Ch 5 Notes - Summary Bare Bones PDF

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• Human Osteology and Osteometry ! • Osteology: the study of bones • Reasons to study bones ◦ They last a long time, so they provide biological evidence for early humans and proto- humans. ◦ Better understand ancient populations, their patterns of growth and development, anatomical adaptations, and overall health. ◦ Solve certain types of forensic cases. ! • Anatomical Planes, Positions, and Directions 1. Sagittal plane: passes through the midline of the body, dividing it into equal left and right halves. i. Any planar slice in this direction that is not midline is called para- sagittal. 2. Coronal plane: divides the skeleton into equal anterior and posterior sections. 3. Transverse plane: cuts the body into upper and lower sections. 4. Frankfort Horizontal Plane: a position that aligns the lower border on the left eye orbit with the superior aspect of the external ear openings. 5. Anatomical structure for a human: i. Standing ii. Feet pointing forward

iii. Arms by sides iv. Palms facing up v. Thumbs pointing away from the body • The Skeleton 1. Cranial: bones that make up the skull 2. Postcranial: bones that make up the body 3. Axial: elements that lie along the axis of the body 4. Appendicular: part of the limbs ! • The Axial Section ◦ Includes all the bones of the skull and the vertebral column • Skull: consists of the cranium, mandible, ear ossicles, and hyoid. Consists of 29 bones ▪ Unpaired: bones that lie along the midline • Vertebral column: ▪ Cervical vertebrae: 7 vertebra, shows the least variation among and within the mammalian species. • First cervical vertebra: atlas for the Greek god of heavy burdens. It is the only vertebra without a body, or centrum. • All other cervical vertebra have a transverse foramen

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▪ Thoracic vertebrae: lie within the thorax, or chest (12). • The ribs attach to the centrum of each vertebra and the sternum at their distal ends. • Thorax: expands and contracts to move air in and out of the lungs. ▪ Lumbar vertebrae: 5 vertebrae that are the largest. ! Sacrum: consists of 5 vertebral bones that fuse to form one element • Makes up part of the pelvic girdle. • Os coxa: hip bones Coccyx: 4 vertebral bones (our tails) Ribs: attach to the vertebral centra, each rib has a head, neck, and shaft. ▪ True ribs: the top 6 or 7 ribs that each have their own costal cartilage ▪ False ribs: the remaining ribs that don't have any costal cartilage ▪ Floating ribs: the bottom 2 ribs; they do not articulate with the thoracic vertebra and do not extend to the sternum Sternum (breastbone): consists of the manubrium, the body, and the xiphoid process.

! • The Appendicular Skeleton

◦ Consists of the bones of the extremities (shoulder girdle, pelvic girdle, arms, hands, legs, and feet). • The Shoulder Girdle ▪ Comprised of the clavicle and the scapula ▪ Clavicle (collarbone): first skeletal element to ossify during development ▪ Scapula (shoulder blade): large, flat, triangular bone on the posterior aspect of the thorax. • Long Bones ▪ Diaphysis: the shaft of the bone ▪ Ossify within a cartilaginous matrix ▪ Metaphysis: the end of the diaphysis ▪ Physis: the end of the metaphyses where bone growth takes place • The Arm ▪ Humerus: the bone of the upper arm! and the largest bone in the upper limbs. • The Forearm ▪ Include the radius and ulna ▪ Ulna: provides for a stable elbow joint ▪ Radius • The Wrist and Hand ▪ The wrist and hand has 27 bones ▪ Carpals: the 8 bones of the wrist

▪ Metacarpals: the 5 bones of the palm ▪ Phalanges: the 3 bones of each finger (with exception of the thumb) • The Leg ▪ Femur: largest bone in the skeleton ▪ The best bone to measure for estimating a person's height ▪ The femur is larger in diameter among males ▪ It is also used to determine ancestry because the femur shape varies among populations. • The Lower Leg ▪ Consist of the tibia and fibula ▪ All of a person's weight is put upon the tibial plateau ▪ Patella (kneecap): largest sesamoid bone • The Ankle and Foot ▪ 26 bones in each ankle and foot ▪ Tarsals: the 7 bones of the foot ▪ Metatarsals: the 5 digital rays ▪ Halux: distal phalange (exception of the large toe) ! • Osteometry ◦ The study and measurement of the human skeleton

◦ The measurements are used to compare and contrast the morphology and size of different populations, calculate stature, and determine sex and ancestry. ◦ Convention: how anthropologists measure the skeleton according to mutually agreed upon standard points and techniques ◦ Bregma: "the point where the sagittal and coronal sutures meet" ◦ Spreading calipers: have outwardly arcing arms that are able to reach around the cranium ◦ Sliding calipers: used when chord measurements are not required...