L9 Flashcards
What is included in the axial and appendicular skeletal system?
Skull, vertebrae, ribs, sternum and hyoid bone
Limb bones, bones of pectoral and pelvic girlde
What is the function of the skeletal system?
Protect organs Support body Movement Produce new RBC Metabolic reservoir
When does bone development start and finish?
Week 8 and finishes at 20 years.
What 2 ways can ossification occur?
Intramembranous
Endochondral
What is intramembranous ossification?
Direct mineralisation of connective tissues (MESENCHYME).
Cells divide/condense around capillary network growing radially fusing together replacing connective tissue.
Starting point = primary ossification centre
Connective tissue remaining is penetrated by blood cells and undifferentiated MESENCHYME to give rise to bone marrow.
E.g. Skull, mandible and clavicle.
Endochondral ossification
Cartilaginous template made from mesenchyme .
Template replaced by bone via OSTEOGENESIS.
Diff ossification centre emerge, primary in diaphysis, secondary in epiphysis.
A bone collar is produced, the primary centre develops from here.
Epiphyseal plate exists between the diaphysis and epiphysis.
How is bone maintenance regulated?
Calcium Phosphorous Vitamins A - Bone remodelling C - connective tissue D - calcium absorption
What is the connective tissue surround bone and cartilage?
Bone is periosteum
Cartilage is perichondrium
What 4 cell types are bone comprised of?
What 2 cells are responsible for bone remodelling?
Osteoprogenitor cells
Osteoblasts(remodel)
Osteocytes
Osteoclasts(remodel)
What is compact bone’s structure?
Covered by periosteum
Lamella is laid by osteoblasts
HAVERSIAN CANAL in the centre contains vascular/nerve supply.
Osteoblasts trapped + turn to osteocytes. Each osteocyte occupies its own LACUNAE. Radiating from this are minute canals (CANALICULI). Nutrients travel in this to the osteocyte.
What are some features of spongy bone?
AKA cancellous bone
Irregular lamellae
Red bone marrow surrounds it
Highly vascular
What are the 5 diff bones?
Long Short Flat Irregular Sesamoid
How many bones are there in the body?
Is there a diff between at birth and fully grown?
How many are in:
Skull, Spine, Thorax, Arm, Pelvis, and Leg?
At birth 270 bones
206 by adulthood
Skull - 29 Spine - 26 Thorax - 25 Arm - 64 Pelvis - 2 Leg - 60
Name the diff bones needed to know in this module?
Skull - 29 - Hyoid + inner ear
Spine - 26
Thorax - 25 - Ribs (24, 12 pairs) and sternum
Arm - 64 - Scapula, Humerus, radius, carapals, metacarpals, phalanges
Pelvis 2 - Ilium, ischium and pubis
Leg 60 - Femur, tibia, fibula, tarsals, metatarsals, phalanges.
What are the 3 classes of joints?
Synovial : joint capsule + synovial cavity permitting movement. Classified into 6 types: 1 - Plane - intercarapal 2- Hinge - knee 3 - Saddle - carpometacarpal 4 - Condyloid - metacarpophalangeal 5 - Ball and socket - hip 6 - Pivot - radioulnar
Fibrous joints: connected by collagen, do not permit movement.
E.g. the skull
Cartilaginous joints:
Connect via cartilage to allow some movement.
E.g. growth plates + intervertebral discs
