General Anatomy (Osteology)

Question 1

What is osteology?

Answer 1

• osteology is the study of bones
• bone is a living tissue. It has blood vessels, lymph vessels and nerves
• bones have an organic framework of fibrous tissue and cells among which inorganic salts are deposited
• bone matrix - contains inorganic salts, primarily calcium phosphate and some calcium carbonate, and collagen fibers.
• These and a few other salts are deposited in the framework of collagen fibers, a process called calcification or mineralisation.
• Mineral salts confer hardness of bone while collagen fibers give bone its great tensile strength.
• The process of calcification occurs only in the presence of collagen fibers.

Question 2

How do bones work?

Answer 2

Bone structure is somewhat similar to reinforced concrete that contains structural metal reinforcement rods or bars. These metal reinforcements are commonly called rebar. Protein strands make up the rebar of bone. Calcium and phosphorus mineral crystals deposited around the protein strands are somewhat like the concrete poured around the rebar in reinforced concrete. The protein strands provide the tensile strength that holds everything together and the minerals provide the solid structure. If bones were made only of protein, they would be too flexible. If bones were made solely from minerals, the skeleton would be too brittle.

Question 3

What is the skeleton divided in?

Answer 3

For the convenience of study, the skeleton is divided into axial and appendicular parts.

Question 4

What is the axial skeleton?

Answer 4

The axial skeleton consists of 80 bones that form the axis of the body and which supports and protects the organs of the head, neck, and trunk.
• Skull
• Auditory ossicles
• Hyoid bone
• Vertebral column
• Thoracic cage

Question 5

What is the appendicular skeleton?

Answer 5

The appendicular skeleton is composed of 126 bones of the upper and lower limbs and the bony girdles, which anchor the appendages to the axial skeleton.
• The shoulder girdle (the scapula and clavicle)
• The upper limb (the humerus, ulna, radius and bones of the hand)
• The pelvic girdle (the hip bone)
• The lower limb (the femur, tibia, fibula and bones of the foot)

Question 6

What are the functions of the bones?

Answer 6

1. support - Support the body. Eg. pelvis
2. levers for muscles (movements / locomotion) - Muscles are attached to the bones. When muscles contract, the bones act as levers to allow movements. Eg. humerus
3. protection to brain, heart, lungs, etc. - Bones protect important organs such as the brain, heart, and lungs. Eg. Skull, ribs
4. production of blood cells - Blood cells (red blood cells, white blood cells, platelets are produced in the red marrow of bones). Eg. Vertebrae, sternum, pelvis
5. storehouses for calcium and phosphorus - The calcium and phosphate can be released or stored in the bone to maintain constant concentration of these ions in body fluids. Eg. All bones

Question 7

What are the two types of stem cells?

Answer 7

hemopoietic (which can produce blood cells) and stromal (which can produce fat, cartilage and bone)

Question 8

What are the two types of marrow?

Answer 8

There are two types of bone marrow: red marrow (also known as myeloid tissue) and yellow marrow.

Question 9

What does the red and yellow marrow contain?

Answer 9

Red blood cells, platelets and most white blood cells arise in red marrow; some white blood cells develop in yellow marrow.

Question 10

What happens when there is severe blood loss?

Answer 10

the body can convert yellow marrow back to red marrow in order to increase blood cell production.

Question 11

What does the bone matrix contain?

Answer 11

• Inorganic mineral salts provide bone’s hardness – hydroxyapatite (calcium phosphate) & calcium carbonate
• Organic collagen fibers provide bone’s flexibility – their tensile strength resists being stretched or torn
• Bone is not completely solid since it has small spaces for vessels and red bone marrow
– spongy bone has many such spaces
– compact bone has very few such spaces

Question 12

What is the difference between spongy and compact bone?

Answer 12

Spongy
- area - makes up the inner cavity of the bones
- porosity - more
- also known as - cancellous tissue
- functional unit - trabeculae

Compact
- area - outer covering
- porosity - less
- also known as - cortical tissue
- functional unit - osteons

Question 13

What is Diaphysis?

Answer 13

Long central shaft

Question 14

What is epiphysis?

Answer 14

Rounded ends of long bones

Question 15

What is epiphyseal plates?

Answer 15

Plates of cartilage, known as growth plates which allow growth in length childhood

Question 16

What is a cancellous bone?

Answer 16

Where blood cells are made?

Question 17

What is a compact bone?

Answer 17

Gives strength to the hollow part of the bone

Question 18

What is the periosteum?

Answer 18

Ligaments and tendons attach to the periosteum

Question 19

What is marrow cavity?

Answer 19

Where white blood cells are made

Question 20

What are the classifications of bones?

Answer 20

• Every adult skeleton contains 206 major bones, which can be divided into six broad categories according to their individual shapes.

• Long bones (Eg. Humerus, phalanges)
• Flat bones (Eg. Cranium)
• Sutural bones (Eg. Cranial sutures)
• Irregular bones (Eg. Facial bones)
• Short bones (Eg. Tarsus and carpus)
• Sesamoid bones (Eg. Patella)

Question 21

What do flat bones do?

Answer 21

Protect internal organs
- cranial bones
- scapulae
- sternum
- ribs

Question 22

What do the long bones do?

Answer 22

Support weight and facilitate movement?
- humerus
- radius
- ulna
- metacarpal
- phalanges
- metatarsal
- tibia
- fibula
- femur

Question 23

What are short bones?

Answer 23

Cube shaped
- tarsals
- carpals

Question 24

What are irregular bones?

Answer 24

Complex shapes
- vertebrae
- sacrum

Question 25

What are sesamoid bones?

Answer 25

Reinforce tendons
- patella

Question 26

What are bone surface markings?

Answer 26

Markings are distinct features seen on a bone. They occur wherever fibrous tissue or muscle is attached to the bone.

Question 27

What are the different types of bone markings?

Answer 27

• elevation
  linear elevation – line, ridge, crest
  rounded elevation – tubercle, tuberosity, malleolus, trochanter sharp elevation – spine, styloid process
• facets
  small, smooth, flat areas
• depressions
  small – pit or fovea
  large – fossa
  has length – groove or sulcus
  when bridged by a ligament or a bone – notch or incisura foramen – perforation or hole
  canal or meatus – perforation that has length. A canal has an orifice (os or ostium) at each end

Question 28

What are periosteal arteries?

Answer 28

Accompanied by nerves supply the periosteum and compact bone

Question 29

What are epiphyseal veins?

Answer 29

Carry blood away from long bones

Question 30

What nerves accompany the blood vessels that supply bones?

Answer 30

The periosteum is rich in sensory nerves sensitive to tearing or tension

Question 31

What are heterotrophic bone?

Answer 31

• HO is the process by which bone tissue forms outside of the skeleton usually in the soft tissue
• can be caused by surgery or trauma to the hips and legs
• most common examples are horse riders where they develop it in their thighs or buttocks

Question 32

What is the difference between osteomalacia and osteoporosis?

Answer 32

• def - demineralization of the bones
• presence - adults
• signs and symptoms - weakness of the muscles and fragile bones
• causes - deficiency in vitamin D
• treatment - injections of vitamin D
• def - reduction of the bone mineral density
• presence - > or equal to 65 years women
• signs and symptoms - curving of the back and risk for fractures
• causes - deficiency in calcium and phosphorus, drugs, inherited, endocrine disorders, alcohol drinking.
• treatments - healthy lifestyle, calcium supplements and natural calcium diet

Question 33

What are rickets and osteomalacia?

Answer 33

-Rickets - in children prior to epiphyseal fusion, vitamin D deficiency results in growth retardation associated with an expansion of the growth plate

-Osteomalacia - in adults the hypocalcemia and hypophosphatemia that accompany vitamin D deficiency result in impaired mineralization of bone matrix proteins

Question 34

What is osteoporosis?

Answer 34

Osteoporosis is a bone disease that occurs when the body loses too much bone, makes too little bone, or both.

Question 35

What happens as a result of osteoporosis?

Answer 35

bones become weak and may break from a fall or, in serious cases, from sneezing or minor
bumps. Osteoporosis means “porous bone.”