Bone Types & Skeleton Map
Name the five main types of bones by shape.
Long, short, flat, irregular, sesamoid.
Osteoblast, osteoclast, osteocyte, osteogenic cell
Write a “+” or “–” for each factor: (+ = beneficial for bone density, - = detrimental to bone density)
Normal estrogen and testosterone levels
Weight-bearing exercise
Smoking and heavy alcohol use
Normal hormones: +; weight-bearing exercise: +; smoking and heavy alcohol: –.
Define synarthrosis, amphiarthrosis, and diarthrosis by how much movement they allow.
Synarthrosis – immovable joint; amphiarthrosis – slightly movable joint; diarthrosis – freely movable joint
Name the three main regions of a long bone from one end to the other.
Proximal epiphysis, diaphysis, distal epiphysis.
Give 1 example of a long bone and say whether it is part of the axial or appendicular skeleton.
Example: femur, humerus, radius, ulna, tibia, fibula, metacarpals, metatarsals, phalanges; all are appendicular.
“A fetus’s skeleton starts as cartilage and slowly turns into bone.” Name the process this describes and explain why in 1 sentence.
Ossification; it is the process where cartilage is gradually replaced by bone tissue.
Write a “+” or “–” for each factor:
Long-term poor diet low in calcium and vitamin D
Aging into older adulthood
Frequent safe sun exposure
(+ = beneficial for bone density, - = detrimental to bone density)
Poor diet: –; older age: –; frequent safe sun exposure: +
Describe what is mainly between the bones in each structural joint type: fibrous, cartilaginous, and synovial.
Fibrous joint – dense fibrous connective tissue; cartilaginous joint – cartilage (hyaline or fibrocartilage); synovial joint – a fluid-filled synovial cavity with articular cartilage on bone ends
On a simple long bone drawing, label the diaphysis and both epiphyses. Explain in 1 sentence what the diaphysis is.
Diaphysis – the shaft or long middle portion of the bone between the epiphyses.
The skull and vertebrae belong to which subdivision of the skeleton, axial or appendicular? Explain the main job of this subdivision in 1 sentence.
Axial skeleton; it mainly provides support and protection for the brain, spinal cord, and organs in the thorax.
A runner’s femur thickens over years of training because it is constantly under mechanical stress. Identify the process (ossification, bone remodeling, or bone growth) and explain what two types of bone cells are working together to make this happen.
Bone remodeling; osteoclasts remove older or stressed bone while osteoblasts lay down new, stronger bone in response to stress.
Pick one “+” factor and one “–” factor for bone density from the study guide list, and explain in 2–3 sentences how each affects osteoblast and osteoclast activity.
Helpful factors (normal hormones, weight-bearing exercise, sun/vitamin D) tend to increase osteoblast activity or balance it with osteoclasts, increasing or maintaining bone mass. Harmful factors (smoking, poor diet, aging, certain medicines) increase osteoclast activity or decrease osteoblasts, reducing bone mass over time.
For skull sutures, name the structural class, functional class, and location in the body.
Structural: fibrous; functional: synarthrosis; location: between the bones of the skull.
What is the metaphysis, and what important structure did it contain while the bone was still growing?
Metaphysis – region between diaphysis and epiphysis; it contained the epiphyseal plate (growth plate), which later becomes the epiphyseal line after growth stops.
A student says, “The femur is part of the axial skeleton because it helps you stand up.” Explain in 2–3 sentences why this is incorrect, using the word “movement” at least once.
The femur is in the appendicular skeleton, which is mostly for movement of the limbs, not for forming the central axis. Standing and walking use the femur to move the lower limb, while the axial skeleton (skull, vertebral column, ribs, sternum) supports and protects the central body.
Place the correct letter (O, R, or G) next to each situation and justify one of them in 1–2 sentences.
O - Ossification, R - Remodeling, G - Growth
a) A broken tibia heals as new bone replaces damaged tissue.
b) A child’s femur gets longer at the growth plate.
c) A baby’s cartilage skeleton becomes bone.
a) R – bone remodeling; b) G – bone growth; c) O – ossification
A patient has done no weight-bearing exercise for years and has a long-term poor diet low in calcium and vitamin D. Describe, in 3–4 sentences, what is likely happening to their bone density over time and why.
Lack of exercise and poor diet reduce calcium availability and mechanical stress, so osteoblast activity is low while osteoclast activity continues. Over time, more bone is broken down than built, leading to lower bone density and higher risk of fractures.
Fill in the blanks:
a) Pubic symphysis: structural class, functional class, and location
b) Intervertebral joints: structural class, functional class, and location
Pubic symphysis – cartilaginous; amphiarthrosis; between the left and right pubic bones in the pelvis. Intervertebral joints – cartilaginous; amphiarthrosis; between vertebral bodies of the spine.
Describe where red bone marrow and yellow bone marrow are mainly found in a typical adult long bone and give the main function of each.
Red marrow – mainly in the epiphyses and spongy bone; function: blood cell production. Yellow marrow – mainly in the medullary cavity of the diaphysis; function: fat storage and energy reserve
Draw a simple stick-figure skeleton and label at least 3 axial bones and 3 appendicular bones. Under your drawing, list each labeled bone in a T-chart with the headings “Axial” and “Appendicular.”
Axial examples: skull, vertebrae, ribs, sternum. Appendicular examples: humerus, radius, ulna, pelvis (hip bone), femur, tibia, fibula, scapula.
Create a 4-cell “job description chart” for osteogenic cells, osteoblasts, osteoclasts, and osteocytes. In each box, write a 1-sentence job description that starts with “I am a ___ and I mainly…”
Osteogenic cell – stem cell that becomes bone-forming cells; osteoblast – builds new bone matrix; osteoclast – breaks down bone matrix; osteocyte – maintains bone tissue and senses stress
Design a mini “bone health plan” for a 16-year-old athlete who wants strong bones for life. Include at least 3 specific behaviors from the study guide factors and explain briefly how each helps bone density.
Example: do regular weight-bearing exercise (stimulates osteoblasts); eat a diet rich in calcium and vitamin D (provides building materials and supports mineralization); get frequent safe sun exposure (supports vitamin D production and calcium absorption); avoid smoking and heavy alcohol use (prevents excessive bone breakdown).
Make a 3-column table (Joint, Structural Class, Functional Class) and fill it in for: skull sutures, first rib–sternum, pubic symphysis, intervertebral joints, shoulder, hip, knee, and ankle.
Skull sutures – fibrous, synarthrosis
First rib–sternum – cartilaginous, synarthrosis or amphiarthrosis (depending on level taught; often “cartilaginous, synarthrosis”)
Pubic symphysis – cartilaginous, amphiarthrosis
Intervertebral joints – cartilaginous, amphiarthrosis
Shoulder – synovial, diarthrosis
Hip – synovial, diarthrosis
Knee – synovial, diarthrosis
Ankle – synovial, diarthrosis
Draw a long bone and:
Label diaphysis, proximal epiphysis, distal epiphysis, and one metaphysis
Shade and label the medullary cavity and at least one nutrient artery
Show where red marrow and yellow marrow are located
Then, in 2–3 sentences, explain why the bone needs nutrient arteries.
Nutrient arteries deliver oxygen, nutrients, and calcium to bone cells so osteoblasts, osteoclasts, and osteocytes can stay alive and active. Without blood supply, bone tissue would die and could not remodel, grow, or repair itself.