Digestive system-drhunter

Functions of the spleen

A major organ of the immune system that removes old RBCs, produces new blood cells & acts as a blood reservoir.

Lymphatic system

A complex network of thin vessels, valves, ducts, nodes and organs which collects, filters & clears fluid coming from around the tissues.

Lymph

Tissue fluid that has diffused into lymphatic capillaries.

Lymph node

Organs of the lymphatic & immune system through which the fluid percolates while being exposed to white blood cells which can destroy bacteria, viruses & other microbes which may have gotten into the tissue.

Functions of the Spleen

Remove old red blood cells; Major organ of the immune system; Acts as a reservoir for blood; Erythropoiesis

Erythropoiesis

Production of red blood cells.

Functions of the Thymus

Maturation & differentiation of T cells; Positive & negative selection

Positive selection

Allowing T cells that react against foreign antigen to grow & mature.

Negative selection

Selecting T cells that react again self antigens to be removed from the population.

Immune system

A complex network of cells, tissues & organs which protect the body.

Specific immune response

Production of activated T cells & B cells against a single antigen.

Natural killer cells

Non-specific phagocytes that engulf & kill pathogens.

Chemotaxis

Chemicals that call white blood cells to the damaged area.

Antigen

Any substance that can initiate an immune response.

Pathogen

any disease-producing agent (especially a virus or bacterium or other microorganism).

Neutrophil

The type of white blood cell in the highest concentration in peripheral blood that phagocytizes antigen & forms pus.

Agglutination

Clumping of microorganisms or blood cells, typically due to an antigen-antibody interaction.

MHC

A complex of proteins on the surface of cell that identifies self.

Complement

A series of proteins that when activated can destroy invading microbes.

IgM

First antibody made in response to antigen.

IgG

Antibody type in highest concentration in circulating blood that can also cross the placenta between mother & fetus.

IgA

Antibody present in body secretion such as Breast milk & saliva.

IgE

The only antibody which can bind mast cells @ cause allergic reactions.

Helper T Cells

Recognize antigen fragments, activate, & produce cytokines that activate other cells & orchestrate the immune response

Cytokines

Small protein hormones that may stimulate or inhibit many normal cell functions like growth & differentiation.

Primary response

Occurs over about 2 weeks after the first exposure to an antigen.

Secondary response

The faster, more specific & effective reaction that occurs as a result of immunologic memory.

Lymphocytes

The second most numerous white blood cells in the circulating blood.

Mendelian Genetics

The pattern of inheriting characteristics that follows the laws formulated by Gregor Mendel in that each person has only two alleles for each trait.

Alleles

Different forms of a gene.

Gene

A segment of DNA on a chromosome that codes for a specific trait.

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait.

Dominant

An allele that, if present, is always fully expressed.

Recessive

An allele that can only be expressed in the homozygous state.

Codominant

Occurs when two alternate alleles of the same trait are present & both are fully expressed.

Incomplete dominance

Occurs when two alternate alleles for the same trait are present in an individual & each are partially expressed so the phenotype of the heterozygote is in between the phenotype of the two homozygotes.

Phenotype

An organism's physical appearance, or visible traits.

Genotype

The DNA makeup of an organism inherited from parents.

Recessive Phenotype

The only way to express the recessive in your phenotype is to homozygous in your genotype.

Punnett Square

A chart that shows all possible allele combinations resulting from a genetic cross.

Gametes

Haploid sex cells.

Titre

The concentration of an antibody in the serum of an individual.

Major blood group antigens

A, B, O, Rh

Herd Immunity

The resistance to the spread of a contagious disease within a population that results if a high enough proportion of individuals are immune to the disease, especially through vaccination.

R0

The number of secondary infections that result from a single infected individual entering a population of entirely susceptible individuals.

Herd Immunity Threshold

The percent of a population that needs to have immunity to the prevent spread of a disease.

Epidemic

The occurrence of more cases of a disease or illness than expected in a given community or region or among a specific group of people over a particular period.

Endemic

A disease regularly found among people in a geographic area.

Pandemic

An outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population.

Negative pressure isolation

A room with a ventilation system that allows air to flow into the room but prevents contaminated air from escaping the room.

N95 respirator

Mask with small, tightly woven pores that protects the wearer from airborne infection.

Contact Isolation Precautions

Used for infections, diseases, or germs that are spread by touching the patient or items in the room (ex: MRSA, VRE, diarrheal illnesses, open wounds, RSV).

Droplet precautions

Must be followed for a patient known or suspected to be infected with pathogens transmitted by large-particle droplets expelled during coughing, sneezing, talking, or laughing. (ex: influenza, rhinovirus, pertussis and group A streptococcus)

Airborne precautions

Methods of infection control that must be used for patients known or suspected to be infected with pathogens transmitted by airborne droplet nuclei. (ex: Aspergillus & Tuberculosis)

Functions of Thymus

A major organ of the immune system that serves as the site for maturation & differentiation of T cells & conducts positive & negative selection.

Apoptosis

Programmed cell death.

Non-specific defenses

Includes mechanical factors, chemical factors, antimicrobial proteins, natural killer cells, phagocytes, inflammation & fever.

Specific defenses

Immune functions directed against identifiable antigens on bacteria, viruses, fungi, or other infectious agents.

Antimicrobial proteins

Peptides that inhibit microbial reproduction & provide short-term, nonspecific resistance to pathogenic bacteria & viruses

Hypersensitivity

An exaggerated response by the immune system to a substance that does not normally initiate a response.

Allergy

The production of IgE by the immune system to a foreign but frequently harmless substance resulting in release of histamine upon subsequent exposure.

Anaphylaxis

A life threatening allergic reaction involving edema, bronchoconstriction & vasodilation.

Autoimmunity

Occurs when the body's immune system reacts to self antigen resulting in the destruction of the body's own tissues.

Acquired immunity

Production of antibodies & lymphocytes after exposure to a specific antigen.

Passive acquired immunity

Results when a person receives protective substances (Ab) produced by another human to prevent disease once exposed. (ex. Antivenin)

Active acquired immunity

A form of protection where the body reacts to produce protection against a particular disease; producing immunologic memory.

Natural acquired immunity

Protection from a disease that results from contracting the disease & recovering from it.

Artificial acquired immunity

Protection from a disease obtained from inoculation or vaccination with a particular antigen.

Lupus (SLE)

A chronic autoimmune disease characterized by inflammation of various parts of the body causing tissue & organ damage.

Psoriasis

An autoimmune disorder resulting in a chronic skin condition producing red lesions covered with silvery scales.

Acquired immunodeficiency syndrome (AIDS)

A group of clinical signs & symptoms associated with suppression of the immune system by HIV & marked by opportunistic infections, secondary neoplasms, & neurological problems.

Edema

A puffy swelling of tissue from the accumulation of fluid.

Interstitial fluid

The liquid found between the cells of the body that provides much of the liquid environment of the body.

Macrophage

Specialized monocytes that migrate into tissues & are involved in the detection, phagocytosis & destruction of bacteria & other harmful microorganisms.

Peyer's patches

Large collections of lymphoid tissue found in the walls of the small intestine.

Antibodies

Biologically active proteins, produced by plasma cells, that attache to a specific antigen.

Helper T cells

Lymphocytes that orchestrate the immune response by producing lymphokines to activate other immune cells against the invader.

Killer T cells

Lymphocytes that use enzymes to destroy cancer cells & those body cells infected by virus.

Supressor T cells

Lymphocytes that inhibit the function of T cells & B cells once an infection has been controlled.

Memory cells

Long-lived lymphocytes capable of responding to a future infection with the same pathogen, long after the exposure that prompted its production.

Antigen-presenting cells (APCs)

Immune cells that process protein antigens & show them on their surface in a form that can be recognized by lymphocytes to initiate the specific immune response.

HIV

A virus that attacks and destroys the human immune system, resulting in the development of AIDS.

Functions of Blood

Transportation, regulation & protection.

Transportation (Blood)

Blood brings O2 to cells, takes CO2 away from cells, brings nutrients to cells & takes waste away from the cells.

Regulation (Blood)

Blood helps control body temperature, pH balance & water content of the body.

Protection (Blood)

Blood protects the body from excess bleeding by clotting, contains specialized immune cells to help fight off infection & disease.

Plasma

All liquid components of the blood. (~55%)

Serum

Plasma minus the clotting factors.

Formed elements of blood

Erythrocytes, leukocytes & thrombocytes. (~45%)

Hematopoiesis

Blood cell formation.

Hemoglobin

An iron-containing protein in red blood cells that reversibly binds oxygen.

Hemolysis

The rupture or destruction of red blood cells.

Granulocytes

Neutrophils, eosinophils, basophils

Agranulocytes

Lymphocytes & monocytes

Diapedesis

The passage of white blood cells through intact blood vessel walls into tissues.

Inflammation

The redness, local heat, swelling & pain caused when tissue is damaged.

Pus

A collection of tissue fluid, bacteria, dead and dying tissue cells, white blood cells and macrophages in an inflamed area.

Abscess

A pus-filled cavity.

Pyrogens

Chemical substances that cause fever.