Skeletal Flashcards
is an organ made up of several different tissues working together
Bone
Different bone tissues
bone tissue
cartilage
dense connective tissue
epithelium
adipose tissue
nervous tissue
Bone tissue is also known as?
Osseous
The entire framework of bones and their cartilages is called?
Skeletal system
The study of bone structure and the treatment of bone disorders is referred to as?
Osteology
Skeletal System: Functions
•Support
-structural framework
•Protection
-protects the most important internal organs
•Assistance in movement
-muscles attach to bones
•Mineral homeostasis (storage and release)
-It stores several minerals, especially calcium and phosphorus
•Blood cell production
-Red bone marrow-Hemopoiesis- blood making (RBC,WBC, and platelets)
•Triglyceride storage
-Yellow bone marrow (adipose cells store triglycerides)
is one that has greater length than width.
Long bone
growing between) is the bone’s shaft or body-the long, cylindrical, main portion of the bone.
Diaphysis
growing over; are the proximal and distal ends of the bone.
Epiphysis
are the regions between the diaphysis and the epiphyses.
Metaphysis
are the proximal and distal ends of the bone.
Epiphyses
are the regions between the diaphysis and the epiphyses.
Metaphyses
is a thin layer of hyaline cartilage covering the part of the epiphysis where the bone forms an articulation (joint) with another bone.
Articular cartilage
is a tough connective tissue sheath and its associated blood supply that surrounds the bone surface wherever it is not covered by articular cartilage.
Periosteum
Also known as marrow cavity, is a hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow and numerous blood vessels in adults.
Medullary cavity
is a thin membrane that lines the medullary cavity. It contains a single layer of bone-forming cells and a small amount of connective tissue.
Endosteum
is about 15% water, 30% collagen fibers, and 55% crystallized mineral salts.
Extracellular matrix
The most abundant mineral salt is calcium phosphate
Extracellular matrix
It combines with another mineral salt, calcium hydroxide [Ca(OH)2], to form crystals of what?
Hydroxyapatite
minerals crystallize and the tissue hardens.
Calcification
It is initiated by bone-building cells called
Osteoblasts
Bone’s hardness depends on the?
crystallized inorganic mineral salts
Bone’s flexibility depends on its?
collagen fibers
When the need for particular minerals arises or as part of bone formation or breakdown, bone cells called
Osteoclasts
secrete enzymes and acids that break down both the mineral salts and the collagen fibers of the extracellular matrix of bone.
Osteoclasts
a layer of hyaline cartilage that allows the diaphysis of the bone to grow in length
Epiphyseal plate or growth plate
unspecialized bone stem cells derived from mesenchyme (the tissue from which almost all connective tissues are formed)
Osteoprogenitor cells
They are the only bone cells to undergo cell division; the resulting cells develop into osteoblasts.
Osteoprogenitor cells
A type of cell that are found along the inner portion of the periosteum, in the endosteum, and in the canals within bone that contain blood vessels.
Osteoprogenitor cells
bone-building cells.
Osteoblasts
They synthesize and secrete collagen fibers and other organic components needed to build the extracellular matrix of bone tissue, and they initiate calcification.
Osteoblasts
surround themselves with extracellular matrix, they become trapped in their secretions and become osteocytes
Osteoblasts
mature bone cells
Osteocytes
are the main cells in bone tissue and maintain its daily metabolism, such as the exchange of nutrients and wastes with the blood.
Osteocytes
Like osteoblasts, this cell do not undergo cell division
Osteocytes
huge cells derived from the fusion of as many as 50 monocytes (a type of white blood cell) and are concentrated in the endosteum.
Osteoclasts
breakdown of bone extracellular matrix (process)
Bone resorption
about 80% of the skeleton is?
compact bone
about 20% of the skeleton is?
Spongy bone
strongest form of bone tissue.
Compact bone tissue
Found beneath the periosteum of all bones and makes up the bulk of the diaphyses of long bones.
Compact bone tissue
Provides protection and support and resists the stresses produced by weight and movement.
Compact bone tissue
Composed of repeating structural units called
Osteon
Osteons or also called?
haversian systems
It is a circular plates
Concentric lamellae
Between the concentric lamellae are small spaces.
Lacunae
Lacunae contain ___ ?
Osteocytes
small channels that are filled with extracellular fluid.
Canaliculi
It is a trabecular or cancellous bone tissue
Spongy bone tissue
A bone tissue that does not contain osteons
Spongy bone tissue
A type of tissue that always located in the interior of a bone, protected by a covering of compact bone.
Spongy bone tissue
Spongy bone tissue consists of lamellae that are arranged in an irregular pattern of thin columns called
Trabeculae
filled with red bone marrow and yellow bone marrow (in other bones).
Macroscopic spaces
blood cell production occurs in adults.
Hemopoiesis
enter the diaphysis through many interosteonic canals and supply the periosteum and outer part of the compact bone.
Periosteal arteries
passes through a hole in compact bone called the nutrient foramen
Nutrient artery
enter the metaphyses of a long bone
Metaphyseal arteries
enter the epiphyses of a long bone
Epiphyseal arteries
is the ongoing replacement of old bone tissue by new bone tissue.
Bone remodeling
the removal of minerals and collagen fibers from bone by osteoclasts
Bone resorption
the addition of minerals and collagen fibers to bone by osteoblasts.
Bone deposition
consists primarily of water, which accounts for its resilience, contains no nerves or blood vessels, and surrounded by a layer of dense irregular connective tissue, the perichondrium
Cartilage
three types of cartilage tissue in the body:
- Hyaline
- Elastic
- Fibrocartilage
look like frosted glass when freshly exposed, provide support with flexibility and resilience, and Chondrocytes are spherical
Hyaline cartilages
which cover the ends of most bones at movable joints
Articular cartilages
which connect the ribs to the sternum (breastbone)
Costal cartilages
which form the skeleton of the larynx (voicebox) and reinforce other respiratory passageways
Respiratory cartilages
which support the external nose
Nasal cartilages
cartilage that can be found in the external ear
Elastic cartilage
the flap that bends to cover the opening of the larynx each time we swallow
epiglottis
highly compressible with great tensile strength and it consist of roughly parallel rows of chondrocytes alternating with thick collagen fibers
Fibrocartilage
Location of fibrocartilage
•padlike cartilages (menisci) of the knee discs •between vertebrae
Cartilage grows in two ways:
- appositional growth
- interstitial growth
cartilage-forming cells in the surrounding perichondrium secrete new matrix against the external face of the existing cartilage tissue
appositional growth
the lacunae bound chondrocytes divide and secrete new matrix, expanding the cartilage from within.
interstitial growth
How many bones does normal human have?
206 bones
Human skeleton is divided into 2 groups, what are those?
•Axial
•Appendicular
forms the long axis of the body and includes the bones of the skull, vertebral column and rib cage protect, support, or carry other body parts.
Axial
consists of the bones of the upper and lower limbs and the girdles (shoulder bones and hip bones) and it help us move from place to place (locomotion) and manipulate our environment.
Appendicular
Different shape of bones:
- Long bones
- Short bones
- Flat bones
- Irregular bones
- Sutural bones
- Sesamoid bones
longer than they are wide, has a shaft plus two ends which are often expanded
(bone shape)
Long bones
roughly cube shaped; almost as wide as they are long(bone shape)
Short bones
thin, flattened, and usually a bit curved
(Bone shape)
Flat bones
have complicated shapes(bone shape)
Irregular bones
also known as Wormian bones; occur where the interlocking joints of the skull, called sutures, branch and isolate a small piece of bone. (Bone shape)
Sutural bones
A type of bone that is a small bone commonly found embedded within a muscle or tendon near joint surfaces.
Sesamoid bones
Functions of Bones:
- Support.
- Protection.
- Movement.
- Mineral and growth factor storage.
- Blood cell formation.
- Triglyceride (fat) storage.
- Hormone production.
external layer (bone texture)
Compact bone
internal layer made up of honeycomb of small needle-like or flat pieces called trabeculae (bone texture)
Spongy bone
Spongy bone’s internal layer made up of honeycomb of small needle-like or flat pieces called ____?
trabeculae
The shaft. Surrounds a central medullary cavity, contains yellow marrow in adults
Diaphysis
bone ends. articular (hyaline) cartilage covers the joint surface of each, this Grows separately from the shaft
Epiphysis
A glistening white, double-layered membrane, covers the external surface except joints
Periosteum
covers internal bone surfaces and it contains osteogenic cells that can differentiate into other bone cells
Endosteum
(hematopoietic) within the trabecular cavities of spongy bone of long bones and flat bones
Red marrow
(fats) in the medullary cavity
Yellow marrow
A unit of bone
Osteon (Haversian System)
Opening in the center of an osteon and it Carries blood vessels and nerves
Central (Haversian) canal
Canal perpendicular to the central canal
Perforating (Volkman’s) canal
looks like a poorly organized, even haphazard, tissue
Spongy bone
contain irregularly arranged lamellae and osteocytes interconnected by canaliculi. No osteons are present.
Trabeculae
-cell
-osteoid, the organic part of the matrix
ground substance (composed of proteoglycans and glycoproteins)
-collagen fiber
Organic compound
mineral salts, largely calcium phosphates
Inorganic compounds
Two types of bone development
- Endochondral ossification
- Intramembranous ossification
a bone develops by replacing hyaline cartilage.
Endochondral ossification
a bone develops from a fibrous membrane and the bone is called a membrane bone.
Intramembranous ossification
Except for the clavicles, essentially all bones below the base of the skull form by __?
Endochondral ossification
forms the cranial bones of the skull (frontal, parietal, occipital, and temporal bones) and the clavicles
Begins about week 8 of development
Intramembranous ossification
chondroblasts divide less often and the plates become thinner and thinner until they are entirely replaced by bone tissue
epiphyseal plate closure
negative feedback hormonal loop that maintains Ca2+ homeostasis in the blood
Control of remodelling
Response to Mechanical Stress and holds that a bone grows or remodels in response to the demands placed on it.
Wolff’s law
sustained high blood levels of Ca2+ can lead to undesirable deposits of calcium salts in the blood vessels, kidneys, and other soft organs, which may hamper their function
Hypercalcemia
determine whether and when remodeling occurs in response to changing blood calcium levels.
Hormonal controls
determines where remodeling occurs.
Mechanical stress
the physician’s hands coax the bone ends into position
closed (external) reduction
the bone ends are secured together surgically with pins or wires
open (internal) reduction
includes a number of disorders in which the bones are poorly mineralized
Osteomalacia (“soft bones”)
characterized by excessive and haphazard bone deposit and resorption
Paget’s Disease
-refers to a group of diseases in which bone resorption outpaces bone deposit
-bones become so fragile
-bone mass declines and the bones become porous and light
Osteoporosis
decrease osteoclast activity and number, and partially reverse osteoporosis in the spine.
Bisphosphonates
drugs used to lower cholesterol levels, have an unexpected side effect of increasing bone mineral density up to 8% over four years
statins
monoclonal antibody drug _____ significantly reduces fractures in men fighting prostate cancer and improves bone density in the elderly.
denosumab