A&P Chapter 7 Skeletal System: Bone Formation, Repair and Osteoporosis Flashcards
What is Osseous tissue?
Hardened connective tissue consisting of cells, mineral deposits and collagen.
What is bone (as an organ)?
The skeletal structure consisting of osseous tissue, a variety of different types of bone cells, blood vessels, nerve, cartilage, fibrous connective tissue and adipose tissue.
What are the functions of the Skeletal system?
- Support; bones support the body’s weight.
- Protection; bones protect the brain and other internal organs. Bone also produces WBC’s important for immune response.
- Movement; Bones provide attachment points for muscles which allow for movement of the body, breathing, eye movement ect…
- Electrolyte balance; Bones act as a storage reservoir for Calcium and phosphate ions.
- Acid-Base balance; Alkaline salts (basic) released by bones buffer against changes in blood pH.
- Blood formation; bone marrow located in the center of many bones is the site of blood cell formation.
What is the Periosteum?
Outer covering of bones consisting of fibrous connective tissue and a layer of bone forming cells.
Layer of OSTEOGENIC stem cells between the Periosteum and the compact bone deep to it.
Provides for the attachment of muscles, connective tissues of tendons fuse with the periosteum.
What is Compact bone?
Dense layer of osseous tissue that makes up the outer portion of a bone creating a hollow center.
What is the Marrow Cavity?
Inner compartment of a bone that contains bone marrow.
What is Bone marrow?
Soft tissue composed of adipose tissue and or HEMATOPOIETIC tissue that is responsible for blood cell formation.
What is Yellow Marrow? Where is it found?
Yellow marrow is adipose tissue left behind in most long bones of ADULTS.
What is Red Marrow? Where is it found?
It is HEMATOPOIETIC tissue that is responsible for blood cell formation. It is found in the long bones of children and in the axial skeleton of adults as well as the heads of the Femur and Humerous bones.
What is the Endosteum?
The thin layer of reticular connective tissue that lines the marrow cavity, it also contains osteogenic cells.
What is spongy bone?
Lighter, less dense bone found at the ends of long bones or middle of flat bones. Spongy bone is always covered by compact bone and periosteum.
Spongy bone is affected more than compact bone by Osteoperosis.
What is the Diaphysis?
The main shaft of a bone usually where muscles attach.
What is the Epiphysis?
The end of a bone that articulates with other bones to form a joint.
What is the epiphyseal plate/line?
A layer of hyaline cartilage that separates the epiphysis from the diaphysis. In children and adolescents this is the zone of dividing cells that allows bones to grow longer, the GROWTH PLATE.
In adults the hyaline cartilage transitions into bone creating the epiphyseal LINE.
What are Nutrient foramina?
Perforating holes that allow blood vessels to enter the bone and transport nutrients and waste.
Bone or osseous tissue is what kind of tissue class? And as such it has what BASIC components?
It is Connective tissue, as such it has cells, fibers and ground substance.
What are the basic bone cells?
Osteogenic cells, Osteoblasts, Osteocytes, and Osteoclasts.
What are Osteogenic cells?
Stem cells; Undifferentiated cells that will mature and become osteoblasts.
What are Osteoblasts?
Bone forming cells which actually sythesize the hard bone matrix.
What are Osteocytes?
Mature osteoblasts that live in Lacunae.
What are Osteoclasts?
Large muti-nucleated cells whose job is to dissolve bone.
What does the Ruffled border on an Osteoclast do?
Secretes a protease and hydrochloric acid to dissolve osseous tissue.
What is the non-cellular, ground substance of osseous tissue called?
Bone Matrix
What is bone matrix comprised of?
Organic and Inorganic protein matter.
What is the Organic protein matter of bone matrix? How much of it forms bone matrix in a healthy person?
It is primarily collagen, proteoglycans and glycoproteins. It comprises 1/3 of bone matrix.
The organic protein matter gives bones their flexability.
What is the Inorganic matter of bone matrix? How much of it forms bone matrix in a healthy person?
Mostly, Hydroxyapatite and Calcium Carbinate, with a smaller amount of other minerals and ions. It comprises 2/3 of bone matrix.
It is responsible for the bone strength and rigidity.
Bone matrix is said to be a COMPOSITE, what does this mean?
That it is a combination of two or more structural components, the Organic matter and the Inorganic matter.
What gives Bone matrix its strength and rigidity?
The Inorganic matter approx. 2/3 of total bone matrix.
What gives bone matrix its flexability?
Organic protein matter, approx. 1/3 of total bone matrix.
Describe Compact Bone
Dense osseous tissue that encloses marrow cavity and surrounds spongy bone.
The matrix of compact bone is organized into units called?
Osteons
Describe an Osteon
A central canal (Haversian canal) surrounded by concentric rings of bone matrix called Lamellae. Lacune with Osteocytes are encased in the bone matrix with Canaliculi connecting the lacunae.
What is a Central/Haversian Canal?
A long canal at the center of an Osteon that contains blood vessels and nerves.
What are Canaliculi?
Tiny ducts that connect lacunae to one another and allow osteocytes to communicate.
What are Volkman’s Canals?
Ducts carrying blood vessels and nerves from nutrient foramina to central canals or from one central canal to another.
What are Circumferential Lamellae?
The layers of osseous tissue that encases all the osteons in a bone into one bone.
How do Osteocytes communicate with each other?
Tiny canaliculi allow for communication via gap junctions.
Describe Spongy Bone
Consists of a meshwork of thin rods and plates (called TRABECULAE) of osseous tissue giving the bone a sponge like appearance. .
The TRABECULAE are organized in a specific manner so they can resist stress.
Where is Red Marrow found?
Pelvis, skull, ribs and in the head of the femur and humerous. Basically the axial skeleton in Adults.
As children and infants, red marrow is in almost every bone.
Where is blood marrow for transplant harvested from?
The Ilium
What is Yellow marrow?
Primarily adipose tissue