Skeletal System Flashcards
Skeletal System
Job: structure and support
Organs: bones, cartilage, ligaments
Hematopoiesis
MARROW
Production of RBCs = red bone marrow
Fat storage/long-term energy storage = yellow BM
Where is red marrow located when bones are fully formed
Femur, hip bones, some skull bones, and some in sternum
Top end of bone
Epiphysis
Bone shaft
Diaphysis
Bone type composition
25% spongy bone - marrow located here
75% compact bone - no marrow
Where does blood run through an osteon?
Central canal (Haversian’s canal)
What are the rings of an osteon called?
Lamella
Osteoblast’s job
Lays down rings (lamella) and sets up ground substance (osteoid)
How do nutrients from the blood reach the outermost lamella and osteocytes?
Canaliculi
Osteocyte’s job
Takes care of maintenance inside the osteon
Osteoclast’s job
Breaks down bone; macrophage-like cells
Osteogenic cell’s job
Bone stem cells
Long bones
Any bones where they are longer than they are wide
Short bones
About the same long as they are wide
Example: carpals and tarsals
Flat bones
**intramembranous ossification
Example: sternum, skull, scapula
Irregular bones
Example: hip bones, vertebra
Sesamoid bones
Small, seed-shaped bone embedded in a tendon; strengthens the tendon and can withstand heavy pressure
Example: patella, “thumb kneecaps”
Functions of the skeletal system
- Structure and support - blob of goo without it
- Protection - rib cage and sternum protect the heart and lungs
- Storage - fat, minerals (PO4, Ca++, Mg), hematopoiesis (marrow)
Intramembranous ossification
For flat bones
Lay down membrane model and ossify on either side of it
Endochondral ossification (inside cartilage)
For long and short bones
1. Starts as a cartilage model
2. Chondrocytes die and for the medullary cavity (bone marrow here)
3. Osteoblasts invade and starts laying down osteoid and becomes vascularized
Which bone development process is involved in growth?
Endochondral ossification - bone chasing cartilage
What does the axial skeleton consist of?
Skull, vertebral column, thoracic cage
What are the skull bone categories?
Neurocranium - case around the brain; helmet
Facial bones - passageway for air and food