Blood Components Flashcards
What are the 3 functions of blood?
Transport
Regulation
Protection
What does the blood transport?
- O2 from lungs and CO2 to lungs
- Nutrients from digestive tract to body tissue
- Waste from cells to kidneys
- Hormones from endocrine glands to target organs
What does the blood regulate in the body?
- pH through blood buffers
- Body temperature
- Water content through interactions with ions and proteins
How does the blood protect the body?
- Contains antibodies and WBCs to destroy pathogens.
- Haemostasis prevents excessive blood loss
What are the components of plasma?
Proteins, water, platelets, leukocytes, erythrocytes, others solutes
What are the main components of blood?
Platelets, red blood cells, plasma, white blood cells
List some characteristics of blood
Thicker than water (more viscous) Flows more slowly than water pH 7.35 to 7.45 Temperature 38° C Total adult volume 4 – 6 litres Adult female 4 - 5L Adult male 5 – 6L Infants and children have lower blood volumes
What can haematology testing can tell you about your patient?
Diagnose anemia, infection, hemophilia, blood-clotting disorders, and leukemia
What are the functions of RBC?
- Carry oxygen
- Contains haemaglobin (Hb), an oxygen-carrying protein that provides blood with its red colour
- Increases surface area for rapid entry and exit of O2 by diffusion
What are the functions of WBC?
Defend against disease by pathogens, toxins,
cancer and damaged cells
What are the functions of platelets?
Release chemicals which promote blood clotting
Form a platelet plug in a ‘hole’ of damaged tissue to prevent
blood loss
Aggregate other platelets
Describe the structure of RBC
Flexible structure to move through narrow capillaries. No nucleus or organelles (no cell division)
Describe some characteristics of platelets
Platelets, are small, colorless cell fragments in our blood that form clots and stop or prevent bleeding. They are made in our bone marrow
Describe some characteristics of WBC
There become increased level of WBC in the presence of microorganisms, strenuous exercise and after anaethesia and surgery
Where are WBC located?
Blood vessels
Lymphatic system
Skin, lungs and spleen
When would the rate of RBC production increase?
After excessive bleeding, when availability of O2 is low and inadequate production of RBC
What does too many red blood cells do to your blood?
Makes its too viscous
What does too few red blood cells do?
Cause tissues to lack O2
What is Haemoglobin
Hemoglobin is the protein molecule in red blood cells that carries oxygen from the lungs to the body’s tissues and returns carbon dioxide from the tissues back to the lungs.
What is Haematocrit?
The haematocrit (Hct) or packed cell volume (PCV) is the percentage of whole blood that is made up by the red blood cells
What is Haemoglobin made up of?
Protein with 4 Haemoglobin molecules attached. Each Hb can carry 4 oxygen molecules and is considered fully saturated
What is the life cycle of a RBC?
Macrophages in spleen and liver phagocytose aged or damaged RBC Breakdown of Hb releases haeme and globin Globin = converted to amino acids for protein synthesis Haeme = degraded into iron that can be stored or used to produce new Hb or bilirubin Bilirubin is excreted into bile and then faeces
Describe Eosinophils
- Combat parasites and helminths
- Also involved in allergic response
- Primarily in the gut and adipose tissue, thymus and bone marrow.
Describe Basophils
- Primarily in the blood
- Key role in inflammatory reactions
- Contain heparin and histamine
Describe Neutrophils
Fastest to respond to bacterial tissue damage
Engulf pathogens by phagocytosis
Short life span (minutes to days)
Numbers increase during bacterial infections
Describe Fixed Macrophages
Make up 3-8% of circulating WBC
The normal pH of the blood is?
7.35 - 7.45
The percentage of whole blood that is made up by the red blood cells is called the
Haematocrit
State four functions of platelets.
- Platelets release chemicals which increase vasoconstriction
- The intrinsic pathway is initiated by a platelet factor
- Facilitate clot retraction to draw the edges of the wound together
- Platelets immediately release chemicals to stimulate the healing process.
The production of red blood cells increases when there is higher levels of what in the blood?
Erythropoietin
A low platelet count may cause?
Excess bleeding
Aged red blood cells are destroyed mainly by macrophages in the
Spleen
An adult human contains about _____ pints of blood
4-6 pints
Neutrophils and macrophages are active in?
Phagocytosis
The primary site of hemopoiesis in adult humans is in the?
Red bone marrow
Which blood cell type is elevated in a parasitic infection ?
Eosinophils
Vascular spasms and platelet plug formation are steps in
Hemostasis
Which formed elements of the blood are produced from fragments of cells?
Thrombocytes
Describe monocytes
• Produced in the bone marrow and then migrate to tissue. They are the largest type of WBC. They act as phagocytes, produce cytokines and are involved in antigen presentation.
Describe Macrophages
Circulating in the blood as free-wondering macrophages or fixed in specific tissue sites. Specialised in detection, phagocytosis and destruction of pathogens
