Intro to Histology & Blooc

Question 1

What type of stain is haemotoxylin?

Answer 1

Haemotoxylin stains tissues blue/purple. It binds to acidic/anionic components of tissues. It stains tissues that are basophilic such as the phosphate groups of nucleic acids. Therefore the nucleus of a cell stains blue/purple.

Question 2

What type of stain is eosin?

Answer 2

Eosin stains tissues orange/pink. It binds to cationic components of tissues. It stains tissues that are acidophilic such as ionised amino groups of proteins, whether they are intracellular or extracellular.

Question 3

What are the 4 tissue types?

Answer 3

connective tissue, epithelia, muscle, neural tissue

Question 4

What is the difference between parenchyma and stroma?

Answer 4

Parenchyma is the functional cells, stroma is the supportive cells.

Question 5

What are the features of connective tissue?

Answer 5

Relatively few cells, mainly extracellular matrix. Extracellular matrix contains fibres and ground substance. Ground substance contains extracellular fluid.

Question 6

What are the different classes of connective tissue?

Answer 6

• embryonic
  
  • connective tissue proper
  • • loose
    • dense
    • • regular
      • irregular
  • specialised
  • • cartilage
    • bone
    • adipose tissue
    • blood
    • haemopoietic
    • lymphatic

Question 7

What are the different types of blood cells?

Answer 7

• red blood cells
  
  • white blood cells
  • • granulocytes
    • • neutrophils
      • eosinophils
      • basophils
    • mononuclear leukocytes
    • • monocytes
      • lymphocytes
  • platelets

Question 8

What are the features of red blood cells?

Answer 8

Biconcave, no nucleus, no organelles, 7.2 micron diameter, 120 day life span

Question 9

What are reticulocytes?

Answer 9

Reticulocytes are immature red blood cells. They are released from the bone marrow into the blood stream where they mature into red blood cells. They have a rough ER which can be picked up with special stains. They are released after haemorrhage or haemolysis.

Question 10

What are the features of platelets?

Answer 10

They are cell fragments (no nucleus), are 2-4 microns in diameter, have a lot of granules and have a lifespan of 8-10 days.

Question 11

What is the function of platelets?

Answer 11

Platelets are involved in haemostasis (blood clots), in releasing growth factors, in vasoconstriction, in inflammation

Question 12

What are the features of granulocytes?

Answer 12

They have prominent granules in their cytoplasm and have multi-lobated nuclei.

Question 13

What are the features of mononuclear leukocytes?

Answer 13

They have non-lobated nuclei.

Question 14

What is the function of white blood cells?

Answer 14

They are involved in the immune system. They are present in the blood but function in the tissue - blood is just the transport.

Question 15

What are the features of neutrophils?

Answer 15

Neutrophils are a granulocyte white blood cell. Neutrophils are 1.5 to 2 times the size of red blood cells and their nuclei have 3,4 or 5 segments. There are 3 types of granules in the cytoplasm. They are only seen in the tissue if there is an acute inflammatory response occurring. They stain pink.

Question 16

What are the features of eosinophils?

Answer 16

Eosinophils are a granulocyte white blood cell. They are the same size or bigger than neutrophils, they have a bilobed nucleus, have specific granules and are involved in allergic reactions. They stain red.

Question 17

What are the features of basophils?

Answer 17

Basophils are a granulocyte white blood cell. They have a bilobed nucleus and have granules that contain histamine. They stain blue.

Question 18

What are the features of lymphocytes?

Answer 18

Lymphocytes are a mononuclear leukocyte white blood cell. They are the smallest white blood cell (slightly larger than red blood cells), without much cytoplasm. There are three main types, B, T and NK. They are involved in immunity.

Question 19

What are the features of monocytes?

Answer 19

Monocytes are a mononuclear leukocyte white blood cell. They are the largest white blood cell. Their nucleus is bean shaped. They are the precursors of macrophages.

Question 20

What is haemopoiesis?

Answer 20

Haemopoiesis is the generation of new blood cells. It occurs in red bone marrow. Adults only have red bone marrow in their axial skeleton and upper femur. All cells are generated from a haempoietic stem cell. Production is tightly controlled by growth factors and the microenvironment.

Question 21

How to red blood cells develop (erythropoiesis)?

Answer 21

When developing the cells have a nucleus and rough ER so are basophilic. As they develop, the cells become smaller and less basophilic and eventually the nucleus is extruded and phagocytosed.

Question 22

How do granulocytes develop?

Answer 22

Initially they have a single larger nucleus, but as they develop the nucleus becomes segmented.