Muscular System

Objectives:

1.Review anatomical terminology.

2.Review types of joint movements.

3.Compare and contrast types of muscle.

What is the opposite of:1. Inferior

2. Anterior

3. Medial

4. Distal

5. Superficial

More review and assignments:

• Figure 17-2 (Lab Manual)

• Venn diagram of the three types of muscle. Add any other general information you know about muscle.

• Homework: – Add Chapter 8 roots, prefixes, and suffixes

to medical terminology sheet (Vocabulary quiz on Wednesday!!!)

– Medical journal article on a disease or disorder of the muscular system due on test day

Muscle Tissues1. Skeletal muscle tissue (“voluntary”)

– Long, threadlike cells– Striations: alternating light and dark cross-

markings– Each cell has many nuclei just beneath the cell

membrane.

Muscle Tissues (cont.)2. Smooth muscle tissue (“involuntary”)

– No striations– Cells are shorter than skeletal muscle, spindle-

shaped, and have one, centrally located nucleus.– Line walls of internal organs

Muscle Tissues (cont.)

3. Cardiac muscle tissue – heart– Striated and joined end-to-end– Each cell has only one nucleus. ???

Types of Muscle Tissue (p.185):

Skeletal Muscle Actions

• Movement depends on type of joint the muscle is associated with

• Origin & Insertion:– Origin – the end of the muscle that is

fastened to a relatively immovable or fixed part

– Insertion – the end connected to the movable part on the other side of the joint

– When muscles contract, its insertion is pulled toward its origin (EX: biceps brachii)

Interaction of Skeletal Muscles

• Prime mover – the muscle responsible for MOST of the movement (aka, agonist)

• Synergist - ???

• Antagonist - ???

Major Skeletal Muscles• Names may indicate location, size,

shape, action, number of attachments, or direction of muscle fibers:

• Pectoralis major

• Deltoid

• Extensor digitorum

• Biceps brachii

• Sternocleidomastoid

• External oblique

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Muscles of Facial Expression

• “It takes more muscles to frown than it does to smile.”

• More than 600 skeletal muscles in the body – 60 in the face!– 40 used to frown– 20 used to smile

• Smallest muscle is the stapedius, in the middle ear

• Largest - ???

• Longest - ???

Muscles of Facial Expression (p.188) and Mastication (p.190)

***Epicranius has 2 parts: frontalis and occipitalis.

Muscles That Move the Head

Add these muscles to your head drawing.