Skeletal & Muscular Systems

Muscular & Skeletal Systems

BIOLOGY I

The skeletal system is composed of 206 bones that, along with cartilage, tendons, and ligaments, make up the framework or skeleton of the body.

​What is the skeletal system?

The skeleton can be divided into two main parts. The axial skeleton consists of 80 bones. The primary bones of the axial skeleton are the skull, spine, ribs and sternum (thorax).

​Axial Skeleton

The appendicular skeleton consists of 126 bones. The primary bones of this skeleton are the shoulder or pectoral girdle, arms, hands, pelvic girdle, legs and feet.

​Appendicular Skeleton

Multiple Select

Which of the following are part of the APPENDICULAR skeleton? (select all that apply).

• hands

• ribs

• skull

• legs

• Bones provide shape, support, and the framework of the body.

• Bones protect internal organs.

• Bones serve as a storage place for minerals such as salts, calcium, and phosphorus.

​Functions of Bone

Draw

What do you think we would look like if we didn't have bones? Draw a picture!

• Bones play an important role in hematopoiesis - the formation of blood cells that takes place in bone marrow.

• Bones provide a place to attach muscles.

• Bones make movement possible through articulation

​Functions of Bone

LONG bones include the femur (thigh), tibia (larger shin), fibula (smaller shin bone), humerus (upper arm), radius (larger forearm), and ulna (smaller forearm).

​Bones can be classified by SHAPE

SHORT bones include the carpals of the wrist and tarsals of the ankle.

​Bones can be classified by SHAPE

FLAT bones include the skull, sternum (breastbone), and scapula (shoulder bone).

​Bones can be classified by SHAPE

IRREGULAR bones include the vertebrae (spine), and sacrum (pelvic).

​Bones can be classified by SHAPE

Multiple Choice

What type of bone is pictured?

• long

• flat

• short

• irregular

Multiple Choice

What type of bone is pictured?

• long

• flat

• short

• irregular

The muscular system consists of all the muscles of the body. These make up approximately 42% of total body weight, and are composed of long, slender cells known as fibers. The fibers are different lengths and vary in color from white to deep red.

​What is the muscular system?

Each muscle consists of a group of fibers held together by connective tissue, and enclosed in a fibrous sheath or fascia.

​Muscle Cells

Muscles cause movement, help to maintain posture, and produce heat. There are 3 types, classified according to function and appearance:

​3 Types of Muscle

​Involuntary, stimulated through electrical impulses

Cardiac Muscle

​Voluntary, work in pairs (flexion and extension)

Skeletal Muscle

​Involuntary, organs and vessels

Smooth Muscle

Multiple Choice

Which of the following is NOT one of the three types of muscle?

• Cardiac

• Atrial

• Skeletal

• Smooth

Multiple Choice

What type of muscle is shown?

• cardiac

• skeletal

• smooth

• strong