Skeletal System

Question 1

Name the two tissue types that form the skeleton

Answer 1

Cartilage and bone

Question 2

List the functions of the skeletal system

Answer 2

Supporting, Protecting. Provides a system of levers, with which the skeletal muscles work to move the body. Bones store lipids and many minerals (most importantly, calcium). The red marrow cavities of bones provide a site for hematopoiesis (blood cell formation).

Question 3

Locate and identify the three major types of skeletal cartilages.

Answer 3

Hyaline Cartilage: Provides sturdy support with some resilience. Most skeletal cartilages are composed of Hyaline Cartilage. Ends of ribs, nose, elbow joints, hip joints, wrists and fingers.
Elastic Cartilage: Is much more flexible than Hyaline cartilage, and it tolerates repeated bending better. Only the cartilages of the external ear and the epiglottis (which flops over and covers the larynx when we swallow) are elastic cartilage.
Fibrocartilage: Consists of rows of chondrocytes alternating with rows of thick collagen fibers. Fibrocartilage which has great tensile strength and can withstand heavy compression, is used to construct the intervertebral discs and the cartilages within the knee joint.

Question 4

Name the four main groups of bones based on shape.

Answer 4

Long, Short, Flat and Irregular

Question 5

Identify surface bone markings and list their functions.

Answer 5

Projections or Processes that grow out from the bone and serve as sites of muscle attachment or help from joints.
Depressions or Cavities: Indentations or openings in the bone that often serve as conduits for nerves and blood vessels.

Question 6

Identify the major anatomical areas on a longitudinally cut long bone.

Answer 6

1. Diaphysis or shaft, smooth surface comprised of compact bone.
2. Epiphysis, the end of the long bone. Notice that it is composed of a thin layer of compact bone that encloses spongy bone.
3. Articular Cartilage, which covers the epiphyseal surface in place of the periosteum. The glassy hyaline cartilage provides a smooth surface to minimize friction at joints.
4. Epiphyseal Plate, May still be visible. A thin area of Hyaline cartilage that provides for longitudinal growth of the bone during youth. Once the leg bone has stopped growing, these areas are replaced with bone and appear as thin, barely discernible remnants.
5. In adult, the central cavity of the shaft (medullary cavity) is a storage region for adipose tissue, or Yellow Marrow, In infant, this area is involved in forming blood cells, and so Red Marrow is found in the marrow cavities. In adult bones, the red marrow is confined to the interior of the epiphyses, where it occupies the spaces between the trabeculae of spongy bone.
6. If you are examining a fresh bone, look to see if you can distinguish the delicate endosteum lining the shaft. It also covers the trabeculae of the spongy bone and lines the canals of compact bone.

Question 7

Explain the role of inorganic salts and organic matrix in providing flexibility and hardness to bone.

Answer 7

The hardness of bone is due to the inorganic calcium salts deposited in its ground substance. Its flexibility comes from the organic elements of the matrix, particularly the collagen fibers.

Question 8

Locate and identify the major parts of an osteon of compact bone.

Answer 8

blank

Question 9

Long Bones

Answer 9

Humerus: Arm, Brachium L R
Radius and Ulna: Forearm L R Radius outside, Ulna inside
Femur: Thigh, L R
Tibia and Fibula: Leg L R Fibula outside, Tibia inside.
Metacarpals and Metatarsals: Bones middle part of the hand, bones that form sole and instep. L R
Phalanges: Fingers, Toes L R

Question 10

Short Bones

Answer 10

Carpals: Wrist bones L R 8 bones each
Tarsals: Ankle, Heel, Arch L R 7 bones each

Question 11

Irregular Bones

Answer 11

Vertebrae: 33 vertebrae

Pelvic Bones: Hip bones Ilium on each side. Pubis in front, both sides. Ischium in back, both sides.

Question 12

Sesamoid Bones

Answer 12

Patella Knee Caps L R

Question 13

Bones in the Axial Skeleton

Answer 13

Skull, Vertebral column, Thoracic cage (ribs & sternum), some bones of pelvic girdle

Question 14

Bones in the Appendicular Skeleton

Answer 14

Bones of pectoral girdle, Upper limb, Lower limb, some bones of pelvic girdle

Question 15

Articular Cartilages

Answer 15

cover the bone ends at movable joints

Question 16

Costal Cartilages

Answer 16

Found connecting the ribs to the sternum (breastbone)

Question 17

Laryngeal Cartilages

Answer 17

Largely construct the larynx (voice box)

Question 18

Tracheal and Bronchial Cartilages

Answer 18

Reinforce other passageways of the respiratory system

Question 19

Nasal Cartilages

Answer 19

Support the external nose

Question 20

Intervertebral Discs

Answer 20

Separate and cushion bones of the spine (vertebrae)

Question 21

Elastic Cartilage

Answer 21

Cartilage supporting the external ear.

Question 22

number of bones in an adult human

Answer 22

206

Question 23

Describe Compact Bone

Answer 23

Looks smooth and homogeneous

Question 24

Describe Spongy Bone

Answer 24

Composed of small trabeculae (bars) of bone and lots of open space.

Question 25

Diaphysis

Answer 25

Shaft of the long bone

Question 26

Epiphysis

Answer 26

End of the long bone. Distal and Proximal ends.

Question 27

Articular Cartilage

Answer 27

Covers the epiphyseal surface in place of the periosteum. The glassy hyaline cartilage provides a smooth surface to minimize friction at joints.

Question 28

Epiphyseal Plate

Answer 28

If still growing you will see a thin area of hyaline cartilage that provides fro longitudinal growth of the bone during youth. Once the long bone has stopped growing, these areas are replaced with bone and appear as thin, barely discernible remnants...the epiphyseal lines.

Question 29

Central Cavity of the shaft

Answer 29

essentially a storage region for adipose tissue, or yellow marrow. infant it is involved in forming blood cells, so red marrow is found in the marrow cavities. In adult bones, the red marrow in confined to the interior of the epiphyses, where it occupies the spaces between the trabeculae of spongy bone.

Question 30

Osteon

Answer 30

Structural units of bone

Question 31

Osteocytes

Answer 31

are mature bone cells that make up most of the cell population. each Osteocyte occupies a Lacuna, a pocket sandwiched between layers of matrix. The layers are called Lamellae. Osteocytes cannot divide, and a lacuna never contains more than on osteocyte. Narrow passageways called Canaliculi penetrate the lamellae, radiating through the matrix and connecting lacunae with one another and with sources of nutrients, such as blood vessels in the central canal.