Thick sleeve of loose connective (areolar) tissue that surrounds each muscle fiber (myofiber), creating room for blood capillaries and never fibers to reach every muscle fiber
A thicker connective tissue that wraps muscle fibers together in bundles called fascicles
A fibrous sheath that surrounds the entire muscle belly. It blends into connective tissue between the muscles
Series Elastic Components
The tendons of the muscles
Each is made of several hundred myosin, molecules of protein
Shaped like a golf club, bundled together to create thick filaments
Composed of two intertwined strands of a protein called fibrous actin, likened to a bead necklace
Also part of the thin filament. When a muscle is relaxed, it blocks the active sites and prevents myosin from binding to them
A smaller calcium-binding protein bound to each tropomyosin. When bound, it changes shape.
Tropomyosin and Troponin act like a switch to determine when the fiber can contract and when it cannot.
Not Regulatory Proteins
Actin and Myosin
Made of a huge springy protein called Titin. They flank each thick filament and anchor it to a structure called the Z Disc to stabilize the thick filament, center it between the thin filaments, and prevent overstretching
Used to extend the myosin heads in preparation of the power stroke but not used in the actual power stroke. Also used in relaxation in order for another cycle to occur.
A Z-Disc at either end, about 2-2.25 nanometers is the optimum resting length
Has dark A Bands alternating with lighter I Bands
Each consists of thick filaments lying side by side. Part of the A band, where thick and thin filaments overlap, is especially dark. In this region, thin filaments surround each thick filament
A light region in the middle of the A Band. The thick filaments originate at a dark M Line in the middle of the H Band
A dark narrow line that bisects each light I Band providing anchorage for the thin filaments and elastic filaments
A neurotransmitter; the electrical signal (nerve impulse) traveling down a nerve fiber causes the synaptic vesicles to undergo exocytosis, releasing ACh into the cleft. ACh thus functions as a chemical messnger from the nerve cell to the muscle cell
A broad sheet of tendon, refers to tendons associated with certain abdominal, lumbar, hand, and foot muscles.
The muscle that produces most of the force during a particular joint action. In flexing the elbow, for example, the prime mover is the brachialis
A muscle that aids the agonists. For example, the biceps brachii and the brachialis are synergists. A synergist may stabilize a joint and restrict these movements, or modify the direction of a movement so that the action of the prime mover is more coordinated and specific.
A muscle that opposes the prime mover. It maintains some tension on a joint and limits the speed or range of the agonist, preventing excessive movement, joint injury, or inappropriate actions. For example, the triceps brachii is an antagonist to the brachialis.
a muscle that prevents a bone from moving
Entirely contained within a particular region, having both its origin and insertion there
Acts upon a designated region but has its origin elsewhere
Internal/External Abdominal Oblique, Transversus Abdominus, and Rectus Abdominus
The plasma membrane of a muscular fiber, carries electrical action potential.
Constituted of a T Tubule and two Terminal Cicternae
The Sarcoplasmic Reticulum
A reservoir of calcium ions; it has gated channels in its membrane that open at the right times to release a flood of Ca^2+ into the cytosol, where the calcium activates the muscle contraction process. The T Tubule signals the SR when to release these calcium bursts
The body's ability to detect change, activate mechanisms that oppose it, and thereby maintain relatively stable internal conditions
French physiologist who observed that the internal conditions of the body remain constant even when external conditions vary
Coined the term homeostasis for the tendency to maintain internal stability
A process of making numerous observations until one feels confident about drawing generalizations and predictions from them. Used in anatomy, Descriptive.
Begins by asking a question and forming a hypothesis - an educated speculation or possible answer to the question, which must be falsifiable. Used in physiology. Experimental.
An explanatory statement or set of statements derived from facts, laws, and confirmed hypothesis.
Information that can be independently verified by any trained person
A generalization about the predictable ways in which matter and energy behave. It is the result of inductive reasoning based on repeated, confirmed observations.
Levels Which Organisms are Categorized
Organism, Organ Systems, Organs, Tissues, Cells, Organelles, Molecules, Atoms
Defines the boundaries of the cell, governs its interactions with other cells, and controls the passage of materials into and out of the cell
Extensions of the plasma membrane that serve primarily to increase a cell's surface area
Hairlike processes that beat in waves called a power stroke that pushes along matter
The whiplike tail of sperm
The material in the nucleus
Fine thread of dark matter composed of DNA and protein
Small granules of protein and RNA found in the nucleoli, in the cytosol, and on the outer surfaces of the rough ER and nuclear envelope. They "read" coded messages (mRNA) and assmble amino acids into proteins specified by the code.
A small system of cisternae that synthesize carbohydrates and put the finishing touches on protein and glycoprotein synthesis
A package of enzymes bounded by a single until membrane that digest and dispose of worn out mitochondria and other organelles in a process called autophagy.
The digestion and shrinkage of surplus cells by their own lysosomal enzymes; programmed death
Neutralize free radicals and detoxify alcohol, other drugs, and a variety of blood-borne toxins. Peroxisomes also decompose fatty acids into two-carbon acetyl groups, which the mitochondria then use as an energy source for the ATP synthesis.
Organelles specialized for synthesizing ATP. The inner membrane has folds called cristae. The space between the cristae, the matrix, contains ribosomes used in ATP synthesis; and a small circular DNA molecule called mitochondrial DNA (mtDNA)
A collection of protein filaments and cylinders that determine the shape of a cell, lend it structural support, organize its contents, direct the movement of substances through the cell , and contribute to movements of the cell as a whole.
Made of the protein actin
Thicker and stiffer than microfilaments. They resist stresses placed on a cell and participate in junctions that attach some cells to their neighbors. In epidermal cells, they are made of keratin and occupy most of the cytoplasm
A cylinder made of protofilaments that radiate from the centrosome and hold organelles in place, form bundles that maintain cell shape and rigidity.
A vesicular process that brings matter into a cell
Releases material from a cell
a selective form of phagocytosis or pinocytosis
The process of copying genetic instructions from DNA to RNA
Converts the language of nucleotides into the language of amino acids, which occur mainly in the cytosol and on the outside of the rough ER and nuclear envelope
Base Pairs of DNA
Base Pairs of RNA
Proteins that pass through the membrane; usually glycoproteins
Do not protrude into the phospholipid layer but adhere to one face of the membrane. It is typically associated with a transmembrane protein and tethered to the cytoskeleton.
Many of the chemical signals by which cells communicate cannot enter the target cell but bind to surface proteins called receptors, usually specific for one particular messenger
Composed of layers of closely spaced cells that cover organ surfaces, form glands, and serve for protections, secretion, and absorption
Tissue with more matrix than cell volume, often specialized to support, bind together, and protect organs
Containing excitable cells specialized for rapid transmission of coded information to other cells
Tissue composed of elongated, excitable cells specialized for contraction
The most abundant protein in the body, forming the fibers of many connective tissues in places such as the dermis, tendons, and bones
A tough structural protein, gives strength to the nails, hair, and skin surface
Bone-forming cell that arises from an osteogenic cell, deposits bone matrix, and eventually becomes an osteocyte. They synthesize the soft organic matter of the bone matrix, which then hardens by mineral deposition
A mature bone cell formed when an osteoblast becomes surrounded by its own matrix and entrapped in lacunae, which are interconnected by slender channels called canaliculi
Macrophage of the bone surface that dissolves the matrix and returns minerals to the extracellular fluid
Secrete the matrix and surround themselves with it until they become trapped in little cavities called lacunae.
Cells enclosed in lacunae. A cartilage cell, a former chondroblast that has become enclosed in a lacuna in the cartilage matrix
Cartilage growth from within, by multiplication of chondrocytes and deposition of new matrix in the interior
The deposition of new tissue at the surface
Touch receptors form the Merkel Disc
Protect body against pathogens
Produces lipid-filled vesicles that release glycolipids by exocytosis to waterproof the skin
Only in thick skin, does not stain well, no nucleus or organelles
Up to 30 layers of dead, scaly, keratlinized cells
Levers acted upon by muscles
Glide across one another in multiple directions
Protect soft organs
Cylinder of compact bone
Marrow cavity (medullary cavity) lined with endosteum (osteogenic cells and reticular connective tissue)
Enlarged ends of bones to strengthen joint and attach ligaments
Shaft covered in it, outer fibrous layer of collagen and inner osteogenic layer of bone forming cells
Little or no movement
Immovable fibrous joints
Overlapping beveled edges
Straight, non-overlapping edges
Some movement while chewing; attachment of tooth to its socket
Most movable of fibrous joint; two bones bound by ligament; radius-ulna and tibia-fibula
Bone joined by hyaline cartilage; rib-sernum
Bones joined by fibrocartilage; pubic symphysis-intervertebral discs