G7: ITS A LIFESTYLE

This is my G7 Moment

Vasodilation

enlargement of vessel diameter (lowers blood pressure)

Vasoconstriction

narrowing of vessel diameter (increase blood pressure)

Baroreceptor reflex

Pressure sensors called baroreceptors monitor changes in arterial pressure.

Capillaries

Deliver blood close to nearly all body cells (gas exchange & salt exchange happen here)

Arteriosclerosis

Hardening of the arteries (happens because of high blood pressure)

Atherosclerosis

Cholesterol accumulates in arteries over time and builds up plaques in the arteries. Blood has too much difficulty to move in, might result in stroke or heart attack.

embolus

Clot that circulates in the bloodstream

Angioplasty

Angioplasty is a medical procedure used to treat blocked or narrowed blood vessels. It involves inserting a balloon-tipped catheter into the affected artery and inflating it to widen the vessel and improve blood flow. This helps restore average blood circulation and can relieve symptoms such as chest pain or shortness of breath.

Aneurysm

part of an artery weakens and balloons outward, caused by disease, inborn defect, or injury. If it bursts, blood loss can be serious or fatal

Heart Attack

Damage or death of heart muscle due to reduced blood flow to the region

Heart Failure

Heart is weakened and cannot pump enough blood to meet the body’s need

Bypass Surgery

Surgical procedure that creates an alternative route for blood flow, bypassing blocked arteries. Used to treat coronary artery disease and improve blood supply to the heart.

Arrhytmias

Irregular Heart Rhythm: some are abnormal, some are not.

Atrial Fibrillation

Irregular heart rhythm characterized by rapid and chaotic electrical signals in the atria. Increases risk of blood clots, stroke, and heart failure. Symptoms include palpitations, dizziness, and shortness of breath. Treatment options include medication, cardioversion, and catheter ablation.

Ventricular Fibrillation

Abnormal heart rhythm characterized by rapid, chaotic contractions of the ventricles. It can lead to cardiac arrest and is a medical emergency requiring immediate defibrillation.

Major Risk Factors for Cardiovascular Disease

Inherited predispositions

Elevated Blood Lipids

Hypertension

Obesity

Smoking

Lack of Exercise

Age 50+

Inflammation due to infections

High blood levels of C-reaction protein

Elevated Blood levels of homocysteine

Rheumatic Fever

Body produces antibodies that mistakenly attack heart valves

Endocarditis

Microbes attack heart valves directly

Lyme disease

complications include inflamed heart muscle

Myocarditis

Heart inflammation

Blood

a sticky fluid, fluid connective tissue consists of plasma, blood cells, and platelets

Blood Plasma

Fluid part of blood called plasma, made up of mostly water

P

Plasma Proteins

Determine blood’s fluid volume

Two-thirds of plasma proteins are albumin

Red blood cells (erythrocytes)

Carry oxygen and carbon dioxide

White blood cells (leukocytes)

defend against foreign cells, also remove dead or worn-out cellsp

platelets

release substances that begin blood clotting

last only a week

millions circulate in the blood

Hemoglobin

Protein that carries oxygen

oxygen binds to the heme groups (contains iron) to create oxyhemoglobin

“Heme” is the molecule that binds to oxygen

oxyhemoglobin

Compound formed when oxygen binds to hemoglobin in red blood cells, allowing for transportation of oxygen throughout the body.

AKA Oxygenated Hemoglobin

Factors influencing amount of oxygen hemoglobin can carry

Amount of oxygen present

Temperature and acidity of tissues

Macrophages

remove dead cells from blood

Span of Red Blood Cells

About 120 days

Producers of Red/White Blood Cells

Stem Cells in Bone Marrow

Complete Blood Count (CBC)

Tallies number of red blood cells, white blood cells, and platelets in one liter of blood

Erythropoietin (EPO)

EPO stimulates stem cells to produce more red blood cells

Comes from the Kidneys which monitor the blood count

Blood Types Difference

Differences come from variations in surface markers on red blood cells

The surface markers are sugars or carbohydrates

Markers that are NOT part of a person’s body are antigens

Two blood groups

Rh group (protein)

ABO group (sugar)

ABO Blood typing

chemical analysis to determine blood type

Blood Type AB

Has both A and B markers

type O

No marker, UNIVERSAL DONOR

Rh factor

another type of surface marker

Rh typing

determines the presence or absence of the Rh factor

Rh positive (Rh+)

Rh negative (Rh-)

Hemolytic Disease of the Newborn

If Rh- a female gets pregnant by an Rh+ male, the fetus may be Rh+; Rh antibodies will enter the new fetus’ bloodstream if another pregnancy occurs.

Hemostasis

means: “stopping bleeding”

prevents blood loss

can seal tears or punctures in relatively small blood vessels

Process of Blood Clotting

When a blood vessel is ruptured —> Vessel wall contracts in a spasm —> Constricts the blood vessel for up to 30 minutes —> Platelets arrive and clump together —→ Creating a temporary plug —> Serotonin is released to prolong the spasm and attract more platelets —> Blood coagulates into a gel and form a clot.

Other Means of Clot Formation

Intrinsic clotting mechanismF

Factor X

Part of Intrinsic Clotting Mechanism, protein in blood plasma is activated and triggers reactions that produce thrombin.

Thrombin

Enzyme that acts on fibrinogen, causes the fibers to stick together into a net that entangles lbood cells and platelets

Extrinsic Clotting Mechanism

Injury to Blood Vessel —> Wall of Vessel Contracts —> Platelets stick to collagen fibers of damaged vessel —> More permanent clot florms

Embolism

Occurs in the heart, lungs, or brain if the clot shuts down the organ’s blood supply.

Stroke

may involve an embolus, when blood flow is blocked to some part of the brain and affected area dies

may be mild or more damaging

Wound Healing

First Step: Formation of Blood Clot

Second Step: Phagocytes clean up debris

Third Step: Scab begins to form

Fourth Step: Minimize blood less/Minimize chance of infection

Anemia

Red blood cell disorder, cells not delivering enough oxygen, ex: iron-deficiency anemia, pernicious anemia, and aplastic anemia (cancer)

Malaria

Significant cause of hemolytic anemia

Caused by protozoan transmitted by mosquitoes

Infectious mononucleosis

1. Caused by Epstein-Barr virus

2. Triggers overproduction of lymphocytes

HIV

Attacks white blood cells, Causes AIDS

Leukemias

Often called blood cancers, Results from cancer of the bone marrow

Carbon Monoxide Poisoning

Prevents hemoglobin from binding oxygen

Septicemia

bacteria releases toxins that poison the blood [example staph A (Staphylococcus aureus)]

Toxemia

Caused by metabolic poisons in the body.

Three lines of defense protect the body

physical barriers

innate immunity

adaptive immunity

Antigen

foreign substance that triggers body’s immune response

example: virus, toxins, and cancer cells

physical barriers

intact skin,

linings of body cavities and tubes

chemical barriers to infection

NOT considered part of immune system

innate immunity

Preset responses to infections present from birth and carried out by white blood cells and blood proteins. The responses themselves are only general and not specific to type of antigen.

adaptive immunity

Changes over lifetime, but the response is tailored to a particular attacker. It takes about 7-10 to develop the response, unlike innate which is immediate.

Neutrophils

phagocytes that follows chemical trails to infected, inflamed or damaged tissue

form a net that traps nearby invaders

blow apart at contact with complement and other signaling molecules

Eosinophils

White blood cell that targets parasites too big for phagocytes

Basophils

Circulating white blood cells that targets parasites too big for phagocytosis

Macrophage

phagocytic white blood cell in tissue fluid

Dendritic cells

alert the immune system

B cells and T cells

Recognize specific antigens

The Lymphatic System

Picks up fluid lost from capillaries and return it to the bloodstream, other key task is defense

Lymph

tissue fluid that has moved into lymph vessels

Lymph Vascular System

Functions in drainage, delivery, and disposal; also picks up fats absorbed from small intestine and delivers them to bloodstream

Lymph Nodes

located at intervals along lymph vessels

spleen

filters blood, also serves as a holding station for lymphocytes

Thymus

location where T cells multiply and become specialized

Barriers to Infection

1) Skin provides a strong defense against external bacteria

2) Digestive tract lining includes “friendly” bacteria that help protect

3) Vaginal lining includes Lactobacillus (helps maintain low pH unfriendly to most bacteria and fungi)

Lysozyme and other chemicals

present in tears, saliva, and gastric fluid

protect the body

Urine’s low pH and flushing action

Protects the Urinary tract against infection

Mild diarrhea

Can rid lower GI tract of pathogens

Complement System

Complement raises a flag and says there is trouble, recruits neutrophils to go take care of the foreign substance. Complement protein is what raises the flag for foreign substances.

Inflammation

fast, general response to tissue damage or infection

mast cells and basophils respond to an antigen or complement proteins by releasing HISTAMINES

Histamines

causes arterioles to dilate, increasing blood flow

makes capillaries leak, causing swelling.

Fever

Body temperatures rises above normal

develops when macrophages release interleukins

Interleukins

stimulates brain to release prostaglandins

Functions of Adaptive Immunity

1) Recognition of self versus non-self

2) Specificity (make receptors for only one kind of antigen)

3) Diversity

4) Memory (some B and T cells first formed held in reserve for future needs)

Lymphocytes (B Cells)

Specialized for different roles:

Effector cells

Memory cells

Plasma cells (Makes antibodies)

Specialized white blood cells that play a crucial role in the immune response by producing antibodies to target and eliminate specific pathogens.

B cells

T Cells

Specialized white blood cells that play a crucial role in the immune system by recognizing and destroying infected or abnormal cells in the body.

MHC

Markers present on cells recognized as “self”

Antigen-presenting cell

Engulfs an antigen and cuts into pieces using enzyme

Antibodies

mark invaders, other mechanisms prevent them from harming body cells

Five classes of antibodies

Collectively called immunoglobulins (lgs)

lgM, lgD, lgG, lgA, and lgE

Immunoglobulin G

The primary antibody in blood activates complement, neutralizes toxins, protects the fetus, and is secreted in early milk

Natural Killer (NK) cells

present in tissues and organs of the lymphatic system

can detect and kill virus-infected body cells and some cancers

Cytotoxic T Cells

release various killer substances to attack target cells

Vaccination

stimulates immunity, contains an antigen,

First injection confers active immunity

later booster shot causes more effector cells and memory cells to form, provides long-lasting immunity

Antibodies (2)

can be “borrowed” by another person to provide temporary ability to fight pathogens

Immunotherapies

manipulating the body’s immune mechanism

Immunotoxins

monoclonal antibodies bound to toxins, bind to an antigen on a cancer cell