Exam 3

Hematopoiesis

Blood Cell Formation

Periosteum

The outer layer of the bone connected to the contact bone by sharpeys fibers

Osteoblasts

Bone forming cells

Osteoclasts

Bone destroying cell

Osteogenic

Stem Cell

osteocytes

Mature bone cells

Red Bone Marrow

In all flat bones and it helps make red blood cells

osteon

The structural unit of bone

Lamellae

weight bearing

column- like, circles in circles

central canal

contains blood vessels and nerves

Perforating ( Volksman) canal

connect and send material and message from central canal to central canal

Lacunae

small cavities that contain osteocytes

Canaliculi

hairlike small canals that connect lacunae to each other and the central canal

Tracbecule

Hard plates/spines that make up spongey bone

osteoid

Liquid secreted by osteoblasts

Hydroxaptites

mineral salts purpose is to make bones hard.

ossification

To harden into bone tissue

Intramembranous ossification

Bone is forming between two membranes. the way flat bones are created

Endochondral ossification

Bones are growing from cartilage. bone forms by replacing hyaline cartilage. how most long bones are formed.

The steps of baby forming bone

1- Boney collar is made around the Diaphais/ shaft

2 -hardens with minerals that break down to create empty cavities

3-Periosteal bud comes in the supply blood

4- Diaphysis get longer, a secondary ossifaction appear in the epiphyses

Interstital Growth

Growth in length happens during birth-17 years

Appositional growth

growth in the width of bones to support the new weight of longer bones

Epiphyseal plate zones

Proliferation (division) chondrocytes multiply

• Hypertrophic (growth) chondrocytes get larger

• Calcification (hardening) cells start to die off

• Ossification (osteogenic) osteoblast cones in and makes new bone tissue

Growth Hormone

makes epiphyseal plate grow faster

Thyroid Hormone

amplifies growth hormones

Testosterone and estrogens

makes epiphyseal plate grow faster

Acondrondroplastic Dwarfism

Little limbs with normal size head and torso.

Pituitary

Normal Porportions with short statue.

Acromegaly

Thick Face, hands, chest

Gigantism

Abnormal Growth in length

Woff’s Law

A bones grow/ remodels in response to stress placed upon it.

Hypocalcemia

Blood Calcium deficiency

Hypercalcemia

Blood calcium excess

Calcitriol

Increasing circulation of calcium hypocalcium

Parathyroid Hormone (PTH)

Tells the kidneys to absorb more calcium. hypocalcium

Calcitonin

Tells the osteoclast to to releasing calcium Hypercalcium.

Roles of calcium

Transmission of nerve impulses

• Muscle contraction

• Blood coagulation

• Secretion by glands and nerve cells

• Cell division