Bio 156 complex Histology: MUSCLE TISSUE

what is muscular tissue?

tissue that allows the body to move

Excitable

muscle cells respond to stimulus

contractile

muscle cells shorten and create a pulling force

Muscle contraction

when a muscle pulls on bones, it can cause them to move

voluntary movement

movement under conscious control like opening a book

involuntary movement

movement that happens without conscious control, like your pupils getting smaller in bright light

what are the 3 subclasses of muscular tissue?

Skeletal Muscular Tissue

Cardiac Muscular Tissue

Smooth Muscular Tissue

what is the main function of skeletal muscle tissue

skeletal muscle allows voluntary body movements, like walking, facial expressions, and maintaining posture

where is skeletal muscle tissue found in the body?

it is primarily attached to bones throughout the body

what are the main characteristics of skeletal muscle tissue cells?

they are striated, multinucleated, long, and arranged in bundles

what does it mean that skeletal muscle is striated?

it has a striped appearance under a microscope because of the regular arrangement of actin and myosin proteins

what does multinucleated mean, and why do skeletal muscle cells have multiple nuclei?

multinucleated means having more than one nuclei. skeletal muscle cells have many nuclei because multiple myoblasts fuse together to form one long muscle fiber.

what are the 2 main contractile proteins in skeletal muscle tissue

actin and myosin

what percentage of your body mass is made up of skeletal muscle?

about 40%

how does skeletal muscle help regulate body temperature?

it produces heat as a byproduct of muscle contractions, helping maintain a stable body temperature.

what is shivering, and why does it occur

shivering is the involuntary contraction of skeletal muscles in response to a lower-than-normal body temperature. it produces heat

what is a myocyte and where does it develop from

myocyte is a muscle cell that develops from myoblasts derived from the mesoderm

how is skeletal muscle tissue organized?

it is arranged in bundles surrounded by connective tissue

memory tips

S- striated M- multinucleated B- bundled B-primarily attached to Bones V- voluntary

what is the main function of cardiac muscle tissue?

It contracts to pump blood throughout the body

where is cardiac muscle tissue found in the body

it is only found in the walls of the heart

what are the characteristics of cardiac tissue under a microscope?

it appears striated, meaning it has a striped appearance and it only has one nuclei, usually in the center of the cell

Is cardiac muscle tissue voluntary or involuntary?

involuntary meaning it works without conscious control

what are cardiomyocytes?

cardiomyocytes are the individual cells that make up cardiac muscle tissue

what are intercalated discs?

specialized cell junctions that connect neighboring cardiac muscle cells

what are the 2 types of junctions found in intercalated discs

Anchoring junctions and Gap junctions

what are the functions of anchoring junctions?

they hold neighboring cells together

what are the functions of Gap Junctions?

they allow electrical signals to pass between cells so they can coordinate contractions

how are cardiac muscle arranged?

they connect to form long, branching muscle fibers that work together in a coordinated way

what does cardiac muscle have in common with skeletal and smooth muscle

cardiac muscle shares the striated appearance of skeletal muscle and the involuntary function of smooth muscle.

what is the function of smooth muscle?

it moves substances through the body, like pushing food through the digestive tract and controlling blood flow through blood vessels.

where is smooth muscle tissue found in the body?

in the walls of hollow organs, like the stomach, intestines, bladder and blood vessels

what are the main characteristics of smooth muscle cells?

they are nonstriated, spindle shaped, and have one centrally located nucleus.

is smooth muscle voluntary or involuntary

its involuntary, meaning it works without conscious control

how does smooth muscle differ from skeletal and cardiac muscle?

smooth muscle has no visible striations, has one nucleus per cell and contacts involuntarily. skeletal and cardiac are both striated.