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Human Remains Using the Forensic Science Textbook by Funkhouser read Chapter 12Human Remains. Complete the Following: 1. Activity on page 274---Identifying Bones 2. Activity on page 275---Estimating Height, 3. Activity on page 278—Determining Sex Using the Os Pubis 4. Activity on page 279---Determining Sex using Skull features 5. Activity on page p 282 Determining Age Using the Epiphyses 6. Draw a diagram that illustrates the difference between male and female pubic bone. Label pubic arch, pubic body, ventral arch( in female) Objectives- pg. 269. After reading this chapter, you will understand: 1. How anthropologists can use bones to determine whether remains are human; to determine the sex, age, and sometimes race of an individual; to estimate the height; and to determine when the death may have occurred. You are responsible for knowing: 1. How to distinguish between a male and a female skeleton. 2. Give the age range after examining unknown remains 3. Describe the differences in skull features among the three major racial categories 4. Estimate the height by measuring the long bones 5. Describe the livor mortis, rigor mortis, and algor mortis 6. Anything else I decide to add. Quiz over pages 269-274 Human Remains--Notes Forensic Science Textbook by Funkhouser read Chapter 12-Human Remains. A pathologist or medical examiner usually determines the time of death. This is done most accurately if the body is found within the first 24 hours of death. One of many ways to help determine the time of death is indicators such as: Algor mortis Livor mortis Rigor mortis Algor mortis refers to the cooling rate of the body after death. The body cools at a rate of approximately 1-11/2 oF per hour until it reaches the environmental temperature Livor mortis refers to the pooling of blood in the body after the heart stops, caused by gravity. It will appear on the skin as a purplish red discoloration and can indicate the position of the body at the time of death. There is no livor mortis in the areas that touch the ground or that are constricted by other objects because the capillaries are compressed, preventing blood pooling. Livor mortis begins within 30 minutes of death and is most evident after 12 hours after death. After that, the discoloration of livor mortis will not move regardless of how the body is disturbed. This can be useful in determining whether a body has been moved after death Rigor mortis refers to the rigidity of the skeletal muscles after death. As soon as a person dies, the muscles relax, the ATP (adenosine triphosphate) in the muscles begin to break down, fluid concentrations change, and the muscles become rigid. Because rigor mortis begins in the smaller muscles, it is seen first in the face, neck, and jaw. The noticeable stiffness of rigor mortis occurs within 2 or 3 hours after death and is gone within approximately 30 hours, leaving the body limp. The effects of rigor begin to disappear in the same order as they began, the small muscles becoming limp first, then the larger muscles of the trunk, arms, and legs. Rigor mortis is also affected by the environmental conditions such as temperature, dehydration, condition of muscles, and their use prior to death. Forensic Anthropology: Skeletal Remains Forensic anthropology is a type of applied physical anthropology that specializes in the human skeletal system for purposes of identifying unknown remains. Forensic Anthropologist study skeletons whose identities and circumstances of death are unknown or questionable. HUMAN vs. ANIMAL BONES Osteology-the study of bones Humans and animals have different skeletal structures, different bones, and different shaped bones. The human bone can be distinguished from animal bone through microscopic examination of the cellular structures. Bones have holes or osteons in them to carry their blood supply. Microscopic examination shows that in animals the osteons for a regular pattern, but in humans the osteons are arranged in a more chaotic pattern. THE SKELETON Human adult skeleton has 206 bones Ossification sites –sites where growth takes place and found on many bones. Vital functions of skeleton provides structure and rigidity for the body Shelters and protects soft tissue and internal organs Provides sites for the attachment of muscles, tendons, and ligaments that allow the body to move. Stores minerals and houses sites that produce red blood cell Skull – surrounds and protects the brain Sternum and rib cage- encase the heart and lungs Tendons and ligaments are structurally similar but function differently. Muscles are connected to the bones by tendons. Bones are connected to each other or to joints with ligaments. Joints-points where a muscle is connected to two different bones and contracts to pull them together. Marrow-produces red blood cells and cells of the immune system. Bones serve as a storage area for minerals such as calcium and phosphate Bone tissue can also clean the body by removing heavy metals and other foreign elements from the blood. Bones can be classified as: 1. long—are longer than they are wide; they include bones in the arms, legs, hands, and feet. 2. short-are approximately as long as they are wide; they are found in the wrist and ankle. 3. flat-are flat and enclose soft organs; they include most bones in the skull, the scapula, sternum, hip bone, and rigs 4. irregular-are irregularly shaped; they include the vertebrae and some of the bones in the skull. STATURE-ESTIMATING HEIGHT USING LONG BONES A PERSON’S STATURE CAN BE ESTIMATED BY EXAMINING ONE OR MORE OF THE LONG BONES. The long bones used for this are the femur, tibia, humerus, and radius. Men and women have different proportions of long bones to total height, so separate formulas have been developed. If complete long bones are available, the following formulas may be used to estimate height within a range of + 7.5 cm. To estimate the height of a female (cm) H=femur length X 2.21 + 61.41 H=tibia length X 2.53 + 72.57 H=humerus length X 3.14 + 64.97 H=radius length X 3.87 + 73.50 To estimate the height of a male (cm) H=femur length X 2.23 + 69.08 H=tibia length X 2.39 + 81.68 H=humerus length X 2.97 + 73.57 H=radius length X 3.65 + 80.40 SEX DETERMINATION The os pubis, sacrum and ilium of the pelvis are bones that have the most obvious differences between men and women. The shape of the skull mandible, and the size of the occipital proturbance (bump) at the back of the skull to determine male or female traits. Men tend to have larger bones than females. Males have larger areas for muscle attachment. The sacrum is straighter in females & more curved in males. The space in the middle of the pelvic bone is larger in women to make birthing easier. To make the surest determination of sex, one can compare 3 basic characteristics of the os pubis o 1. the width of the pubic arch-larger angle in females than males o 2. the width of the pubic body-narrower in males than females o 3. the existence of the well defined ventral arch (bony ridge on the lower side of the female pubic bone.)---males do not have a ventral arch. The ventral arch does not usually appear in its easily recognizable form until a woman is in her mid-20’s. A precursor arc, (a small bony line) first appears around the age of 14. p277 fig 2 Dorsal-upper side Ventral-under side DIFFERENCES IN SKULL FEATURES Determine Age with a skull Epiphyses-growth plates found at the end of the long bones. They form in adolescence and fuse to the bone in early adulthood. Function is to allow for growth. Diaphysis-Shaft of bone. Makes up most of the long bones’ length. Iliac crest-found at the top of the hip bone Clavicle-also known as the collarbone. Its medial ends meet in the center of the body. Closure of cranial sutures Teeth erupting The epiphyses fuse to the bone during adolescence and can be examined in 4 stages 1. Stage 1- non union with no epiphysis (there is no growth plate yet.) 2. Stage 2- Nonunion with separate epiphysis (the growth plate is formed but not attached) 3. Stage 3- Partial union of the epiphysis (growth plate is beginning to attach to the bone.) 4. Stage 4- Complete union of the epiphysis (growth plate is completely attached and smooth.) These stages happen in different ages in different bones and in males and females. Table 1- General age determination using epiphyseal union of the medial clavicle. Stage of Union Nonunion without separate epiphysis Nonunion with separate epiphysis Partial union Complete union Male 21 or younger Female 20 or younger 16-21 17-20 17-30 21 or older 17-33 20 or older Table 2- General age determinations using epiphyseal union of the iliac crest Stage of Union Nonunion without separate epiphysis Nonunion with separate epiphysis Partial union Complete union Male 16 or younger Female 11 or younger 13-19 14-15 14-23 17 or older 14-23 18 or older Estimating age based on Cranial Sutures Sutures-immovable joints where bones are joined together. They are visible as seams on the surface. Sagittal suture-located along the top of the skull, dividing the right from the left and runs from the top of the skull to the middle of the back of the skull. Coronal suture-runs from the temporal area on one side over the top of the skull to the other side. Lambodial suture-located on the back of the skull. If the sagittal suture is completely closed (not visible at any point) Male – the individual is 26 yrs. Of age or older Female-the individual is 29 yrs. Of age or older If the sagittal suture is completely open (visible at all points) Male – the individual is younger than 32 yrs. of age. Female- the individual is younger than 35 yrs. of age. Looking at these 2 criteria together, it could be said that the sagittal suture is not likely to be open if a male is older than 32 and not closed if younger than 26. For a female, the suture is not likely to be open after 29 and not closed if younger than 35. If the skull shows complete closure of all 3 major sutures (no visible lines): Male-the individual is older than 35. Female-the individual is older than 50. Determine the age of the skulls provided based on cranial sutures. P 285 Determining age using the os pubis The closing of the epiphysis is a good method to determine age in younger skeletal remains. Once the epiphyses are closed, forensic anthropologists observe degenerative changes to determine age. One of the best areas to determine age in adults is from the pubic symphysis, which is the area where the 2 hip bones come together in front. As a person ages, the 2 bones may rub together, producing changes or wear patterns. The symphyseal face of the pubic bone undergoes a regular metamorphosis, or change, from puberty onward. The pattern on the symphysis goes from being in regular rows or furrows in younger individuals, to smooth with an oval surface, to a breakdown of the bone in older individuals. Determination of Race Three major anthropological racial groups based on observable skeletal features 1. Caucasoid-includes people of European, Middle Eastern, and East Indian descent. 2. Negroid-includes people of African, Aborigne and Melanesian descent 3. Mongoloids-include people of Asian, Native American, and Polynesian descent Major differences in skull features 1. Caucasoids-have a long, narrow nasal aperture; triangular palate; oval orbits; narrow zygomatic arches; and narrow mandibles. 2. Negroids-have a wide nasal aperture; a rectangular palate; square orbits, and a more pronounced zygomatic arches. The long bones are longer and have less curvature and a greater density. 3. Mongoloids-have a more rounded nasal aperture; a parabolic palate; rounded orbits, wide zygomatic arches, and a more pointed mandibles. p 286 FACIAL RECONSTRUCTION Facial reconstruction uses standard tissue thickness and facial muscles to build a new face on a skull. Steps in facial reconstruction include: Establish gender, age and if possible-race. Glue tissue markers to landmarks directly on the skull for tissue thickness Mark muscle insertion points Select data set to use for the particular skull, and mount markers for the exact thickness of tissue. Mount eyes in the sockets, centered and at the proper depth. Apply clay to the skull following its contours, using the depth of the tissue markers and muscle insertion points. Make measurements to determine the nose thickness and length and the mouth thickness and width. Cover the skull with layers of skin and add details of the face Lab Activity “Talking Bones” Step 1 Determining the Number of Individuals in a Co-Mingled Remains Step 2-Determine the Relative Age, Trauma, and Presence of Disease Step 3-Record all information regarding each bone on the Skeleton Inventory Form for all recovered bones and bone fragments Step 4-Determining Ancestry Step 5-Determining Gender Step 6-Determining Stature Step 7 Summary Findings and Site drawing