Lecture 13: Bone Physiology 1 Flashcards
What is Cortical Bone?
hard outer layer, dense; especially thick in the shaft of long bone
What is another name for cortical bone?
Compact bone
What is cancellous Bone?
sponge-like tissue
What is another name for cancellous Bone?
Trabecular
What is the subchondral tissue?
smooth tissue at the ends of bones, which is covered by cartilage
What is cartilage?
connective tissue present in adults; also tissue from which most bones develop in children
True/False: Sharks have cartilaginous skeletons and do not have bones
True
What helps sharks to be buoyant?
lighter bodies and low-density oils
What is the periosteum?
tough, thin outer membrane covering the bones
What is beneath the periosteum?
tunnels and canals through which blood and lymphatic vessels run to bring nutrients to the bone
What might attach to the periosteum?
muscles, ligaments, and tendons
How are bones classified?
By their shape
What are the different shapes of bones?
long, short, flat, or irregular
Primarily, bones are ___ or ___.
long or short
How many bones are in the human skeleton?
206
How many axial bones are in the human body?
80
What color are axial bones?
tan
Give examples of axial bones.
head, facial, hyoid, auditory, trunk, ribs, and sternum
How many appendicular bones are there?
126
What color are appendicular bones?
purple
Give examples of appendicular bones.
shoulders, wrists, hands, legs, hips, ankles, and feet
What is the function and location of osteoblasts?
forms new bone tissue (builder) and is located in the bone
What is the function and location of osteoclast?
Absorbs and removes unwanted tissue; large cell formed in the bone marrow
What is the function and location of Osteocytes?
Helps maintain bone as living tissue; found within the bone
What is the function and location of Hematopoietic cells?
Develop into RBC, WBC, and platelets; found in bone marrow
Where are fat cells located?
bone marrow
How much of total bone mass is cortical?
80%
What is trabecular bone?
spongy tissue located at the ends of long bones, near joints, interior of vertebrae
Compare the turnover of cortical vs trabecular bone.
Cortical (compact) bone has a slower turnover than trabecular
What is the endosteum?
membrane that lines the center of the bone marrow
What is the Epiphyseal Plate?
growth plate also called the physis thin layer of cartilage, site of longitudinal and circumferential bone growth
What is an osteon??
the main unit of compact bone made of concentric bone layers that surround a long tube, the Haversian canal
What are lamellae?
concentric bone layers
True/False: Bone Deposition and Resorption are normally in Equilibrium (except in growing bones), so total bone mass remains constant
True
Each new section of bone is an ______.
Osteon
What stimulates bone turnover and increases osteoblasts?
Growth hormone
Describe a bones strength in proportion to bone stress?
bone thickens when subjected to heavy loads
True/False:Shape of bone can be rearranged for proper support of
mechanical forces by depositing and resorbing bone
according to stress patterns
True
Describe the strength of bones in children vs elderly.
Bones in children (rapid bone deposition/absorption) are not brittle vs. elderly people with brittle bones (slow deposition/absorption)
True/False: Bones of athletes become much heavier than bones
of nonathletes
True
What stimulates osteoblast deposition and calcification of bone?
continual physical stress
What happens when a bone is fractured?
Fracture of a bone activates Osteoblasts and new
bone forms at broken ends of bone (callus)
Why is calcium and phosphorous important for the body?
helps bone and teeth structure
Most of Calcium and Phosphorus are stored in the adult body as _______.
Hydroxyapatite
Calcium is stored as ______ and also in
______.
intracellularly and extracellular fluid
What 3 organs control calcium levels?
bone, gastrointestinal tract, kidneys
Where is calcium absorbed?
GI Tract
Where is calcium excreted from?
Kidneys and most is reabsorbed
Bone remodeling occurs ______, breaking
down Hydroxyapatite by Osteoclasts
continually
What is the site of Hematopoiesis?
Bone marrow
What can Immature cell in bone marrow develop as?
RBCs, WBCs, platelets
