A&P 2 - Chapter 18: Blood

what is blood?

continuously regulated connective tissue

the three interrelated components of the cardiovascular system

blood - platelets, erythrocytes, leukocytes

heart

blood vessels - veins, capillaries, arteries

what is the order that blood is transported through the cardiovascular system ?

heart

arteries

capillary beds (O2 nutrients / CO2 waste)

veins

heart

what are the functions of blood (3 main functions)

TRANSPORTATION (of oxygen from lungs to body tissues, metabolic waste from tissues to lungs/kidneys/liver, nutrients from GI tract to body cells, and hormones)

REGULATION (pH via buffers, body temperature, fluid balance)

PROTECTION (blood loss - clotting, and immunity/ immune responses)

what is the minimum percentage of blood someone would have to lose to receive a blood transfusion?

30-40%

Blood components: erythrocytes

red blood cells

transport respiratory gases

Blood components: leukocytes

white blood cells

defend against pathogens

Blood components: platelets

help form clots to prevent blood loss

Blood components: plasma

fluid portion of blood that contains plasma proteins and dissovled solutes

hematocrit

the percentage of total blood volume that is occupied by red blood cells

blood is a S———-

solution!

polar, charged substances dissolve easily. non polar substances require a carrier protein

blood is a C———

colloid!

blood contains many plasma proteins like albumin, globulin, fibrinogen, and other clotting proteins, enzymes, and hormones

all of which are produced in the liver

what do plasma proteins exert to help maintain blood volume and blood pressure

colloid osmotic pressure

four types of plasma proteins

albumins, globulins, fibrinogen, regulatory proteins

albumins

the smallest and most abundant

exert the greatest colloid osmotic pressure

act as transport proteins

globulins

we got the smaller alpha globulins and larger beta globulins which act as transporters for some water insoluble molecules

and there are also gamma globulins → DEFENSES (immunoglobulins/antibodies)

fibrinogen

contributes to clot formation when converted to active form, fibrinogen

SERUM - is plasma with clotting proteins removed

what is serum

plasma with clotting proteins removed

regulatory proteins (plasma proteins)

less than 1%

includes enzymes and hormones

hemopoiesis means

to make blood

production of formed elements occurs in the red bone marrow. how many new cells does it make per day?

100 billion

stem cells aka ____ stem cells are also p______

hemocytoblasts

stem cells are pluripotent meaning they can differentiate into many types of cells

what are the two different lines that hemocytoblasts produce

myeloid line and lymphoid line

myeloid line

basically makes everything else

erythrocytes, leukocytes (not lymphocytes), megakaryocytes (these produce platelets)

lymphoid line

forms ONLY lymphocytes

erythrocytes

small and flexible! they are flexible bc of this lattice work of the protein spectrin

has a biconcave shape (like a disc donut). this gives the cell a large surface area allowing for gas exchange (O2 can move in and out)

major factor of blood viscosity

they don’t have a nucleus or organelles because they just want to absolutely PACK themselves with hemoglobin.

they stack in a single file line like they are in first grade, called rouleau - like a ROUL of coins

what is hemoglobin and the difference between oxyhemoglobin and deoxyhemoglobin

hemoglobin is a red-pigmented protein

oxyhemoglobin- oxygenated, maximally loaded with oxygen

deoxygenated- deoxygenated, when some oxygen is lost

what is a heme

an organic ring with an iron ion in its center

this is where oxygen attaches

the structure of a hemoglobin molecule

iron → oxygen attached to iron → heme → four globins (alpha chains and beta chains) → hemoglobin

Erythropoietin (EPO) feedback cycle

a hormone produced by the kidneys that controls erythropoiesis (production of red blood cells)

stimulus: low blood oxygen

receptor: kidneys detect stimulus

control center: kidneys respond to the low blood oxygen by releasing erythropoietin (EPO)

EPO is going to target red marrow and cause myeloid cells to release more erythrocytes into circulation. these erythrocytes are going to increase the bloods oxygen carrying capacity

negative feedback: the increase in blood oxygen is going to inhibit release of EPO