Bone, Marrow, Vssels And Blood Flashcards
What types of bone excise in our body?
Long Short Flat Irregular Sesamoid (seed shape)
What is the structure of long bones? And what is their function?
Longer than they are wide
Femur = longest, fingers= shortest
Mostly found in appendicular skeleton
They support the weight of the body and facilitate movement
What is the structure and function of short bones?
Approximately as long as they are wide
Eg, wrist and ankle joints (Carpals in wrist, tarsals in ankle)
They provide stability and some movement
What is the structure and function of flat bones?
They are somewhat flattened with roughly parallel opposite edges
Skull (occipital), thoracic cage (sternum and rib), pelvis (ilium)
They protect internal organs
Provide large areas of attachments for muscles
What is the structure and function of irregular bones?
Vary in shape/structure so don’t fit into any other category
Often complex shape
Protect internal organs
Vertebrae protect spinal chord
Pelvis (sacrum) protect pelvic cavity organs
Provide anchor points for muscle groups
What is the structure and function of sesamoid bones?
They are embedded in tendons
Small, round bones found in tendons of hands, knees and feet
They are usually generated postnatally like the patella
They protect tendons from stress and damage, fro repeated wear and tear
What is cancellous bone? (Sometimes called spongy bone)
It’s in the middle of bones and forms a network of fine bony columns that combine strength and lightness.
In the spaces between these columns is filled with bone marrow.
What is compact bone? (Sometimes called cortical)
Forms the external surfaces of bones
Thin at head of bones, thick in the middle
Makes up 80% of the bones mass (heavy)
What are the 2 types of bone marrow and their functions?
Red-to replenish blood cells (haemopoiesis)
Yellow-shock absorber and energy source
Describe red bone marrow .
Full of developing blood cells
Rich blood supply
Only found in cancellous/spongy bone
Describe yellow marrow and state an unusual ability it has?
Full of adipocytes
Poor blood supply
Can convert to red blood marrow in anaemia (eg after severe blood loss)
In cancellous (spongy bone) what is a trabeculum and what is it made up of?
A bony structure or beam
It consists of numerous osteocytes embedded in the irregular lamella of bone.
Osteoblasts and osteoclasts on their surfaces remodel them.
What do osteoblasts do?
They make bone
They are regulated by hormones
What are osteoclasts?
They destroy/ remodel bone.
What do osteocytes do?
They recognise stress when it is placed upon the bone and send a message to osteoblasts to make more.