ch 3 - blood

tissue type & elements that make up blood

• connective tissue

• formed elements (cellular)

  • erythroctyes (rbc)

  • leukocytes (wbc)

  • platelets (cell fragments)

• extracellular matrix (plasma)

water-based fluid suspending formed elements in blood, allowing blood to flow through vessels

plasma

functions of blood (3)

transportation: delivering absorbed nutrients, diffusing oxygen, releasing hormones

defense: leukocytes protecting body from external pathogens, internal body cell malfunctions

homeostasis: blood dissipating/conserving heat through blood flow

hematocrit, centrifuge

blood test measuring erythrocyte percentage in a blood sample

• centrifuge: equipment spinning blood to separate cellular elements from lighter plasma - heaver elements sink to bottom of tube

which element has the greatest quantity in blood: leukocytes, erythrocytes, or platelets?

erythrocytes / RBC

describe the components of a blood sample spun in a centrifuge:

• plasma

• buffy coat

• hematocrit

plasma: water, proteins, nutrients, hormones

buffy coat: leukocytes, platelets

hematocrit: erythrocytes

normal blood hematocrit %’s (male & female)

male: 42-52%

female: 37-47%

anemia

depressed hematocrit %

polycythemia

elevated hematocrit %

describe the following characteristics of blood:

• colour

• viscosity

• temperature

• pH

• body weight (% & L for males and females)

colour:

• oxygenated = bright red

• deoxygenated = darker red (hemoglobin in blood is rich in iron, which reacts to oxygen when exposed)

viscosity: 5x thicker than water (formed elements & plasma proteins)

temperature: 38 degrees C (friction and resistance)

pH: avg 7.4 (slightly basic)

body weight: 8% of adult body weight

• males = 5-6L

• females = 4-5L

plasma

• % of water

• names of plasma proteins

• other substances

extracellular matrix in blood → 92% water

• plasma proteins

  • albumin

  • globulins

    • alpha, beta

    • gamma

  • fibrinogen (antibodies)

• hormones (insulin, oxytocin)

• electrolytes (sodium, potassium, calcium)

• dissolved gases (o2, co2, N)

• organic nutrients (vitamins, lipids, glucose, amino acids)

• metabolic wastes (co2, urea)

albumin (% of plasma protein, organ producing it, main functions)

54% of plasma proteins - produced by liver

• allows transport in blood (binds to fatty acids, steroid hormones)

• maintains osmotic pressure (holds water in blood vessels)

globulins (% of plasma protein, types → organ producing it, main functions)

38% of plasma proteins

aplha, beta globulins

• produced by liver

• transport substances, maintain osmotic pressure

gamma globulins

• produced by leukocytes

• also known as antibodies (for immunity)

fibrinogens (% of plasma protein, types → organ producing it, main functions)

7% of plasma proteins - produced by liver

• essential for blood clotting

hemostasis (def + name the steps)

process of body sealing a ruptured blood vessel

1. vascular spasm

2. platelet plug formation

3. coagulation

vascular spasm

(hemostasis → step 1)

• blood vessel damaged → smooth muscle wall severely contracts

  • contraction brought on by endothelin chemicals

• blood flow is constricted

• ~ 30 mins

platelet plug

(hemostasis → step 2)

• platelets clump at damaged site

• become spiky, sticky as they bind to exposed collagen and endothelial lining

• forms platelet plug using plasma’s glycoprotein = von willebrand vactor

• chemicals released into blood plasma by platelets

  • ADP (adenosine diphosphate) reinforces the plug

  • serotonin maintains vasoconstriction

  • prostaglandins, phosphilipids maintain vasoconstriction

coagulation

(hemostasis → step 3)

• blood clot made of fibrin protein begins to form

• fibrin network traps formed elements of blood as a clot

fibrin

protein involved in coagulation step of hemostasis

• insoluble protein derived from blood plasma protein fibrinogen (ALSO KNOWN AS ANTIBODIES)

describe the hemostasis process as best as you can using the steps

clotting factors & pathways

chemicals prompting reactions activating other clotting factors during coagulation stage of hemostasis

• extrinsic pathway: triggered by tissue damage

• intrinsic pathway: triggered by vessel wall damage

• → both merge into the Common Pathway

• 12 known clotting factors (I - XII)

intrinsic pathway

(hemostasis → coagulation → clotting factors)

triggered by vessel wall damage

• clotting factors all present in bloodstream

• clotting factors lead to activation of factor X → activates Common Pathway

extrinsic pathway

(hemostasis → coagulation → clotting factors)

triggered by tissue damage

• tissue factor / Factor III begins clotting factors

• clotting factors lead to activation of Factor X → activates Common Pathway

common pathway

(hemostasis →