Movement Systems Flashcards
Excitation-contraction coupling
The physiological process of converting a neural impulse into a mechanical response.
Action potential
An explosion of electrical activity caused by a neural impulse.
All-or-none principle
The principle stating the strength of a neural electrical signal is independent of the magnitude of the stimulus so long as the neural threshold is achieved.
Cardiac muscle tissue
Striated involuntary muscle tissue found in the heart.
Smooth muscle tissue
Muscle tissue in the gut and internal organs that is involuntarily controlled. It does not fatigue easily and does not contact quickly.
Skeletal muscle tissue
The voluntary muscles attached to bones via tendons (thick fibrous connective tissue) that produces human movement. Contains many nuclei, fatigues easily, and cannot easily sustain prolonged max-effort contractions.
Sarcoplasm
The cytoplasm of a muscle fiber.
Glycogen
The stored form of glucose found in the liver and muscles.
Myofibrils
Parallel filaments that form muscle.
Myofilaments
The filaments of myofibrils composed of actin and myosin.
Actin
The thin filaments of muscle myofilaments where myosin bind to contract muscles.
Myosin
The thick filaments of myofilaments with a fibrous head, neck, and tail that bind to actin.
Sarcomere
The contractile unit of muscle tissue.
Z line
The lateral boundary of the sarcomere where the myofilament actin attaches.
Organelle
Any of a number of organized or specialized structures within a living cell.
Endomysium
The connective tissue covering each muscle fiber. Also contains capillaries and nerves.
Epimysium
Fibrous elastic tissue that surrounds a muscle.
Fasciculi
Bundles of muscle fibers; the singular is “fascicle.”
Perimysium
The connective tissue that covers a bundle of muscle fibers. 150 individual muscle fibers.
Tendons
A strong, fibrous cord made of collagen that attaches muscle to bone.
Periosteum
A dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints.
Neuromuscular junction
The space between a motor neuron and muscle fiber.
Neurotransmitter
A chemical messenger that transmits messages between neurons or from neurons to muscles.
Acetylcholine
The neurotransmitter released by an action potential at the neuromuscular junction.
Sliding-filament theory
The interaction of actin and myosin that describes the process of muscle contraction.
Slow-twitch or type I muscle fibers
Slow-twitch, fatigue-resistant muscle fibers with high mitochondrial density.
Ideal for long endurance activities.
Often called oxidative fibers.
High liability to recruitment
Mitochondria
An organelle with a double membrane and many folds inside responsible for generating the chemical energy needed for biochemical reactions.
The powerhouse of the cell.
Fast-twitch muscle fibers or type II muscle fibers
Fast-twitch fibers contract quickly and with greater force than slow-twitch fibers.
Moderate liability to recruitment
Type IIa Fibers
Fast-twitch, moderately fatigable muscle fibers with moderate mitochondrial density.
Derive energy from anaerobic metabolism (energy made without the presence of oxygen), do not require oxygen to function, and are ideal fibers for longer bouts of anaerobic movement
Type IIx Fibers
Fast-twitch, fast-fatigable muscle fibers with low mitochondrial density.
Fire with great power and strength.
Lower capillary density.
Size principle of fiber recruitment (aka Henneman principle)
Principle stating that motor units are recruited in order according to their recruitment thresholds and firing rates.
Fusiform muscle
Spindle-shaped with a large muscle belly like the biceps muscle
Convergent muscle (aka triangular muscle)
Broad on one end with fibers converging and narrowing on the other end, like the pectoralis major (chest)
Muscle fibers converging from a broad origin (fixed point where the muscle attaches closest to the torso) to a single tendon of insertion (fixed point where the muscle attaches furthest from the torso).
Circular muscle
Surrounds external openings of the body, which are sometimes referred to as sphincters
Parallel muscle fibers
Run parallel along the axis of the muscle, like the sartorius, a long muscle in the thigh
Pennate muscles
Muscles with fascicles that attach obliquely (diagonally)
Penniform muscles
Muscle fibers that run diagonally in respect to the tendon similar to a feather.
Unipennate muscle
Muscle fibers extending from one side of a central tendon.
Bipennate muscle
Muscle fibers extending from both sides of a central tendon.
Multipennate muscle
Muscle fibers extending from both sides of multiple central tendons.
Muscle actions
Force production by a muscle that can result in a change of length (i.e., shortening or lengthening) or no length change at all.
Concentric muscle action
When the length of a muscle shortens as tension is produced.
Eccentric muscle action
When the length of a muscle increases as tension is produced.
Isometric muscle action
When the length of a muscle remains constant as tension is produced.
Stretch-shortening cycle
The cycling between the eccentric (stretch) action of a muscle and the concentric (shortening) action of the same muscle.
Can be improved by implementing plyometrics.
Joint
An articulation between two bones in the body.
Bone marrow
The soft, spongelike tissue in the center of most bones containing stem cells of red or white blood cells or platelets.
Cancellous bone
The meshwork of spongy tissue (trabeculae) of mature adult bone, typically found at the core of vertebral bones and the ends of the long bones.
Supports shifts in weight distribution
Has open spaces that may house bone marrow
Compact bone
A denser material, also known as cortical bone, making up the hard structure of the skeleton.
Made of calcium and minerals.
Can withstand compressive forces.
Fibers are arranged in a honeycomb pattern.
Osteogenesis
The process of bone formation or remodeling.
Cells called osteoblasts play a significant role in this process by depositing new bone material.
Myositis ossificans
A condition when bone tissue forms within a muscle or other soft tissue as a result of trauma or injury.
Cartilage
Firm, flexible connective tissue that pads and protects joints and structural components of the body.
Wolff’s Law
The explanation for bone adaptations as a result of the loads placed on them.
Fibrous joints
Joints with fibrous connective tissue joining two bones that allow for very little movement.
Cartilaginous joints
Moderately movable joints made of fibrocartilage or hyaline cartilage.
Synovial joints
Fluid-filled joints found between bones that move against one another.
Non-synovial joints
Joints that lack a fluid junction.
Articular capsule
The envelope surrounding a synovial joint.
Synovial fluid
A viscous fluid found in the cavities of synovial joints.
Arthrokinematics
The broad term meaning joint motion that can be used in reference to all joint motions.
Close-packed joint position
The most stable joint position, when the connective tissue is taut and neighboring bones have the most contact.
Loose-packed joint position
The less stable joint position represented by any other joint position other than close-packed.
Golgi tendon organ
The proprioceptive sensory organ that senses muscle tension in a tendon and inhibits muscle action.
Feedback loop
The return of a system’s output as input for a future action.
Muscle spindle
The proprioceptive sensory organ that senses muscle stretch in a muscle and promotes muscle action.
Ligament
Tough bands of connective tissue made of collagen and elastin connecting bone to bone.
Help prevent excessive movement within a joint.
Elastin
A highly elastic connective tissue allowing many tissues to retain their shape.
Varus
An abnormal joint movement away from the midline of the body (i.e., bowlegged).
Joint capsule
A thin, strong layer of connective tissue containing synovial fluid in freely moving joints.
Valgus
An abnormal joint movement toward the midline of the body (i.e., knock-kneed).
Periochondrium
The connective tissue enveloping cartilage everywhere except at a joint.
Articular cartilage
A form of hyaline cartilage located on the joint surface of bones.
Blocks pain signals and reduces compressive stress.
Nociceptors
Pain-sensitive nerve endings.
Hyaline cartilage
A transparent cartilage found on most joint surfaces and in the respiratory tract, which contains no nerves or blood vessels.
Fibrocartilage
An elastic and tough tissue containing type I and type II collagen.
Meniscus
A form of fibrocartilage present in the knee, wrist, acromioclavicular, sternoclavicular, and temporomandibular joints.
Elastic cartilage
Flexible cartilage present in the outer ear, inner ear, and epiglottis.
Epiglottis
A piece of elastic cartilage in the throat that opens during breathing and closes during swallowing.
Circulatory system
A closed system circulating blood through the body, consisting of the heart, blood vessels, and blood.
Facilitate the exchange of oxygen and carbon dioxide
Transport of nutrients from the digestive system to body tissues and serves as a clearing house for the biochemical waste products resulting from physical activity
Closed system
A physical system that does not allow for the movement of matter into or out of the system.
Arteries
Blood vessels carrying oxygenated blood away from the heart and to the tissues.
Veins
Blood vessels carrying blood toward the heart to remove waste and pick up more oxygen.
Capillaries
Fine-branching blood vessels forming a network between the arterioles and venules, where transport of nutrients and oxygen or carbon dioxide occurs on a microscopic scale.
Arterioles
The smaller branches of the arteries leading to the capillaries.
Venules
The small branches of the veins gathering blood from the capillaries.
Atrium
One of the two upper cavities of the heart passing blood to the ventricles. The plural is “atria.”
Ventricle
One of the two lower cavities of the heart passing blood to the body or to the lungs.
Pulmonary arteries
Blood vessels moving blood from the heart to the lungs.
Pulmonary veins
Blood vessels returning oxygenated blood to the heart from the lungs.
Aorta
The main artery in the body that supplies oxygenated blood to the circulatory system.
Pulmonary circulation
The blood flow between the heart and the lungs.
Systemic circulation
The blood flow between the heart and the rest of the body.
Superior vena cava
The blood vessel moving blood from the upper body and head to the heart.
Inferior vena cava
The blood vessel moving blood from the lower body to the heart.
Metabolism
All of the chemical processes that occur in the body to support life including converting food into energy.
Atrioventricular (AV) valves (aka tricuspid)
Valves between the atria and ventricles preventing the backward flow of blood during cardiac contractions.
Cardiac cycle
The action of the heart from the start of one heartbeat to the beginning of the next.
Systole
The heartbeat phase where muscle contraction moves blood from the heart chambers to the arteries.
Diastole
The heartbeat phase where the cardiac muscle relaxes and the heart chambers fill with blood.
Sinoatrial (SA) node
The pacemaker of the heart that generates the first electrical signal of a heartbeat and stimulates the atria to contract.
Atrioventricular (AV) node
The nerve node between the right atrium and right ventricle that propagates the electrical signal from the SA note to more distal heart nerves that cause ventricular contraction.
Stroke volume
The amount of blood pumped by the left ventricle of the heart in one contraction.
Heart rate
The number of heartbeats per minute.
Pulse
A rhythmical throbbing of the arteries as blood is propelled through them.
Blood pressure
The force of blood pushing against the walls of the arteries during the two phases of the cardiac cycle.
Systolic
The pressure in blood vessels when the heart beats (ventricular contraction).
Diastolic
The pressure in blood vessels when the heart rests (ventricular filling).
Hypotension
Low blood pressure measuring 90/60 mm Hg or lower.
Hypertension
High blood pressure measuring more than 140/90 mm Hg.
Cardiac output
How much blood the heart is pumping per minute.
Blood volume
The total volume of blood within the circulatory system of an individual.
Peripheral resistance
The vascular resistance of the arteries to blood flow.
Blood viscosity
The thickness and “stickiness” of blood and how it affects its flow through the blood vessels.
Antibodies
Blood proteins that combine with other substances in the body to recognize foreign bodies as part of the immune response.
Lymph
The colorless fluid of the lymphatic system.
Interstitial fluid
The fluid found between cells.
Respiration
The intake of oxygen and subsequent release of carbon dioxide in an organism.
Pulmonary ventilation
The process of exchange of air between the lungs and the ambient air.
Inspiration
Breathing air into the lungs.
Expiration
Breathing air out of the lungs.
Diaphragm
The dome-shaped muscle that separates the lungs and pleural cavity from the abdomen.
Diffusion
The passive movement of molecules or particles along a concentration gradient or from regions of higher concentration to regions of lower concentration.
Thoracic cavity
The chest cavity enclosed by the ribs, sternum, and spinal column.
Intra-alveolar pressure
The pressure within the alveoli that changes throughout respiration.
External respiration
The exchange of gases between the lungs and the blood.
Internal respiration
The process of diffusing oxygen from the blood into the interstitial fluid and into the cells.
Hormones
Chemical messengers stored, created, and released by endocrine glands.
Made of amino acids, lipids, or peptides (chains of amino acids).
Endocrine glands
Ductless glands releasing hormones that remain within the body.
Exocrine glands
Glands that produce and release substances through ducts or openings on the body’s surface.
Amino acids
Simple organic compounds known as the building blocks of proteins.
Steroids
A class of chemicals characterized by their carbon structure, working to reduce inflammation and the activity of the immune system.
Electrolytes
Minerals in the body that have an electric charge.
Glucose
A simple sugar the body uses for energy production on the cellular level.
Insulin
A hormone produced in the pancreas to regulate blood sugar.
Testosterone
A steroid hormone found in both males and females.
Osteoporosis
A skeletal condition that results in weak or brittle bones.
Catabolic
Metabolic activity involving the breakdown of molecules such as proteins or lipids.
Protein synthesis
The process of arranging amino acids into protein structures.
Anabolic
The process of creating larger molecules from smaller units.
Growth hormone
A hormone released by the pituitary gland that stimulates growth in animal cells.
Insulin-like growth factor
A protein similar to insulin that stimulates growth of cells.
Cortisol
A catabolic hormone released in response to physical and emotional stress.
Ketone bodies
Molecules released by the liver in starvation states for an alternate energy source.
Ketosis
A metabolic process that occurs when the body does not have enough carbohydrates for energy; the liver metabolizes fatty acids to produce ketones as a replacement energy source.
Catecholamines
Hormones released by the adrenal glands into the blood as a result of stress.
Peristalsis
The muscular contractions of the smooth muscle of the digestive tract, which moves food through the digestive tract.
Chyme
A pulpy, acidic fluid that moves from the stomach to the small intestines containing partially digested food and gastric juices.
Bile
A bitter greenish-brown alkaline fluid aiding digestion, secreted by the liver and stored in the gallbladder.
Salivary amylase
An enzyme found in saliva that converts starches and glycogen to more simple sugars.
Integumentary system
Organ system protecting the body; composed of skin, hair, and nails.
Epidermis
The outermost layer of the skin.
Dermis
Deep to the epidermis; holds blood vessels, sweat glands, and hair follicles.
Hypodermis
The deepest layer of skin housing fat cells and connective tissues.
