Chapter 6 Flashcards
‘Osteo’ means?
Bone
What is Diaphysis?
The shaft of a bone
What is Epiphysis?
The end(s) of a bone
Articular (Hyaline) cartilage covers what part of the bones?
covers the ends of moveable bones
What is the Medullary (Marrow) cavity?
space inside bone that contains marrow
What is the Periosteum?
fibrous membrane that covers the outer portion of a bone
tendons attach here
What is Endosteum?
the lining of the medullary cavity
What is the Epiphyseal plate?
area that causes bone to elongate & becomes ossified (bone) in adults
area that contains hyaline cartilage in growing bone
What is Osteoporosis?
Loss of bone mass, making them more susceptible to fracture. Associated with aging.
What is a Fracture?
Any disruption in the continuity of a bone.
What is a Osteogenic cell?
a stem cell that differentiates to become an Osteoblast
What is an Osteoblast?
cells that lay down collagen fibers and matrix to form bone
What is a Osteocyte?
mature osteoblast, bone cells, sense the various stressors on bone
What is a Osteoclast?
bone dissolving cells
What does bone marrow fill?
Spongy bone area
What are the 2 types of bone marrow?
Red & yellow bone marrow
What is red bone marrow?
hemopoietic tissue
What is yellow bone marrow?
Adipose tissue
not hematopoietic
What is Ossification/ Osteogenesis?
formation of bone
What is remodeling?
The change of the size and shape of bones to accommodate the changing forces applied to the skeleton.
What is Interstitial growth?
Adding matrix.
When this occurs in the hyaline cartilage of the epiphyseal plate, the bone grows in length.
What is Appositional growth?
Deposition onto the surface of bone. Increases the diameter of a bone
What is the normal range of Blood calcium?
9.2 to 10.4 mg/dL
What is Intramembranous ossification?
- produces flat bones, ex. skull, clavicle, scapula
- bone develops from membranes
What is Endochondral ossification?
- hyaline cartilage matrix is laid down initially, then ossification occurs replacing this cartilage
Chondral = cartilage
produces most bones
when bones start to form everything is mostly cartilage
What is Hypocalcemia?
low blood calcium, muscle is unable to relax, tetany
What is Hypercalcemia?
high blood calcium, nerves and muscles are slow torespond; weakness, sluggish reflexes, poss. cardiacarrest
What is Calcitriol?
- a form of vitamin D, is stimulated by absorption of UV light
- this hormone raises blood calcium!!!*
How does Calcitriol raise blood calcium?
this hormone raises blood calcium by:
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 the blood calcium level
released by parathyroid glands
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 does an osteoclast do?
Removes calcium from bones
What does an osteoblast do?
Places calcium in bones
What is spongy bone?
loosely packed bone
usually found inside of the epiphysis
What are Trabeculae?
thin plates of calcified tissue that provide a lattice appearance to spongy bone
What is compact bone?
densely packed bone
usually located in the outer diaphysis
What is the matrix?
mostly Hydroxyapatite, a calcium phosphate salt, and some calcium carbonate
* The organic portion is mostly collagen*
