Muscular System

Muscular System

The topic of Chapter 6 in the book.

Muscle Function

Muscles are responsible for all types of body movement.

Muscle Contraction

Muscles function by contracting or shortening.

Three Muscle Types

Skeletal muscle, Cardiac muscle, Smooth muscle are the basic muscle types in the body.

Muscle Cell Shape

Muscle cells are elongated (muscle cell = muscle fiber).

Contraction Cause

The contraction of muscles is caused by the movement of microfilaments.

Prefixes 'myo' and 'mys'

'Myo' and 'mys' prefixes refer to muscle.

Prefix 'sarco'

The prefix 'sarco' refers to flesh.

Skeletal Muscle Attachment

Most skeletal muscles are attached by tendons to bones.

Multinucleate Cells

Skeletal muscle cells are multinucleate.

Striated Muscles

Skeletal muscles are striated, showing visible banding.

Voluntary Muscles

Skeletal muscles are voluntary and subject to conscious control.

Muscle Surrounding

Skeletal muscle cells are surrounded and bundled by connective tissue.

Endomysium Function

Endomysium wraps around a single muscle fiber.

Perimysium Content

Perimysium wraps around a fascicle (bundle) of muscle fibers.

Epimysium Coverage

Epimysium covers the entire skeletal muscle.

Fascia Definition

Fascia is the connective tissue outside the epimysium.

Tendon

A tendon is a cord-like structure.

Aponeurosis

An aponeurosis is a sheet-like structure.

Muscle Attachment Sites

Muscles attach to bones, cartilages, and connective tissue coverings.

Direct phosphorylation

The process of directly phosphorylating ADP to regenerate ATP

Creatine phosphate (CP)

High-energy molecule in muscle cells for energy transfer

ADP is left

Fate of ADP after ATP is depleted

Creatine phosphate regenerates ATP

By transferring energy to ADP

CP supplies last

About 20 seconds before being exhausted

Anaerobic glycolysis

Glucose breakdown without oxygen

End product of anaerobic glycolysis

Pyruvic acid and some ATP

Lactic acid from pyruvic acid

Conversion in anaerobic glycolysis

Aerobic respiration

Metabolic pathways in mitochondria for energy production

Muscle fatigue

Result of lactic acid production

Oxygen debt

Repayment needed to remove accumulated lactic acid

Isotonic contractions

Myofilaments sliding for muscle shortening

Isometric contractions

Muscle tension increases without shortening

Muscle tone

Some fibers contracted even in a relaxed muscle

Voluntary muscle movements

Controlled by skeletal muscles

Smooth muscle tissue

Found in the walls of hollow organs

Cardiac muscle tissue

Striated muscle found in the heart

Connective tissue wrappings of skeletal muscle

Epimysium, perimysium, and endomysium

Muscle contraction energy source

Adenosine triphosphate (ATP)

Muscle contractions

Isotonic and isometric types

Muscle movements

Flexion, extension, abduction, adduction, etc.

Prime mover muscle

Major muscle responsible for movement

Antagonist muscle

Muscle opposing the prime mover

Synergist muscle

Aiding muscle in movement

Naming skeletal muscles

Based on location, shape, and action

Slide 6.38 topic

Head and Neck Muscles

Slide 6.39 topic

Trunk Muscles

Slide on Deep Trunk and Arm Muscles

Slide on Muscles of the Pelvis, Hip, and Thigh

Slide on Muscles of the Lower Leg

Slide on Anterior Superficial Muscles

Slide on Posterior Superficial Muscles

Muscular Dystrophy

Disorder causing muscle degeneration

Duchenne MD

Disorder lacking a protein for sarcolemma maintenance

Myasthenia Gravis

Disorder leading to weakness due to acetylcholine receptor shortage