Blood and Circulation & The Human Defense System

Flashcards about blood and the human defense system.

Why is blood considered a connective tissue?

It links all cells and organs in the body.

What are the two main components of blood?

A fluid portion (unformed) and a solid portion (formed).

What is the average volume of blood in the human body?

4-6 liters

What percentage of blood volume does plasma constitute?

55%

What is the primary component of plasma?

Liquid water (91%)

What are the formed elements of blood?

Red blood cells (RBCs), white blood cells (WBCs), and platelets.

From what common source do all blood cells develop?

A population of stem cells in red bone marrow.

What is the significance of 'Pluripotent' stem cells in the context of blood cell differentiation?

These cells have the potential to differentiate into any type of blood cell or into cells that produce platelets.

Where is red bone marrow primarily located?

Ribs, vertebrae, sternum, and pelvis.

What controls RBC production?

A negative-feedback mechanism sensitive to the amount of O2 reaching the tissues via the blood.

What is the primary function of erythrocytes?

Carry oxygen to tissues.

What cellular components do erythrocytes lack?

A nucleus and mitochondria.

Where are dead red blood cells broken down?

Spleen and liver.

What is hematocrit?

The ratio of the volume of red blood cells to the total volume of blood.

How does fetal hemoglobin differ from adult hemoglobin?

Fetal hemoglobin can bind oxygen with greater affinity than the adult form.

What does a shift to the right on the hemoglobin dissociation curve indicate?

Less affinity for oxygen (oxygen given off).

What is the first line of defense in the human defense system?

Preventing organisms from entering the body.

What are examples of the first line of defense?

Skin and mucus membranes.

What is the second line of defense?

Leukocytes (WBCs).

What is the difference between adaptive and innate immunity?

Adaptive: antibodies produced by the body; Innate: non-specific immunity (no antibodies).

What is a pathogen?

Any agent of disease (bacteria, virus, worm, fungus, etc.)

What are the chief functions of leukocytes?

Defense of the body against invaders such as viruses, bacteria, and other foreign particles.

How do macrophages attack pathogens?

Engage in amoeboid movement to move to sites of infection and engulf by endocytosis (phagocytic attack).

How specifically do Lymphocytes attack pathogens?

Specific defense, as the antibodies are designed to target only a certain foreign invader.

What is an antigen?

A protein marker on a cell membrane that identifies the type of cell.

What do Cytotoxic T cells do?

Attack foreign cells or body cells infected by viruses.

What do Helper T Cells do?

Stimulate the activation and function of both T cells and B cells.

What do Suppressor T Cells do?

Inhibit the activation and function of both T cells and B cells.

What is the function of Plasma B cells?

Produce antibodies specific to certain pathogens (Humoral Response).

What do Memory B/T cells do?

Create long term immunity.

What is the function of Killer (cytotoxic) T cells?

Attack and kill pathogens once antibodies have attached to invader antigens.

What is the function of Suppressor T’s cells?

Regulate the action of the humoral immune system and prevent autoimmunity

What is the purpose of the lymphatic system?

Protect you from infection and keep a healthy balance of fluids throughout your body.

What is the role of lymph nodes?

Lymph (fluid) and lymphocytes (B and T Cells) travel through the lymph vessels and into the lymph nodes where the lymphocytes destroy harmful substances.

What role does Histamine play in an allergic reaction?

The histamine molecule then binds to an H1 receptor on the target cell (smooth muscle in the skin and nasal lining) and causes a reaction

What are platelets and their function?

Cell fragments that play an essential role in the clotting of blood and in plugging breaks in blood vessels.

What initiates blood clotting?

A tear in the platelet.

What is the role of thromboplastin in the clotting process?

When platelets burst on contact with a break in a vessel wall, they release compounds that combine with other blood components to form a protein known as thromboplastin

What is Agglutination?

The clumping of blood cells caused by antibodies attaching to antigens

Which blood type has A antigens and anti-B antibodies?

Type A

Which blood type has B antigens and anti-A antibodies?

Type B

Which blood type has A and B antigens and neither anti-A or anti-B antibodies?

Type AB

Which blood type has neither type A nor type B surface antigens and Plasma has both anti-A and anti-B antibodies?

Type O

What can occur if the baby receives Rh+ factor from the father, but the mother is Rh-?

The baby’s blood will come into contact with the mother’s immune system at birth

What is the function of Anti A Serum?

Contains A Antibodies (this means it is against A antigens)

What is the function of Anti B Serum?

Contains B Antibodies (this means it is against B antigens)

What type of cells does HIV target and destroy?

Helper T Cells

What are zoonoses?

Diseases or infections that are naturally transmissible from vertebrate animals to humans.

How do vaccines protect against diseases?

The spread of contagious disease is contained.

Why don’t antibiotics work on viruses?

Viruses use the organelles of the host cell to reproduce, and as such do not have any internal functions to disrupt