Chapter 18 - Blood Flashcards
(79 cards)
T/F - Blood is considered a connective tissue
True
Plasma
- Non-living fluid matrix
- The fluid portion of the blood containing plasma proteins and dissolved solutes
- 90% water
- > 100 dissolved solutes including nutrients, gases, hormones, wastes, proteins, inorganic ions
- Plasma proteins are most abundant solutes –> remain in blood and are not taken up by cells –> Proteins produced mostly by liver (ex: albumin, ⍺ & β- globulins, fibrinogen, and other proteins involved in clotting) –> 60% albumin, 36% globulins, 4% fibrinogen
- Some are produced by leukocytes (ex: gamma-globulins) and other organs (ex: regulatory protein)
Formed elements
Living blood “cells” suspended in plasma (fluid portion of blood)
- Include erythrocytes, leukocytes, and thrombocytes (platelets)
- WBCs are the only complete cells
- RBCs have no nuclei or other organelles
- Platelets are cell fragments
- Most formed elements survive in bloodstream only few days
- Most blood cells originate in bone marrow and do not divide
Color of blood when oxygen-rich and poor
- Oxygen-rich –> bright red/scarlet
- Oxygen- poor –> dark red
Explain the bluish appearance of our veins
- Bc of the fact that we can see the blood moving the superficial veins in the skin
- Lower-energy light wavelengths (ex: red) are absorbed by the skin and higher-energy wavelengths like blue are reflected back to the eye
What is the average and range of blood?
- Average volume –> 5 L
- Range ~4 - 6 L
- 5-6L for males and 4-5 L for females (lower because menstrual cycle)
- Sustaining a normal blood volume is important in maintaining blood pressure
- ~8% of body weight
Viscosity increases if the amount of substances, especially _________, increases
Erythrocytes
Plasma concentration
Relative concentration of solutes (proteins, ions, etc) in plasma
- Normally about 0.9% concentration
- Determines if fluids move in or out of the plasma by osmoses as blood is transported through capillaries –> ex: person is dehydrated –> plasma becomes hypertonic and fluid moves into the plasma from surrounding tissues
- Used when determining IV solution concentrations, which are usually isotonic (same solute concentration) to plasma
Temperature of blood
- Almost 1 degree C (or 2 degree F) higher than measured body temp
- Body = 37 degree C = 98.6 degree F
- Blood = 38 degree C - 100.4 degree F
Blood pH
- Between 7.35 - 7.45
- Plasma proteins have 3D shape that is dependent upon H+ concentrations
- The neurtral/normal range for our body
- pH < 7.35 in blood = acid –> acidosis
- pH> 7.45 in blood = base –> alkalosis
Layers and percentages of each of blood
- Plasma on top (~55%)
- WBCs and platelets in buffy coat (<1%)
- Erythrocytes on bottom (~45%)
Whole blood
Plasma membrane and formed elements
- Can be separated into liquid.cellular components using a centrifuge
Hematocrit
Percent of blood volume that is RBC
- 47% +/- 5% for males
- 42% +/- 5% for females
- Low level means anemia
- High level means patient is dehydrated, lives in high altitude, and participated in blood doping
- Influenced by testosterone by stimulating the kidney to produce the hormone erythropoietin (EOP) –> promotes erythrocyte production –> higher hematocrit
Why is blood sticky and metalic?
- Sticky because it has glucose
- Metalic because there is iron in erythrocytes
What are the functions of blood?
1.) Distributing substances
- Deliver O2 and nutrients to body cells
- Transport waste to lungs and kidneys for elimination
- Transporting hormones
2.) Regulating blood levels of substances
- Maintaining body temperature by absorbing (especially skeletal muscle cells) and distributing heat
- Maintaining normal pH using buffers; alkaline reserve of bicarbonate ions –> blood absorbs acids and base from body cells and blood maintains chemical buffers that bind and release H+ to maintain pH until the excess is eliminated from body
- Maintaining adequate fluid volume in the circulatory system –> osmotic pressure pull fluid back into capillaries to help maintain normal fluid balance
3.) Protection
- Preventing blood loss using clotting
- Preventing infection with antibodies, complement proteins, WBC
Colloid osmotic pressure (COP)
Osmotic pressure exerted by plasma proteins
- Responsible for draining fluids into the blood and preventing excess fluid loss from blood capillaries into the ISF –> helps maintain blood volume/ pressure
Albumin
- Smallest and most abundant plasma protein
- Has the greatest colloid osmotic pressure to maintain because it’s the most abundant
- Transport substances within blood (ex: ions, hormones, some lipids)
- ~58-60% of plasma proteins
- Substance carrier
- Blood buffer –> can act as a sponge if there are pH changes –> can absorb acid or release acid if not enough
- May bind to a protein to inactivate drugs –> control concentration
Globulins
~ 37% of plasma proteins
- Second largest group of plasma proteins
- ⍺-globulins (smaller) and β-globulins (larger) primarily bind and transport certain lipids, hormones, some metals, and ions
- Gamma-globulins, immunoglobulins/antibodies: Play a part in the body’s defenses
- Proteins that are used as antibodies and form antibodies
- Can attach to bacteria to inactivate it and mark the bacteria for distraction
Fibrinogen
- ~4% of plasma proteins
- A clotting protein
- After trauma, fibrinogen is converted into long, insoluble strands of fibrin (which helps form a blood clot)
- Associated with the function of platelets –> platelets are used when there is a breach in blood vessel –> platelets try to seal and fibrogen forms a sticky net to hold them in palce
What are the plasma proteins in plasma?
1.) Albumin
2.) Globulins
3.) Fibrinogen
4.) Regulatory proteins
What are the other solutes in plasma?
1.) Electrolytes
2.) Nutrients
3.) Respiratory gases
4.) Wastes
Erythrocytes (RBCs)
- Small, flexible, biconcave disks, anucleate, no organelles
- Diameters larger than some capillaries
- Packed with hemoglobin for gas transport (>97% hemoglobin)
- Contain plasma membrane protein spectrin (provides flexibility to change shape) and other proteins
- Major contributor to blood viscosity
- No mitochondria (bc it would take from the O2 being transported), ATP production anaerobic, do not consume O2 they transport
- Hemoglobin binds reversibly with oxycen
- Males = 13-18g/100mL; Females = 12-16g/100 mL
Oxygenated: Maximally loaded with O2
Deoxygenated: When some O2 is lost
Hemoglobin structure
- Gobin composed of 4 polypeptide chains (globins) (2 ⍺ and 2 β chains)
- 4 heme groups per molecule of hemoglobin –> has 4 Fe 2+ – can bind up to 4 molecules of O2 (weak attachment to quickly attach/release)
- CO2 binds to the globin protein molecule
Heme: portion of hemoglobin that binds iron, which transports O2 –> made of a porphyrin ring with Fe 2+ in the center –> O2 binds to Fe+ - Heme gives color
- 250 million Hb in each RBC
What is the ferrous state of iron? What is the ferric state of iron?
Ferrous state of iron = Fe 2+ (only state in which oxygen can bind to)
Ferric state of iron = Fe 3+