PNB 2265 Exam 1 |Questions and
answers| 2026 Update
what type of tissue is blood categorized as
fluid connective tissue because its matrix is plasma
what is the composition of blood
-plasma
-white and red blood cells
-cell fragments made of platelets or thrombocytes
what are the physical properties of blood
-mostly water (plasma)
-has a neutral pH of 7.4 which allows it to take on a regulatory role in the body
how much volume in the human body does blood take up on average
-about 4-6 liters which is about 7% of our bodyweight
-its always in proportion to our body size
what are teh general functions of blood
-transport
-regulation
-protection
due to its composition, what properties does blood act similar to that of
-water
-because blood is primarily made up of plasma and plasma is made up of water, blood
as a tissue takes on many properties similar to water
-solutes discovered in blood serve to maintain osmotic balance between tissues &
osmotic environment
what kinds of materials does blood tend to transport
-nutrients
-wastes
-gases (O2, CO2)
how does blood act as a regulator in terms of general functions
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-it has a neutral pH of 7.4
-its osmolarity
-its temperature of about -38 degrees C makes it a good buffer and maintenance for
temperature
-acts when fluids is lost to injury, etc.
how does blood serve as a protective function
-it has components of the immune system that contribute to fighting off infections
what makes up fractionated blood
-about 46-63% plasma for the liquid portion
-about 37-54% formed elements which include red & white blood cells and cell
fragments/platelets
why does blood separate into other layers overtime
-blood is a homogenous mixture, but it will start to fractionate into different layers when
it sits for a long time
where is the plasma in a fractionated blood sample
where is the formed elements in a fractionated blood sample
what makes up the Buffy coat in a fractionated blood sample
-white blood cells
-platelets
what is contained within formed elements
-platelets which make up about 0.1%
-red blood cells & white blood cells which make up about 99%
what makes up the concentration of plasma
-7% plasma proteins
-1% other solutes
-92% water
what is the role of plasma given its elemental qualities
transports organic & inorganic molecules, formed elements & heat
what are the different kinds of plasma proteins
-60% albumin
-35% globulins
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-4% fibrinogen
-<1% regulatory proteins
what is albumin
-a plasma protein
-makes up about 60% of proteins
-helps to create osmotic pressure & environment w/ tissues, minimizes water movement
through osmosis
-also transports lipids, hormones and steroids
-can change to maintain balance
what are globulins
-a plasma protein
-makes up about 35% of proteins
-transports immunoglobulins which are also called antibodies & other globulins which
make antibodies
what is fibrinogen
-a plasma protein
-makes up about 4% of proteins
-essential for clotting and the process of clotting
what are regulatory proteins
-a subtype of plasma protein
-makes up less than 1% of proteins
-includes enzymes, proenzymes and hormones
what are other solutes related to blood
-electrolytes: eg; plasma salt
-organic nutrients: eg; lipids, carbs, amino acids
-organic wastes: eg; urea, creatinine, bilirubin
what are platelets
fragments of megakaryocytes for clotting
what are leukocytes
-white blood cells which fight against infection
what are the different kinds of white blood cells
-neutrophils: 50-70%
-cosinphils: 2-4%
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-basophils: <0.1%
-lymphocytes: 20-30%
-monocytes: 2-8%
what are erythrocytes
-red blood cells
-deliver oxygen and remove carbon dioxide
what is a hematocrit
-the volume red blood cells occupy in a blood sample
-typically expressed as a %
-normally you can let the sample sit out but a centrifuge speeds up the separating
reaction
-normally about a 50/50 ratio but the test allows you to quickly see any major
imbalances in plasma & formed elements
how is plasma defined in a hemotocrit
-a supernatant; made up by formed elements in a pellet
how is a hematocrit different from plasma
-it is the percentage of volume that is taken up by red blood cells only
-the value is the same regardless of the sample size because your hematocrit only
looks at your composition of blood and the ratio of components relative to eachother
what do formed elements refer to in terms of a hemotocrit
-refers to all of the cell and cell fragment components of blood
-when blood is fractionated, white blood cells & platelets are located in a really thin layer
in the middle called the Buffy coat
what is the major limitation of hematocrits
-not actually able to see the individual cells
-you would need to see them under a microscope in a complete blood count
-a complete blood count would allow youn to be able to see individual cells, size, shape,
etc.
why is blood a target for disease
-HIV attacks helper T lymphocytes, weakens the immune system, making affected
individuals susceptible to other diseases (causes AIDs)
-there are now highly effective treatments & prophylactics available for people with
access and the ability to pay for these treatments
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