Section 3 Final Flashcards
What is Diaphysis?
the shaft of a bone
What is Epiphysis?
the end(s) of a bone
What does Articular (Hyaline) cartilage cover?
ends of moveable bones
What is the Periosteum?
a fibrous membrane that covers the outer portion of a bone
What is the Medullary (Marrow) cavity?
space inside bone that contains marrow
What is the Endosteum?
the lining of the medullary cavity
What is the Epiphyseal plate?
the area that contains hyaline cartilage in growing bone, area that causes bone to elongate, becomes ossified (bone) in adults
What are the steps of bone fracture repair?
(1)Hematoma forms around fracture site
(2)Granulation tissue forms
- hematoma becomes infiltrated with capillaries, fibroblasts, macrophages, osteoclasts, osteogenic cells
(3)Callus formation
- fibroblasts lay down collagen, “soft callus” is formed which is made up of fibrocartilage
(4)Remodeling
- bone tissue is laid down replacing cartilage, this forms the bony (hard) callus
- initially spongy bone is laid down, the outer portion of the bone is converted (remodeled) into compact(cortical) bone
What’s an Osteogenic cell?
a stem cell that differentiates to become an Osteoblast
What’s an Osteoblast?
cells that lay down collagen fibers and matrix to form bone
What is an Osteocyte?
mature osteoblast, bone cells, sense the various stressors on bone
What is an Osteoclast?
bone dissolving cells
What is matrix composed of?
mostly Hydroxyapatite & the organic portion is mostly collagen
What is Hydroxyapatite?
a calcium phosphate salt with some calcium carbonate
What is an osteon?
the basic structural unit of compact bone
Where is the Central canal located and what does it contain?
located at the center of the Osteon, contains vessels and nerves
What is the Concentric lamellae composed of and what does it surround?
concentric layers of matrix that surround the Central canal
What is the Lacuna?
the space that houses a osteocyte
What are Canaliculi?
“tiny canals” that connect lacuna
What are Perforating canals?
channels that contain vessels and nerves, connect adjacent osteons and osteons to the outer surface of bone
What vitamin is Calcitriol and what is it stimulated by?
a form of vitamin D
stimulated by absorption of UV light
How does Calcitriol raise blood calcium?
a. Increasing absorption in the Small Intestine.
b. Stimulates calcium removal from bones (Osteoclast).
c. Causing the Kidney to retain calcium in the blood.
What Hormone lowers blood calcium levels?
Calcitonin
How does Calcitonin lower blood calcium levels?
a. Inhibiting Osteoclast.
b. Stimulate Osteoblast (places calcium into bone).
What does the parathyroid hormone do?
this hormone raises blood calcium levels
how does the parathyroid hormone raise blood calcium levels?
a.Stimulating Osteoclast.
b.Causing the Kidneys to retain calcium in the blood.
c.Stimulates the production of Calcitriol.
d.Decreases Osteoblast activity.
What’s the normal range of blood calcium?
9.2 to 10.4 mg/dL
What’s Hypocalcemia?
low blood calcium
muscle is unable to relax, tetany
Whats Hypercalcemia?
high blood calcium
** results in nerves and muscles becoming slow to respond; weakness, sluggish reflexes, poss. cardiac arrest**
