EXERCISE PHYSIOLOGY Movement (kinesiology): anatomy . physiology . biochemistry . physics Control of movement: motor control . anatomy . neurophysiology Bioenergetics of movement: biochemistry . endocrinology Control of the bioenergetics of movement: biochemistry . enzymology molecular biology Enhancement of performance: molecular biology . cell biology . signal transduction physics . motor control Movement and health: nutrition . biochemistry biology . immunology . endocrinology . oncology . pathophysiology . toxicology

To deal with all this stuff we need a cellular view of the world

Cells & Stuff

ATP provides energy to build and repair cell structures and membranes. We consume oxygen when the molecules in the food are metabolized to CO2 and H2O and the energy from this process is used to synthesize ATP.

Membranes which surround cells and organelles are very sensitive to physical trauma and chemical attack

Typical Cell Membrane

Cell membranes allow the outside to be different from the inside Ca+ Ca+

A Liver Cell

Microtrabecular Lattice aka: Cytoskeleton

Heart Cells

Kidney Cells

Testes Cells

Organs Cells with the same function are organized as organs: kidney, adrenal, liver, etc. Organs with supporting functions are organized as organ systems: cardiovascular system (heart, veins, arteries), endocrine system (pituitary, hypothalmus, adrenal, pancreas …), etc.

Liver Following Different Treatments Liver from Liver from Liver from Sedentary-Ethanol Control Run-Ethanol

Stores and transmits genetic information in the form of DNA Stores and transmits genetic information in the form of DNA. Genetic information (as messenger RNA) can pass from nucleus into cytoplasm, where amino acids are assembled into proteins Nucleus mRNA

Sequence of DNA molecules codes for a sequence of amino acids of a protein. Different sequences of DNA molecules (genes) code for different proteins. Transcription of DNA sequence into mRNA sequence is tightly controlled by transcription activators and repressors which are in turn controlled by metabolic, hormonal, of other signaling processes.

Endoplasmic reticulum Extensive membranous network of tubules and flattened sheets Granular ER has ribosomes attached, which are the sites of protein synthesis Smooth ER stores and releases calcium Granular ER Smooth ER

Golgi apparatus Series of cup-shaped, flattened membranous sacs associated with numerous vesicles Function is to concentrate, modify and sort newly synthesised proteins prior to secretion from the cell

Mitochondrion 1 m Krebs’ cycle -oxidation of fatty acids Large surface area Selective permeability Electron transport chain 1 m

Active Transport & Life Energy for active transport which maintains cellular integrity comes mainly from mitochondria … If mitochondrial function declines then total cell function declines, possibly resulting in cell death … If a sufficient number of cells die then organ failure results … possibly leading to death of the individual

Active Transport Cells spend a tremendous amount of energy moving compounds into the cell (or into the endoplasmic reticulum) and other compounds out of the cell through Active Transport

Active Transport of Sodium & Potassium

This next set of slides is here to introduce the concept that the reason we get changes with exercise is not to win medals in athletic competition but rather to avoid the toxic effects of exercise.

Membranes & Necrosis Membranes which surround cells and organelles are very sensitive to physical trauma, or to chemical damage caused by oxygen radicals or chemical radicals

An intact cell membrane acts as a barrier for (among other things) charged particles such as calcium.

A damaged cell membrane will allow (among other things) charged particles to enter the cell or organelle.

Membranes & Necrosis Damage to cell membranes or to endoplasmic reticulum membranes allows calcium (and other ions) to leak into cell cytoplasm – increasing osmotic pressure and causing swelling

Membranes & Necrosis Increased membrane permeability leads to swelling of the endoplasmic reticulum and more calcium leaks. Calcium activates lysosomal enzymes which digest lipids leading to more membrane leaks.

Membranes & Necrosis Mitochondria take up calcium and greatly reduce ATP synthesis – leading to poor repair of membranes and increased damage. Mitochondria swell up while cellular membranes fragment and lysosomal enzymes continue to digest cellular components

Membranes & Necrosis When the cell membrane is damaged, or “dying”, the cell synthesizes and releases cytokines which initiate an inflammatory process