Anatomy Flashcards
What is the function of the osteoblasts?
To lay down new bone during skeletal development and remodelling.
Osteoblasts interacts with other cell types inc osteocytes and haematopoietic stem cells.
What is the function of osteocytes?
To respond to mechanical strain and to send signals of bone formation to the bone surface that modify their microenvironment which regulate both local and systemic mineral homeostasis
What is the function of osteoclasts?
Degrade bone to initiate normal bone, remodelling and mediate bone loss in pathologic condition by increasing their resorptive activity.
What is the texture of bone?
Smooth, hard bone called compact bone that forms the outer layer of bones.
What is the texture of compact bone?
Smooth, hard and heavy compared to spongy bone
What is the texture of spongy bone?
Softer and weaker than compact bone + more flexible
(1) How are bones formed?
Intramembranous ossification: formed directly in connective tissue e.g. skull and clavicle
(2) Chondral ossification
When cartilage is ossified e.g. arm and leg bones
Ossification is the formation of bone from membrane or cartilage
Two classification method
Cranial and Post-Cranial
Axial and Appendicular
Difference between cranial and post-cranial
Cranial: skeletons of skulls only
Post-cranial: part of all the skeleton besides the skull
Difference between axial and appendicular
Axial: originate on the axial skeleton (the bones in the head, neck and core of the body)
Appendicular: originate on the bones that make up the body’s limbs
Classification of bones by shape
Long bones and Short bones
Long bones
- Longer than they are wide
- Limb bones and metacarpals and matatarsals
Short bones
- Cube-shaped bones (in wrist and ankle)
- Sesamoid bones (within tendons e.g patella)
- Vary in size and number in different individuals
Classification of bones by shape
(Flat bones and Irregular bones)
Flat
- Thin, flat, slightly curved
- Sternum, scapulae, ribs, most skull bones
Irregular bones
- Complicated shapes
- Vertebrae, coxal bones
What Sagittal Plane of the body?
Vertical Plane running from front to back; divides the body or any of its parts into right and left sides.
What is sagittal plane?
It divides body into left and right
What is coronal plane?
It cuts body into anterior and posterior
What is transverse plane?
It cuts body into superior and inferior
What are the 8 directional terms used in anatomy?
Lateral: Towards the left and right sides
Medial: Towards the middle
Anterior (Ventral): Front
Posterior (Dorsal): Back
Superior (Cranial): Up
Inferior (Caudal): Down
Proximal: Close to the centre of the body
Distal: Away from the centre of the body
What is the structure of typical long bone
Diaphysis:
- Tubular shaft form long axis
- Compact bone surrounding medullary cavity
Epiphyses
- Bone ends
- External compact bone; internal spongy bone
- Articular cartilage covers articular surfaces
- Between is epiphyseal line: Remnant of childhood bone growth at epiphyseal plate
