Chapter 7:2 Skeletal System

Key Terms (Vocabulary) Appendicular skeleton Axial skeleton Carpals Clavicles Cranium Diaphysis Endosteum Epiphysis Femur Fibula Fontanels Foramina Humerus Joints Ligaments Medullary canal Metacarpals Metatarsals Os coxae Patella Periosteum Phalanges Radius Red marrow Ribs Scapula Sinuses Skeletal system Sternum Sutures Tarsals Tibia Ulna Vertebrae Yellow marrow

Human skeletal system is made up of 206 bones Bone Functions: Framework: bones form a framework to support the body’s muscles, fat, and skin Protection: bones surround vital organs to protect them Levers: muscles attach to bones to help provide movement Production of blood cells: bones help produce red and white blood cells and platelets Storage: bones store most of the calcium supply of the body in addition to phosphorus and fats Bones vary in shapes and sizes depending on where they are located in the body Bones in the extremities (arms and legs) are called long bones

Parts of a bone The long shaft is called the diaphysis The two end of a bone are called the epiphysis The medullary cavity (canal) is located within the diaphysis The medullary cavity is filled with yellow marrow, which is mainly the storage for fat cells The endosteum is a membrane that lines the medullary cavity and keeps the marrow intact Red marrow is found in certain bones and it produces red blood cells, platelets, and some white blood cells Red marrow is used to diagnose blood diseases The outside of the bone is covered with a tough membrane called the periosteum The periosteum is necessary for bone growth because it contains blood vessels, lymph vessels, and osteoblasts

Axial Skeleton Appendicular Skeleton Skull Spinal Columns Ribs Breastbone Shoulder girdle Arm bones Pelvic girdle Leg bones

The Skull The cranium is a spherical structure that surrounds and protects the brain 8 cranial bones: 1 frontal 2 parietal 2 temporal 1 occipital 1 ethmoid 1 sphenoid Sutures

Facial Bones 14 facial bones 1 mandible (lower jaw) 2 maxilla (upper jaw) 2 zygomatic (cheek) 2 lacrimal (inner aspects of the eyes) 5 nasal 2 palatine (roof of the mouth)

Spinal Column Spinal column is composed of 26 bones called vertebrae 7 cervical (neck) 12 thoracic (chest) 5 lumbar (waist) 1 sacrum (back of pelvic girdle) 1 coccyx (tailbone) Pads of cartilage tissue called intervertebral disks separate the vertebrae

Thoracic Cavity 12 pairs of ribs 7 true ribs 5 false ribs (last 2 are “floating” ribs Sternum is also called the breastbone 2 clavicles are attached to the sternum by ligaments

Bones of the upper body 2 clavicles (collarbones) 2 scapulas (shoulder blades) 1 humerus (upper arm) 1 radius (lower arm, thumb side) 1 ulna (larger bone in lower arm) 8 carpals (wrist bones) 5 metacarpals (palm of the hand) 14 phalanges (3 on each finger and 2 on the thumb)

Bones of the lower body 2 os coxae (hip bones) 1 femur (thigh) 1 patella (kneecap) 1 tibia (shin bone) 1 fibula (smaller bone) 7 tarsals (ankle) 5 metatarsals (instep of foot) 14 phalanges (2 on the big toe, 3 on the rest)

Joints Joints are where 2 or more bones come together Ligaments help hold long bones together at the joint 3 main types of joints: Synovial Joint: freely moveable (ball-and-socket and hinge joints) Amphiarthrosis: slightly moveable (ribs to thoracic vertebrae and joint between the 2 pelvic bones) Synarthrosis: immovable (suture joints in the cranium)

Disease and Abnormal Conditions Arthritis Osteoarthritis: most common, chronic disease that usually occurs as a result of aging Most frequently affects the hips and knees Symptoms include joint pain, stiffness, aching, limited range of motion Rheumatoid arthritis: chronic inflammatory disease that affects the connective tissues and joints Scar tissue and atrophy of bone and muscle tissue

Disease and Abnormal Conditions Bursitis Inflammation of the bursae Bursae are small fluid filled sacs surrounding the joints Symptoms include severe pain, limited movement, and fluid accumulation in the joint

Disease and Abnormal Conditions Fractures Greenstick: bone is bent and splits Closed: complete break of bone with no damage to the skin Compound (open): bone breaks and ruptures the skin Impacted: broken bone ends jam into each other Comminuted: bone fragments into more than 2 pieces Spiral: bone twists and breaks Depressed: piece of skull bone moved inward Colles: breaking and dislocation of the distal radius **PICTURES TO COME**

Disease and Abnormal Conditions Osteomyelitis Bone inflammation Osteoporosis Softening of the bones Ruptured Disk The intervertebral disk ruptures or protrudes out of place Spinal Curvatures Kyphosis Lordosis Scoliosis