Biological anthropology of the human skeleton

ANT 3514C – Introduction to Biological Anthropology

Lab 4: Human Osteology
Use Appendix A of Your Textbook as a Guide. You may also refer to the following websites for this lab and any that follow: http://www.eskeletons.org/, http://

humanorigins.si.edu/evidence/3d-collection, and https://human.biodigital.com/ (for this website you will need to create an account but it is free!)
Lab Objectives:

• Apply positional terminology to describe the relationships of osteological features

• Identify and label the largest bones and features of the human skull and skeleton

• Identify the human dental formula and different tooth types

• Examine the functional implications of different skeletal regions

• Understand the dynamic biology of the human skeleton over an individual’s lifespan

Purpose: To provide an introduction to basic osteological knowledge.

Osteology is the detailed study of bones and teeth. It should come as no surprise that for many centuries people have been heavily invested in studying human anatomy for its medical applications. The fundamentals of human anatomy were understood by most ancient civilizations, and the study of anatomy in Western universities – even through the Middle Ages – was founded on the antique writings of the Greek physician Aelius Galenus (“Galen”) from the late 100’s A.D. Ironically, the laws of the Roman Empire that Galen served forbade the dissection of human beings, and therefore his anatomical descriptions were based not on the direct study of humans, but rather the comparative study of animals such as pigs and primates. It wasn’t until the Renaissance that intellectual curiosity in the human body was reborn and the study of human anatomy was pursued again in earnest. Principal among these anatomists were figures such as Henry Gray (of “Gray’s Anatomy”) and Georges Cuvier, who pushed the study of comparative anatomy to new limits and founded the field of paleontology.

While the skeleton plays an obvious role as the support system for the rest of the body—making movement possible, and protecting vital organs like the heart, lungs, and brain—a new understanding is emerging of bones as an important, dynamic organ of the body. Your bones achieve their shape thanks to the influence of the muscles, blood vessels, and nerves that surround them, but continue to change throughout life in response to activity, nutrition, and disease. In addition to vital metabolic and physiological functions, bones produce a hormone (an important messaging molecule in the body) named osteocalcin that plays a vital role in your body’s ability to maintain healthy blood sugar, regulate testosterone levels, and stave off depression.

Despite its deep roots in the study of anatomy, human osteology, especially in terms of variation and development, is still the subject of much new research utilizing state-of-the-art methods. Bone histology, laser scanning, computed tomography, and strain analyses are just some of the newest techniques used at both the micro and macro scale to examine the properties of human bone from every angle. Using such powerful methods, biological anthropologists are able to answer questions about human identity, ancestry, lifestyle, development, and evolution from studying bones alone

STATION 1: Anatomical Directions/Planes

Observe the articulated human and macaque skeletons, both in anatomical position, to answer the following questions. The definitions of these terms always have the same meaning, but the direction they point in will change based on an animal’s normal posture. For instance, think about how you, a biped, normally stand vs. a quadruped, like a dog (or a horse, or a baboon).

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Anatomical Plane Definitions:

• Coronal Plane:

Divides the body into anterior and posterior halves.

• Sagittal Plane:

Divides the body into left and right halves.

• Transverse Plane:

Divides the body into superior and inferior halves

Use the definitions on page 2 of this lab to answer the following questions about the articulated human and macaque skeletons: (1 pt)

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A is ______________________ or ______________________ to B on the human skeleton.

C is ______________________ or ______________________ to D on the macaque skeleton.

F is ______________________ to G on both the macaque and human skeleton.

The blue line runs along the ________________________ plane of the human skeleton.

STATION 2: Skull

The skull plays an important role in understanding evolutionary history. (1.25 pts)

( Photo credit: eskeletons.org )

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Name the three sutures marked with #s. Name the three bones marked with letters.

1. _______________________________ A. _______________________________

2. _______________________________ B. _______________________________ 3. _______________________________ C. _______________________________

4. Which two bones make up the zygomatic arch?

STATION 3: Dentition

Because teeth preserve well in the fossil/archaeological record, they are often used in constructing phylogenetic relationships among living and extinct organisms. (1.25 pts) Examine the following pictures and answer the following questions.

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1. What are the four human tooth types?

2. What is the human dental formula? Please write out in the standard order.

3. Name the bone that holds the upper teeth and the bone that holds the lower teeth.

STATION 4: Vertebral Column

Examine the vertebral column. There are 24 movable vertebrae – 7 cervical, 12 thoracic, and 5 lumbar. The sacrum and coccyx are fused vertebrae and form part of the bony pelvis. (0.5 pt) Watch this video: https://www.youtube.com/watch?v=9kweC-1XCoY.

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1. The vertebrae bear body weight, anchor ligaments and muscles, and protect the spinal cord. What is the name of the repeating structure that separates each unfused vertebra?

2. Which group of vertebrae articulates with the ribs?

STATION 5: Pelvis

The human pelvis protects and supports abdominal organs, while anchoring muscles of the abdomen and lower limb. It is an area that provides critical information on locomotion patterns and sex determination. (1 pt)

1. Which three bones fuse to form the os coxa? Underline the bone on which you sit.

2. Just observe the ball-and-socket hip joint. Notice how the femoral head articulates with the acetabulum in this video (https://www.youtube.com/watch?v=gQnMPHoDGEc). You will see how this joint looks different from the shoulder joint in Station 6. (No written response is required here.)

STATION 6: Upper limb

Observe the provided specimen and the articulated skeleton near this station when answering these questions. (1.5 pts)

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1. Which bone of the lower arm is on the same side as your pinkie? _________________ 2. Which bone of the lower arm is on the same side as your thumb? _________________

3. A) List the two bones that, along with the humerus, form the shoulder joint.

B) Name the two features of the distal humerus that articulate with the radius and ulna at the elbow joint.

4. Compare the shoulder joint (https://www.youtube.com/watch?v=5pjk_yW-JsU) to the hip joint in Station 5.

STATION 7: Hands & Feet

Compare the articulated hand (http://www.eskeletons.org/boneviewer/nid/12537/region/hands/ bone/Articulated%20hand) and foot (http://www.eskeletons.org/boneviewer/nid/12537/region/ feet/bone/Articulated%20foot) . The rays or digits are numbered one through five beginning with the thumb or big toe. (0.5 pt)

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1. What are some of the differences you observe between the hand and the foot? How can these differences be attributed to function?

Reading Assignment: Ruff CB (2006) Gracilization of the modern human skeleton. American Scientist 94(6): 508-514. (2 pts)

Do not copy from the text without proper quotation marks and attribution.

1. Define the following terms as they apply to skeletal material. Be sure your definitions make sense in an osteological context:

a. Robust:

b. Gracile:

2. Describe how bone properties change during the normal aging process throughout a modern human lifespan. (You can draw a diagram illustrating this if you wish, but if you do its meaning must be clear to receive credit.) Note that there are two phases to describe: 1) bone growth as the individual grows to maturity, and 2) bone degeneration in old age.

3. What cultural explanations have been used to account for the gracilization of the human skeleton during our recent evolution?

After Lab Activity: (1 pt)

Use Appendix A of your text and the following terms list to label the skeleton.

Sternum

Frontal

Parietal

Mandible

Metatarsals

Clavicle

Scapula

Humerus

Patella

Tibia

Ulna

Fibula

Metacarpals

Os Coxa (also innominate bone)

Femur

Carpals

Tarsals

Radius

Vertebra

Phalanges (use this term twice)