Presentation on theme: "Human Skeletal System. _________________________ of the Human Endoskeleton 1. Body framework, support and protection 2. Base for muscle attachment (tendons."— Presentation transcript:
Human Skeletal System
_________________________ of the Human Endoskeleton 1. Body framework, support and protection 2. Base for muscle attachment (tendons and ligaments are continuous with the periosteum). Bone and muscles together act as levers. 3. Forms some types of blood cells. (Red marrow produces erythrocytes [RBC], thrombocytes, [platelet] and some leukocytes[White blood cell]) Red marrow is found in most bones in infants. In adults it’s found in the skull, ribs, sternum, vertebrae, clavicle and pelvis. 4. Storage area for: a. inorganic salts b. yellow marrow (stores fats)
Classification of Bones – have greater length than width and long longitudinal axes and expanded ends. Ex. Arm and leg bones
Classification of Bones bones – somewhat cube- shaped and have less prominent ends. Ex. Wrist and ankle bones
Classification of Bones Flat bones – flattened surface; for protection; plate-like with a broad surface for muscle attachment. Ex. Ribs, cranium, sternum
Classification of Bones bones – connect to other bones, variety of shapes. Ex. vertebrae
Classification of Bones bones – small, occur often in tendons due to compression. Ex. Patella (kneecap)
Types of Bone Cells Osteoprogenitor cells – cells that undergo mitosis to produce osteoblasts Osteoblasts – form bone, deposit bony matrix around themselves. Osteocytes – bone cells isolated in matrix Osteoclasts – form from monocytes (a type of white blood cell); function to dissolve/reabsorb matrix.
Long Bone ______________________ Structure Diaphysis – shaft (long part) of the bone. Made of compact bone with a long hollow center. Medullary canal – a hollow chamber and contains fatty yellow bone marrow Epiphysis – forms a joint with another bone. Expanded end. Made mostly of spongy bone with a thin layer of compact bone on the surface.
Long Bone Macroscopic Structure Trabeculae – branching bony plates. Spaces between trabeculae are filled with red bone marrow Periosteum – covering of fibrous tissue. Forms and repairs bone tissue Articular cartilage – hyaline cartilage found at the edge of bones. Endosteum – thin layer of squamous cells that line spaces of spongy bone and the medullary cavity.
Haversian System- microscopic structure of long bones (_______________________) Matrix – made of mineral salts of calcium and phosphorus for hardness and collagen fibers for strength Canalculi – small canals that project from lacunae and are routes for nutrients and wastes of osteocytes
Haversian System- microscopic structure of long bones (compact) Lacuna with osteocyte – small spaces between lamallae that contain mature bone cells (osteocytes) Haversian Canal – contains blood vessels and nerves
_________________________________ Ossification – bone formation Human Embryo Skeleton – composed of hyaline cartilage and fibrous connective tissue membranes. Ossification is replacement of connective tissue by bone, takes 6-7 weeks.
Ossification Intramembranous – the formation of bone directly on or within fibrous connective tissue (mesenchyme) Endochondral – formation of bone within a hyaline cartilage
How long bones grow in length and witdth Length – _______________ plate Width – occurs by osteoclasts destroying lining of the medullary cavity to widen the diameter. At the same time, osteoblasts from periosteum lay down new matrix on the outside of the bone.
Factors affecting Growth/Development of Human Bone _______________________– necessary for calcium absorption, extremem lack causes rickets Vitamin A – necessary for bone reabsorption Vitamin C – needed for collagen synthesis (for flexibility) ____________ – from various glands Physical stress – exercise or lack of it
Types of Joints ___________________ – junction of two or more bones Immovable joint – bones separated by fibrous tissue or cartilage
Types of Joints __________________ movable joint – connected by fibrocartilage disk or ligaments ___________________ movable joint – ends of bone covered by articulating cartilage. Joint capsule is made of outer layer of ligaments and an inner layer of synovial membrane.
Possible ways to protect freely movable joints ______________ – flattened pads of fibrous cartilage. ______________ – closed, fluid-filled sacs reduce friction. Synovial fluid – contained in a joint capsule.
Types of Freely Movable Joints Ball and socket - movement in all planes and rotational movement around a central axi. __________________ – allows sliding and twisting. Opposing surfaces nearly flat or slightly curved.
Types of Freely Movable Joints ______________ – allows movement in one plane only. Bone surfaces are concave and convex. ______________ – allows movement around a longitudinal axis. Rounded process articulates with or rotates in a bony fossa
Types of Freely Movable Joints __________________ – allows for movement in different planes, no rotation. Form when an oval shaped condyle fits into an elliptical cavity. __________________ – allows for a wide variety of movement. Articulating surfaces are complementary concave and convex surfaces.
Types of Joint Movement ______________ – decreasing the angle between two bones. ______________ – increasing the angle between two bones.
Types of Joint Movements ___________________ – moving away from midline. __________________– moving toward a midline
Types of Joint Movement _________________– moving around an axis. Circumduction – describes a circle, includes flexion, extension, abduction and adduction.
Types of Joint Movement __________________ – turning upward. Pronation – turning downward