actin binding sites available)
5. Calmodulin activates myosin kinase
6. Myosin kinase activate myosin ATPase
7. Contraction coupling continues until Ca++ is released from calmodulin and is pumped back into SR and ECF.
D. Same game, Different Name
Smooth Skeletal
-Varicosities-in diffuse -Axon terminal in synaptic cleft neuromuscular junction
-Caveolae-extensions of the -T-tubules and terminal cisterns
-Most Ca++ comes from ECF -Most Ca++ comes from SR
-Actin/Myosin in diagonal pattern - Actin/Myosin in horizontal pattern
-dense bodies