Name:
Group: _______________
Date: ____________
Skeletal Investigations – Student Workbook pages 133 to 136
Label the structures:
Observations of a Long Bone
Overall
Shape:
Periosteum
Colour:
Properties:
Spongy bone vs Cow
Compact bone
Colour:
Thickness:
Location:
Hardness:
Epiphyseal
Colour:
growth plate
Thickness:
Location:
(Calf)
Articular
Colour:
cartilage
Texture:
Thickness:
Location:
Marrow
Cow
Colour:
Texture:
Malleability:
Thick/Thin?
Calf
Calf
Analysis
What is the advantage of having thicker compact bone at the diaphyses?
Why is there spongy bone in the epiphyses?
Why do you think that long bones are hollow?
What is the advantage of the articular cartilage? How would movement be affected if there was no
cartilage at the epiphyses?
Long bones are found in the limbs and ten to be long relative to their diameter. They are also curved
to give them strength. Each has a shaft and two enlarged ends.
 List several long bones in the human skeleton.
 Suggest two reasons why it is an advantage for the ends of long bones to be enlarged.
For more information:
http://www.ivy-rose.co.uk/HumanBody/Skeletal/Skeletal_System.php
http://depts.washington.edu/bonebio/ASBMRed/structure.html
Name: Answer Key
Group: _______________
Date: ____________
Skeletal Investigations – Student Workbook pages 133 to 136
Investigation 1: Studying a fresh bone
Label the structures:
periosteum
cartilage
Spongy bone
Compact bone
marrow
Growth plate
Observations
Structure
Observations
Overall
Shape: longer than it is wide, enlarged at the ends, hard smooth surfaces
Diaphysis: long thinner shaft of bone
Epiphysis: enlarged ends of bone, rounded parts
Periosteum
Colour: dark, reddish brown (filled with blood vessels)
Texture: dried, leathery
Thickness: very thin, like skin
Spongy bone vs Colour: darker cream or tan
Compact bone
Thickness: fairly thick; 3-7 cm
Location: inside epiphyses
Whiter than spongy
1 – 2 cm
surrounds diaphysis
Epiphyseal
growth plate
Colour: darker than spongy bone
Thickness: fairly thin; less than 1 cm
Location clear line dividing spongy bone in the epiphysis
Articular
cartilage
Colour: brighter white than bone
Texture: smooth, glassy
Thickness: fairly thin, less than 1 cm
Location: ends of ephiphyses
Marrow (cow vs Colour: creamy yellow
calf)
Texture: softer than bone, compressible
Darker than cow marrow, reddish
softer than cow marrow
Analysis
Compare the thickness of compact bone at the epiphysis and diaphysis. What is the advantage of
having thicker compact bone at the diaphyses?
Compact bone is much stronger than spongy bone. The diaphyses needs to be able to absorb large
tension forces.
Why is there spongy bone in the epiphyses?
Spongy bone has more spaces where blood vessels and bone marrow is found. It is also much
lighter than compact bone so it decreases the overall weight of the skeleton. The hollows inside
spongy bone include many arches which help it to withstand large compression forces.
Why do you think that long bones are hollow?
The hollow in long bones is called the medullary cavity. It is filled with red marrow at birth and
gradually changes to yellow marrow which contains more fat. Marrow is essential in forming all
types of blood cells.
Also, if long bones were solid, their weight would greatly increase the mass of the person, making it
much more difficult to move.
What is the advantage of the articular cartilage? How would movement be affected if there was no
cartilage at the epiphyses?
The articular cartilage is a hard, smooth surface that lines the ends of bones inside moveable joints.
If there was no cartilage the bones would grind against each other, damaging their ends and
making movement very painful.
Long bones are found in the limbs and ten to be long relative to their diameter. They are also curved
to give them strength. Each has a shaft and two enlarged ends.
 List several long bones in the human skeleton.
 Suggest two reasons why it is an advantage for the ends of long bones to be enlarged.
Femur, tibia, fibula, humerus, radius, ulna, metacarpals, metatarsals, phalanges
The enlarged diaphyses have room on the inside for spongy bone which is necessary for forming
blood cells. They need to be large enough to form a reliable moveable joint. Their size also makes
it possible for ligaments to be attached.
For more information:
http://www.ivy-rose.co.uk/HumanBody/Skeletal/Skeletal_System.php
http://depts.washington.edu/bonebio/ASBMRed/structure.html