Bone Tissue & Terminology Flashcards
A bone is composed of several types of tissue
Osseous (bone) tissue
Cartilage
Dense connective tissue
Epithelium
Adipose tissue
Nervous tissue
As a result, each bone is considered an organ
Epiphysis
End of the bone
Surfaces that form joints with other bones are covered with a layer of (hyaline) ARTICULAR CARTILAGE -covers the bone where it meets another bone
Contains RED BONE MARROW
Diaphysis
Long cylindrical portion in the middle
Lined by PERIOSTEUM (outside) and ENDOSTEUM (inner)
Encloses the MEDULLARY (MARROW) CAVITY, which contains
YELLOW BONE MARROW
Metaphysis
Contains a layer of hyaline cartilage called the EPIPHYSEAL GROWTH PLATE (allows the diaphysis to grow in length)
4 types of cells present in bone tissue
Osteogenic cells – act as stem cells
Osteoblasts – produce the extracellular matrix
Osteoclasts – break down the extracellular matrix
Osteocytes – mature bone cells that maintain its metabolism
bone cells are surrounded by what?
an extracellular matrix
Water (15%)
Collagen fibers (30%)
Crystallized mineral salts (55%)
(e.g., calcium phosphate, calcium carbonate, hydroxyapatite)
Compact Bone Tissue
Stronger (protection, resists stresses)
Consists of tightly-packed concentrically arranged lamellae called osteons
Beneath the periosteum of ALL BONES
Most of the diaphysis of long bones
Heavy and harder to move
Spongy (Cancellous) Bone Tissue
Lighter (reduces the weight of a bone)
Consists of irregular lamellae called trabeculae, between which are spaces filled with marrow
Most of the interior of short, flat and irregular bones
Most of the epiphysis of long bones
Narrow rim surrounding the medullary cavity (long bones)
lighter and easier to move
two types of bone tissue
Compact Bone Tissue
Spongy (Cancellous) Bone Tissue
OSTEOPOROSIS
Bone tissue continually undergoes remodeling (bone resorption & bone deposition)
If bone resorption > bone deposition, bone mineral density decreases
Typically affects spongy bone tissue more than compact bone tissue, and leads to increased risk of fracture (e.g., hips, vertebrae, wrists)
What can cause osteoporosis?
Aging (e.g., estrogen reduction after menopause in women)
Lifestyle – diet (e.g., low Ca++ & Vit D), lack of exercise, smoking, high alcohol consumption
Certain medications (e.g., corticosteroids)
How can you prevent osteoporosis
Prevention/treatment:
Diet modifications (e.g., Ca++ & Vit D)
Weight-bearing exercise – especially in adolescence!!! (higher peak bone mass)
Limit smoking and alcohol consumption
Medications (e.g., bisphosponates)
Fall prevention
Red Bone Marrow
Composed of developing blood cells, adipocytes and fibroblasts within a network of reticular fibers
Produces red blood cells, white blood cells, and platelets
Yellow Bone Marrow
Composed mainly of adipose (fat) cells
What type of bone marrow is present in babies and as you age
All newborn bone marrow is RED
As a person ages, much of this is converted to YELLOW bone marrow
Red bone marrow persists in some adult bones (e.g., skull, vertebrae, hip bones, the epiphyses of long bones in the limbs)
Functions of the Skeletal System
Support and protection
Assists movement
Produces blood cells
Stores minerals and lipids
Functions of the Skeletal System Support and protection
Bones serve as a structural framework that supports and protects the internal organs
Functions of the Skeletal System Assists movement
Bones serve as attachment sites for skeletal muscles
Functions of the Skeletal System Produces blood cells
Red bone marrow produces red blood cells, white blood cells, and platelets
Functions of the Skeletal System Stores minerals and lipids
Minerals (e.g., calcium, phosphorus) in the extracellular matrix of bone tissue can be released into the blood
Triglycerides stored in yellow bone marrow can be released into the blood
Lone bone
Greater length than width
Mixture of compact bone (shaft) and spongy bone (ends)
(humerus)
Short bone
Nearly equal length and width
Spongy bone surrounded by a thin layer of compact bone
(trapeziod, wrist bone)
Flat bone
Composed of two parallel plates of compact bone enclosing a layer of spongy bone
(sternum)
Irregular bone
“Complex” shapes with variable amounts of compact and spongy bone
(vertebra)
sesamoid bone
Develop within tendons
(reduce wear and tear)
(patella)
Depressions/openings found on bones
fissure
foramen
fossa
sulcus
meatus
fissure
Narrow slit between adjacent parts of bones through which blood vessels or nerves pass. Superior orbital fissure of sphenoid bone
foramen
Opening through which blood vessels, nerves, or ligaments pass. Optic foramen of sphenoid bone
Fossa
Shallow depression. Coronoid fossa of humerus
Sulcus
Furrow along bone surface that accommodates blood vessel, nerve, or tendon. Intertubercular sulcus of humerus
Meatus
Tubelike opening. External auditory meatus of temporal bone
Projections/outgrowths
Condyle
facet
tubercle
process
condyle
Large, round protuberance with a smooth articular surface at the end of a bone. Example: Lateral condyle of femur
facet
Smooth, flat, slightly concave or convex articular surface. Example: Superior articular facet of vertebra
what bones does the Axial Skeleton consist of?
head
neck
trunk
80 bonies that lie around the longitudinal axis of the body
what bones does the Appendicular Skeleton consist of?
126 bones of the upper/lower limbs and the “girdles” that connect them to the axial skeleton
tubercle
variably sized rounded projection
Process
projections or outgrowths on bone that form joints or attachment points for connective tissue, such as ligaments
WRite out projections/outgrowths
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