BL Bone, Bone Marrow, Blood And Blood Vessels Flashcards
What are the types of bones?
Long
Short
Irregular
Sesamoid
Flat
Describe long bones
Examples
Longer than they are wide
Mostly in appendicular skeleton
e.g. femur
Function of long bones
Support the weight of the body
Facilitate movement
Describe short bones
Examples
As long as they are wide
e.g.. wrist and ankle bones
Function of short bones
Provide stability and some movement
Describe flat bones
Examples
Flattened with roughly parallel opposite edges
e.g. sternum, ribs, ilium
Function of flat bones
Protection of internal organs
Area for attachment of muscles
Function of irregular bones
Provides anchor points for muscles
Protect internal organs:
- Vertebrae protect spinal cord
- Sacrum protects pelvic organs
Functions of sesamoid bones
Protect tendons from stress and damage from wear and tear
Where is yellow bone marrow found?
Medulla region of bone
Where is red bone marrow found?
Ends of long bones
Only in cancellous bone
What are the main cells of yellow bone marrow?
Adipose tissue
Contains stem cells that can become cartilage, fat or bone cells
Function of red bone marrow
Site of haemopoiesis
Function of yellow bone marrow
Shock absorber
Energy source - adipose
Compare and contrast red and yellow bone marrow
Red:
- full of developing blood cells
- rich blood supply
- only in cancellous bone
- site of haematopoiesis
Yellow:
- full of adipocytes
- poor blood supply
- shock absorber + energy source
Growth factor for RBCs
Erthyropoietin
Growth factor for granulocytes
Granulocytes stimulating horomones
Growth factor for lymphocytes
Interleukins
Growth factor for platelets
Thrombopoietin
Describe sinusoids
Incomplete basement membrane
Intracellular gap so that cells can get in and out
Pathway of newly formed RBCs
Venule > intermediate vein > larger vein > vena cava
Pathway of newly formed WBCs
Venule > intermediate vein > larger vein > vena cava
How long does it take for RBCs to mature?
2 days
What is flow in capillary controlled by?
Precapillary sphincters
Function of precapillary sphincters
Control flow in capillaries
Controls fluid exchange between capillaries and body tissues
Structure of veins
Tunica intima - endothelialcells
Tunica media - smooth muscle + elastic fibres
Tunica adventica - elastic fibrous capsule
Have valves
Structure of arteries
Tunica intima - elastic membrane
Tunica media - smooth muscle + elastic fibres
- thicker in arteries than veins
Tunica adventica - collagen + elastic fibres
Smaller lumen than veins
What is vasculogenesis?
Formation of new blood vessels
What is angiogenesis?
Formation of new blood vessels from existing blood vessels
What is intussusception of vessels?
Splitting of one vessel into two
Takes minutes to hours
What is pericyte?
A stem cell that sits over the top of capillaries
Function of pericytes
Prevents endothelial cell proliferation
Maintains tight capillaries
Function of collateral blood vessels
Provide alternative path for arterial blood flow
