GP final exam preparation Flashcards
(51 cards)
Name the 3 germ layers
Bilaminar embryonic disc becomes trilammar disc
- Ectoderm: (EVERYTHING EXTERNAL) Epidermis, CNS, PNS, eyes, internal ears neural crest cells and connective tissues of the head
- Mesoderm: (MUSCLE) Skeletal muscles, blood cells, serosal linings, CVS, cartilages, bones, tendons, dermis
- Endoderm: (EVERYTHING ENCLOSED) Epithelial linings of the resp and GI tract, glandular cells of the digestive organs- pancreas
Types of collagen (5)
Type I - bONEstructural collagen (bone, skin/dermis, tendons, ligaments)
Longitudinal fibrils
bundled into parallel collagen fibres
Type II - single fibres (hyaline cartilage)
Type III - Reticular fibres (branched / supporting meshwork)
Located around soft tissues, i.e. liver, spleen, bone marrow, lymphoid tissues
Type IV - Meshwork arrangement
located in basement membranes
Type VII - ‘anchoring collagen’
Links ECM to the basement membrane.
Name the CLASS types of enzymes and functions ‘OTHILL’
O: Oxidoreductases
Transfer electron/hydrogen/02 atom. From one substraight to another.
e.g. dehydrogenases, oxidase, oxygenase, catalase
T: Transferases
Transfer from functional group e.g Kinase transferases
H: Hydrolase
Transfer functional group to water, using H20 to break down water
I: Isomerase
Intramolecular changes in a substrate, group changes to a different location e.g
L: Lygase
Joining of 2 molecules by forming new bands e.g DNA ligase at end of DNA replication
L: Lyases
Removal or addition of a group to a substrate e.g dopamine or serotonin
Naked Vs Enveloped viruses
Naked:
-Capsid (protein coating) but no outer lipid membrane.
-More resilient, resist heat, dry conditions, UV radiation
-Protein coating is robust
-Causes lysis of host cell
- High survival rate
- Triggers strong immune response because doesn’t look like host
e.g Parvovirus, Adenovirus, polio virus
Enveloped:
- LIPID membrane
-Less resilient, destroyed by hot temp, acid environments, detergents
- Membrane more susceptible to environmental stressors
- Releases by budding
- Doesn’t cause lysis of host cells
- Low survival rate
- Not detected as easily because they mimic host cell
e.g HIV, influenza virus
Types of necrosis
-Coagulative
-Liquefactive (brain)
- Caseous (TB) cheese like appearance
-Fibrinoid autoimmune, vasculitis, necrotic foci surrounded by intact & fragmented neutrophils
- Fat necrosis (chalky white fatty deposits)
Hallmarks of cancer cells
- Sustained proliferative signalling
- evade growth suppressors
- resist cell death
- Replicate immortality
- Inducing angiogenesis
- Activating invasion and metastasis
- Invade immune system
- Abnormal metabolic pathways
Discuss Autosomal dominant
- Single mutated allele (heterozygous for the disease)
- Generally does not skip a generation
- Males and females are usually affected equally
-Huntington’s disease
- Marfan syndrome
- Myotonic dystrophy
Discuss Autosomal recessive
- Affected person has both mutated allele (homozygous) OR carriers have one affected allele (heterozygous)
- Common to skip a generation
- Males and females are usually affected equally
- Most commonly, two heterozygous parents (carriers) can produce a homozygote offspring.
- Cycstic fibrosis
- Sickle cell anaemia
- Phenylketonuria (PKU)
X- Linked dominant
- Twice as prevalent in females
- Affected males will always pass it on to females
- Doesn’t skip generation
- No male-to-male transmission
- Rett syndrome
- Fragile X syndrome
- Rickets
X linked recessive
- Prevalent in males (because males only have one X chromosome and therefore they will always be affected (never carriers)).
- Females are generally the carriers
- Affected females will always pass it to 100% of male offspring
- It’s common to skip a generation
- No male-to-male transmission
Examples
- Duchenne muscular dystrophy
- Hemophilia A & B
- Glucose-6- phosphate dehydrogenase deficiency
Discuss Trisomy disorders
- Trisomy 13, Patau syndrome
Cleft lip, extra fingers and toes, small eyes, mental retardation
Poor prognosis - Trisomy 18, Edwards syndrome
Similar to down syndrome, with clenched fist, overlapping fingers and rocker bottom feet
Poor prognosis
Trisomy 21, Down Syndrome
- Short stature, decreased muscle tone, almond eyes, flat face, flat occupit
Testing:
Decreased signs of trisomy disorder
unless increase of hvG = trisomy 21
Discuss sex chromosome disorders
XXY (extra X chromosome)
Only occurs in males
Klinefelter syndrome, tall stature gynaecomastia, small testes, osteoporosis, decrease body hair
45X or 45 XO
Tunner syndrome, only monosomy consistent with life
- short stature, oedema of ankles/ wrists, webbed neck, amenorrhea, infertility
Types of blotting
Southern: DNA
Northern: RNA
Western: Protein
Dot RNA, DNA and protein
Discuss the process of blotting
Technique used to manipulate DNA and RNA. It involved cutting and rejoining DNA.
Separate molecules using gel mixture
Transfer molecules transfer onto a solid surface.
Identify molecules: techniques to identify specific nucleic acids or genes
What is the difference between Osteomalacia, Osteoporosis and Osteoarthritis
Osteomalacia: (Rickets) soft bones due to vitamin D deficiency,
Osteoporosis: Decreased bone density, due to low calcium intake and changes in estrogen
Osteoarthritis: degenerative joint disease where cartilage breaks down
What does ELISA test stand for and explain test
Enzyme Linked Immunesorbent Assay
Diagnostic test that detects antigen- antibody binding through colour change
Antigen is placed in well of plate, serum added to well (horseradish) antibody binds to targets making a colour change
Name WBC and actions
Neutrophills: kill bacteria, fungi, foreign debris
Leukocytes
Mast cells
Eosinophils: Cirulate in the blood, some are in mucosal lining e.g Resp, GI and GI. Defends against helminthic parasites
Basophils: Bind to IgE
Innate Vs Adaptive
Innate immune system:
-Immediate response (within first 12 hours): first line of defence to response to invading pathogens/microbes.
- Non-specific and no memory: recognises common pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). It has no memory.
-Key components: includes physical barriers (i.e. skin/mucous membranes), chemical barriers (i.e. stomach acid), and immune cells and proteins (i.e. complement, phagocytes (neutrophils/macrophages), dendritic cells, mast cells, NK cells and ILCs.
Adaptive immune system:
- Delayed response (days to weeks)
- Specific response and memory: more specific response to antigens on pathogens with a targeted response. Also forms memory of an antigen once it is exposed to it (this provides a stronger response to it upon re-exposure).
-K components: B and T lymphocytes, antibodies.
Active vs Passive
Active: Microbial antigen (via vaccine or infection) lasts days or weeks then recovery with immunity the cells have a memory
Passive: Serum (antibodies) from immune individual is then administered via a serum to uninfected individual causes infection. However, not stored in long term memory
Discuss the 5 Isotypes
IgM: 5 Subuits (pentamer), found on surface of B cells, very first stages of immune response
IgA: Prevents attachment of microorganisms to mucous. Found in saliva, tears, colostrum, breast milk, resp, GI and UT secretion
IgG: 4 subclasses (G1,G2,G3,G4), only one that goes over the placenta
IgE: Binds to allergens, involved in allergy, triggers histamine from mast cells, protects against parasitic worms
IgD: Functions on the B cells as part of the BCR
Cell cycle
G0: No replication but growth
Interphase
G1: Growth of cell
Check point
S: DNA synthesis/ replication
Histone synthesis nucleus
Check point: no genetic abnormalities
G2: DNA check and repair (irreparable - apoptosis)
Communication pathways
Endocrine: Circulates through blood distant target cells, Hormones such as insulin/glucagon, oestrogen/ testosterone, adrenaline
Paracrine: Regulate nearby cells such as histamine, IL
Autocrine: Hormones that act on the same cell that secreted them. Growth factors in tumour growth
Virus replication
R A PURple Apple May Redden
Attachment: To receptor on host cell
Penetration: Into the cell
Uncoating: Capsid shed
Replication: Synthesis of viral messenger RNA and nucleic acid synthesis of viral protein for new capsid
Assembly: Capsid forms around nucleic acid
Maturation: Final changes within a immature virus
Release: By budding forming envelope
Sliding filament theory
Mechanism of muscle contraction.
Thick (Myosin) and thin filament (actin) muscle fibers, slide past during muscle contraction whilst remaining at constant length.
Myosin filament uses ATP to “walk” along the actin filaments with their cross bridge.
