Health Sciences 2300A/B Study Guide - Midterm Guide: External Occipital Protuberance, Supraorbital Ridge, Mastoid Part Of The Temporal Bone
1 May 2018
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Bone and Axial Skeleton – Exam Study Guide
What are the main functions of the skeletal system?
The skeletal system supports and is the structural framework for the body. It is an attachment
point for muscles, tendons and protects organs from damage. It also stores minerals, releases
calcium and can produce bone marrow.
How are bones classified?
1. Type of Bony Tissue
- Cortical
- Spongy
2. Shape of Bone
- Long
- Short
- Flat
- Irregular
- Sesamoid
What are the differences between cortical bone and spongy bone?
Cortical Bone
Makes up bone surfaces (found in all bones) and is made of osteons (concentric lamellae
around a Haversian canal). The osteons are parallel for strength.
Spongy Bone
Makes up the interior of bones and does not osteons which lightens the bones. Lamella are
arranged in irregular patter on columns (trabeculae), while the space b/w the trabeculae allows
for bone marrow growth.
Clinical Correlate - Describe osteoporosis and how it affects the bone.
Results from a reduction in the quantity of bone tissue which causes bones to become brittle
and fracture easily. There is more free space in the bone due to loss of bony tissue.
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and fracture easily. There is more free space in the bone due to loss of bony tissue.
Clinical Correlate - How does bone mass differ in males and females?
At birth males and females have the same bone density, while we can continue to increase it
until the age of 30. Males tend to reach a higher peak than females do. Females have a massive
drop in bone mass b/w 50-60 due to menopause.
Describe the anatomy of a typical long bone and give an example.
Long bones have to a close to equal distribution of compact and spongy bone and are curved
for strength. Ex. Femur.
Describe the anatomy of a typical short bone and give an example.
They are light because they are primarily made of spongy bone - with an equal length and
width and are cube shaped. Ex. Wrist.
Describe the anatomy of a typical flat bone and give an example.
Provide surface area for muscle attachment. Mostly compact bone, but some are spongy. Ex.
Skull and sternum.
Describe the anatomy of a typical irregular bones and give an example.
Vary in shape and proportion of compact to spongy while most have a complex shape. Ex.
Vertebrae and scapula.
Describe the anatomy of a typical sesamoid bone and give an example.
Develop in tendons and increase lever arm so muscles don't have to apply as much force to get
as much monument. Ex. Patella.
Describe the cells of the bone and each cell in the lineage.
Starts off with the osteoprogenitor cell (similar to stem cell) Becomes an osteoblast
Becomes an osteocyte Osteoclasts are separate
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How do the axial and appendicular skeleton connect?
Shoulder girdle
→ Scapula
→ Clavicle
- Pelvic girdle
→ Os coxae
Describe the structural organization of the skeleton and list the bones in axial skeleton.
The axial skeleton is organized starting with the:
1. Skull (Cranial and facial bones)
2. Hyoid bones (sits in the middle of the neck)
3. Vertebral column
4. Thorax (Sternum and ribs)
Clinical correlate - You are playing tag indoors with a friend, and you run into a screen
door. You notice that blood and clear fluid is dripping out of your nose. What has
happened?
The cribiform plate has fractured, (crista galli ruptures) allowing membranes around the brain
to rip and CSF fluid flows through the nose.
Clinical Correlate - What is a cleft palate and why is it so serious?
It occurs when 2 palatine processes fail to join during prenatal development and could be
accompanied by a cleft lip. Prevents baby from forming suction, thus preventing them from
eating.
Clinical Correlate - Why is a blow to the pterion so serious?
An important artery runs behind the pterion - if the artery severs, there is a lot of bleeding in
The only bone that isn’t connected to any other bones (apart from sesamoid bones)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Bone and axial skeleton exam study guide. The skeletal system supports and is the structural framework for the body. It is an attachment point for muscles, tendons and protects organs from damage. It also stores minerals, releases calcium and can produce bone marrow. How are bones classified: type of bony tissue. Makes up bone surfaces (found in all bones) and is made of osteons (concentric lamellae around a haversian canal). Makes up the interior of bones and does not osteons which lightens the bones. Lamella are arranged in irregular patter on columns (trabeculae), while the space b/w the trabeculae allows for bone marrow growth. Clinical correlate - describe osteoporosis and how it affects the bone. Results from a reduction in the quantity of bone tissue which causes bones to become brittle and fracture easily. There is more free space in the bone due to loss of bony tissue. and fracture easily.
