Bone Biology Flashcards
(44 cards)
The human skeleton is composed of ___ bones
206
When does the bone mass in the skeleton reach maximum density?
30 years old
Skeleton at birth contains how many bones?
300
Adult skeleton contains how many bones?
206
What is the axial skeleton?
- skull vertebral column, rib cage
- visceral skeleton (lower jaw, upper jaw, branchial arches, hyoid bone)
What is the appendicular skeleton?
bones of upper and lower limbs
The classification of human skeleton bones can be characterized by 5 shapes, what are they?
- long
- short
- flat
- irregular
- sesamoid
What is the function of long bones?
support weight and facilitate movement
What is the shape of short bones?
cube-shaped
What is the function of flat bones?
protect the internal organs
These type of bones have complex shapes
irregular bones
These type of bones reinforce tendons
sesamoid bnes
Long bones have a tubular bone shaft which consists of
bone collar surrounding a hollow medullary cavity
The hollow medullary cavity is filled with what?
yellow bone marrow in adults
What are the epiphyses? What do they consist of?
- found at ends of bone
- consist of internal spongy bone covered by a layer of compact bone
What is the epiphyseal line and where it is located?
- located between epiphyses and diaphysis
- remnant of epiphyseal plate
What is the external surface of the bone covered by?
periosteum which has the blood supply
What is the internal surface of the bone lined by?
endosteum which is a connective tissue membrane
Describe the general structure of short, flat, and irregular bones.
- thin plates of periosteum (outside)
- endosteum-covered spongy bone (inside) which houses bone marrow between trebeculae
How do you differentiate between cortical bone and trabecular bone?
- trabecular bone has holes
- cortical bone has no holes
Describe the general blood supply of long bones
- diaphyseal nutrient artery: most important for long bone
- diaphyseal nutrient artery divides into ascending and descending branches –> supply inner 2/3 or cortex and medullary cavity
- metaphyseal and epiphyseal arteries –> supply the ends of bones
- periosteal arterioles –> supply outer layers of cortical bone
Describe the general bone supply of large irregular bones, short bones, and flat bones
- superficial blood supply from periosteum
- form large nutrient arteries which penetrate into medullar bone
The periosteum and large nutrient arteries of the large irregular bones, short bones and flat bones ___ freely.
anastamose
**EXAM QUESTION ** What are the 6 functions of the human skeleton?
- support
- supports softer tissues
- provides points of attachment for skeletal muscles - protection
- internal organs, preventing injury (ex. cranial bones for brain, vertebrae for spinal cord, ribcage for heart and lungs) - assisting movement
- skeletal muscles attached to bones –> muscles contract –> bones move - resevoir for mineral
- Ca and P
- when minerals needed, bone releases minerals in the blood to balance minerals in body - storage of energy
- with age, red bone marrow –> yellow bone marrow
- yellow blone marrow consists mainly of adipose cells and few blood cells - production of blood cells
- red bone marrow inside larger bone cells which produce blood cells