Bone Tissue Dynamic Tissue full of cells blessed

Bone Tissue Dynamic Tissue, full of cells, blessed are you among tissues and blessed is the fruit of thy marrow, red blood cells

Objectives Name tissues and organs of skeletal system n State its functions n Classify four types of bone by shape n Describe general features of long bone n List cells, fibers, and ground substances n

The skeletal system, what’s up with that? n n Bones, cartilage, and ligaments make it up Functions include… – – – Support: hold us up Protection for soft, weak organs Movement; leverage for muscles Blood formation: also cells of immune system Electrolyte balance: Calcium & Phosphate stores Acid/Base balance: absorbing/releasing alkaline salts – Detoxification: takes up heavy metals

What do you need electrolytes for? Definition: Any of various ions, such as sodium, potassium, or chloride, required by cells to regulate the electric charge and flow of water molecules across the cell membrane. Calcium: Activates your muscles Phosphates: are needed for ATP

Bones classified by shape n n Long bones, include humerus of arm, phalanges, femur. Rigid levers for muscles to act on

Short Bones dude he said bones n n Equal in length and width Limited in motion Carpals in wrist Tarsals in ankle

Flat bones n n Protect soft organs Examples include the ribs, sternum, scapula, os coxae (hip bone), and cranial

Irregular bones Irregular n Fit no preconcieved categories n Rebels, maverics n Include vertebrae, and bones in the skulll n

Parts of the long bone This will aid you on Friday’s lab n n n n Cylinder of dense white tissue: enclosing medullary cavity (contains marrow) At the ends: spongy (cancellous bone) Shaft: daphysis Heads: epiphysis Joints covered with articular cartilage Nutrient foramina: small holes to let in blood vessels Peristoneum: external sheath, helps attach bones and muscle Endosperm: internal lining of bone

Cells Osteogenic cells: in endosteum, AKA: stem cells n Osteoblasts: make the bone matrix, mineralize the bone. Non-mitotic. n Osteocytes: former Osteoblasts that have gotten trapped in the matrix. They reside in lacunae. Communicate where more bone is needed. n

The matrix n n n 1/3 organic; collagens 2/3 inorganic; hyrdoxyapatite, calcium carbonate, and trace elements The mineral component gives support, the organic protein gives flexibility

Compact Bone n n Transverse slices show concentric lamellae – layers of matrix arranged around Haversian canals This is the basic structural unit of bone

Bone Marrow n Soft Tissue in the medullary cavity & spaces in spongy bone – Red: hemopoietic: makes red blood cells, looks like blood, but thicker – Yellow: this is what middle aged people have instead of red bone marrow, doesn’t produce blood, but it can revert to red bone marrow. Adults only have red marrow in certain spots – Gelatinous: found in old age: yellow has turned to reddish jelly.

Bone Growth and Remodeling n n n The wily bone, it changes throughout life to accommodate our selfish, needs. Tension leads to individual spines and ridges Those who do heavy manual labor have denser bones

Growth Mechanisms n n Interstitial growth: adding more matrix internally Appositional growth: add more matrix to the surface. It starts with osteogenic cells which develop into osteocytes. This is the only way adult bone can grow. – Why is bone growth so complicated? – interstitial bone growth impossible (too rigid) so all bone growth must occur on surfaces – appositional growth OK for width, but not for length (because of articular cartilage) – interstitial growth essential for length, so this must be cartilaginous to start with – then, need to create free surfaces within growing cartilage for bone deposition – so, chondrocytes hypertrophy to create cavities, then secrete calcified (stiffened) cartilage to prevent cavities collapsing when cells die – bone can then be deposited on free internal surfaces, as the temporary calcified cartilage is removed

Healing Fractures

Types of Fractures

Bad Breaks n Broken femur

Broken Collar Bone

Fractured Skull

Chapter 8 the chapter of skeletons that you will be tested on, determining the future of those of you not yet accepted to prestigious colleges. Have fun at Mc. Donald’s. Thank you for serving my freedom fries. n Cranial bones correspond to lobes of brain Parietal bone Occipital bone Frontal bone Temporal bone n Note sutures where bones have fused together

Temporomandibular Joint Syndrome

Temporomandibular Joint Syndrome n n n one of the most complicated joints in the body. Moves in many directions During chewing, it sustains an enormous amount of pressure. contains a piece of special cartilage called a disk that keeps the skull and the lower jawbone from rubbing against each other. Problems from strain, abnormal chewing, or arthritis can lead to acute pain Treatment depends on severity. For mild cases; analgesics, heat therapy, massage

Cleft pallet n n split in the roof of the mouth resulting in a passageway into the nose. can be corrected with surgery. likelihood of cleft lip and cleft palate can be reduced if a woman takes folic acid before pregnancy and through the 1 st trimester of pregnancy. Warning disturbing image of cleft pallet babies to follow

Cleft Pallet In the past, it was also known as a hare lip and was more conspicuous even with surgery n In some cases speech impediments remain n

Vertebral Column n n Cervical area: around neck Thoracic vertebrae noted for spinous process Lumbar: lower back Sacrum: at the back of the pelvis

n n n Thoracic vertebrae attach to the ribs Sacrum once thought to be the seat of the soul Originally 5 bones in infants it fuses around age 16 and is one by age 26

Upper Limbs n Humerus – hemispherical head that attaches to the shoulder in a ball and socket joint – Radius and ulna articulated by the other end

Radius vs. Ulna Death match n n n Ulna is longer Radius has the large styloid process and a rounder head Warning gruesome vile bloody images to follow

So many people break these bones.

Metacarpals n n n Bones of the palm Look like extensions of the fingers, so they seem much longer than they really are. Phalanges are the actual finger bone

Femur Attaches to the ox coxae (hip) at the spherical head n Attaches to the patella, fibia and tibia at the other n

Bones of the lower leg n n Tibia: thicker, stronger, weight bearing Fibula: slender, stabilizes the ankle, bears no weight. – Can be removed at times to replace other lost bone. n Warning horrible, disgusting, Sweet mother of mercy why? images to follow

The photograph below shows long jumper, Llewellyn Starks, who suffered a compound fracture to his right tibia and fibula when attempting a jump at the 1992 New York games. The bone can be clearly seen protruding through Stark's leg.

Dr. Leonard “Bones” Mc. Coy U. S. S. Enterprise