skeletal system

Question 1

Musculoskeletal system

Answer 1

Components of the musculoskeletal system works in harmony in order to provide movement for the human body. The musculoskeletal system, also known as the locomotor system, includes the skeleton, joints, ligaments, muscles, tendons, and accessory structures.

The skeleton provides the bony framework and the muscles assist the body to move. The musculoskeletal system also works in coordination with other systems such as the nervous and cardiovascular systems.

Question 2

The Skeleton

Answer 2

Movement is possible because many bones are used as levers. The skeleton is also a living structure as the cells of the bone are living organism even though it is hard and filled with calcium deposits. Bones are organs due to being composed of several types of tissues.

The adult human body has 206 bones with more than half of the bones found in hands, wrists, feet, and ankles. Minerals that make up the bones are primarily calcium and phosphorus and the marrow within the bones contribute to homeostatic functioning of the body

Question 3

Skeleton Function: Support

Answer 3

provides shape, framework, and support for the human body

Question 4

Skeleton Function: Protection

Answer 4

provides protection for vital organs and soft tissues

Question 5

Skeleton Function: Movement

Answer 5

provides locomotion (walking, movement) by attachment of muscles, tendons, and ligaments

Question 6

Skeleton Function: Hematopoiesis

Answer 6

produces red blood cells, white blood cells, and platelets. Red bone marrow is responsible for manufacturing the cells. Red marrow are in the ends of long bones, bodies of vertebrae, and in flat bones

Question 7

Skeleton Function: Storage

Answer 7

storage for calcium and phosphorus

Question 8

Bones

Answer 8

are living tissue and contain blood and lymphatic vessels and nerves. Bone tissue comprises of two types. Compact bone is hard and dense and forms the shaft of long bones and the outer layer of other bones. Spongy bone is composed of small boney plates and resembles a sponge. It contains more spaces than compact bones. Spongy bone are in the ends of long bones containing red marrow.

Question 9

Long bones

Answer 9

have an extended shape and provide the body with support and strength. They act as levers and support the body frame. Examples includes femur, tibia, and radius

Question 10

Short bones

Answer 10

approximately cube shaped, which facilitates movement and assists in transfer of forces. Examples include the tarsals and the carpals

Question 11

Flat bones

Answer 11

are broad surfaces for muscle attachment and protection. Examples include cranial, ribs, pelvis, ilium, and sternum

Question 12

Irregular bones

Answer 12

are similar to short bones but irregular in shape. They serve as special functions or attachment of other structures or articulations. Examples include the facial, vertebrae, bones of the middle ear (malleus, incus, and stapes)

Question 13

Joints

Answer 13

points at which bones join or attach to each other are known as joints or articulations. Joints determine which motions are possible because of their attachments. Joints are classified according to the degree of movement.

Question 14

Immovable joints

Answer 14

also known as synarthrosis, are immoveable in the adult. Joints between the skull bones. These joints are not firmly fixed in infants but become fused by adulthood because of interlocking projections. Immovable joints have no motions

Question 15

Slightly moveable joints

Answer 15

also known as amphiarthroses, are slightly moveable and have a slight degree of motion or flexibility. Examples include the spinal column, symphysis pubis, and articulations between the ribs. Cartilage lies between the articulating bones

Question 16

Freely movable joints

Answer 16

also known as diarthroses, are freely movable, allowing movement in various directions. These joints contain ligaments and cartilage. Examples of freely movable joints include the ends of long bones such as the knees, elbows, shoulders, hips, etc. Types of freely movable joints – freely moveable joints are classified according to their structure and range of movement.

Question 17

Types of Freely Moveable Joints

Answer 17

Hinge 
Ball-and-socket 
Pivot 
Gliding 
Condyloid 
Saddle

Question 18

Ligaments

Answer 18

are strong fibrous bands that hold bones together. Ligaments produce stability in the joint. Allow for flexibility, stretching, and movement. An example of ligaments is the cruciate (cross-shaped) ligaments of the knee, anterior and posterior. A ligament is said to originate in the bone or structure that is more stationary and insert into the bone that does most of the movement.

Question 19

Cartilage

Answer 19

is a type of connective tissue, which is soft, flexible, and organized into a system of fibers. Three types of cartilage are: articular, fibrous and reticular. Articular covers the ends of long bones such as the knee and hip joints. Fibrous cartilage is strong and rigid such as the symphysis pubis. Reticular cartilage is the most pliable and found in the auditory canal. Cartilage has no blood supply and receives oxygen and nutrients by diffusion.

Question 20

Skull

Answer 20

is composed of separate bones. The face includes the only movable bone in the skull known as the mandible. There are 6 bones in the ear, 3 for each side which includes 1 pair of malleus (hammer), 1 pair of incus (anvil), 1 pair of stapes (stirrup).

Question 21

Thoracic (rib) cage

Answer 21

Thorax cavity is formed by 12 pairs of flat, narrowed bones known as the ribs. Ribs are arranged in pairs with 12 on each side. Elastic cartilage are on the ends of the ribs to allow expansion of the chest and abdomen. The ribcage protects the internal structures such as the heart, lungs, and liver and great thoracic blood vessels. The thoracic cage is also a supportive structure for bones of the shoulder girdle. The floor of the thorax is the muscular diaphragm.

Question 22

Sternum

Answer 22

also known as the breastbone, which is a flat, sword-shaped bone in the center of the chest opposite of the thoracic vertebrae. The sternum consists of 3 sections with the manubrium on top, body in the middle, and xiphoid process projecting out at the bottom.

Question 23

Vertebral column

Answer 23

Cervical Vertebrae - 7

Thoracic Vertebrae - 12

Lumbar Vertebrae - 5

Sacrum Vertebrae - 1

Coccyx - 1

Question 24

Upper extremities

Answer 24

Upper extremities – Upper extremities consists of clavicles, scapula, humerus, ulna, radius, carpals, metacarpals, and phalanges.

The clavicles are long thin bones, scapula a flat triangular bone, and the humerus is the long bone of the upper arm.

The forearm consists of two bones with the ulna being the larger and the radius the smaller bones.

The carpals are the small irregular bones that support the base of the palm in the wrist. Metacarpals are long slender and slightly curved bones and the phalanges are the finger bones.

Question 25

Lower extremities

Answer 25

Lower extremities – consists of the femur, tibia, fibula, patella, tarsals, metatarsals, and phalanges. The femur is the body’s longest and strongest bone, which supports the weight of the body. The patella is a sesamoid bone that protects the front of the knee and buried in a tendon passing over the joint.

The tibia is the shinbone and is the long weight-bearing bone of the lower leg. The fibula is smaller than the tibia and is not weight bearing or attached to the knee. The ankle consists of 7 tarsal bones in which the calcaneus (heel) is the largest.

The five metatarsal bones form two arches longitudinally and transversally across the foot.

Question 26

Pelvic girdle

Answer 26

Pelvic girdle – two large, irregularly shaped bones form the pelvic girdle or pelvis. The pelvis supports the spinal column and protects part of the digestive, urinary, and reproductive systems. Pelvis’ in a woman is larger and wider than a man’s is. The angle of the pelvic arch is less than 90 degrees in men and greater than 90 degrees in women.

Question 27

Pelvic girdle: Ilium

Answer 27

the upper flaring portion of the pelvis, usually identified as the hipbone.

Question 28

Pelvic girdle: Ischium

Answer 28

stronger lower portion of the pelvis, also known as the floor of the pelvis.

Question 29

Pelvic girdle: Symphysis pubis

Answer 29

where pubic bones meet in front. A pad of cartilage joins the bones.