Immunology Study Guide Flashcards
Innate Immunity
1st Line of defense, immediate, creates physical chemical barriers, phagocytosis occurs.
Adaptive Immunity
2nd Line of defense. Delayed, specific, develops memory antibodies, T-cells, cytokines.
Natural Killer Cells
Kills cells infected with viruses, mediates antibody dependent cellular activity during adaptive response.
Interferons
Chemical messengers coordinate defense against viruses and intracellular parasites.
Innate Lymphoid Cells
• Mainly in barrier tissues of skin, intestine, lungs
• Regulates tissue immunity
Hematopoietic Stem Cell (HSC)
• Progenitor of all immune cells
• Retains ability to regenerate
• Retains ability to differentiate many different cell types
• Hematopoiesis
Phagocytosis
Cellular uptake of particulate materials via engulfment.
B-Cells
•Differentiate in bone marrow
•Mature in peripheral tissues
•Recognizes specific antigens and differentiates to plasma cells secreting antibodies.
Lymphocytes
•Principle mediators of adaptive response.
•Circulate continuously through blood, lymph, migrating into tissue spaces and lymphoid organs.
•B Lymphocytes- Humoral immunity- activated cell becomes antibody producing plasma cell/B memory cell
•T Lymphocyte- White blood cells: cell mediated immunity
T-Cells
Type of Lymphocyte that matures in the thymus.
There are two main types of T-cells:
•Helper T-cells: Stimulate B-cells, make antibodies, helps killer cells develop.
•Killer T-cells: Directly kill cells that have already been infected by a foreign invader.
Coordination of Immune Response
Innate Response: Immediate defense
•Neutrophils engulf and destroy invaders using anti microbial toxins
•Macrophages phagocytose by releasing cytokines and recruiting more cells
•Bacteria coated with lysis
•Macrophages migrate to lymph nodes and stimulate adaptive response
*Adaptive response: recognition memory occurs in the following:
•T-cells activate migrate to periphery, mediate adaptive immunity
•Peripheral APCs induce T H cells release cytokines recruit T c cells
•Activated antigen specific B-cells co-stimulated by T H cells and differentiated into plasma cells secretes antibodies
•Antibodies bind target antigens
•Tc cells lyse infected cells
Immunoglobulins
IgG- Most common antibody in the blood; antibacterial, antiviral, antitoxin, crosses placenta, creates passive immunity in newborn.
IgM- Bound to B lymphocytes in circulation. First to increase in immune response. Involved in blood ABO Type incompatibility reaction.
IgA- Found in secretions such as tears, saliva, mucus membranes, and colostrum providing protection for newborn child.
IgE- Binds to mast cells in skin and mucous membranes; when in contact with allergen causes histamine response, inflammation follows.
IgD- Attached to B cells; activates B cells.
Cytokine Storm
Referred to as hypercytokinema. Uncontrolled release of cytokines. Triggered by infectious agents such as, H1N1 influenza and COVID-19. Acute respiratory distress syndrome associated with significant number of deaths during COVID-19 pandemic.
Mast Cells
Connective tissue cells in mucosa of respiratory and digestive tracts. Release chemical mediators histamine in connective tissue.
Herd Immunity
High percentage of population vaccinated and have had infection of disease, decreases chance of acquiring and spreading an infectious disease.
Autosomal Recessive Traits
•Rare
•Expressed only when a person inherits two alleles for the trait
•Appears with equal frequency in both sexes
•Often skips generations
•Shows up more than when (consanguinity) mating between closely related people occurs
Autosomal Dominant Traits
Expressed when just one allele present. Does not skip generations. Appears with equal frequency in both sexes.
X-Linked Recessive Traits
•Appear more frequent in males
•Often, affected males born to unaffected mothers. Skips generations
•Fathers unaffected
X-Linked Dominant Traits
•Appear in males and females (more often in females)
•Don’t skip generations
Trisomy 21/Down Syndrome
Prevalence: 1 in 700 births (US)
Phenotypes:
•Low setting eyes
•Slower to develop speech than others
•Tongue slightly sticks out
•Flattened face
•Almond shaped eyes
•Small hands and feet
•Palmer crease
•Shorter height as children and adults
*Trisomy means 3 copies a chromosome instead of two.
Trisomy 18/Edward Syndrome
Prevalence: 1 in 5,000 births (US)
Phenotypes:
•Majority of infants affected experience growth deficiency
•Difficulty feeding, breathing
•Developmental delays
•Craniofacial malformations
•Heart defects present at birth
*Cause: Extra 18th chromosome due to non disjunction in meiosis.
Trisomy 13/Patua Syndrome
Prevalence: 1 in 16,000 births
Phenotypes:
•Individuals may have severe intellectual disability
•Heart defects
•Spinal cord abnormalities
•Cleft lip or cleft palate (roof of mouth opening)
•Small of underdeveloped eyes (microphthalmia)
•Extra fingers or toes
•Weak muscle tone
•Many infants die within first days/weeks of life
*Cause: Extra 13th chromosome due to nondisjunction in meiosis
Klinefelter Syndrome (47 XXY)
Prevalence: 1 in 500 to 1 in 1,000 male births
•Phenotypes: Small firm testes, small penis, sparse pubic, armpit, and facial hair.
•Tall stature and abnormal body proportions (long legs, short trunk).
•School age children diagnosed when referred to doctor to evaluate learning disabilities or in adolescence when puberty not progressing.
•Adult males infertility
•Increased risk rare breast cancer tumor (extragonadal germ cell tumor)
*Cause: Extra X chromosome due to nondisjunction in meiosis
Monosomy X/Turner Syndrome (45, X)
Prevalence: 1 in 2,000 to 1 in 2,500 (female birth)
Phenotypes:
•Females are often shorter than average ( no growth spurt during puberty)
•Non-functioning ovaries
•No breast development or menstruation
•Infertility
•Broad chest widely spaced nipples
•Heart murmur associated w narrowing aorta.
•Develop HTN
*Cause: One copy of X chromosome d/t nondisjunction in meiosis
*Note: Monosomy occurs when only one member of a pair of chromosomes is present.
Translocations
Transfer of chromosomal segment from one location in genome to another.
•Reciprocal translocation- Exchange of genetic material between non-homologous chromosomes
•Robertsonian translocation- Occurs when two acrocentric chromosomes break then fuse together.
Phenylketonuria
Disorder of amino acid metabolism causes intellectual disabilities, cognitive behavioral abnormalities d/t build up of amino acid phenylalanine. Defect in phenylalanine hydroxyl war activity.
Maple Syrup Urine Disease (MSUD)
Disorder in metabolism of branched-chain amino acids due to loss of one or more subunits in branched-chain alpha-Leto acid dehydrogenase (BCKD) complex involved in their breakdown.
Homozygous
Having two identical alleles at corresponding points on a chromosome pair.
Heterozygous
Having two different alleles at corresponding points on a chromosome pair.
Zellweger Syndrome
•Peroxisomal disorder that is rare. •Autosomal recessive affects 1 in 50,000 to 100,000.
•Rapid progression high mortality rate
•Craniofacial abnormalities
•Hypotonia
•Severe neuro developmental delay
•Hepatomegaly parent 80% of cases
•elevated liver enzymes and renal cysts present
