Bio chapter 6

Hemopoiesis

Blood cell production

Hemopoiesis occurs where in the fetus and newborn

Present in all developing bones

Hemopoiesis occurs where is an adult

Coxal bones, ribs, breastbone, vertebrae, skull

The type of connective tissue that’s in the Merrow cavity of most bones in the adult body

Reticular connective tissue

Function or purpose for red bone marrow

Produces red blood cells, white blood cells, and platelets

Function or purpose for yellow bone marrow

Serves as an energy reserve

Diaphysis

Shaft, main portion

Epiphysis

Proximal and distal ends of bone

Metaphysis

Region between epiphyseal growth plate, and epiphyseal line

Articular cartilage

Thin layer of highly cartilage, covering part of the epiphysis where bone forms in articulation (joint) with another bone. Reduced friction and absorbs shock where joints freely move

Medullary (marrow) cavity

Hollow cylindrical space within diaphysis that contains yellow bone marrow (in adults)

Periosteum

Surrounds outer surface of bone, wherever it is not covered by articular cartilage. Protects and nourishes bone, two layer membrane, attachment point

Endosteum

Thin incomplete cell layer that lines the medullary cavity. Involved in bone growth and remodeling, contains mostly: osteoblasts, osteoclasts and osteogenic cells

Epiphyseal plate

Found in growing bone layer of highland cartilage that allows diaphysis to grow in length would be found in a 10-year-old girl

Epiphyseal line

After age 18 to 21 bone stops growing, cartilage in epiphyseal growth plate is replaced by bone found in 50 year-old man

4 major types of bone cells

Osteoclasts, osteoblasts, osteocytes, osteogenic cells

Osteocyte

The type of bone cell that lives in a lacuna and maintains bone tissue

Osteogenic cells or osteoprogenitor

type of bone cell that is a type of stem cell that continually divides

Osteoblasts

Bone builder

Osteoclasts

Bone breaker

Bone resorption

Release enzymes and acids that digest the mineral components of bone matrix allows the minerals to be freed to rest of body osteoclasts are responsiblefor resorption

ECM is composed of three main minerals

25% water 25% collagen fibers 50% crystallized mineral salts

Collagen fibers

Flexibility

Crystallized mineral salt

Hardness

Osteon

Components of compact bone are arranged into repeating structural units compact bone contains osteons

Trabeculae

Lamallae are arranged in a lattice of thin columns, spongy bone contains it

Canaliculi

Connect lacuna, forming a system of interconnected canals that provide routes for nutrients and oxygen to reach osteocytes

Lamallae

Structural support bone remodeling mineral storage

Central canals

Nutrients and waste transport, communication, and bone health

Intramembranous

Bone forms from embryonic, connective, tissue, arranged, and shaped like layers that look like membranes

Endochondral

Replacement of hyaline cartilage models by bone

Age range when bones can lengthen and thicken

2-18

Process of new bone being formed at epiphyseal growth plate

As bone grows new cartilage cells are formed on the epiphyseal side of the plate while old cartilage cells on the diaphyseal side of the plate are replaced by bone

When do epiphyseal lines appear in females

18-20

When do epiphyseal lines appear in males

20-22

The hormone responsible for closure of the Epiphyseal plate

estrogen

Minerals critical for bone growth and remodeling

Calcium, phosphorus, magnesium

Vitamins critical for bone growth and remodeling

A,C,D,K and B12

Hormones that are critical for bone growth and remodeling

Growth, thyroid and calcitriol

Needed to produce collagen

Vitamin c

Needed to absorb calcium from digestive tract

Vitamin D

Open fracture

Project through skin and are more dangerous due to infection and or uncontrolled bleeding

Closed fracture

Completely internal and can only be seen on x-rays

One of the most important functions of bones

To store minerals in particular stores 99% of the bodies calcium

The three areas of the body targeted by hormones to increase or decrease calcium levels

Bones, kidneys, intestines

What hormone is secreted when blood calcium level levels are too high

Calcitonin it promotes bone formation and decreases blood Ca2+ levels

Which hormone is secreted when blood calcium levels are too low

Parathyroid hormone is secreted and increases the number in activity of Osteoclasts which steps up pace of bone resorption

In what kind of situations can people lose bone mass

Bedridden patients or fractured bone in a cast

What can occur in bone tissue in the elderly

Loss of bone mass (osteopenia) and brittleness

Some risk factors for osteoporosis

Middle aged or elderly, Thin or small body build, smoking, inactive lifestyle or family history of osteoporosis

Some factors that include calcium loss in the urine

High sodium intake, low calcium intake, high protein intake, caffeine consumption, certain medication