Skeletal System

Functions of the Skeletal System Support- framework that supports body and gives it shape Protection- for delicate organs, heart, lungs, brain, any internal organs Movement- bones act as levers for muscles Mineral storage- calcium & phosphate Blood cell formation- hematopoiesis

Skeletal Organization There are 206 bones in the adult body and they fall into 2 Categories: 1. Axial Skeleton 2. Appendicular Skeleton

Skull Vertebral column Thoracic cage Axial Skeleton Consists of the bone and cartilage that supports and protects the head, neck and trunk: Skull Vertebral column Thoracic cage

Axial Skeleton

Bones of the axial skeleton The skull bones:

Sinal Cavities Frontal Sinus Ethmoid Sinus Sphenoid Sinus Maxillary Sinus Warm and moisten air Lighten the skull Enhance voice resonance

The Vertebral Column Cervical Vertebrae (7) Thoracic Vertebrae (12) Axial Skeleton The Vertebral Column Cervical Vertebrae (7) Thoracic Vertebrae (12) Lumbar Vertebrae (5) Sacrum Coccyx

The Thoracic Cage Sternum True Ribs (7) False Ribs (3) Axial Skeleton The Thoracic Cage Sternum True Ribs (7) False Ribs (3) Floating Ribs (2)

Axial Skeleton Sacrum & Coccyx

Appendicular Skeleton Includes: 1. Pectoral Girdle 2. Upper Limbs 3. Pelvic Girdle 4. Lower Limbs

Bones of the Pectoral Girdle Appendicular Skeleton Bones of the Pectoral Girdle

Bones of the Upper Limbs Appendicular Skeleton Bones of the Upper Limbs Humerus Ulna Radius 8 Carpals 5 Metacarpals 14 Phalanges

Appendicular Skeleton Bones of the Pelvic Girdle

Appendicular Skeleton The Lower Limbs (Legs) Femur Patella Tibia Fibula 7 Tarsals 5 Metatarsals 14 Phalanges

Types of Bones Long Bones- metacarples, metatarsals, phelangies, humerus, ulna, radius, tibia, fibula Short Bones- carpals, tarsals Flat Bones- rib, scapula, skull, sternum Irregular Bones- vertebrae, facial bones Sesamoid- patella

Bone Classification

What type of bones do you think the following are? Ribs Phalanges Pelvic bone Skull bones Ulna/ Radius Nasal bone Mandible

Fibrous connective tissue. Cartilage. Vascular tissue. Anatomy of a Long Bone Bones are organs which means they are composed of many types of tissues: Fibrous connective tissue. Cartilage. Vascular tissue. Lymphatic tissue. Adipose tissue. Nervous tissue.

Bone cells that aid in remodeling Osteoblast Builds new bone Mature bone cell Osteocyte OsteoblastsOsteoblasts are responsible for building new bone and lie at the centre of bone physiology. Their functions include the synthesis of collagen and the control of mineralisation. OsteoclastsOsteoclasts are specialised cells that resorb bone. They work by sealing off an area of bone surface then, when activated, they pump out hydrogen ions to produce a very acid environment, which dissolves the hydroxyapatite. OsteocytesBone adapts to applied forces by growing stronger in order to withstand them; it is known that exercise can help to improve bone strength. Osteocytes are thought to be part of the cellular feed-back mechanism which directs bone to form in the places where it is most needed. They lie within mineralised bone and it is thought that they may detect mechanical deformation and mediate the response of the osteoblasts. Osteoclast Eats bone

Anatomy of a Long Bone Epiphysis: The end of each long bone Diaphysis: The shaft of the bone Hyaline Cartilage: on the outer surface of the epiphysis to assist growth Periosteum: Completely encloses or wraps around the bone (very tough) Compact bone: Very thick with no gaps around the diaphysis Spongy bone: numerous branching plates and spaces in the epiphysis. Marrow: Red or yellow in the center of bones.

Anatomy of a Long Bone spongy bone Proximal compact bone epiphysis Endosteum diaphysis epiphyseal line yellow marrow Sharpey’s fibers Distal epiphysis periosteum hyaline cartilage

STOP!! Label the human skeleton worksheet You have 10 minutes to quiz each other on the skeleton. With a partner you will then construct out of toothpicks and other materials the skeleton.

Bone Formation Most bones develop from masses of hyaline cartilage shaped like future bones. This occurs while still in the uterus as a fetus- usually the first two months.

Bone Formation The cartilage begins to break down and disappear first in the diaphysis. At the same time the periosteum begins to form, the cartilage calcifies and blood vessels begin. periosteum cartilage calcified cartilage

Bone Formation Osteoblasts (bone forming cells) from the periosteum begin to develop compact bone around the diaphysis. The epiphysis cartilage continues to grow and calcify. This is called the primary ossification center- just before birth Compact bone

Bone Formation The secondary ossification center begins to form spongy bone in the epiphysis but is not complete. The medullary cavity forms which will later house the marrow. The diaphysis elongates. Medullary cavity Secondary ossification (Spongy bone) After birth and into childhood

Bone Formation The diaphysis elongates further. Spongy bone forms and compact bone thickens until length and structure is complete. The epiphyseal plates (growth plate) tell the bone when to stop growing.

Bone Formation Adult bone: everything is fully grown! Cartilage is only left at the ends of the epiphysis. Marrow is now fully formed also

bone cartilage calcified cartilage epiphyseal line epiphyseal plate Fetus: 1st 2 months Endochondral Ossification 2o ossification center bone cartilage calcified cartilage Just before birth epiphyseal line epiphyseal plate Childhood Adult

Use the cut outs to create the steps of bone formation. STOP!! Use the cut outs to create the steps of bone formation. You may create a book, foldable, etc. Place each step in the correct order. Label all the appropriate parts in each step. Give a brief description in your own words about what is happening in each step. Use page 130-131 for more help HW project: Children's story to illustrate

Repair of bone fractures Types of bone breaks Simple- skin is not pierced (most breaks) Compound- skin is pierced Complete- bone is broken in half Partial- broken lengthwise but not two parts Comminuted- broken into several pieces Spiral- twisted

What kind of fracture is this? It’s kind of tough to tell, but this is a _ _ _ _ _ _ fracture.

Repair of bone fractures

Bone Repair: Electrical stimulation of the fracture site: Increases speed and completeness of healing The e- stimulation inhibits PTH and slow osteoclasts down from reabsorbing bone 2. Ultrasound treatment: Daily treatments reduce healing time of broken bones by 25-35% 3. Free vascular fibular graft technique: Transplant fibula in arm Gives good blood supply not available in other treatments 4. Bone substitutes: Crushed bone from cadaver- but risk of HIV and hepatitis Sea bone- coral Artificial bone- ceramic

Discuss these questions with a partner: STOP!! Discuss these questions with a partner: What type of bones break the easiest? Why? What type of bones do not break easily, why? Why are blood vessels important in bones and in repairing them?

Bone strength lab

Bones and movement Bones and muscles interact to cause movements Joints are the junction between bones that allow movement. Three types of joints: Fibrous joints Cartilaginous joints Synovial joints

Immovable Joints (formed by a thin layer of dense connective tissue) Fibrous Joints Immovable Joints (formed by a thin layer of dense connective tissue) suture pubis symphisis

Cartilagenous Joints Slightly Movable Joint (Hyaline and fibrocartilage found in-between vertebrae, end of long bones and between ribs and sternum

Synovial Joints Freely moveable (includes most joints; contain ligaments, tendons and synovial fluid for smooth movement

Knee Joint (Synovial)

Types of freely movable joints Bones and movement Types of freely movable joints Saddle: carpal and metacarpal bones of thumb Ball and socket: shoulder and hip joints Pivot- rotation only: proximal end of radius and ulna Hinge- up and own movement in one plane: knee and elbow Gliding- sliding and twisting: wrist and ankle Condyloid- movement in metacarpals and phalanges

Gliding Hinge Pivot Condyloid Saddle Ball and socket

Diseases of the Skeletal System: Osteoporosis- bone reabsorption outpaces bone deposit; bones become lighter and fracture easier Factors: age, gender (more in women) hormone decrease insufficient exercise (or too much) diet poor in Ca++ , protein, or vitamin D smoking

Osteoporosis 29 40 84 92

Diseases of the Skeletal System: Rickets- vitamin D deficiency Osteomalacia- soft bones, inadequate mineralization in bones, lack of vitamin D Pagets Disease- spotty weakening in the bones, breaks down old bone faster than it rebuilds new bone. Common in old age. Rheumatoid arthritis- autoimmune reaction effecting the joints surrounding bones and movement.

Case study and research Finish children story Book work and practice labeling and worksheets