BLOOD

Plasma

transporting all the nutrients, electrolytes, nitrogenous waste, which are metabolic wastes, hormones, gases, CO2

protein in plasma

plasma protein- albumin

-most abundant, smallest, going to make blood thick, manufactured by liver

Function: binding proteins, transport hydrophobic fatty acids and hormones

-contributes to osmotic pressure

osmolarity

concentration of dissolved particles in the plasma (blood) H-L concentration

hematocrit

ratio of RBC, or erythrocytes to the total volume of blood that you have

formed elements

solid parts (heaviest) buffy coat: leukocytes and platelets (<1% of whole blood), erythrocytes (45% of whole blood)

high blood osmolarity BV

high particles, low water concentration

water is going to move into the BV

high blood osmolarity tissue

low particles, high water concentration

low blood osmolarity (blood to tissue) BV

low particles, high water concentration

low blood osmolarity tissue

-high particles, low water concentration

hypoproteinemia

Deficiency of plasma proteins

severe starvation,

• dietary protein deficiency

• liver diseases that impact protein

synthesis,

• protein loss via urine (kidney disease),

• protein loss via skin (severe burns)

Viscosity

resistance to a fluid to flow due to cohesion of molecules

oil and honey= high v (less flow)

plasma proteins- Globulins

transport iron, lipids, and vitamins

plasma proteins- fibrinogen

precursor to fibrin

essential for blood clotting

produced by liver

erythrocytes

not a true nucleus, no mitochondria(anaerobic)

Function: picked up inhaled O2 and distribute to tissues: pick up CO2 waste at tissues and take to lungs

-biconcave disc, flexible to move through capillaries and and spleen

How many oxygen molecules can one molecule of hemoglobin carry?

4

What is attached to each globin chain?

A heme group

What is hemoglobin called when oxygen is bound to the iron?

Oxyhemoglobin

Where does hemoglobin bind oxygen in the body?

in the lungs

What is hemoglobin called when oxygen is NOT bound to iron?

Deoxyhemoglobin

Why are erythrocytes (red blood cells) red?

Because they contain hemoglobin, which carries oxygen

cytoskeleton protiens

spectrin and actin- keep shape of RBC

each iron ion in heme binds to

one oxygen molecule

Leukocytes (WBC)

-granulocytes (granules in cytoplasm)

1. neutrophils

2. eosinophils

3. basophils

-agranulocytes (no granulocytes)

1. lymphocytes

2. monocytes

granulocyte- Neutrophil

most abundant of all WBC’s

3-5 lobes

granules contain lysosome

Function: release lysosome phagocytize bacteria

granulocyte- Eosinophils

less abundant 2-4% of WBC’s

abundant in mucous membrane of respiratory, digestive, lower urinary tracts

acidic granule

phagocytize antigens that cause allergies and induce histamine release by basophils

Granulocytes: Basophils

rare

Secretes histamine – vasodilator, opening blood vessels for neutrophils and clotting proteins to move to connective tissue fast

secretes heparin – an anticoagulant, prevents blood clotting to allow other WBCs access to the tissue
allergens, pathogens, parasites

Agranulocytes: Lymphocytes

2nd most abundant WBC

smallest WBC, smaller in blood larger in connective tissue

destroy infected cell w virus

cancer cells

foreign cells such as parasites

cytoplasm small, big nucleus

Agranulocytes: Monocytes

largest WBC

in bloodstream then travel into macrophages

phagocytic cells engulfing microorganisms

antigen presenting cell

osmotic pressure

filtration-going from blood to tissue

reabsorption-going from tissue to blood

hemostasis

cessation of bleeding

mechanisms- Secrete vasoconstrictors to narrow vessel, stick together to form platelet plugs, secrete procoagulants (clotting factors)

What is the main function of platelets (thrombocytes)?

They play a major role in blood clotting

hemostatic mechanism

Vascular Spasm

prompt constriction of blood vessel

serotonin released as vasoconstrictor

hemostatic mechanism

Platelet plug formation

collagen fibers exposed when vessel breaks, allows adhesion

serotonin released as vasoconstrictor

hemostatic mechanism

Coagulation

clotting most effective but complicated

Goal: convert fibrin to fibrinogen

Procoagulants

clotting factors

-fibrinogen, tissue thromboplastin

extrinsic

chemicals being released from tissue

intrinsic

have chemicals being released from the platelets inside your body

Coagulation

reaction produces Thrombin

Thrombin converts fibrin into fibrin polymers (web like)

POSITIVE FEEDBACK

Erythropoiesis

RBC production, 3-5 days

steps of erythropoiesis

1. Reduction in cell size (HSC → CFU).

2. Increase in cell number — CFU has receptors for erythropoietin (hormone from kidney), becomes an erythroblast, and multiplies.

3. Erythroblasts synthesize hemoglobin.

4. Loss of nucleus and organelles → becomes a reticulocyte, enters bloodstream, ribosomes disintegrate in 1–2 days → forms a mature erythrocyte.

WBC Lifecycle- Leukopoiesis

• production of WBCs, similar to RBC formation.

• CFUs have receptors for colony-stimulating factors (CSFs).

• Lymphocytes and macrophages release CSFs in response to infections or inflammation.

• CSFs stimulate specific WBC production:

  • Bacterial infection → Neutrophils increase

  • Allergic/parasitic reaction → Eosinophils increase

• Locations:

  • Granulocytes + Monocytes: produced in red bone marrow.

  • Lymphocytes: produced in bone marrow, mature in thymus, then stored in spleen & lymph nodes

antigen

is a molecule on the surface of a red blood cell that your immune system can recognize.
In blood typing, these are A or B glycopolipid markers that determine your ABO blood type

Antibody

is a protein in your blood plasma that recognizes and binds to foreign antigens.
In blood typing, antibodies attack RBCs that have antigens you do NOT have, causing agglutination

What is hemorrhagic anemia?

Anemia caused by blood loss.
This can be from trauma, injury, surgery, heavy menstrual bleeding, or internal bleeding. Loss of blood = loss of RBCs

What is hemolytic anemia?

Anemia caused by the destruction (lysis) of red blood cells.
In maternal–fetal mismatch (Rh– mom, Rh+ baby), Anti-D antibodies cross the placenta and destroy fetal RBCs → baby develops hemolytic anemia

What is biliverdin, and when is it formed?

Biliverdin is a green/yellowish pigment made when macrophages break down heme during RBC hemolysis. It is the first breakdown product before it becomes bilirubin.

What is bilirubin, and what happens to it?

Bilirubin is a yellow pigment formed when biliverdin is converted by macrophages. It binds to albumin in the blood, is carried to the liver, and then released into bile JAUNDICE

Circulatory System Functions

1) Transport

• Carries O₂, CO₂, nutrients, hormones, waste, and heat.

• Hemoglobin in RBCs is the main oxygen carrier.

2) Protection

• WBCs fight infections & remove debris.

• Platelets + clotting prevent blood loss.

• Antibodies identify and help destroy foreign cells.

3) Regulation

• Maintains pH, body temperature, and fluid balance (osmotic pressure).

Functions of White Blood Cells

WBCs defend against threats and adjust based on the infection:

Type of WBC	Function
Neutrophils	First responders; fight bacterial infections.
Lymphocytes (B & T cells)	Produce antibodies, kill infected cells, immune memory.
Monocytes → Macrophages	Big phagocytes; clean up debris, present antigens.
Eosinophils	Fight parasites, active in allergic reactions.
Basophils	Release histamine, intensify inflammation.

WBC production (leukopoiesis) increases depending on the infection (ex: more neutrophils if bacteria)

Hemoglobin & the Heme Group

• Hemoglobin = 4 globin chains, each with 1 heme group.

• Each heme binds 1 O₂ molecule → so 1 hemoglobin carries 4 O₂.

Function:

• Pick up O₂ in lungs → become oxyhemoglobin

• Release O₂ in tissues → become deoxyhemoglobin

Iron (Fe²⁺) in the center of heme is the O₂-binding site.

Clotting (3 Phases)

1. Vascular Spasm

• Damaged vessel constricts immediately to reduce blood loss.

2. Platelet Plug Formation

• Platelets stick to exposed collagen.

• They release chemicals that make other platelets stick → positive feedback → temporary plug.

3. Coagulation (Fibrin Formation)

• Fibrinogen (soluble) → fibrin (insoluble) threads.

• Fibrin forms a mesh that traps RBCs and fully seals the wound.

RBC Life Cycle (Production → Death)

Production: Erythropoiesis (3–5 days)

1. HSC → CFU (cell gets smaller).

2. CFU responds to erythropoietin (EPO) → becomes erythroblast.

3. Erythroblasts make hemoglobin.

4. Lose nucleus → reticulocyte enters bloodstream → matures into erythrocyte.

Circulation

• RBCs live 120 days.

Death/Disposal (Hemolysis)

• Happens in spleen & liver (“erythrocyte graveyard”).

• Macrophages break RBCs apart:

  • Globin → amino acids

  • Iron (Fe) → recycled

  • Heme → biliverdin → bilirubin → bile → feces

Hypoxemia & Negative Feedback

Hypoxemia = low blood oxygen.

How the body corrects it:

1. Kidneys detect low O₂.

2. Kidneys release EPO.

3. EPO stimulates more RBC production in red bone marrow.

4. More RBCs → more hemoglobin → higher O₂-carrying capacity.

5. Hypoxemia corrected → EPO levels drop.

This is classic negative feedback

Blood Typing: Antigens & Antibodies

Your RBCs have antigens; your plasma has antibodies against the antigens you don’t have.

Blood Type	Antigens on RBC	Antibodies in Plasma	Can Receive From
Type A	A antigen	Anti-B	A, O
Type B	B antigen	Anti-A	B, O
Type AB	A & B antigens	None	A, B, AB, O (universal recipient)
Type O	No antigens	Anti-A & Anti-B	O only (universal donor)

If the wrong blood is mixed → antibodies cause agglutination (clumping and destruction).

Maternal–Fetal Mismatch (Rh Incompatibility)

Problem:

• Mom = Rh–

• Baby = Rh+

First Pregnancy

• Usually safe unless there’s a placental leak/miscarriage.

• Mom becomes sensitized and makes Anti-D antibodies.

Second Pregnancy (with Rh+ baby)

• Mom’s Anti-D antibodies cross the placenta.

• They attack fetal RBCs → hemolytic anemia in the baby.

This is why Rh– mothers receive RhoGAM to block antibody formation