A&P Exam 5 (Part 1)

Blood, Immunity, and CNS (brain/spinal cord) from lecture

Blood volume is ___% of total body weight

8

Normal male blood volume (in liters)

5-6

Normal female blood volume (in liters)

4-5

Components that make up the blood

formed elements (red/white blood cells, platelets) and plasma

Hematocrit

the ratio of formed elements and plasma

In reality, hematocrit is what?

the % of erythrocytes

Normal hematocrit for males

47% ± 5%

Normal hematocrit for females

42% ± 5%

Blood is what type of tissue?

connective

Cells produce matrix and plasma in the blood (t/f)

false

Blood plasma

extracellular liquid matrix

What elements make up blood plasma?

plasma proteins, electrolytes, nutrients, nitrogenous wastes, and respiratory gases

Function of blood plasma

transport, temperature regulation, solvent

Blood plasma is __% water

90

Plasma proteins

most abundant solute in blood, not taken up by cells or used for fuel/nutrients

Where are most plasma proteins produced?

the liver

Types of plasma proteins

albumen, globulins, and clotting proteins

Albumen is __% of plasma proteins

60

Globulins are __% of plasma proteins

36

Clotting proteins are ___% of plasma proteins

4

Albumen function

maintain plasma osmotic pressure, transport substances, and be a pH buffer

Globulins function

transport substances, protection via antibodies

Clotting protein function

prevent blood loss via fibrinogen and prothrombin

Electrolytes

maintain normal blood pH (bicarbonate) and osmotic pressure (sodium)

Examples of electrolytes

sodium, potassium, calcium, and bicarbonate ions

What nutrients are part of blood plasma?

glucose and fatty acids

Glucose is ___ (homeostatically regulated/not homeostatically regulated)

homeostatically regulated

Fatty acids are ___ (homeostatically regulated/not homeostatically regulated)

not homeostatically regulated

Nitrogenous wastes in blood plasma

lactic acid, urea, creatinine

Respiratory gases in blood plasma

carbon dioxide and oxygen

Carbon dioxide is mostly bound with what?

bicarbonate ions in the plasma

Oxygen is most bound to what?

hemoglobin in red blood cells

Blood serves delivery function for which parts of blood plasma

electrolytes, nutrients, nitrogenous wastes, and respiratory gases

Erythrocyte characteristics

red blood cells (RBCs), biconcave discs with thin centers, no mitochondria/nuclei, few other organelles, arise from hemocytoblasts

What function does the biconcave shape of the RBC serve?

perfect shape for gas exchange, 30% more surface area

What effect does not having a mitochondria have on RBCs?

anaerobic generation of ATP, no consumption of oxygen

Why is it good that RBCs are bad at oxygen consumption?

it makes them perfect for gas transport

Discounting water, RBC are 97% _______?

hemoglobin

Life span of RBCs

120 days

Erythropoiesis

formation of erythrocytes in red bone marrow

Hemocytoblast

“stem cell,” that all blood cells arise from

Once committed to a certain cell pathway a stem cell cannot change back (t/f)

true

Reticulocyte

young RBC

From hemocytoblast to reticulocyte is a ____ day process

15

After ___ days, a fully mature reticulocyte will be released from the bone marrow

2

RBC count measures what?

the rate of RBC formation

Reticulocytes should be ___% of all RBCs in healthy people

1-2

Thrombocytes

platelets, no nucleus, contain actin/myosin

Formation of platelets

stem cells forms a megakaryblast, megakaryoblast extensions rupture into fragments (platelets)

Function of platelets

hemostasis, mostly the temporary plug

Hemostasis

stoppage of bleeding, positive feedback system

Three phases of hemostasis

vascular spasms, platelet plug formation, coagulation

What is the purpose of vascular spasms?

prevention of blood loss

Platelet plug formation steps

exposure of collagen → platelets swell and form spikes, sticking to collagen → release chemicals to attract more platelets → plug forms

What stops of the attraction of platelets after the plug has formed?

the chemical prostacyclin (PGI2)

Prostacyclin is produced/released by _____

endothelial cells of the vessel lining

Coagulation

blood transformed from a liquid into a gel, involves 30 different procoagulants (clotting factors)

Clotting factors are the same things as platelets (t/f)

false

Vitamin K role in coagulation

synthesis and activation of clotting factors

Final reactions of coagulation

Chemicals released from platelets in the presence of calcium → formation of prothrombin activator → prothrombin to thrombin → fibrinogen to fibrin → clot stabilization → clot retraction

Prothrombin

a plasma protein

Prothrombin activator

converts prothrombin to thrombin

Thrombin

an active enzyme that converts fibrinogen to fibrin

Fibrinogen

protein of plasma, soluble

Fibrin

not soluble, glue platelets in clot together, becomes gel-like and traps formed elements

Clot forms and stabilizes in ____ minutes after vessel damage

3-6

Clot retraction

actin and myosin in platelets contract, pull on fibrin strands which squeezes out serum

Serum

plasma without clotting factors

Leukocyte characteristics

white blood cells (WBCs), complete cells, 1% of total cells

WBC are different from the other formed elements because they have _______

nuclei and organelles

Types of WBCs

neutrophils, eosinophils, basophils, lymphocytes, monocytes

WBCs main function

defense against invading organisms

The immune system is an organ system (t/f)

false

Immune system

functional system, includes innate and adaptive responses/immunity

Innate immunity

non-specific, responds in minutes to protect body from all pathogens, includes external body membranes and internal defenses

Examples of innate immunity

skin, inflammation, fever, etc

Adaptive immunity

specific, takes longer and works with innate immunity, includes hormonal/cellular immunity

Examples of adaptive immunity

B cells and T cells

WBCs in the immune system

mobile army of defense against bacteria, viruses, parasites, toxins, and tumor cells

Phagocytes

“cell eating,” particle is engulfed in vesicle which fuses with lysosome, enzymes digest particles

Neutrophils

most abundant WBC, follows and surrounds particles, becomes phagocytic when in contact with pathogen

Macrophages

“big eaters,” monocytes, leave bloodstream and enter tissues

Natural killer (NK) cells

target general pathogens, kill cancer and virus-infected cells by direct contact, induce apoptosis

Apoptosis

programmed cell death, induced by NK cells

Confer immunity

resistance to disease, only B and T cells, specific in pathogens they target

Phagocytes, neutrophils, macrophages, and natural killer cells are not part of immunity or resistance to pathogens, but function in detection and defense (t/f)

true

5 mechanisms for mobility in phagocytosis

leukocytes, margination, diapedesis, amoeboid movement, positive chemotaxis

Leukocytes (in mobility)

injured cells release chemicals that cause release of neutrophils from red bone marrow

Margination

in inflamed areas, vessel endothelial cells sprout cell adhesion molecules, precursor to diapedesis

Cell adhesion molecules (CAMs)

provide foothold for neutrophils to cling to the inner walls of capillaries

Diapedesis

“leaping across,” WBCs move through an intact vessel wall, transport to other parts of the body

Amoeboid movement

movement in tissue spaces by forming cytoplasmic extensions

Positive chemotaxis

follow chemical trails of damaged cells and other leukocytes

Lymphocytes in immunity

created from hemocytoblasts in red bone marrow

T lymphocytes (T-cells)

immature lymphocytes travel to thymus, go through positive/negative selection, function in cell mediated response but do not produce antibodies, must come in contact with other cells

Thymus is present in _____ (infants/children/adolescence), enlarges in _____ (infants/children/adolescence), and atrophies in ______ (infants/children/adolescence)

infants, children, adolescence

Function of thymus in T-cell formation

site of the 2-3 day selection process to produce T-lymphocytes which are then considered immunocompetent but naive

Immunocompetence

lymphocytes are able to recognize one specific antigen (foreign protein) by binding to it

Self-tolerance

lymphocytes must be relatively unresponsive to self-antigens

Positive selection

T cells must recognize the major histocompatibility complex (MHC)