A&P Chapter 4 Flashcards
Thread-like structures that extend from one end of the muscle fiber to the other
Myofibrils
The process by which ions are moved across the cell wall to return to a polarized state
Repolarization
The muscle in a group of muscles that has the major role in movement
Prime Mover
The longest muscle in the human body, it is located in the anterior compartment of the thigh and flexes both the hip and knee when it contracts
Sartorius Muscle
The connective tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers
Perimysium
A bundle of skeletal muscle cells bound together by connective tissue and forming one of the constituent elements of a muscle
Muscle Fasciculus
A condition caused by damage, either through trauma or infection, to the facial nerve, resulting in an inability to move the facial muscles on the affected side
Bell Palsy
A prime mover; a muscle that contracts to provide most of a desired movement
Agonist
An organic compound in muscle tissue that can store and provide energy for muscle contraction
Creatine Phosphate
An iron-containing red pigment, similar to hemoglobin, that is found in muscle fibers
Myoglobin
The repeating patterns of striation units that appear a long each skeletal muscle fiber
Sarcomeres
The bones and voluntary muscles of the body
Musculoskeletal System
Deep muscles of the medial compartment that adduct, flex, and internally rotate the thigh
Pectineus Muscles
A chemical neurotransmitter that serves as a mediator in both the sympathetic and parasympathetic nervous system
Acetylcholine
The thin transparent sheath surrounding a striated muscle fiber
Sarcolemma
An electrochemical event associated with cell membrane depolarization that occurs when a cell or tissue has been activated by a stimulus
Action Potentials
A method of action of muscle contraction involving how sarcomeres shorten, with thick and thin filaments sliding past each other toward the center of the sarcomere from both ends
Sliding Filament Model
The linear muscle of the midline of the abdomen
Rectus Abdominis
An enzyme that causes muscle relaxation by helping to break down acetylcholine
Acetylcholinesterase
Movement of the eyes in various directions
Extraocular Movements
Areas of alternating, colored bands of skeletal muscle fiber
Striations
Muscles of respiration that elevate the first two ribs during inspiration
Scalene Muscles
The component that makes up most of the thick protein filaments of the myofibrils
Myosin
A moveable part of the body to which a skeletal muscle is fastened at a moveable joint
Insertion
One of the two types of smooth muscle, it is formed into sheets of muscle (as in the walls of blood vessels), small bundles of muscles (as in the iris of the eye), or single cells (as in the capsule of the spleen)
Multiunit Smooth Muscle
The short muscle that adducts the thigh
Adductor Brevis
Sheets of muscle found in the digestive, reproductive, and urinary tracts
Visceral Smooth Muscle
A test used to evaluate the integrity of the Achilles tendon for possible rupture
Thompson Test
The junction between a motor neuron and a muscle fiber; one type of a synapse
Neuromuscular Junction
The strong tendon that joins the muscles in the posterior leg to the calcaneus
Achilles Tendon
An actin-binding protein that regulates muscle contraction and other actin-related mechanical function of the body
Tropomyosin
An intracellular protein to which calcium binds, resulting in muscle contraction
Calmodulin
The largest muscle of the chest wall; it adducts and internally rotates the shoulder
Pectoralis Major
Chemicals produced by neurons that stimulate electrical reactions in adjacent cells
Neurotransmitters
A special group of four muscles that forms a cap over the proximal humerus and ties the humerus to the scapula; it controls rotation at the shoulder joint
Rotator Cuff
Conduction areas between cells (eg, in visceral smooth muscle) that interconnect individual muscle cells
Gap Junctions
Located in the posterior compartment of the leg; flexes and laterally rotates the knee and extends the hip
Biceps Femoris
The ability of a muscle to generate its own electrical activity
Intrinsic Automaticity
The delicate connective tissue surrounding individual muscular fibers
Endomysium
Muscle contained in the anterior compartment of the thigh that extends the knee when contracted
Quadriceps Femoris
The region within the pelvis that contains the structures of the urogenital system
Urogenital Triangle
T-tubules; membranous channels extending inward and passing through muscle fibers
Transverse Tubules
A layer of fibrous connective tissue outside the epimysium that separates individual muscles and individual muscle groups
Fascia
A motor neuron and the muscle fibers that it controls
Motor Unit
A layer of connective tissue that closely surrounds skeletal muscles
Epimysium
A regulatory protein in the actin filaments of skeletal and cardiac muscle that attaches to tropomyosin
Troponin
A metabolic end product of the breakdown of glucose that accumulates when metabolism proceeds in the absence of oxygen
Lactic Acid
Electrochemical changes transmitted by neurons to other neurons and to cells outside the nervous system
Nerve Impulse
The area within the pelvis that contains the anus
Anal Triangle
Branching fibers in cardiac muscle that allow action potentials to pass from cell to cell
Intercalated Disks
Specialized nerve cells that deliver an impulse to muscle cells, causing them to contract
Motor Neurons
An iron-containing protein within red blood cells that has the ability to bind to oxygen
Hemoglobin
Muscles working in opposition to each other
Antagonists
When a cell is at rest, ions are actively transported into and out of the cell to create an electrochemical gradient across the cell membrane
Polarized
The junction between nerve cells across which nervous stimuli are transmitted. Includes the synaptic cleft, presynaptic cell membrane with synaptic vesicles and axon terminal and postsynaptic cell membrane
Synapse
The space between neurons where electrical impulses trigger the release of neurotransmitters, which in turn stimulate an electrical reaction in adjacent neurons
Synaptic Cleft
A system of membranes that transport materials in muscle cells
Sarcoplasmic Reticulum
Fibers that contract causing movement; three types are present in the body: skeletal, smooth, and cardiac
Muscle
A relatively immovable part of the body where a skeletal muscle is fastened at a moveable joint
Origin
The amount of oxygen that liver cells need to convert lactic acid into glucose, as well as the amount needed by muscle cells to restore adenosine triphosphate and creatine phosphate levels
Oxygen Debt
One that passes in many directions over a muscle fiber membrane after stimulation by acetylcholine
Muscle Impulse
Striated muscles that are under direct volitional control of the brain; also called voluntary muscle
Skeletal Muscle
Muscle that is found only in the heart, providing the contractions needed to propel the blood through the circulatory system
Cardiac Muscle
The area below the coccygeus and levator ani muscles, which forms the floor of the pelvis
Perineum
Broad sheets of fibers that may attach to bones or to the coverings of other muscles
Aponeuroses
The rapid movement of electrolytes across a cell membrane that changes the cell’s overall charge. This rapid shifting of electrolytes and cellular charges is the main catalyst for muscle contractions and neural transmissions
Depolarization
Supination of the forearm against resistance to evaluate whether a patient has bicipital tendonitis
Yergason Test
A large dome-shaped muscle that forms the undersurface of the thorax, separating the chest from the abdominal cavity. Contraction of this and the chest wall muscles brings air into the lungs. Relaxation allows air to be expelled from the lungs
Diaphragm
A layman’s term for traumatic soft-tissue injury to the structures of the neck, associated with sudden flexion or extension
Whiplash
The flattened end of a motor neuron that transmits neural impulses to a muscle
Motor End Plate
Groups of muscles that cause extension
Extensor Muscles
Groups of muscles that cause flexion when contracted
Flexor Muscles
Muscles that work together to accomplish a particular movement
Synergists
The component that makes up most of the thin protein filaments of the myofibrils
Actin
Anatomic spaces within the body that are enclosed by fascia
Compartments
Accumulation of blood or fluid in a fascial compartment, typically following trauma, resulting in compression of blood vessels and tissue damage secondary to ischemia and, if not recognized and promptly treated, death of muscle and loss of the limb
Compartment Syndrome
The long muscle that adducts the hip
Adductor Longus
