Skeletal Muscles: Attachments, Naming, and Examples

Flashcards covering muscle attachment points, naming conventions based on action, location, and fiber direction, and specific muscle anatomy.

What are the two points of attachment for skeletal muscles called?

Origin and insertion.

Where is the origin of a muscle typically located?

The origin is located near the midline of the body or on a less movable part of the skeleton.

How is the insertion point of a muscle defined?

The insertion is where the muscle ends by attaching to a bone or tendon; it is the more movable attachment and is the furthest point from the midline of the body.

What is the function and naming origin of the sternocleidomastoid muscle?

It helps bend the neck and rotate the head. It is named for its two points of origin: sterno (breastbone) and clido (collarbone).

Where does the mastoid muscle insert?

It inserts at the mastoid process, which is part of the temporal bone located behind the ear.

What do the terms 'flexor' and 'extensor' indicate in muscle naming?

They indicate the muscle's action, such as flexion (bending) or extension (straightening).

What does the term 'carpi' mean?

Wrist or wrist bones.

Where is the pectoralis major located and what does 'pectoral' mean?

It is a fan-shaped muscle on the anterior chest wall; 'pectoral' means relating to the chest.

Define the terms 'lateralis,' 'medialis,' and 'vastus.'

Lateralis means toward the side; medialis means toward the midline; vastus is a Latin word for huge.

What is the function of the vastus lateralis and vastus medialis?

They are part of the quadriceps that flex and extend the leg at the knee.

What does 'oblique' mean in the context of muscle fiber direction?

Slanted or at an angle.

What does 'rectus' mean regarding muscle fiber alignment?

In straight alignment with the vertical axis of the body.

What is a sphincter?

A ring-like muscle that tightly constricts the opening of a passageway.

How are the fibers of the transverse abdominis muscle aligned?

In a crosswise direction.

What do the names 'biceps' and 'triceps' indicate about their structure?

Biceps means two divisions (bi = two, ceps = head) and triceps means three divisions (tri = three, ceps = head).

What is the action of the biceps brachii and triceps brachii?

They flex and extend the upper arm.

Which muscle is the largest of the buttock, and what does its name mean?

The gluteus maximus; 'maximus' means great or large.

Why is the deltoid muscle named as such?

It is shaped like an inverted triangle, which is the Greek letter delta.

Which three muscles make up the hamstring group?

The biceps femoris, semitendinosus, and semimembranosus muscles.

What are the primary functions of the hamstrings?

Knee flexion and hip extension.