Chapter 8.2 Flashcards
What are the 2 distinct elements of blood?
A fluid portion and a solid portion
What is the fluid portion of the blood called?
Plasma
What does plasma consist of?
Water, dissolved gases, proteins, sugars, vitamins, minerals, hormones, and waste products
How much of the blood does plasma make?
55 percent
What is the solid portion of the blood called?
The formed portion
What does the formed portion of blood consist of?
It consists of red blood cells, white blood cells, and platelets
What does the bone marrow produce?
Red blood cells, white blood cells, and platelets
How much of the blood does the formed portion make up?
45 percent
What is the smallest portion of the blood?
White blood cells and platelets
What is another name for red blood cells?
Erythrocytes
What volume do red blood cells/erythrocytes make of the blood?
44%
What are red blood cells specialized for?
Oxygen transport
What is the oxygen-carrying capacity of the blood dependant on?
The number of erythrocytes present and the amount of hemoglobin the each red blood cell contains
What does a mature mammalian blood cell lack?
A nucleus
What are red blood cells packed with?
280 million molecules of the pigment called hemoglobin
Why does hemoglobin allow large quantities of oxygen to be picked picked up?
Because it has special properties allow it to chemically bind with oxygen
What happens when someone is Anemic?
If there are too few red blood cells or to few hemoglobin pigments in the red blood cells in the bloodstream it reduces the amount of oxygen flowing through the body
What are the symptoms of anemia?
Paleness and fatigue
What is anemia caused by?
A dietary deficiency of iron which is a key component of hemoglobin
What is another name for white blood cells?
Leucocytes
What are leukocytes apart of?
The body’s response to infection
What are the 3 groups of leukocytes?
Granulocytes, monocytes, and lymphcytes
What do Granulocytes consist of?
Neutrophils, Basophils and eosinophils
What can monocytes do?
They can leave the bloodstream and become further specialized as macrophages which can destroy bacteria
What do granulocytes and monocytes typically do?
Engulf and destroy foreign bodies
What do lymphocytes do?
Produce proteins that incapacitate pathogens and allow them to be easily detected and destroyed
What are platelets?
Fragments of cell that that form when larger cells in the bone marrow break apart. These fragments contain no nucleus and break down quickly in the blood
What do platelets play a key role in?
Clotting blood
What are the stages of clotting?
1) injury to blood vessel starts cellular events
2) Substances released by the broken blood vessel attract platelets
3) The collecting platelets rupture and release chemicals that combine with other blood components to produce an enzyme called thromboplastin
What does the thromboplastin react with?
In the presence of calcium ions it reacts with prothrombin to produce thrombin
What is prothrombin?
A plasma protein produced by the liver. It reacts with thromboplastin to produce thrombin
What does the thrombin do?
It reacts with fibrinogen to produce fibrin
What is fibrin?
An insoluble material that forms a mesh of strands around an injured area to trap escaping blood
What is the medium that blood cells are suspended in?
Plasma
How is carbon dioxide transported?
It dissolves in the water portion of the blood to form carbonic acid inside the cytoplasm of red blood cells. It diffuses out of red blood cells into the plasma as bicarbonate ions.
What are the functions of the blood?
Serving as a medium for transporting materials in the body and regulating concentration of substances and heat in the body
How does blood help within the digestive system?
It absorbs many of the nutrients that are end products of digestion and send them to the liver where they are converted to other products
How does blood help to transport waste products?
It picks up uric acid, mineral ions, and other waste products to the kidneys for processing and excretion
What is uric acid?
The end products of protein metabolism. A waste product
How does blood play a role in conveying chemical messengers?
It serves as a medium for transporting hormones
What do hormones play a central role in?
Regulating and coordinating the internal systems of the body
What would happens if hormones couldn’t use the bloodstream as a pathway?
The body would be unable to respond effectively to fluctuations in its environment and would not be able to keep balance
What does temperature regulation involve?
Balancing heat production with heat loss
What does the blood going to the skin do?
Since it is warmer than the skin it loses heat
What happens when the body’s internal temperature become too warm?
The body must rid itself of heat
How does the body rid itself of heat?
Blood transports heat from where it is produced by cellular respiration and muscular activity to the skin. The vessels dilate to increase the amount of blood flowing to increase the amount of heat lost through the skin
What is vasodilation?
When the body dilates blood vessels near the skin to allow heat to escape and rid itself of heat
What are the several methods for releasing heat in the body?
Evaporation of water in sweat
Vasodilation
How can sweating cause problems?
This can cause dehydration if the body needs to rid itself of excess heat during a fever
How is body heat conserved?
Vasoconstriction
What is vasoconstriction?
The construction of blood vessels near the surface of the skin
How does vasoconstriction reduce heat loss?
Since the less blood flows to the vessels near the skin less heat is lost from the body
How does the body increase temperature?
Waves of muscle contractions called shivering increase heat by cellular metabolism and the heat is spread through the blood
What happens if blood pressure is too high in the body?
Vasodilation will reduce the blood pressure
What will happen to the blood vessels if blood pressure is too low?
Vasoconstriction will increase it
How does exercise change the dilation of veins?
Exercise results in vasodilation to increase the blood flow to tissues
What do alcohol and smoking do to the dilation of blood vessels?
They promote vasodilation and cause blood to rush to the surface of skin
How does a countercurrent heat exchange system help to maintain steady temperature in the core of the body?
Deep arteries and veins are adjacent to one another. So warmer blood that flows from the core of the body to extremities exchanges heat with cooler blood returning to the core of the body
What does the proper functioning of all cells depend on?
Capillaries because they are the only vessels that are thin enough for the exchange of matter by diffusion
What are capillaries present in?
Networks and most cells are present next to capillaries
How many capillaries are in the human body?
There are about 1 billion with a surface area of 6300 meters squared
What is a capillary bed?
This is a formation of many capillary vessels lying between a branch of an artery and a branch of a vein
What can happen if cells between capillary bed does not need to be serviced?
Blood can be shunted directly from an artery to a vein, bypassing the capillaries
How can blood bypass capillary beds?
Through the action of sphincters that tighten and close the opening of an artery to a capillary
What is another reason that blood may bypass a capillary?
This may happen when blood is needed in another part of the body. Ex after eating when blood is needed in the intestines
What are cells in the body constantly bathed in?
Interstitial fluid
What must any material exchanged between capillaries and cells past through?
Interstitial fluid
What are the parts of a capillary?
An arterial end
Mid-section
Venous end
What color is blood when it enter the capillary through the arterial end?
Bright red because the hemoglobin is rich in oxygen
What takes place in the mid section of the capillaries?
The diffusion of oxygen and nutrients suspended in the blood’s plasma
What is the direction of diffusion determined by?
The material’s concentration gradient
Why does diffusion have lots of time to occur in the capillaries?
Because the blood flow is slower than anywhere else in the body
What is blood pressure like in capillary beds?
Lower than arteries but higher than the veins
Why is blood pressure in veins lower than blood pressure in capillaries?
Because blood pressure decreases as you move further away from the heart
What is hemophilia the result of?
Insufficient clotting proteins in the blood
What are people with hemophilia treated with?
Injections of a substance called factor VIII, a protein involved in blood clotting that they are missing
What is leukemia?
A cancer of white blood cells
What are the 2 types of Leukemia?
Myeloid and Lymphoid
What is Myeloid Leukemia characterized by?
The presence of too many Leukocytes that are immature and unable to fight infection. They crowd red blood cells and causing anemia and fatigue
What is Lymphoid Leukemia?
Cancer of the lymphocytes. Has the same symptoms of Myeloid leukemia
What are the 2 states that Leukemia can occur in?
Acute or chronic
What is acute Leukemia like?
Symptoms appear suddenly and death follows quickly
What is Chronic Leukemia like?
It may go undetected for years
What is the treatment of Leukemia?
Blood transfusions and chemotherapy. Sometimes a bone marrow transplant
What do blood transfusions do for someone with leukemia?
Increases the number of red blood cells and healthy white blood cells
What is the lifespan of red blood cells?
120 days
What is the lifespan of Granulocytes and monocytes?
A few hours to a few days
