You will be able to List and define the characteristics of muscle tissue List and explain the functions of muscle tissue List and describe the 3 types of muscle tissue Describe and label the types of deep fascia Describe the microscopic appearance of skeletal muscle Label a typical skeletal muscle fiber Label and describe the regions of a sarcomere

The scientific study of muscles

Branch of medicine concerned with the prevention or correction of disorders of the musculoskeletal system

Excitability – the ability to respond to a stimulus Contractility – the ability to shorten when stimulated Extensibility – the ability to be stretched Elasticity – the ability to return to the original size

Motion – body movements as well as moving substances within the body Posture – postural muscles continuously contract when awake to hold the body upright Heat Production – muscular contraction produces 85% of the body’s heat

Location – attached to bones Appearance – striated Nervous Control - Voluntary

Location – The Heart Appearance – striated Nervous Control - involuntary

Location – walls of hollow organs Appearance – non-striated Nervous Control - involuntary

Fascia – sheets or bundles of fibrous connective tissue Superficial Fascia – just beneath the skin Deep Fascia – Holds muscles together Epimysium – covers the entire muscle Perimysium – covers a bundle of muscle fibers Endomysium – covers individual muscle fibers

Tendon – cord-like extension of deep fascia that connects muscle to bone Aponeurosis – a sheet of connective tissue, similar to a tendon that attaches muscles

Highly vascular and highly innervated Need to respond to stimuli (nerves) Uses lots of energy (ATP) so needs blood

Myofibers – muscle fiber (cell) Sarcolemma – plasma membrane Sarcoplasm – cytoplasm Sarcoplasmic Reticulum – ER Transverse Tubules (T-Tubules) – tubes that extend across the myofiber and open to the outside.

Myofibril – structures that make up the fibers Myofilaments – structures that make up the fibrils Sarcomeres – basic functional unit of skeletal muscles

http://www. brookscole http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/muscles/muscles.html

Z-line – end of a sarcomere A-band – dark area made of thick and thin filaments I-band – light area made of only thin filaments H-zone – light area made of only thick filaments

Actin – protein that makes the thin filaments Myosin – protein that makes the thick filaments

http://highered. mcgraw-hill http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/animation__sarcomere_contraction.html

http://highered. mcgraw-hill http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/

You will be able to Define the sliding filament theory. Describe the actions of a muscle fiber when it contracts. Label a diagram of a neuromuscular junction. Describe the biochemical steps of a muscle contraction. Discuss where the energy for muscle contraction comes from. Describe the different types of muscle contractions. Label a myogram of a twitch.

The thin filaments (actin) slide over the thick causing the sarcomere to shorten. This process requires ATP

Where a muscle is innervated (place where a nerve meets a muscle)

Nerve Cell

The nerve that stimulates a muscle to contract

Axon of a motor neuron that attaches to the sarcolemma of the muscle fiber ← Motor End Plate Muscle → ← Neuron

The neurotransmitter (chemical) released by a motor neuron that stimulates a muscle to contract Immunostaining of rat neuromuscular junctions Neurofilament immunofluorescence stain(green) Actylcholine receptor (red)

The combination of the motor neuron and the muscle it innervates                                

An action potential causes the release of Ca+2 ions stimulating the myosin to move the actin filament http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/musc les/muscles.html (labeling picture)

http://bcs.whfreeman.com/thelifewire/content/chp47/4702001.html Narrated Summary with tabs

The body uses ATP for energy This ATP can be produced by the body in 3 ways

ADP + P + Energy → ATP Fast Not a lot of energy

1C6H12O6 → 2C3H6O3 + ATP Glucose is broken down into Pyruvic Acid Needs no oxygen Not a lot of ATP

1C3H6O3 + O2 → CO2 + H2O + ATP Starts with Pyruvic Acid from Anaerobic Needs Oxygen to take place Makes a lot of energy Many Steps - longest

The muscle cells burn off the ATP they have floating around in about 3 seconds. The phosphagen system kicks in and supplies energy for 8 to 10 seconds. This would be the major energy system used by the muscles of a 100-meter sprinter or weight lifter, where rapid acceleration, short-duration exercise occurs. If exercise continues longer, then the glycogen-lactic acid system (anaerobic) kicks in. This would be true for short-distance exercises such as a 200- or 400-meter dash or 100-meter swim. Finally, if exercise continues, then aerobic respiration takes over. This would occur in endurance events such as an 800-meter dash, marathon run, rowing, cross-country skiing and distance skating.

When a muscle fiber is stimulated it either completely contracts or does not contract at all

Threshold Stimulus – the weakest stimulus that can cause a muscle to contract Sub-Threshold Stimulus – a stimulus that is too weak to cause a contraction

A record of the electrical activity of a muscle to determine the type of contraction

A rapid, jerky response to a single stimulus

Latent Period – time between the application of the stimulus and the muscle contraction Contraction Period – time when filament are sliding over each other, causing a contraction Relaxation Period – Time during which filaments are sliding back into place Refractory Period – Time following a contraction during which a muscle is unable to respond to a stimulus

Contraction Period Relaxation Period Latent Period Refractory Period

A sustained contraction

A muscle contracts more forcefully after contracting several times

Tension remains constant but the muscle shortens Lifting something

Tension increases but muscle does not shorten Pulling up on chair

Wasting away of muscle

Increase in the size of muscle fibers