Exam 2: Skeletal System Flashcards
What are the four classes of bones?
- Long bone
- Flat bone
- Irregular Bone
- Short bone
Name an example of long bones.
Humerus
Name an example of a flat bone.
Sternum
Name an example of an irregular bone.
Vertebra
Name an example of a short bone.
triquetral
How are the child long bone and adult long bone different?
In adults, long bones have yellow marrow in the medullary cavity while children have red bone
marrow in the medullary cavity. In adults, there is an epiphyseal line at the metaphysis, while
children have an epiphyseal plate.
Define epiphysis.
expanded ends of long bones; spongy bone surrounded by a thin layer of compact bone
Define diaphysis.
the shaft or long axis of bone; composed of a thick collar of compact bone with surrounds a medullar cavity
What is the medullary cavity?
cavity in the middle of the diaphysis that contains bone marrow; red in kids, yellow in adults
Describe hematopoiesis.
A process that occurs in the RED bone marrow and leads to the formation of blood cells and platelets
T/F: The periosteum covers the marrow cavity.
False; the endosteum covers the marrow cavity, periosteum covers the outside of the bone.
Identify the structure and name its function.
Sharpey’s fibers; they are collagen fibers that attach the periosteum to bone
What does the endosteum cover in bones?
internal surfaces such as canals
What types of cells are in the endosteum?
Osteoblasts and osteoclasts
T/F: The periosteum is double-layered.
T
What are the two layers of the periosteum and what tissue type are they made of?
- fibrous layer (irregular connective tissue)
- osteogenic layer (osteoblasts and osteoclasts)
What are the bone-forming cells?
Osteoblasts
What are the bone-resorbing cells?
Osteoclasts
What is compact bone also known as?
Lamellar bone
What is ossification?
The development of the bony skeleton from the embryonic skeleton.
What are the 2 forms of ossification?
Prenatal and postnatal
What are the two different types of bone tissue? Describe them.
- Compact bone tissue -> made of osteons (structural units of compact bone)
- Spongy bone tissue -. composed of needle like structures called trabeculae (structural units of spongy bone) -> looks like a honeycomb
T/F: Spongy bone in the epiphysis contains red bone marrow in children and adults.
T
T/F: There is no red bone marrow in the medullary cavity of adults.
T
What do Sharpey’s fibers attach together?
periosteum and compact bone
Collagen fibers run in opposite directions in adjacent lamellae to _____
resist twisting
Where are lacunae located?
Lamella
Where is blood supply found in compact bones?
Haversian canal
What are canliculi?
Tiny canals the connect lacunae to each other and to the Haversian canal to allow from transfer of substances from blood
What is the typical function of flat bones?
Protection
Where are short bones normally found?
areas where there are joints such as wrist and ankle