Anatomy and Physiology

Three Types of muscle

type of muscle that is striated, light and dark, voluntary, neuron controlled

type of muscle that is striated, involuntary, autorhythmiciity, hormones and neurotransmitters change heart rate, etc

type of muscle that has walls of internal strucutres, non-striated, involuntary, and autorhythmicity

Functions of muscle

ringlike bands of smooth muscle that close off outlets by the contraction and relaxation of smooth muscle, and also found in gi tract, urine, flow of lymph, and returns blood to the heart

four properties of muscle tissue

electrical signals as a responce to stimuli that travel down the plasma membrane of cell

types of stimuli

stiulation of actin potential that leads to a sliding of thin filaments across thick filaments

"strecthability," stomach, carciac muscles, allows muscle to contract forcefully when strecthed

ability to return to original size and length

muscle cells are refered to as

connective tissue surrounds and protects muscular tissue which includes

also referred to as hypodermis, it separates muscle from skin and is composed of areolar connective tissue and adipose. provides a pathway for nerves, blood vessels, and lymphatic vessels to enter and exit muscles

stores most of the body's triglycerides and seves as an insulating layer that reduces heat loss, and protects muscle form physical trauma

dense shee of dense irrgular connectve tissue that lines tha body walls and limbs and supports and surrounds muscles and other organs of the body; allows free movement

three layers of connctive tissue in skeletal muscle

type of connective tissue encircling the entire muscle; dense irregular

type of connective tissue surrounds groups of 10-100 muscle fibers separating them into bundles called fascicles; dense irregular

type of connective tissue that penetrates the interior of each fascicle and separates individual muscle fibers from one another; also a thin sheath of areolar connective tissue

cord of dense regulare conncective tissue; parallel bundles of collagen fibers; connects muscle to bone

connective tissue elements that extend as a braod, flat later; type of tendon

tubes of connective tissue containing an inner layer called visceral layer attached to the surface area and an outer layer called parietal layer with attached to the bone

stimulates skeletal muscle; threadlike axon entends from spinal cord to a group of skeletal muscle fibers

small blood vessels found in muscle tissue

enlargement of fibers

increase in the number of fibers

plasma membrane of the cell

thousands of tiny invaginations of sarcolemma; open to the outside of cell; filled with interstitial fluid; where mucle action potiontial travel along sarcolemma and through T tubules to spread throughout mucscle tissue quickly

"cytoplasm," involves glycogen involved in ATP synthesis; myoglobin

only in muscles and binds oxygen to diffuse into muscle resulting in the release into muscle for ATP production

contractile organelles of skeletal muscle that entend the entire length of muscle fiber

inside myofibrils and involved in contraction process; includes thick and thin filaments

2:1 ratio over thick filaments, anchored by z discs, actin

mysoin proteins is associated with which filament

compartment that contains the filament; basic subunit of myofibrils

sarcomere includes

separation of sarcomeres

dark, middle; entire length of thick filament; zone of overlap in sarcomere

lighter less dense; only thin filaments present with z disc in middle

only thick filament found here in sacromere

middle; proteins that hold thick filaments together at center of H zone

Muscle proteins include three kinds of proteins found in the myofibrils

keep the thick and thin filaments in the proper alignment, elasticity
and extensibility to myofibrils and likn them to the sarcolemma and
extracelluar matrix

contracilte proteins in muscle

"motor protein" that push and pull cellular structures to acheive movement by the conversion of ATP, a chemical energy, into mechanical energy; myosin head and myosin tail

contains myosin binding sites where myosin head attaches; contains the regulatory proteins tropomyosin and troponin

In a relaxed muscle, myosin is blocked from binding to actin becase strands of ______ cover the mysoin-binding sites on actin

holds tropomyosin strands in place and undergoes a cange in shape when Ca++ binds to it resulting in moving tropomyosin away from mysoin-binding site

calcium binds to troponin and chages shap to move tropomyosin away from myosin-binding site on actin where myosin binds to actin

structural protein results in stability, extensibility, and elasticity of myofibrils and includes the following proteins

contraction and relaxation of skeletal muscle fibers involves

process that is essential for contraction of muscle to occur

the first step of conctraction cycle

second step of contraction cycle

third step of contraction cycle

forth step of contraction cycle

Step connecting muscle action potential propagating along sarcolemma and through T-tubules to cause a contraction or sliding of filaments

increase of Ca++ at cytosol

contains large resevoir of Ca++ to be released into the cytosol

miscule action traveling along sarcolemma and into t-tubules results directly in the release of calcium from to where

plasma membrane of the muscle cell

uses ATP to move Ca++ from cytosol to SR

propagation of action potential means that calcium release channels are open or closed

calcium binding protein in SR which helps SR to have 10000x as many calcium molecules as cytosol in relaxed muscle

indicates how forcefulness of muscle contraction depends on length of the sarcomeres within a muscle before contraction begins