Nervous System

Nervous System - The nervous system is the body's control center and communication network within the body. 

Central Nervous System - The brain and spinal cord are the primary structures and are classified as the central nervous system. 

Peripheral Nervous System - The peripheral nervous system (PNS) is composed of the nerve cells and their fibers that branch off from the brain and spinal cord.  The PNS connects the brain and spinal cord with receptors, muscles, and glands. 

Somatic system consists of efferent neurons that transmit messages or impulses to voluntary skeletal muscle under conscious control.

Autonomic system consists of efferent neurons that transmit impulses to involuntary muscles and glands.

The ANS consist of two pathways; the sympathetic pathway and the parasympathetic pathway. 

The sympathetic pathway stimulates visceral activities under stressful conditions, which results in acceleration of metabolism, heart rate, and breathing and adrenal hormone release. 

When the stressful stimulus subsides, the parasympathetic pathways bring the visceral activities back to normal, (i.e. decreasing heart rate and breathing, relaxing the muscles, etc.).  The parasympathetic pathway helps to conserve and restore body resources.

Endocrine System

Endocrine system—system of glands; secretes hormones to regulate bodily function.

Testosterone—anabolic hormone; responsible for male sex traits.
Estrogen—influences fat deposition on hips, buttocks, and thighs; responsible for female sex traits.

Growth hormone—anabolic hormone; responsible for bodily growth up until puberty.

Insulin—regulates energy and glucose metabolism in the body.

Cardiorespiratory System

Cardiorespiratory system—cardiovascular and respiratory systems.  Named for the organs from which it is made: "cardio," which means heart, and "vascular," which represents the blood vessels that carry blood to all parts of the body.  Cardiovascular system is comprised of the heart, blood vessels, and blood. 

Heart is a fist-sized muscle found slightly to the left of your sternum in the chest cavity. 

Cardiac muscle—shorter, more tightly connected than skeletal muscle; involuntary; fires synchronously.

Atria—smaller, superior chambers of the heart; receive blood from veins.

Right atrium—gathers deoxygenated blood returning to the heart.
Left atrium—gathers oxygenated blood from the lungs.

Ventricles—larger, inferior chambers of the heart; pump blood out.

Right ventricle—pumps deoxygenated blood to lungs.
Left ventricle—pumps oxygenated blood to the body.

Arteries—carry blood away from the heart.

Veins—transport blood back to the heart.

Arterioles—small branches of arteries; end in capillaries.

Capillaries—smallest blood vessels; site of gas, chemical, and water exchange.

Venules—very small veins; connect capillaries to larger veins.

Heart rate—the rate at which the heart pumps; average untrained adult = 70-80 bpm.

Stroke volume—amount of blood pumped with each contraction

Cardiac output—volume of blood pumped per minute; heart rate × stroke volume.

Cardiorespiratory Response to exercise:

• Increases—cardiac output, breathing efficiency, oxygen transport and use, use of fats for fuel, mental alertness, ability to relax and sleep, tolerance to stress, lean body mass, metabolic rate.

• Decreases—resting heart rate, cholesterol, blood pressure, and the risks of heart disease, blood clots, depression, anxiety, obesity, and diabetes.

Muscular System

Tendons—connect muscle to bone; provide anchor for muscles to produce force.
Fascia—outer layer of connective tissue surrounding a muscle.

Fascicles—bundle of individual muscle fibers.

Muscle fiber—cellular components and myofibrils encased in a plasma membrane.
Sarcomere—produces muscular contraction; repeating sections of actin and myosin.

Slow twitch (Type I) muscle fibers are small in size and have excellent oxidative (aerobic) properties. 

Fast twitch (Type IIa) muscle fibers are an intermediate type of fiber and are sometimes referred to as FOG (fast oxidative / glycolytic) muscle fibers. 

Fast twitch (Type IIb) muscle fibers are also large fibers, but they depend on glycogen for fuel rather than glucose or fatty acids, and does not use oxygen. 

Recruitment Order - During a normal muscle contraction, muscle fibers are recruited according to the ‘size principle’.

• Small type I muscle fibers recruited first

• Large Type II fibers recruited later when the effort increases

• Size of Type II is approximately twice the size of Type I

Motor unit—one motor neuron and the muscle fibers it connects with.

Energy Systems

Energy- Energy is produced from the food we eat.

Bioenergenics - Study of energy in the body.

Metabolism - The process in which nutrients are acquired, transported, used, and disposed of by the body.

Aerobic—requires oxygen.
Anaerobic—without oxygen.
Adenosine Triphosphate (ATP) - is a substance in a cell used primarily as the source for muscle contraction and force, and is the most immediate source of energy for a cell. 

Energy Systems:

• ATP-PC system – anaerobic alactic system  - immediate source of energy (10 seconds or less), and contributes 8% of the energy supply for maximal activities up to 2 minutes in length.

• Lactic Acid System – anaerobic lactic system  - short-term source of energy (10 seconds to 2 minutes).

• Aerobic System  – long-term source of energy.

Skeletal System

Skeletal system functions—supports, protects, allows bodily movement.

Axial skeleton—skull, rib cage, and vertebral column.

Appendicular skeleton—upper and lower extremities, shoulder and pelvic girdles.
Ligaments—connects bone to bone; little blood supply; slow to heal.

Non-synovial joints—no joint cavity, connective tissue, or cartilage; little to no movement.
Synovial Joints—held together by joint capsule and ligaments; greatest capacity for motion.

Joint types—roll, slide, and spin.

• Hinge—elbows, ankles; sagittal plane movement.

• Ball-and-socket—shoulders, hips; most mobile, all three planes of motion.

anatomical position

Planes of motion

There are three basic imaginary planes that pass through the body. 

 Sagittal plane divides the body or structure into the right and left sides. 

 Frontal plane (coronal plane) divides the body or structure into anterior and posterior portions

 Transverse plane (horizontal plane) divides the body or structure into superior and inferior sections.

Joint movements

Muscle action

Concentric contraction – the muscles shortens (contracts) as it moves against force.

Eccentric contraction - the muscle lengthens in the direction of force.

Static contraction – when no visible movement occurs (concentric or eccentric) and the resistance matches the muscular tension.