Chapter 7: Skeletal System

What are the functions of bursae?

Act as cushions and help reduce friction.

What structures make up the skeletal system?

Bones, cartilage, ligaments, and tendons associated with bones.

What bone is located in the thigh?

Femur.

What bones are located in the leg?

Fibula and tibia.

What is the symphysis pubis?

Joint where the two pubic bones meet.

What is the name of the central indentation in the superior margin of the sternum?

Jugular (suprasternal) notch.

What is the patella?

Kneecap.

What are the names of the three small bones located in the middle ear?

Malleus, incus, stapes.

What are floating ribs?

Ribs that do not have an anterior attachment.

What are the functions of the intervertebral disks?

Serve as shock absorbers and allow the vertebral column to bend.

What is the function of the hyoid bone?

Serves as a base for the tongue and as an attachment for several muscles associated with swallowing.

What is an amphiarthrosis?

Slightly movable joint.

What is the difference between spongy bone and compact bone?

Spongy bone is lighter and less dense than compact bone.

What are the five functions of the skeletal system?

Support, protection, movement, storage, blood cell formation.

What is the difference between true ribs and false ribs?

True ribs attach directly to the sternum by costal cartilage. The costal cartilage of false ribs does not reach the sternum directly.

How is the blood calcium level maintained in the body?

When blood calcium levels decrease, calcium is released from the bones. When blood calcium levels increase, excess calcium is stored in the bones.

How many pairs of ribs are present in the human skeleton?

12 pairs.

How many bones make up the skeleton of an adult?

206 bones.

How many vertebrae make up the vertebral column?

26 vertebrae.

How many bones make up the skull?

28 bones.

What are the functions of the pelvic girdle?

Attaches lower extremities to axial skeleton; provides a strong support for the weight of the body; provides support and protection for the urinary bladder, a portion of the large intestine, and reproductive organs.

What are the two divisions of the skeleton? What structures are included in each division?

Axial: bones of the head, vertebral column, ribs, sternum. Appendicular: free appendages and their attachments to the axial skeleton.

Where is the epiphyseal plate located in a long bone?

Between the diaphysis and the epiphysis.

What structures make up vertebrae?

Body, vertebral arch, vertebral foramen, transverse processes, spinous process.

Where is red bone marrow found in the adult?

Bones of the skull, ribs, sternum, clavicles, vertebrae, pelvis.

What two bones make up the pectoral girdle?

Clavicle and scapula.

What is another name for the clavicle?

Collarbone.

What happens to the epiphyseal plate when long bones stop growing?

Completely ossifies.

When does an individual stop growing in length?

Early 20s.

What are bursae?

Fluid-filled sacs.

What is the function of the facial bones?

Form the basic framework and shape of the face.

What does the lateral malleolus do?

Forms the lateral bulge of the ankle.

What is a diarthrosis?

Freely movable joint.

What bones make up the cranium?

Frontal, parietal, occipital, temporal, sphenoid, ethmoid.

What is the name of the shallow depression on the scapula where the head of the humerus connects to the scapula?

Glenoid cavity.

What influences bone growth in the body?

Growth hormone from anterior pituitary and sex hormones from the ovaries and testes.

What is the function of fibrocartilaginous pads located in the knee?

Help stabilize the knee joint and act as shock absorbers.

What is the function of the cranium?

Houses the brain.

What bone is located in the upper arm?

Humerus.

How do long bones grow in length?

Hyaline cartilage grows by mitosis in the epiphyseal plate, chondrocytes next to the diaphysis age and degenerate, and then osteoblasts ossify the matrix to form bone.

What type of cartilage is found in the epiphyseal plate?

Hyaline cartilage.

What three bones fuse to form a coxal bone?

Ilium, ischium, pubis.

What is a synarthrosis?

Immovable joint.

What is the function of the appendicular skeleton?

Movement.

What is an example of an amphiarthrosis?

Ribs connected to the sternum by costal cartilage; symphysis pubis; joints between the vertebrae.

What is an articulation?

Place where two bones come together.

What is ossification?

Process of bone formation.

What is the function of red bone marrow?

Produces blood cells.

What are the functions of the thoracic cage?

Protects the heart, lungs, and great vessels; supports bones of the shoulder girdle; plays a role in breathing.

What is the function of the patella?

Protects the knee joint.

What bones are located in the forearm?

Radius and ulna.

What is an example of a synarthrosis?

Sutures in the skull.

What is an osteon?

The microscopic unit of compact bone.

What are sinuses and what is their function?

The sinuses are air-filled cavities that reduce the weight of the skull.

Describe the following parts of a diarthrosis: a. Articular cartilage: b. Joint cavity: c. Joint capsule: d. Synovial membrane: e. Synovial fluid:

a. Articular cartilage: Composed of hyaline cartilage; covers the ends of the opposing bones of the joint. b. Joint cavity: Space that separates the opposing bones of the joint. c. Joint capsule: Encloses the components of the joint. d. Synovial membrane: Inner layer of the joint capsule that secretes synovial fluid into the joint cavity. e. Synovial fluid: Lubricates the joint.

State the location of the following bones making up the hand: a. Carpal bones: b. Metacarpal bones: c. Phalanges:

a. Carpal bones: Wrist b. Metacarpal bones: Palm of the hand c. Phalanges: Bones of the fingers

How many vertebrae are included in each of the following divisions of the vertebral column? a. Cervical: b. Thoracic: c. Lumbar:

a. Cervical: 7 b. Thoracic: 12 c. Lumbar: 5

Describe each of the following structures that make up a long bone: a. Diaphysis: b. Medullary cavity: c. Epiphysis: d. Articular cartilage: e. Periosteum: f. Nutrient foramina: g. Endosteum:

a. Diaphysis: Shaft of a long bone consisting of compact bone. b. Medullary cavity: Space inside the shaft of a long bone. c. Epiphysis: Expanded portion of the end of a long bone. d. Articular cartilage: Thin layer of hyaline cartilage that covers the ends of long bones. e. Periosteum: Tough, fibrous connective tissue that covers a long bone except in the region of the articular cartilage. f. Nutrient foramina: Small openings in the diaphysis for the passage of blood vessels. g. Endosteum: Thin connective tissue membrane that lines the medullary cavity.

List examples of each of the following classifications of bone: a. Long bones: b. Short bones: c. Flat bones: d. Irregular bones:

a. Long bones: Thigh, leg, arm, forearm. b. Short bones: Bones of the wrist and ankle. c. Flat bones: Most of the bones of the cranium. d. Irregular bones: Vertebrae and some of the skull bones.

What is the function of each of the following types of bone cells? a. Osteoblast: b. Osteocyte: c. Osteoclast:

a. Osteoblast: Bone formation. b. Osteocyte: Mature bone cell. c. Osteoclast: Breakdown and reabsorption of bone.

Describe the following structures that make up an osteon: a. Osteonic canal (haversian canal): b. Lamella: c. Osteocytes: d. Lacunae: e. Canaliculi:

a. Osteonic canal (haversian canal): Central canal in the osteon. b. Lamella: Concentric rings of hard, calcified matrix that surround osteonic canals. c. Osteocytes: Bone cells. d. Lacunae: Spaces between the rings of matrix that contain bone cells. e. Canaliculi: Small channels that radiate from the lacunae to the osteonic canal.

Describe the following: a. Sacrum: b. Coccyx:

a. Sacrum: Triangular bone located just below the lumbar vertebrae. b. Coccyx: Last part of the vertebral column (tailbone).

Describe the location of the following bones making up the foot: a. Tarsal bones: b. Calcaneus bone: c. Metatarsal bones: d. Phalanges:

a. Tarsal bones: Ankle b. Calcaneus bone: Heel bone c. Metatarsal bones: Instep d. Phalanges: Bones of the toes and ball of the foot