Lab 13 - Blood histology Flashcards
What are the two ways to classify blood based on antigens on red blood cells
ABO
Rhesus
To which individuals could blood type A be given
Only type B and O
Which blood group is the universal donor
Type O - Group O have no antigens on the surface = have the antibodies A and B
So any blood type in ABO system can receive blood from blood O individuals.
Which blood group is the universal reciepient
Type AB
-Individuals with blood group AB have both a and b antigens meaning they have no antibodies so they can accept blood from blood type in the ABO system
Why would the blood of a person with group A blood clot if they received a transfusion of group B blood?
• Due to Group B blood having a ‘A’ antibody and B antigens and Group A have antigen ‘A’. Individuals with group A blood have A antigens on the surface meaning their blood plasma contains against the antigens they don’t have so against B. If they received group B, the B antigens in the donor blood will react with B antibodies i.e antibodies will attack your own rbc’s in the recipient blood causing them to reject the blood and cause blood clotting = stroke
What is the origin of the name of this blood grouping?
Firstly described in rhesus monkeys- found a similar antigen in their red blood cells
What are the other rhesus antigens (not tested for here), and which would make you Rh+ and why?
- Rheus blood types rely on presence of 6 antigens; C, D, E, c, d, e.
- C,D,E make Rh+ due to protein C, D and E found on the surface of rbc’s. Most people are Rh+. If they don’t have these antigens they are Rh-
What proportion of the population is Rh+?
85%
Why can you normally ‘get away with’ being given the wrong rhesus group once?
The body does not usually contain antibodies to these antigens (C,D,E, c, d, e), and they take several months to form, so can get away with being given wrong Rh once (after antibodies are present)
What is the most abundant cell type you see?
Erthrocytes- red blood cell – green blobs
What is diameter of rbc
2 Micrometre thick and 8micrometre wide
Shape of rbc and advantage of this
- Anucleate biconcave disk
- Thinner and lighter in the middle as the tissue is thinner so under microscope, more light passes through.
- Can change their shape to ‘ squeeze through ‘ capillaries.
- All erythrocytes white in the middle as biconcave disc so can twist and move easily and increases surface area
Other cell types in human blood
- Nuclei of WBC’s - appears as blue dots under microscope - can tell which one it is depending on the shape of the nucleus
- They appear multilobed ( more likely neutrophils or monocytes )
- Larger single nuclei - lymphocytes ( T or B )
- Horse shoe shaped - monocyte - slightly more elongated
What is function of neutrophil
Engulf and destroy invading organism
What is size of neutrophil
12 micrometre
Function of lymphocyte
Defence against attack of harmful foreign organism
Function of monocyte
Body’s major phagocyte and mature as a macrophage.
Size of monocyte
80 micrometre
Describe red blood cells of a fish
Contain a nucleus
So they can synthesize proteins, as these proteins are involved in immune response
Describe red blood cells of a rabbit
A lot smaller
Describe red blood cells of a rat
- Biconcave disks - larger SA and more flexible so can squeeze through capillaries
- The nucleus contains genetic info which codes for proteins (Hb), which helps bind oxygen to the Fe+2 ion (haem group).
- But in mammals as RBCs mature, the nucleus is lost as its beneficial to get rid of it, as the cell becomes less demanding(uses less energy)-done through process of hematopoiesis.
What happens when you remove nucleus
Cell becomes smaller and takes up less volume, this means you can then produce more RBCs as there is more space in the blood, so more Hb can be carried, thus more O2 in body.
What happens as proteins in RBC begin to break down
The body gets rid of the cell (in spleen/liver) and produces new ones through the stem cells in the bone marrow (red bone marrow found in flat bones-pelvis, collar bone etc)
Describe RBC’s of frog, fish or bird
- RBCs are larger and have a nucleus
- This also means bird, fish and amphibians are less evolved as their erythrocytes are involved in immunological functioning, where they can secrete substances to combat infection and pathogens.
- In a frog, the nucleus of a WBCs is similar size to that of RBC, however, it can expand in size, so it can carry more Hb.
Diameter of arteriole
50 micrometre
What makes up the tunica interna?
- Made up of one layer of endothelial cells
- Innermost tunica layer of an artery or vein
- Supported by an internal elastic lamina
- Endothelial cells are in direct contact with blood flow
- Simple squamous epithelia
- Provides frictionless surface for movement of blood - no blood clotting
What separates the tunica interna from the tunica media?
Internal elastic lamina
What is the major component of the tunica media and what is its function?
- Made of smooth muscle ( about 40 layers )
- Regulators of blood flow between the arteries and the delicate capillaries = allows blood vessels to wider and narrow = more efficient exchange of gases and nutrients when blood is within the capillary beds
How is the tunica media of most arteries innervated?
- ANS nervous system - sympathetic branch
- Innervates smooth msucle of most arteries = nerve supply to artery
Describe the composition of the arterial adventia.
Several layers of longitudinal, collagenous connective tissue- tough outer protective coat
What is the vasa vasorum?
- Supplies tunica media and externa of large vessels
- Vessels in the walls - network of small blood vessels that supply the walls of large blood vessels, such as elastic arteries e.g. aorta and large veins e.g. vena cava
- In large arteries you get smaller blood vessels within the blood vessel - cause if you have large artery, tunica media cant be supplied from blood in lumen of vessel
How does the structure of arteries differ from that of veins
- Veins have a relatively thin layer of smooth muscle in the wall - the tunica interna and media are thinner - appear darker
- Veins have a misshapen or collapsed look
- Arteries maintain a tight cylindrical shape
- Veins also have valve flaps to keep the blood from moving backward in the vessel.
- In veins lumen is often less regular and wider.
Red blood cell formation
- Erythropoiesis
- ## Found in stem cell of red bone marrow in flat bones e.g. pelvis, shoulder blades
What is main protein in rbc
Haemoglobin
What is function of haemoglobin
Transport O2 around the body
What happens during immature phase in rbc
Nucleus is coding for haemoglobin – telling ER to produce and manafcautr protein – acuumulate inside of cell
How much cell volume does nucleus make up
50%
