Lecture 3 - The Skeleton Flashcards
define axial skeleton
- skull, spine and ribcage
- the areas of the body you cannot live without (protects necessary organs)
define appendicular skeleton
- the upper and lower extremities and the pelvis
- the areas of the body not necessary for life
what are the 5 sections of the spine?
- cervical spine
- thoracic spine
- lumbar spine
- sacrum
- coccyx
why doesn’t the thoracic spine twist?
- due to ribs not wanting to overlap
- both lumbar and cervical though have a lot of motion
what is the odontoid process and its role?
- sticks out of C2 into C1
- required to make the “no” motion
why is the curvature of the spine so important?
- to take loads
- spine acts as a spring and absorbs load to keep the head steady (for the brain and the eyes)
what are the 6 functions of the skeleton?
- attachments for muscles
- leverage for supplying torque to the joints
- protect vital organs
- support soft tissues
- making new red blood cells (in the bone marrow)
- reservoir for calcium and phosphate
what is wolff’s law of bone?
- bone is laid down in areas of high stress, bone is lost in areas of low stress
- “use it or lose it”
- remodeling process (osteoblasts lay down, osteoclasts absorb)
- “stress” adjusts the balance between the two
what is stress shielding?
- stiff metal implant off loafs the surrounding bone so the bone reabsorbs
- osteoclasts eat away at bones no longer under stress
- due to poor implant design
what are the 5 types of bones?
- long
- short
- sesamoid
- flat
- irregular
what are long bones?
- usually in the extremities
- acts as lever for muscles about the joints (so long)
- knobs on ends are for joint connections
- hollow because they need to be light
what are short bones?
- tightly packed
- provide shock absorption and flexibility of movement
- can bear a lot of load
what are flat bones?
- provide protection to underlying organs
what are irregular bones?
- fulfill multiple roles
- protection and flexibility
- multiple muscle attachments
- vertebra or scapula
- generally a weakness in the body (high mobility so low stability)
what is a condyle/epicondyle?
- a rounded process of a bone that articulates with another bone
- epi just means smaller
what is a facet?
- a small, flat, smooth surface of a bone that is usually a weight-bearing surface
- usually articulate with other facets
what is a foramen?
- a hole in a bone where a nerve passes through (or a blood vessel)
what is a fossa?
- a shallow depression in a bone, usually space for another bone
what is a process or tuberosity?
- a raised section of bone, usually for the attachment of a ligament or tendon
what is diaphysis?
- the shaft of the long bone made of hard cortical bone
- outer lining is the periosteum
- inner lining is the endosteum
- hollow middle is called the medullary canal
what is metaphysis?
- the ends of the long bone made of spongy trabecular bone
- separated from the diaphysis via an epiphyseal plate of cortical bone
what are the bone cell types in short bones?
- more metaphysis and made of spongy trabecular bone
what are the bone cell types in flat bones?
- more diaphysis with a layer of trabecular bone
what are the bone cell types in irregular bones?
- a combination of cortical bone (diaphysis) and trabecular bone (metaphysis)
what are the types of loading on the skeleton?
- compression
- tension
- torsion (twisting)
- shear (sliding)
