Skeletal System Flashcards
Articular Cartilage
Spongy Bone
Epiphyseal line/ plate
Compact Bone
Medullary Cavity
Endosteum
Periosteum
Distal Epiphysis
Metaphysis
Diaphysis
Proximal Epiphysis
6 Functions of the skeletal system
Support
Protection
Assist in Movement
Mineral Homeostasis
Hemopoiesis
Triglyceride (energy) storage
4 Specific Bone Cells
Osteogenitor
Osteoblast
Osteoclast
Osteocyte
Osteogenitor
The stem cell of bones, division
Osteoblasts
Deposit bone cells, decreased blood Ca levels, matrix production
Osteoclast
Formed from monocytes (white blood cells) for destroying bone tissue
Osteocyte
Found in lacuna, mature bone cell
Microscopic structure- What are the two forms of bone?
Compact (dense)
Cacellous (spongy)
6 types of bones
Long
Short
Flat
Irregular
Suture
Sesamoid (bones associated with joints)
What are the 3 parts of a long bone?
Epiphysis
Metaphysis
Diaphysis
What is the structure of the Epihpysis in a long bone?
Articular cartilage, spongy bone, periosteum
What is the structure of the Metaphysis in a long bone?
Epiphyseal plate/ line, periosteum
What is the structure of the Diaphysis in a long bone?
Periosteum, Compact bone, Endosteum, Medullary cavity, Yellow marrow
What is the periosteum and where is it found?
Dnese layer of vascular connective tissue enveloping the bones except at the surfaces of joints
What is the endosteum and where is it found?
Thin vascular membrane of connective tissue that lines the surface of the bony tissue that forms the medullary cavity of long bones
Flat Bone (Frontalis)
Irregular Bone (vetebrae)
Long bone (Femur)
Short Bone (Tarsle)
Suture Bone (Smaller bones located near Occipital, Temporta and Peripheral bones)
Sesamoid Bone (bones associated with joints)
What is another word for Ossification or Bone Formation?
Osteogenesis
When and where does bone growth or ossification start?
Begins in the embryo, 8th-12th weeks of the embryonic development
What are the 2 types of ossification?
Intramembranous
Endochonral
What is another term for Intramembranous Ossification?
Dermal Ossification
What bones are produced by Intramembranous Ossification?
Flat bones of the skull
Some of the facial bones
Mandible
Central part of the clavicle
When does Intramembranous Ossification start?
Begins when Mesenchyme (embryonic tissue) becomes thickened with capillaries, this process begins around the 6th week of the embryonic period
List the 4 steps of Intramembranous Ossification
1) Formation of Ossification Center (formed by osteoblasts)
2) Calcification (hardens)
3) Formation of Trabeculae (trabeculae= woven and messy bone)
4) Development of the periosteum (connective sheath)
Which step of Intramembranous Ossification is this?
Step 2
Which step of Intramembranous Ossification is this?
Step 1
Which step of Intramembranous Ossification is this?
Step 4
Which step of Intramembranous Ossification is this?
Step 3
When does Endochonral Ossification start?
Begins with a hyaline cartilage model, this process begins around the 8th to 12th week of embryonic development
Which bones are produced by Endochonral Ossification?
Upper and Lower Limbs
Pelvis
Vertebrae
Ends of the clavicle
What are the 6 steps of Endochonral Ossification?
1) Development of fetal hyaline cartilage
2) Cartilage calcifies and collar forms around diaphysis
3) 1st Ossification center develops- osteoblasts are in the diaphysis
4) Development of Medullary Cavity
5) 2nd Ossification centers develop- osteoblasts in epiphysis
6) Formation of articular cartilage and the epiphyseal plate
What is the difference between interstitial growth and appositional growth?
Interstitial growth is length
Appositional growth is diameter
Calcium Homeostasis
What happens when calcium levels are normal?
osteoblasts and osteoclasts have the same activity level
Calcium Homeostasis
What happens when calcium levels are low?
You want Ca+ out of bone and into blood
Parathyroid
use osetoclasts to break down the bone matrix so that the Ca+ in blood
Calcium Homeostasis
What happens when calcium levels are high?
you want Ca+ out of blood and into bone
Calcitonin released from parathyroid
osteoblasts build bone to get calcium into the bone
How does Parathyroid regulate Ca levels?
Parathyroid hormone causes increased osteoclasts
in response to when Ca levels are low
How does Calcitonin regulate Ca levels?
Calcitonin causes increased osteoblasts activity which is in response to high Ca levels
How does Sex Hormones regulate Ca levels?
Activity of osteoblasts/ osteoclasts balanced
Estrogen and Testosterone
Osteoporosis
Demineralization and loss of bone tissue
Osteopenia
Insufficient ossification- sets you on the road to osteoporosis
Bone Spurs
Overgrowth of bone, usually associated with joint damage
Rickets
Bending bones, lack of gone tissue, failure of bone to form
Osteomalacia
Adult version of Rickets, bone is broken down and cartilage replaces it
Paget’s Disease
Deformed bone with irregular thinckness or thinness, painful
Osteomylitis
Infection (bone tissue and marrow may be affected)
Fracture Repair Steps
1) Formation of fracture hematoma (bruise) (6-8 hours)
2) Fibrocartilaginous callus formation
Fibroblasts: produce collagen
Chondroblasts: produce cartilage
3) Bony Callus Formation
4) Remodeling- compact bone produced
What step of fracture repair is this?
step 1
What step of fracture repair is this?
Step 3
What step of fracture repair is this?
Step 3
What step of fracture repair is this?
Step 4
