2 (17) Blood Flashcards
(100 cards)
What type of tissue is blood?
connective tissue
What similarities do we see between blood and all other tissues of this type?
- connective tissue is also found in bones and adipose (fat)
- bones and blood both have a matrix
- organic matrix of bone is made of collagen fibers and the inorganic matrix of bone is made of salts; both providing durability to the bone
- matrix of blood is formed of ground substance (fluid—plasma) and fibers
What are the three main functions of blood? Go into detail – do not just list 3 words
(1) Transport
- delivering oxygen from lungs and nutrients from digestive tract
- transporting metabolic wastes to lungs and kidneys
- transporting hormones from endocrine organs to target organs
(2) Regulation
- maintaining homeostasis
- body temperature, pH levels in body tissues, and fluid volume in the circulatory system
(3) Protection
- preventing blood loss
- preventing infection
How is blood different from water?
blood is thicker, heavier, and 3-5 times more viscous than water (this is due largely because of the formed elements)
How does the temperature of blood differ from the average body temperature?
the temperature of blood on average is 100.4, while the normal body temperature is 98.6
What do you see after you put a tube of whole blood in a centrifuge?
3 layers:
- 55% plasma (least dense, so at the top of the tube)
- Less than 1% buffy coat (in the middle of the two) (buffy = leukocytes and platelets)
- 45% erythrocytes (most dense, so at the bottom of the tube)
What are the “formed elements” of blood, and what percent of blood do they usually make up?
the buffy coat (leukocytes and platelets) and erythrocytes make up the formed elements of blood (<46%)
What would you find in the buffy coat?
leukocytes and platelets
Be able to calculate the approximate blood volume of a person if you are given his weight in kilograms. (1 kg = 2.2 lbs.)
- blood is 8% of body weight
Example: Calculate the blood volume (in Liters) of a person who weighs 154 lbs. - answer: 154 lbs./2.2 lbs. = 70 kg.
- 70 kg. x 0.08 (8%) = 5.6 kg
- 5.6 kg. = 5.6 L
remember: the average blood volume is between 4-6 L!
What is an hematocrit and what does it measure?
“blood fraction”; the percent of blood volume that is erythrocytes (RBC’s)
How would the hematocrit of a male typically compare to that of a female? Why does this occur?
Male = 47% plus or minus 5% Female = 42% plus or minus 5%
men have more androgens
women bleed more during menstrual cycle
What is the erythrocyte sedimentation rate and what can it tell us?
- ESR: the rate at which blood cells sediment in a period of one hour
- ESR is a non-specific measure of inflammation: increases during infection, autoimmune diseases, and inflammation; decreases in sickle cell anemia, polycythemia, and hyperglycemia
When we remove the formed elements from blood, what is left?
only plasma
What do we have if we then remove the clotting factors? What is this used for?
- serum is what we would have left if we removed the clotting factors
- this is used for tests because serum still contains ions, nutrients, enzymes, gases, wastes, hormones, and some proteins
- antibodies are also still present
What do we call the stem cell from which all blood cells originate? Where is blood formed in a fetus? After birth?
- stem cells from which all blood originates are called hemocytoblasts through a process called hematopoiesis
- in a fetus, blood is formed by the yolk sac, liver, spleen, thymus gland, lymph nodes, and red bone marrow
- after birth, blood is formed by red bone marrow only
Describe the shape of an erythrocyte. Why is this shape important to its function?
- erythrocytes have the shape of a biconcave disc—flattened discs with depressed centers (lack nuclei and organelles)
- this shape is important because it allows RBC’s to change shape (twist, turn, bend) as necessary to travel through capillaries smaller than themselves
To achieve this shape (erythrocyte), what organelle does the cell have to lose, and how does this affect its ability to function?
since there are no mitochondria, they do not consume any of the oxygen they carry, making them perfect oxygen transporters
Describe a hemoglobin molecule. Is our hemoglobin the same throughout our life time?
- the protein that makes RBC’s red in color and most oxygen carried in blood is bound to hemoglobin
- consists of heme and four polypeptide chains (2 alpha and 2 beta) called globin
- the iron containing pigment (heme) binds easily and reversibly with oxygen
- beta peptides vary throughout our lifetime
Where does the oxygen bind?
to the heme component of the protein hemoglobin in red blood cells
Where can carbon dioxide bind?
at the α-amino group
When oxygen binds with hemoglobin what compound is formed?
oxyhemoglobin
What compound is formed when carbon dioxide binds with hemoglobin?
carbaminohemoglobin
What compound is formed when carbon monoxide binds with hemoglobin?
carboxyhemoglobin
Why would a person appear cyanotic?
the appearance of blue or purplish colored skin due to the tissues of near the skin’s surface having low oxygen concentration in the blood