Lymphatic System + Blood

Lymphatic System Function

Maintain fluid balance

Lymphatic System Process

When arteries + veins meet at capillaries, blood pressure forces fluid and proteins out of vessels and into tissues

Fluid Reabsorbed by Veins

Most, but 3 liters per day

Simple Lymphatic System

Soaks up leaked fluid + carries it back to bloodstream + heart

Bonus Lymphatic System Function

Monitors lymph fluid for harmful things, serve important roles in immune system

Lymph

Fluid collected + carried throughout lymphatic system

Lymphatic Vessels

Transport lymph one-way to heart

Lymph Nodes

Inspect + clean lymph passing through, destroys pathogens with lymphocytes + macrophages

Lymph Pathway

Lymphatic capillaries, collecting vessels, lymph trunks, lymph ducts, veins near heart

Spleen

Largest lymphoid organ, produces lymphocytes

MALT

Set of lymphoid tissues located in mucous membranes throughout body

MALT Examples

Tonsils, Peyer’s patches, appendix

Tonsils

Form ring around pharynx, gather/remove pathogens entered through eating/breathing

Peyer’s Patches

In small intestine, monitor for pathogens in GI tract

Appendix

Prevents pathogens from entering intestinal wall

Pathogens Breakdown

Disease/producers

Pathogen

Any organism/agent that can produce disease in a host

Immune System Function

Defend body from pathogens

Smallpox

Fully eradicated, airborne, billions killed

Rabies

Passed from non-humans, infects brain, fatal

Influenza

Flu, respiratory, pandemic, many strains, COVID-19

Tetanus

Sail bacteria enters wound, contractions, lockjaw

Botulism

Food poison, relaxation of muscles, suffocation

E. Coli

Live in human guts, bloody diarrhea

Tuberculosis

Most deadly, lung, bloody cough, strep throat, UTI, ear infection

Athlete’s Feet

Contagious, damp places

Ringworm

Circular rash, skin-to-skin, pets too

Yeast Infection

Vagina

Giardiasis

Beaver fever, drinking feces contaminated water, cramping/diarrhea

Malaria

Mosquitoes, destroys RBC, fever, chills, fatigue

Tapeworm

Eating undercooked cysts, hooks into intestines, diffuses nutrients, weight loss

Guinea Worm

Drinking water with copepods, mature for year, emerge at skin surface to lay eggs in water

Innate Defenses

Protects body against any pathogen, non-specific

Adaptive Defenses

Once pathogen enters, aimed, specific

Line of Defense

Surface barriers, internal defense, adaptive defenses

Surface Barriers

Skin, mucus membranes

Skin

Forms keratinized layers, releases swear, oils, waxes with toxic chemicals, break allows entrance

Mucus Membranes

Traps pathogens, in respiratory tract, cilia sweep trapped pathogens toward mouth to keep them out of lower respiratory system

Internal Defenses

Phagocytes, natural killer cells, inflammation, proteins, fever

Phagocytes

Neutrophils + macrophages use phagocytosis to engulf + kill pathogens

Natural Killer Cells

“Police” body in blood + lymph, killer cancer cells + virus-infected cells, trigger target cell to undergo apoptosis

Inflammation

Nonspecific response to any tissue damage, redness/swelling/heat/pain, begins with histamine release + other inflammatory chemicals

Histamine

Triggers vasodilation (increased blood flow), attracts pathogens to flood area + phagocytose, destroy pathogen, produce pus

Proteins

Complete, interferons

Complement System

Group of proteins that circulate in blood + become active when encounter pathogens, kill by puncturing cell membranes

Interferons

Released by virus infected cells, trigger cells to make protein that resists infection

Fever

Sign you body is fighting infection

Pyrogens

Chemical released when white blood cells are exposed to foreign substances

Hypothalamus

Triggered by pyrogens to raise body temperature

Acquired Immunity

Body’s earned ability to resist specific pathogens after previously encountering them

Acquired Immunity Process

Obtained in multiple ways, utilizes antibodies

Primary Immune Response

1st pathogen, humoral immune responses, memory cells production, remembers antigens, produce antibodies

Secondary Immune Response

Infected by same pathogen later on (can be repeated)

Memory Cells

Mount faster, powerful immune response against antigen, stop pathogen before symptoms

How Immunity’s Acquired

Active, passive

Natural Active

Infected by pathogen, humoral immune response, create memory cells

Artificial Passive

Vaccinated with dead/weakened pathogen version, humoral immune response, create memory cells

Natural Passive

Antibodies passed from mother to baby, placenta/breastmilk

Artificial Passive

Receive injection of antibodies, COVID-19

Thromb-

Clot

Type of Blood Tissue

Connective tissue

Connective Tissue Component

Matrix

Plasma

Non-cellular, matrix, 55%

Plasma Makeup

Water (90%), Solutes (gases, nutrients, proteins, electrolytes, hormones) (10%)

Erythrocytes

Red blood cells, 45%

Hematocrit

% of blood made of erythrocytes, higher in males

Erythrocyte Facts

Not true cells, lack nuclei/organelles, biconcave discs

Erythrocyte Functions

Transport oxygen from lungs to body cells

Hemoglobin

Protein that uses iron to bind 4 oxygen, each RBC contains 250M molecules

Erythropoiesis

In red bone marrow, produce erythrocytes (lifespan of 120 days)

Leukocytes

White blood cells, <1%, true cells, 1-3 days lifespan, defend against disease

Leukocytes Types

Neutrophils, lymphocytes, monocytes, eosinophils, basophils

Thrombocytes

Platelets, <1%, cell fragments, not true cells, help cloth damaged blood vessels (hemostasis)

Types of White Blood Cells

Neutrophils, eosinophils, basophils, lymphocytes, monocytes

Neutrophils

Most numerous (50-70%), multi-lobed nucleus, attracted to inflammation, use phagocytosis

Eosinphils

2-4%, two-lobed nucleus, use enzymes to digest parasitic worms

Basophils

Rarest (<1%), release histamine

Histamine

Inflammatory chemical attracting other white blood cells to site

Lymphocytes

25%, large nucleus that takes up most of cell, in lymph nodes, types: T-cells, B-cells

Monocytes

3-8%, largest leukocyte, u-shaped nucleus, become macrophages

Macrophage

Phagocyte that engulf viruses + other pathogens

Hemostasis Function

Series of reactions to stop bleeding when blood vessel wall breaks, provides time for it to heal

Hemostasis Purpose

Injury exposes collagen fibers + release proteins, bleed out without it

Step 1: Blood Vessel/Vascular Spasm

Respond to released proteins + damaged/cut vessel, smooth muscle of blood vessel constricts, platelets release serotonin to stimulate vasoconstriction, decrease blood loss for 20-30 mins

Step 2: Platelet Plug Formation

Von Willebrand factor binds platelets to exposed collagen fibers, form platelet plug, bond platelet release chemicals to attract more platelets, make them sticky, clump

Step 3: Coagulation

Blood clotting, tissue factor stimulated by blood, vitamin K + Ca+ form prothrombin activator, convert prothrombin to thrombin, release thrombin so fibrinogen form fibrin, create meshwork of blood cells, erythrocytes get caught in mass with more platelets + form clot, long-lasting to allow healing

Step 4: Clot Retraction + Repair

Cloth shrinks + tightens, damaged tissue begins to heal, clot broken once healed (fibrinolysis)

Blood Type Determination

Presence/absence of antigens + proteins on erythrocytes

3 Antigens/Proteins

A antigen, B antigen, Rh factor (+)

Foreign Antigens

Trigger severe immune response, cannot receive antigens red blood cells don’t have

Blood Function

Transport nutrients, oxygen, + wastes, helps maintain homeostasis, regulate pH, temp.

Blood Protection

Form blood clots, fight infection

Blood Basics

Volume varies with size + sex, about 5 L

Red Blood Formation

Erythropoietin hormone released, oxygen decreases, high altitude, made in bone marrow, damages/destroyed in liver/spleen by macrophages, influenced by vitamins B-12 + folic acid

RBC

Oxygen carrier, break down into heme (iron) + globin (protein), iron needed for hemoglobin synthesis

Hemoglobin

Carries oxygen + responsible for blood color

WBC

Varies between 5-10,000, phagocytic cells

Phagocytic Cell Types

Agranulocytes, granulocytes

Agranulocytes Types

Monocytes, lymphocytes

Granulocytes Types

Neutrophils, basophils, eosinophils