Name: Date: 12/6/17 Section:

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1 1 Name: Date: 12/6/17 Section: Education s purpose is to replace an empty mind with an open one. Malcolm Forbes

2 Chapter 7 Vocabulary Words Forensic Anthropology Vocabulary for Chapter 7 Term Definition 1. Anthropology 2 2. Epiphysis 3. Forensic Anthropology 4. Joints 5. Mitochondrial DNA 6. Ossification 7. Osteoclast 8. Osteobiography 9. Osteocyte 10. Osteoblast 11. Osteoporosis 12. Skeletal Trauma Analysis 13. Sesamoid Bones 14. Epiphyseal Line 15. Cranium

3 3 Objectives By the end of this chapter you will be able to Describe how bone is formed. Distinguish between male and female skeletal remains based on skull, jaw, brow ridge, pelvis, and femur. Describe how bones contain a record of injuries and disease. Describe how a person s approximate age could be determined by examining his or her bones. Explain the differences in facial structures among different races. Describe the role of mitochondrial DNA in bone identification. Anthropology is the scientific study of all aspects of human development and interaction. It studies tools, language, traditions, and social interactions and how we relate to other societies. Physical anthropology studies human differences, especially those by which we can be identified. Forensic anthropology studies these identifying characteristics on the remains of an individual. These unique characteristics can be used to demonstrate the sex, race, height, and physical health of a victim from his or her remains. In Europe in the 1800s, the origins of the races of humans were heatedly discussed. Scientists began using skull measurements to differentiate among individuals. The differences between male and female anatomy, and the formation, aging, and fusing of bones were also examined, laying the framework for today s knowledge. The Luetgert murder case of 1897 accused a sausage maker of killing his wife and boiling down her corpse. Remains found in the factory appeared to be fragments of his wife s skull, finger, and arm. In 1932, the FBI announced the opening of its first crime lab. The Smithsonian Institution became a working partner, aiding in the identification of human remains. Development of Bone Bones originate from living cells called osteoblasts. During the development of the fetus, bones begin as soft cartilage, the same flexible material that makes up our ears. Osteoblasts migrate to the centers of cartilage production and deposit minerals, such as calcium phosphate, that harden to form bone. This process is called ossification and begins during the first few weeks of pregnancy. By the eighth week of pregnancy, the outline of the skeleton has formed and is visible in an X-ray. As bone develops, a protective membrane layer that contains nerves and blood vessels covers the surface of the bone. This membrane, called the perisoteum, serves an important role in keeping bones moist and aiding in

4 the repair of injuries. Throughout our lives, bone is deposited, broken down, and replaced. When an arm or leg is broken, the blood vessels at the area have the ability to increase calcium phosphate deposition to help heal the break. Newly trapped osteoblasts, called osteocytes, form the new bone framework. These cells can no longer produce new bone and become the basic framework for the new bone. Osteoclasts, the second type of bone cell, are specialized to dissolve bone. As bones grow, they need to be reshaped. Simply adding layer upon layer of calcium phosphate would not maintain the proper shape of the bone. Therefore, as bones grow, the osteoclasts secrete enzymes that help dissolve certain areas of the bone. Osteoclasts also aid in maintaining homeostasis within the body. Calcium, a mineral that is vital to normal metabolism, may be borrowed from bone when levels in the blood are low. Osteoclasts dissolve the bone and release calcium into the blood. Continued failure to eat enough calcium can result in a weakening of bones. This condition is called osteoporosis. A third function of the osteoclasts is to remove cellular wastes and debris from the bones. When bones become injured, the osteoclasts secrete enzymes that dissolve the injured or damaged part of the bone so that new, healthy bone can be laid down. Number of Bones How many bones are in the human body? Most medical students will tell you 206. That answer is only partially correct. An adult has 206 bones after all bones have become fully developed. So much about a person is revealed by examination of his or her bones. The term osteobiography literally translates as the story of a life told by the bones. 4

5 CASE STUDIES Elmer McCurdy (1911) Train robber Elmer McCurdy was cornered in a hayloft and killed by gunshot. His body was embalmed with arsenic by the undertaker but remained unclaimed. The undertaker put Elmer on display, charging five cents to view the Bandit Who Wouldn t Give Up. Several years later, his body was claimed by someone claiming to be his brother, and taken to California, where it was coated in wax and displayed in several circuses and amusement parks, and then forgotten. Recently, during the filming of a TV show at the Nu-Pike Amusement Park, someone tried to move what they thought was a dummy and accidentally pulled off his mummified arm. The body was well preserved, yet no medical or dental records existed to give the body a name. Forensic anthropologists measured his facial dimensions, the lengths of his arms and legs, and the symphysis of his pubic bone. These details provided identification evidence for the state to put Elmer McCurdy to rest, once again. The Romanovs (1918) On July 16, 1918, the last royal family of Russia Tsar Nicholas II, his wife Alexandra, four daughters, one son, and their servants died at the hands of a firing squad (Figure 13-25). Bolshevik Jacob Yurosky, who commanded the death squad, boasted that the world would never know what had happened to the royal family. That was true for the next 75 years, until a team of specialists including Michael Baden, William Maples, and forensic odontologist Lowell Levine examined the skeletons discovered in a shallow grave outside of Ekaterinburg, Russia (Figure 13-26). The team was able to determine the age and sex of all nine skeletons. Five were identified as females and four as males. The skulls had all been crushed, making identification difficult. Think Critically Select one of the Case Studies and explain what forensic anthropology techniques were used for identification. 5

6 Primary Learning Objective(s) Students will describe what the skeletal system is (the number of bones and what bones are made of: Students will describe at least two ways in which our bones protect our body. Students will describe how our bones enable movement. Students will discuss why human growth occurs. Students will state ways to keep our bones healthy. The main bones of the human skeleton are: The Skull - Cranium, Mandible and Maxilla Shoulder girdle - clavicle and scapula Arm - Humerus, radius and ulna Hand - Carpals, Metacarpals and Phalanges Chest - Sternum and Ribs Spine - Cervical area (top 7 vertebrae), Thoracic (next 12), Lumbar (bottom 5 vertebrae), Sacrum (5 fused or stuck together bones) and Coccyx (the tiny bit at the bottom of the spine). Pelvic girdle - Ilium, Pubis and Ischium. Leg - Femur, Tibia and Fibula Ankle - Talus and calcaneus. Foot - Tarsals, Metatarsals and Phalanges. How are bones formed? Bones are formed by the ossification of cartilage. What this really means is all bones start off as cartilage (normally in the womb) and they gradually turn to hard bone (ossification) over a period of years. Calcium is needed for strong bone growth. Types of Bones There are 5 types of bones in the human body. These are long bones, short bones, flat bones, irregular bones and sesamoid bones. 1. Long Bones Long bones are some of the longest bones in the body, such as the Femur, Humerus and Tibia but are also some of the smallest including the Metacarpals, Metatarsals and Phalanges. The classification of a long bone includes having a body which is longer than it is wide, with growth plates (epiphysis) at either end, having a hard-outer surface of compact bone and a spongy inner known a cancellous bone containing bone marrow. Both ends of the bone are covered in hyaline cartilage to help protect the bone and aid shock absorption. 6

7 7 2. Short Bones Short bones are defined as being approximately as wide as they are long and have a primary function of providing support and stability with little movement. Examples of short bones are the Carpals and Tarsals - the wrist and foot bones. They consist of only a thin layer of compact, hard bone with cancellous bone on the inside along with relatively large amounts of bone marrow. 3. Flat Bones Flat bones are as they sound, strong, flat plates of bone with the main function of providing protection to the bodies vital organs and being a base for muscular attachment. The classic example of a flat bone is the Scapula (shoulder blade). The Sternum (breast bone), Cranium (skull), oscoxae (hip bone) Pelvis and Ribs are also classified as flat bones. Anterior and posterior surfaces are formed of compact bone to provide strength for protection with the center consisting of cancellous (spongy) bone and varying amounts of bone marrow. In adults, the highest number of red blood cells are formed in flat bones. 4. Irregular Bones These are bones in the body which do not fall into any other category, due to their non-uniform shape. Good examples of these are the Vertebrae, Sacrum and Mandible (lower jaw). They primarily consist of cancellous bone, with a thin outer layer of compact bone. 5. Sesamoid Bones Sesamoid bones are usually short or irregular bones, embedded in a tendon. The most obvious example of this is the Patella (knee cap) which sits within the Patella or Quadriceps tendon. Other sesamoid bones are the Pisiform (smallest of the Carpals) and the two small bones at the base of the 1st Metatarsal. Sesamoid bones are usually present in a tendon where it passes over a joint which serves to protect the tendon.

8 How to Distinguish Males from Females 8 Often, a detective s first question to a forensic anthropologist is whether the skeleton belongs to a male or female. How can one differentiate sex from bone fragments? The overall appearance of the female s skeleton tends to be much smoother (gracile) and less knobby than that of a male s skeleton (robust). A man s skeleton is usually thicker, rougher, and appears quite bumpy. Because of male hormones, muscles are more developed in the male. When muscles are larger, they require a stronger attachment site on the bones. To accommodate the larger muscles and their tendons, the surface of the bone where a muscle and tendon attach is thicker, creating the appearance of a rough or bumpy area. Pelvis One of the easiest methods of determining the sex of a skeleton is to examine the pelvis. Because of the anatomical differences needed for childbearing, this region of the body exhibits many differences. The surface of a woman s pelvis is engraved with scars if she has borne children. During the fourth month of pregnancy, hormones are released that soften the tendons in the pelvic area to help accommodate the developing fetus. These scars can be detected on the pubic symphysis, a cartilaginous area where the bones meet. To distinguish between the male and female pelvis, compare the following: Subpubic angle Length, width, shape, and angle of the sacrum (Figure 13-14) Width of the ileum Angle of the sciatic notch The major bones of the pelvis 1 Joint, 2 Ileum, 3 Sacrum, 4 Coccyx, 5 Joint,,6 Ischium, 7 Pubis symphysis, 8 Obturator foramen.

9 How to Distinguish Males from Females 9

10 How to Distinguish Males from Females 10

11 How to Distinguish Males from Females 11

12 Activity No Bone Matrix Coloring 12 Coloring Directions Lamella (A) - light blue Spongy Bone (B) green Volkman's Canal (F) orange Haversian Canal (D) yellow Compact Bone (E) -- light brown Periosteum (C) pink Lacuna (I) - dark blue Osteocyte (H) red Canaliculi (G) purple 1. What structure connects osteocytes? 2. Osteocytes form rings called 3. What canal is found in the center of the rings? 4. Osteocytes are within chambers called

13 Activity No Anatomy of a Bone -Coloring Epiphysis (a) - at the ends of the bone (do not color). The epiphysis has a thin layer of compact bone, while internally the bone is cancellous. The epiphysis is capped with articular cartilage. Epiphysial line (j) purple. The epiphysial line or disk is also called the growth plate, it is found on both ends of the long bone. Diaphysis (shaft) (b) - do not color. The diaphysis is the shaft of the long bone. It has compact bone with a central cavity. Articular cartilage (c) green - The articular cartilage is found on the ends of long bones. It is smooth, slippery, and bloodless. Color both ends. Periosteum (d) - dark blue - Periosteum is a vascular, sensitive life support covering for bone. It provides nutrient-rich blood for bone cells and is a source of bone-developing cells during growth or after a fracture. Color both sides, it is the outermost layer. Cancellous (spongy) BONE (e) and MARROW (e) red - The cancellous bone is found mainly within the epiphysis and has a textured appearance where it contains red marrow. Color both ends. Compact bone (f) pink - The compact bone is a dense bone found in the diaphysis. Its repeated pattern is arranged in concentric layers of solid bone tissue. The compact bone can be seen as the layer just underneath the periosteum, color both ends. Medullary cavity (g), yellow marrow (g) yellow - The medullar cavity of the diaphysis serves to lighten bone weight and provide space for marrow. Yellow marrow is associated with fat. Endosteum (h)- light blue. This tissue lines the medullary cavity of bone. Thinking Critically Where do you find yellow marrow (be specific)? What type of bone is arranged in concentric layers? Where do you find red marrow? What is the end of the bone called? Spongy bone is also called bone. What cushions the ends of bones at their joints? 13 Worksheet No. 13 Directions: Identify the Skeletal Bones

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15 Worksheet No

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17 Activity No Human Skeleton Hand Puppet 17

18 The Human Skull Generally, the male skull is more massive and bumpier than the female skull. There are many specific differences, but the first step is to review the major bones of the skull. Note the differences between the male and female skulls. The male s frontal bone is low and sloping, whereas the female s frontal bone is higher and more rounded. The male eye orbits tend to be square, whereas the female s eye orbits are more circular. The male s lower jaw is square, with an angle of about 90 degrees. The female s lower jaw is sloped, with an angle greater than 90 degrees. Males also have squarer chins; females chins are rounder or more V-shaped. The occipital protuberance, a bony knob on the male skull, serves as an attachment site for the many muscles and tendons of the neck. Because the muscles in a man s neck are larger than the muscles in a woman s neck, the area of attachment needs to be thicker, creating the protuberance on the male skull. 18

19 The Human Skull 19

20 Worksheet No. 15 The Human Skull Directions: Identify the bones of the Human Skull 20