Chapter 7 Anatomy & Physiology (McGraw Hill)

Osteology

The study of bones

What tissues are found in bones?

Cartilage, ligaments, tendons, marrow, nerves and blood vessels

Functions of bones

support, protect, movement, blood formation, energy, electrolyte balance and acid-base balance

What creates energy storage in bones?

adipose tissue

What bones provide protection?

Flat bones, the ribs and skull

Ligaments

Connect bone to bone

Tendons

Connect muscle to bone

Muscles function

pull, never push

What are bones made of origionally?

Hyaline cartilage

What is the purpose of articular cartilage between bones?

To keep them from grinding

Diaphysis

shaft of a long bone

Epiphysis

End of a long bone

Articular

layer of hyaline cartilage that covers joint surface; allows joints to move more freely

What are the two kinds of marrow?

red and yellow

What is red bone marrow?

produces blood cells

What is yellow bone marrow?

fat

Periosteum

external sheath covering most of bone

Endosteum

thin layer of reticular connective tissue lining marrow cavity

Nutrient Foramen

minute holes in the bone surface that allows blood vessels to penetrate - blood carries things to and from

What is the difference in fetal and adult bone marrow content?

Fetal bones are little and don't have much room so they are primarily full of red marrow to create red blood cells. Adults have more room in their bones, and make more red blood cells but the marrow doesn't take up as much space as it does in children.

What are the layers of flat and long bones?

Compact

Tribecular (Spongy or Diploe)

Compact

Diploe

spongy bone in flat bones - marrow spaced lined with endosteum

Ossification (osteogenesis)

formation of bone

What are the two methods that bones develop?

Intramembranous ossification

Endochondral Ossification

What is intramembranous ossification?

The transformation of mesenchymal (fibrous) tissue into bone.

What is endochondral ossification?

The process of forming an endochondral bone by the replacement of hyaline cartilage

What is achondroplastic dwarfism?

Long bones of limbs stop growing while other bones grow normally

Results in short stature but large head

Caused by spontaneous genetic mutation or inherited as autosomal dominant

What is pituitary dwarfism?

lack of growth hormone, normal proportions with short stature

What is appositional bone growth?

growth in width and thickness

What forms the epiphyseal growth plate?

endochondral ossification

What forms the periosteal?

Intramembranous ossification

Flat bones

thin, flattened, and usually curved

Long bones

longer than they are wide, rigid levers acted upon by muscles; crucial for movement

Short bones

Approximately equal in length and width

Glide across one another in multiple directions

irregular bones

Elaborate shapes that do not fit into other categories

bone is connective tissue that consists of ___________________?

matrix (fibers and ground substance) and cells

What are the 4 principle types of bone cells?

osteogenic cells, osteoblasts, osteocytes, osteoclasts

What is an osteogenic cell?

a cell derived from mesenchymal tissue, which are undifferentiated pluripotent stem cells, with the capacity to produced bone-forming cells

What is an osteoblast?

bone building cell

What is an osteoclast?

cell that breaks down bone

What is an osteocyte?

a bone cell, formed when an osteoblast becomes embedded in the matrix it has secreted.

The histology of compact bone reveals __________________?

Osteons

Describe the inside of compact bone

Concentric lamellae surround a central (Haversion) canal running longitudinally

Perforating (Volkmann) canals - transverse or diagonal passages

Circumferential lamallae fill outer region of dense bone

interstitial lamallae fill irregular regions between osteons

What does a phosphatase do?

Component of DNA, RNA, ATP, bone structure, phospholipids, and pH buffers

What is calcium needed for?

neuron communication, bone structure, muscle contraction, blood clotting, and exocytosis

Hypocalcemia

deficient calcium in blood - overly excitable nervous system - muscle spasms - can cause laryngospasms that can cause suffocation, or fibrillation (cardiac arrest)

What causes hypocalcemia?

vitamin D deficiency, diarrhea, thyroid tumors, underactive parathyroid glands

Hypercalcemia

excessive calcium in the blood - makes ion channels less responsive - weak muscles, cardiac arrest (rarely occurs)

What three hormones regulate calcium homeostasis?

calcitriol, calcitonin, and parathyroid hormone

What does calcitriol do?

vitamin D absorbs from GI tract and reabsorbs from kidneys, in osteoblasts all to put calcium into the blood

What does PTH do?

Increases the production and activities of the osteoclasts.

Increases calcium in the kidneys (weak effect) to put calcium into the blood

What does calcitonin do?

uses calcium from the blood to make bones - stimulates osteoblasts

Why is cholesterol important?

Without it you can't make vitamin D

Calcitriol synthesis

Cholesterol, integumentary, liver, kidney

calcitonin is more important in ________________ and has a weak effect in _____________________ because _______________________

children

adults

osteoclasts more active in children due to faster remodeling

What regulates phosphate homeostasis?

Calcitriol raises phosphate by promoting its absorption by small intestine, PTH lowers blood phosphate levels by promoting its urinary excretion

orthopedics

prevention and correction of injuries and disorders of the bones, joints and muscles

stress fracture

break caused by abnormal trauma to a bone

Pathological fracture (spontaneous)

break in a bone weakened by disease (such as bone cancer or osteoporosis)

nondisplaced fracture

A simple crack in the bone that has not caused the bone to move from its normal anatomic position; also called a hairline fracture.

displaced fracture

A fracture in which bone fragments are separated from one another and not in anatomic alignment.

comminuted fracture

fracture in which the bone is splintered or crushed, broken in multiple fragments

compound fracture

break in the bone where the bone comes through the skin; open fracture

greenstick fracture

bending and incomplete break of a bone; most often seen in children

Healing process of a fracture

hematoma formation, soft callus formation, hard callus formation, bone remodeling

closed reduction

procedure in which the bone fragments are manipulated into their normal positions without surgery

open reduction

involves surgical exposure of the bone and the use of plates, screws, or pins to realign the fragments

cast

normally used to stabilize and immobilize healing bone

Osteoporosis

severe loss of bone density in elderly

kyphosis

hunchback

arthritis

painful inflammation and stiffness of the joints.