Hemaptopoietic System Flashcards
What is blood?
A fluid connective tissue constituting about 7% of our total body weight.
Functions of blood: (3)
Transports various substances
Helps regulate several life processes
Protection against diseases
Components of blood
what makes up to 55% of blood?
Plasma
What is plasma made up of?
92% water, 7% plasma proteins and 1% hormones, organic nutrients, metabolic waste etc
Normal plasma volume..
40 ml per kg
Components of blood
what makes up to 45% of blood?
Erythroytes (RBC) 30 ml per kg body weight
Leukocytes (WBC)
Platelets 1-2% volume
Hematocrit is…
the ratio of red blood cells to plasma.
How can white blood cells be divided into? (5)
Lymphocytes
Monocytes
Neurtrophils
Eosinophils
Basophils
What do red blood cells / Erythrocytes look like? (4)
Shape of a biconcave disk and measure about 7-8 um in diameter
lack ucleus
their cystol contains haemoglobin
consist of a plasma membrane, cytosol and haemoglobin
Life span of Erythrocytes ?
120 days
Functions of RBC? (2)
- transport respiratory gases
- hematopoiesis
Structure of Haemoglobin:
Composed of 4 protein global chains
2 alpha chains and 2 beta chains
Each heme group contains an iron atom in the centre
Can Erythrocytes change shape?
Yes depends on the environment.
Erythrocytes put in a hypertonic medium…
shrink, creates a spiky surfaced
Erythrocytes put in a hypotonic medium…
swell and lose their disk shape
What does sickle cell disease do to Erythrocytes ?
Causes them to change shape
What are less mature Erythrocytes called?
Reticulocytes
When are Erythrocytes considered Reticulocytes?
When they are released from the bone marrow for 2 days.
Characteristics of Reticulocytes: (2)
- contain residual ribonucleoprotein particles which impart a bluish hue to the cell.
- 1-2% of red cells.
What are Leukocytes?
WBC’s
What are Granulocytes? Examples (3)
WBC containing bacteria-combating granules
Neutrophil
Eosinophil
Basophil
What are Agranulocytes?
Examples (2)
Containing no granules
Lymphocyte
Monocyte
Describe Neutrophils:
Give the half life in blood and life span
- one of the largest 12-15 um and most numerous in an adult
- 50-75% of them, about 2-5% are band forms
Half life 6-8 hours
1-4 day life span
What do Neutrophils look like?
- they stain pink or purple
- promenant nucelus segmented into 2-5 lobes joined by a nuclear strand.
Functions of Neutrophils
They are the first line of defence against micro-organims e.g. bacteria.
They are active phagocytes.
How do Neutrophils / Phagocytes work? (3)
Chemically attract microbe
engulf
build phagosome (digestive enzymes present)
eliminate waste products (exocytosis)
Describe Eosinophils: (3)
- about same size as neutrophil
- cytoplasm has orange granules that contains a dense filamentous core of major basic protein (MBP)
- matrix of granules contains lyosomal enzymes
How much eosinophils in the blood?
1-3%
What does the Eosinophil’s MBP do?
Can kill parasitic worms
Describe Basophils:
How much in the blood?
9-10 um size
nucleus containing 2-3 lobes which are often difficult to see because of the large, darks training granules
blood contains 0.5-1% basophils
What do Basophil granules contain? (5)
High concentrations of Heparin Histamin Leukotriens Serotonin Chemotacitc factor
Basophils mediate…
hypersensitivity reaction by binding to IgE antibody.
Describe Monocytes:
How much in blood?
12-15 um
spend about a week in the blood and migrate into tissue where they become tissue macrophages
largest cells in the blood
3-8% in peripheral blood
Life span of Monocytes?
5-8 days
What do Monocytes look like?
Large kidney shaped nucleus
Pale cytoplasm
May contain fine granules, free ribosomes
What do Monocytes do?
They ingest and remove tissue debris and infectious agents.
Describe Lymphocytes
6-12 um
Have 80% T cells, 15% B cells, 5% NK cells
What do Lymphocytes look like?
Single, deeply stained spherical nucleus surrounded by a thin rim of cytoplasm.
What are Thrombocytes?
Platelets
What do Thrombocytes look like?
Non nucleated flat, round or disk shaped 2-5 um.
Help us stop bleeding, involved in hemostasis
Life span of Thrombocytes?
7-10 days
What is Thrombopoietin?
Deficiency of platelets - results in bruising and bleeding.
Where are thrombocytes derived from?
bone marrow - megakaryocytes.
What are megakaryocytes?
Giant cells with multiple copies of DNA in the nucleus.
What do activated platelets look like?
Spiky outer surface and adhere to each other - clumping.
What is bone marrow?
A soft tissue that fills the hollow centre of bones - specialises in production of all the formed elements of blood.
25% are RBC
75% are WBC
What is the most rapidly replicating tissue in the body?
Bone marrow
What is hematopoiesis?
when blood cells are rented to maintain appropriate circulating levels.
What are hematopoietic tissue?
Tissues which actively or potentially produce blood cells.
2 examples of hematopoietic tissue:
Myeloid - identified as ‘red marrow’ of bones, involved in producing RBC and WBC.
Lymphoid tissues - elements of the larger lymphatic system. proliferation of lymphocytes.
All blood cells come from…
Multipotential hematopoietic stem cell (hemocytoblast)
The development of erythrocytes is regulated by…
the hormone
ERYTHROPROTEIN
3 Steps of blood clotting:
Vasoconstriction
- constriction of damaged and lower of blood pressure to slow down flow of blood
Temporary clot
Coagualtion
Hemostasis is…
blood clot formation process.
Blood clot formation:
- exposed collagen (in damaged blood vessel wall) binds and activates platlets
- release of platelet factors
- factors attract more platelets
- platelets aggregate into platelet plug
What blood types are there?
Types A B AB O
What plasma antibodies do A B AB and O blood types contain?
A - B only
B - A only
AB - neither
O - both
What is the Rh factor?
A protein which can either be + or - in blood types. Blood types are inherited.
