Chapters 6, 7, 9 - Pathophysiology 1 Exam 1

Primary organs of the lymphoid system

bone marrow (hematopoiesis), thymus gland

Secondary organs of the lymphoid system

lymph nodes (contain lymphocytes and macrophages), spleen (filters blood), tonsils, peyer patches (contain B cells; produce antibodies)

Chemical mediators with immune function

complement, kinins, clotting factors, cytokines and chemokines

Major complement proteins

C1 to C9

Inflammation

an innate defense and happens after cells are injured regardless of the cause of injury

Five cardinal signs of inflammation

redness, swelling, heat, pain, loss of function

Three main events of inflammation

Increased vascular permeability, Emigration of leukocytes (WBC), Phagocytosis

Emigration of leukocytes

leukocytes roll along the blood vessel walls (margination); selectins, chemokines, and integrin receptors help leukocytes stick to blood vessel walls; emigration or diapedesis; Chemotaxis attracts leukocytes to sites of injury

Phagocytosis

neutrophils and macrophages produce proteolytic enzymes and oxidizing agents to destroy and digest antigens; neutrophils die after phagocytosis and form pus (cellular debris); macrophages remove pus and prepare the site for healing

Increased vascular permeability

Mast cells release vasoactive chemicals; platelets may become present and release clotting and chemotactic factors; fluid is pushed from the blood vessels into tissue because of increased capillary blood pressure and vasodilation (leads to swelling, heat, and redness); prostaglandins also cause pain (can be blocked with aspirin)

Vasoactive chemicals released by mast cells

histamine, prostaglandins, leukotrienes

Healing of tissues after inflammation

reconstructive phase beginning 3-4 days after injury and persisting for 2 weeks; can be longer depending on type of tissue

Serous exudate

watery and clear; low protein; occurs in mild inflammation

Fibrinous exudate

thick and sticky; high protein; occurs in greater injuries

Fibrous and scarring occur as normal tissue replaced by

Fibrous tissue

Systemic responses to inflammation

fever, neutrophilia, lethargy, muscle catabolism, suppressed appetite, induction of sleep

Two types of adaptive immunity

humoral immunity, cell-mediated immunity

Function of humoral immunity

antibodies are produced by B cells to protect body against non-self agents

Exudate

a fluid that leaks out of blood vessels, combined with neutrophils and debris from phagocytosis; transports leukocytes and antibodies; dilutes toxins and irritating substances; transports nutrients for tissue repair

Purulent exudate

pus; occurs in severe injury; contains infective organisms; leukocytes

Hemorrhagic exudate

has RBC in it; occurs in most severe inflammation

All nucleated cells express MHC class I proteins

True

Cytotoxic T cells recognize antigens on MHC class II

False; it recognizes antigens on MHC class I

T cells

cell-mediated immunity (recognizers of antigens on cell surfaces)

T Helper cells recognize antigens

on MHC class II

B cells

humoral immunity (producers of antibodies)

Certain specialized cells express MHC class II proteins

True

Activated cytotoxic T cells (CD8+) proliferate into

memory cells and effector cells

Protein needed for MHC class I binding

CD8

Protein necessary for T helper cells to bind to MHC II proteins

Humoral immunity memory B cells contain

antigen receptors and memory of exposure to an antigen is stored in memory B cell clones, able to respond rapidly to subsequent exposure.

T helper cells (CD4+) recognize

foreign antigen in association with MHC II molecules.

B cells activation

B cells require activation help from T helper cells (CD4+).

Classes of immunoglobulins

The five classes of immunoglobulins are IgG, IgM, IgA, IgD, and IgE.

Effector cells

Have cytotoxic effects by perforins, which are proteins manufactured in cytotoxic T cells that allow granzymes into target cells to degrade DNA and trigger apoptosis.

Cell-mediated immunity

T lymphocytes are programmed to directly attack non-self cells to protect the body, with two types: cytotoxic and helper.

Most common immunoglobulin

IgG

First immunoglobulin produced on exposure to antigens or after immunization

IgM

Immunoglobulin that is primarily found in saliva, tears, tracheobronchial secretions, colostrum, breast milk, and GI/GU secretions.

IgA

Antibody class switching

Dependent on the presence of specific cytokines.

Order of class switching

Activated B cells undergo a switch from IgM and IgD to IgG, IgE, or IgA.

Immunity

State of resistance against infection from a particular pathogen.

Passive immunity examples

Natural passive immunity and artificial passive immunity.

Natural passive immunity examples

IgG transferred from mother to fetus across placenta and through breast milk, providing protection of the infant for the first months.

Artificial passive immunity examples

Injection of antibodies into a person for short-term protection.

Immunoglobulin for inflammatory and allergic reactions

IgE

Active immunity

Occurs as a result of an active infection or immunization.

Autoimmune disease

Can occur if regulatory mechanisms of immune function are disturbed.

Types of passive immunity

Includes mother to fetus (IgG can cross the placenta), mother to infant (IgA from breast milk), and serotherapy (direct injection of antibodies).

Immunizations examples

Vaccines containing altered microorganisms or toxins that stimulate the immune system without pathogenic properties, and vaccines containing live and attenuated agents or killed infectious agents.

Primary response

First exposure to antigen, taking 1-2 weeks for antibody titer to reach efficacy.

Transfer of preformed antibodies

Used for B-cell immunodeficiencies following exposure of an individual with high susceptibility to a disease without adequate time for active immunization.

Antibody injection may

alleviate or suppress effects of antigenic toxin, providing immediate but temporary protection.

Natural active immunity

Natural exposure to antigen leading to the development of antibodies.

Artificial active immunity

Antigen purposefully introduced to the body for stimulation of antibody production via immunization or booster immunization.

Natural immunity

Species specific.

Innate immunity

Gene specific and related to ethnicity.

Secondary response

Repeated exposure to the same antigen, resulting in a more rapid response with efficacy in 1-3 days.

Human DNA organization

Organized into 46 chromosomes, composed of 23 pairs.

Autosomal chromosomes

22 pairs of chromosomes are autosomal.

Sex chromosomes

The 23rd pair of chromosomes is defined as the sex chromosomes.

Genetic disorders groups

Chromosomes abnormalities, Mendelian single-gene disorders, Non-Mendelian single-gene disorders, and Polygenic and multifactorial disorders.

Chromosomal abnormalities generally result

from various genetic factors.

Aneuploidy

Abnormal number of chromosomes, either > or < 46 in humans.

Down Syndrome

An example of autosomal aneuploidy; there's an extra copy of chromosome 21.

Autosomal Aneuploidy examples

Trisomy 18 and Trisomy 13

Edwards Syndrome

Another name for Trisomy 18.

Patau Syndrome

Another name for Trisomy 13.

Describe Trisomy 18

Most affected pregnancies are lost before term; babies are born small and have heart defects, CNS deformities, and severe intellectual disability.

Trisomy 13

Most affected pregnancies are lost before term; associated with abnormal brain structure, severe intellectual disability, and high maternal age.

Klinefelter Syndrome

Usually 1 extra X chromosome: XXY; most common sex chromosome abnormality affecting males, characterized by abnormal sexual development and feminization.

Turner Syndrome

Monosomy X: 1 normal X chromosome but no Y chromosome; affects females with short stature and congenital heart defects.

Meiosis vs Mitosis errors

Meiosis: crossing over errors - chromosome portions lost, attached upside-down, or attached to the wrong chromosome

Mitosis: opportunities for chromosomal breakage and rearrangement.

Cri du Chat Syndrome

The deletion of part of the short arm of chromosome 5; characterized by round face, severe mental disability, and heart anomalies.

Defective Gene Location

Location: autosomal or sex chromosome; Mode of transmission: dominant or recessive.

Mendelian Single Gene Disorders

Usually result from alterations or mutations of single genes.

Marfan Syndrome

An example of an autosomal dominant disorder; falls under connective tissue disorder.

Inheritance of Mendelian Disorders

Majority are inherited from parents; only 15-20% are new mutations.

Pedigrees

May help trace transmission of Mendelian single-gene disorders through families.

Clinical Manifestations of Marfan Syndrome

Tall and slender; long, thin arms/legs; thin fingers (arachnodactyly); cardiovascular lesions.

Fibrillin 1 Gene Mutation

Mutations in this gene on chromosome 15 lead to low levels of fibrillin, causing weakened connective tissue.

Huntington's Disease

Affects primarily the neurologic function; symptoms appear after the age of 40.

Huntingtin Protein

An abnormal amount of this protein is produced in Huntington's disease that causes nerve degeneration.

Sex-linked Disorders in Males

Males always express the disease for a sex-linked (X-linked) disorder due to only one X chromosome.

Examples of Autosomal Recessive Disorders

Albinism, Phenylketonuria (PKU), and cystic fibrosis

Albinism

lack of pigmentation from disrupted melanin synthesis

Phenylketonuria (PKU)

inborn error of metabolism: cannot metabolize phenylalanine; tested for this at birth

Cystic Fibrosis

defect in a membrane transporter for chloride ions in epithelial cells called CFTR

Polygenic traits

Classified by human traits developing in response to more than one gene; examples include height, weight, and intelligence

Teratogenic agents

factors/agents that cause congenital malformations

Examples of teratogenic agents

chemicals (ex. thalidomide), radiation, viral infections (ex. zika virus)

Embryo susceptibility to teratogenesis

3rd-9th week, especially during 4th and 5th weeks during organ development

Hemophilia A

bleeding disorder from lack of factor VIII (clotting factor)

Non-mendelian single-gene disorders

long triplet repeat mutations such as fragile X syndrome, mitochondrial DNA mutations, genomic imprinting

Prader-Willi syndrome

uncontrolled eating and obesity, mental retardation

Angelman syndrome

mental retardation, uncontrolled smiles

Fetal vulnerability before 3rd gestational week

teratogen exposure either damages very few cells or so many that embryo doesn't survive

Fetal vulnerability from 3rd to 9th week

embryo very susceptible to teratogenesis

Fetal vulnerability after the 3rd month

teratogens affect growth or injury to already formed organs

What do teratogenic agents interfere with

cell proliferation, migration, or differentiation