ANALEC MIDTERMS [MUSCULAR SYSTEM]

The ones responsible for all times of body movement.

Muscles

They can contract or shorten.

Muscles

Is the machine of the body.

Muscles

The Three (3) Basic Types of Muscles Found in the Body

1. Skeletal Muscle

2. Cardiac Muscle

3. Smooth Muscle
   
   

Enumerate the Characteristics of Muscles mentioned in the lesson.

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

• Contraction of muscles is due to the movement of microfilaments

• All muscles share some terminology

Prefix myo refers to…?

Muscle

Prefix mys refers to…?

Muscle

Prefix sarco refers to…?

Flesh

Enumerate the Characteristics of Skeletal Muscles

• Most are attached by tendons to bones

• Cells are multinucleate

• STRIATED - has visible banding

• VOLUNTARY - subject to conscious control

• Cells are surrounded and bundled by connective tissue = great force, tires easily

This wraps around a single muscle fiber.

Endomysium

This wraps around a fascicle (bundle) of fibers.

Perimysium

This covers the entire skeletal muscle.

Epimysium

These are on the outside of the epimysium.

Fascia

This blends into a connective tissue attachment.

Epimysium

Cord-like structures

Tendons

Sheet-like structures

Aponeuroses

Enumerate the sites of muscle attachment.

• Bones

• Cartilages

• Connective tissue coverings

Are broad, flat sheets of dense regular connective tissue that connects muscle to bone, fascia, or another muscle.

Aponeurosis

Where can aponeurosis be found?

• Abdominal wall

• Palms and soles

• Scalp

• Neck

• Other regions like the thoracolumbar fascia and fascia over some muscles (e.g. deltoid aponeurosis)

• Cord-like or rope-like

• Attaches muscle to bone

Tendon

• Broad, flat sheet-like

• Attaches muscle to bone, fascia, or another muscle

Aponeurosis

Broad fibrous sheet in the palm.

Palmar Aponeurosis (Palm)

Supports the arch of the foot.

Plantar Aponeurosis (Sole)

Broad sheet connecting frontalis and occipitalis muscles.

Epicranial Aponeurosis (Scalp)

Broad aponeurotic sheet in the back.

Thoracolumbar Fascia

Enumerate the Characteristics of Smooth Muscle

• Has no striations

• Spindle-shaped cells

• Single nucleus

• INVOLUNTARY - no conscious control

• Found mainly in the walls of hollow organs

• Slow, sustained and tireless

Enumerate the Characteristics of Cardiac Muscles

• Has striations

• Usually has a single nucleus

• Joined to another muscle cell at an intercalated disc

• INVOLUNTARY

• Found only in the heart

• STEADY PACE!

Specialized junctions between adjacent cardiac muscle cells.

Intercalated Disc in Cardiac Muscle

Anchors actin filaments of adjacent cells together.

Fascia Adherens (Actin Filaments)

Provides strong mechanical adhesion between cells.

Desmosome (Intermediate Filaments)

Allows ions to pass directly from one cell to another for electrical coupling.

Gap Junction (Connexons)

Found only in cardiac muscle. Absent in skeletal and smooth muscle.

Intercalated Discs

These contains desmosomes, fascia adherens, and gap junctions. Providing both strong mechanical attachment and electrical connectivity.

Intercalated Discs

Striated but has no Intercalated Discs.

Skeletal Muscle

Striated with Intercalated Discs.

Cardiac Muscle

Not striated and has no Intercalated Discs.

Smooth Muscle