NASM CPT 01

NASM CPT 第二章截图

Chapter 2: The basics of exercise science

Definitions that you need to memorize

• Human movement: The kinetic chain (human movement system) is made up of three primary systems. The skeletal system (bones and joints), the muscular system (ligaments, tendons, muscles, and fascia) and the nervous system (peripheral and central nerves).

The nervous system

• Nervous system: One of the primary organ systems in the body. Is a combination of billions of cells that communicate with one another in a network within the body. The central nervous system (CNS) is made up of the spinal cord and brain. The peripheral nervous system (PNS) consists of nerves that connect the spinal cord and brain to the rest of the human body.
• Sensory function: The ability of the nervous system to notice changes in their external or internal environment. This is one of the three main functions of the nervous system.
• Integrative function: The ability that the nervous system has to interpret and analyze sensory information. This allows for adequate decision-making and producing the correct response.
• Motor function: This is the neuromuscular (Muscular and nervous system) response to sensory information. For example your body’s response by muscular contraction when you touch burning hot metal.
• Proprioception: This is the cumulative sensory input to the CNS (Central nervous system) from all of the various mechanoreceptors that can sense limb movement and body position. Proprioception training improves coordination, posture, and balance.
• Neuron: This is the functional unit of the nervous system. The nervous system is made up of billions of neurons. This allows it to communicate outside with the environment as well as internally with itself. Neuron’s transmit impulses through chemical and electrical signals. Neuron’s form the core of the spinal cord, brain and peripheral ganglia that make up the nervous system. A neuron has three main parts: Cell body, axon, and dendrites.
• Sensory neurons (afferent): This is a type of nerve cell that conducts impulses to the central nervous system from a sense organ.
• Interneurons: Interneurons send nerve in pulses between one another.
• Motor neurons (efferent): This is a type of nerve cell that sends impulses to glands, muscles and other effectors. Stimulates muscle contraction to initiate movement.
• Central nervous system and Peripheral nervous system: The CNS or central nervous system is made up of your brain and spinal cord. The PNS or peripheral nervous system branches out from your central nervous system to connect it with the rest of your body.
• Mechanoreceptors: Specialized receptors that respond to pressure inside of tissues and transmit signals through sensory nerves. These respond to forces such as motion, sound waves, pressure, stretching and touch. It can sense the various distortions in the human body.
• Muscle spindles: These are sensory receptors that sit parallel to muscular fibers. These special spindles are able to detect the length of a muscle and how fast it changes length. This helps to regulate the contraction of muscles by way of the stretch reflex mechanism. Its purpose is to help prevent and protect over stretching that could lead to muscular damage.
• Golgi tendon organs: Golgi tendon organs or GTO is another type of specialized sensory receptor. They are found where tendons attached to skeletal muscular fibers. These receptors can sense the change in muscular tension and the rate that this tension changes. When you activate the Golgi tendon organ it will cause a muscle to relax. This is to help prevent injury from excess stress and contraction.
• Joint receptors: These receptors are located around the joint capsule. They respond to acceleration, deceleration, and pressure at the joint. They are able to sense extreme joint positions and send signals in order to prevent injuries.

The skeletal system

• Skeletal system: This is the body’s framework that is comprised of joints and bones. It provides the focus and shapes for bodies. It also creates blood for the human body and stores minerals. The functionality, growth, and maturation of the skeletal system can be affected by activity, nutrition, and posture.
• Bones: Provide protection for vital organs and a resting place for muscles.
• Joints: These are the junctions for muscles, bones and connective tissues where movement occurs. It is also known as articulation.
• Axial skeleton: The area of the skeletal system that contains the rib cage, skull, and vertebral column. It consists of 80 bones.
• Appendicular skeleton: This is the area of the skeletal system that consists of the lower and upper extremities. It’s basically the legs, arms, appendage in appendicular. This contains 126 bones.
• Remodeling: This is the process of formation and resorption of bone. Is the process where the older bone is broken down and taken away by osteoclasts and new bone is made to replace it with cells called osteoblasts.
• Osteoclasts: The cells that help remove bone tissue.
• Osteoblasts: The cells that help create new bone tissue.
• Epiphysis: located at the end of long bones and a place that contains a large portion of red marrow involved in the production of red blood cells. This is one of the main locations for bone growth.
• Diaphysis: This is the long portion of the bone that is considered the shaft. It is much more compact and strong.
• Epiphyseal plate: This is the area of the long bone that connects the epiphysis to the diaphysis. This is a dividing layer of cartilage in cells that grow lengthwise to create the diaphysis.
• Periosteum: This is the dense and fibrous outer layer where muscles attach and a more delicate layer inside that can create bone.
• Medullary Cavity: This is the location where bone marrow is stored and where blood cell formation happens. Is a small cavity that is located in the shaft of the bone.
• Articular Cartilage (Hyaline): This is the inelastic, flexible yet firm type of connective tissue that is located at the end of bones at the joint.
• Depressions: These are flat areas of a bone.
• Processes: This is a part of the bone where ligaments in muscle attach.
• Vertebral column: Made up of 24 bones that create the spinal column. There are 5 lumbar, 12 thoracic and 7 cervical.
• Arthrokinematics: This is the description of joint surfaces when bones are put through a range of motion.
• Synovial joints: These are joined bones that have a fibrous joint capsule. These joints produce synovial fluid that kind of looks like egg whites to protect the joints. Approximately eighty percent of joints in the human body are synovial joints.
• Non-synovial joints: These are joints that are non-movable and exclude the joint cartilage, capsule, and ligaments. Mostly found in the distal joint of the fibula and tibia as well as the skull.
• Ligaments: This is what connects bones to other bones and helps joint support.

The muscular system

• Muscular system: The full collection of all of the muscles in the human body.
• Epimysium: This is the layer of muscular connective tissue on the outside.
• Perimysium: This is the muscular connective tissue in the middle that encompasses the muscle fascicle.
• Endomysium: The deepest layer of the muscular connective tissue that covers muscle fibers.
• Tendons: Connect skeletal muscles to the bone with a band of white, inelastic, dense and tough band of tissue.
• Sarcomere: This is the functional unit of a muscle that produces contractions. It is comprised of actin and myosin. This is the repeating section of a muscle.
• Neural Activation: This is the process of nervous system activation of a muscle fiber by the means of the neuromuscular junction.
• Motor unit: The motor neuron as well as all of the muscle fiber that it innervates.
• Neurotransmitters: These are small chemical messengers that are able to cross the neuromuscular synapse (junction) in order to transmit these and electrical impulses from the nerve to the muscle.

Muscle fiber types

• Type I (slow twitch): These are also known as endurance fibers. They are smaller, produce less power, receive more oxygen and are more mitochondrial dense.
• Type II (fast twitch): These do not have as much endurance, have less oxygen delivery, have short-term contractions, can produce more force and power and are larger than type I fibers.
• Type IIx: These have a low oxidative capacity and or quick to fatigue.
• Type IIa: These have a higher oxidative capacity and will fatigue slower than type IIx. Another name for these is intermediate fast twitch muscle fibers.

Excitation-contraction coupling

This is the process where the nervous system stimulates a muscle in the body to contract. Another name for it is the sliding filament theory. The steps that are seen in the NASM textbook provide 10 different steps from the initiation until the end of the contraction. Here are five steps so that you can more easily memorize the process.

1. Ach is released and binds with receptors that starts an action potential down the T Tubula.
2. This action potential initiates a calcium release (Ca2+).
3. The calcium then binds with troponin which stops the blocking action of tribal myosin that exposes the active binding site for actin.
4. The next thing that occurs is contraction by the myosin cross bridges that alternately detach and attach to actin. This brings the filaments closer to the middle of the sarcomere. In order for actin and myosin to detach every quires ATP.
5. The last step is that Tropomyosin comes back to its location and covers the actin active site. At this point, no more contractions happen.

Muscles as movers

There are 4 primary functions that muscles are categorized into. These are stabilizer, synergist, and agonist.

• Agonist: This is the prime mover
• Synergist: This assists and helps the prime mover
• Stabilizer muscles: These help with stabilizing the joints and the body during movement
• Antagonist: These muscles relax in order to permit the prime mover to do its work.

NASM CPT 第二章截图

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