Basic science Flashcards
basic science, introduction to blood, ANS
what’s particular with the dilantin and opioids in regards to therapy
They’re effective therapies that have been used for decades or millennia without an understanding of their underlying molecular mechanism of action
when did the idea that ongoing study of the structure and function of the human body could improve medical practice emerged ?
Renaissance
what was Popper’s view of the scientific method ?
no experiment can prove a hypothesis true or even increase our confidence in it. Experiments can only prove hypothesis false.
does science in practice conform to Poppers formula ?
No. Science doesn’t always involve explicit testing of hypotheses. Furthermore, hypothesis testing doesn’t merely exclude false hypotheses. It can also increase our confidence in hypotheses we believe are correct.
where are Nav1.7 channels selectively expressed ? what are they ?
in nociceptors (voltage-gated sodium channel)
Inherited erythromyelalgia (IE)
disorder characterized by episodes of redness and pain in the feet and hands. It can often be triggered by warmth or mild exercise.
Is IE hereditary ?
Yes (inherited erythromyelalgia, you dumb)
What cause IE ?
mutations in the Nav1.7 sodium channel (shift the voltage-dependance of the channel to activate to more negative potential; the channel is easier to open)
what causes congenital insensitivity to pain ?
mutation in Nav1.7 that cause non-functional channels
how these data about Nav1.7 are relevant to clinical practice ?
drugs that selectively inhibited Nav1.7 might be especially effective for treating pain.
the 2 numbers you need to remember for cell size (e.coli and red blood cells)
- e.coli is 1 micrometers
- a red blood cell is 7 micrometers
4 primary tissues that are constituting organs and organ systems
- epithelia
- connective tissue (fills space between epithelia)
- muscle (within connective tissue)
- nervous tissue (within connective tissue)
what’s a glycocalyx
cell coat of carbohydrates
ribosome role
translate mRNA into protein (situated on the rER)
sER role
detox and lipid metabolism and synthesis and calcium storage
difference between sER and rER
the sER is way more tubular, less linear
golgi apparatus role
transformation post-transcription pour pouvoir envoyer les protéines nouvellement construite dans la matrice extracellulaire (transport of proteins through cell, and secretion)
- cells goes from CIS TO TRANS
heterochromatin
when the DNA is condensed
euchromatin
when the DNA is dispersed, for transcription
3 main types of cytoskeleton and their role
- microtubules : primary organisation
- intermediate filaments : structural support
- microfilaments : cell movement (like actin)
microtubule is pat of what structure important for mitosis ?
centrosome (important for formation of mitotic spindle)
what is always at the base of the epithelia ?
basement membrane (basal lamina)
how to you name the different kind of epithelium ?
always name them from the shape of the cells that are on the lumen side
what’s the epithelium of the skin ?
stratified squamous (keratinized) : a coat of dead cells on top of alive ones
different cell shape for epithelium
- squamous (mou, rond)
- cuboidal (cube)
- columnar (colonnes)
different cell number for epithelium
- simple (une couche)
- stratified (+ une couche)
- pseudostratified (tous touche à la BM, mais pas organisé pcq plein de petites cellules qui poussent)
different stratum epithelium of the skin
from the top of the skin
- stratum CORNEUM
- stratum GRANUSOLUM
- stratum SPINOSUM
- stratum GERMINATIVUM
- basement membrane
most commun type of connective tissue ?
collagen fibrils
what are the 2 types of connective tissue ? Qu’est-ce qui les différencient ?
- CT proper : loose, intermediate, etc.
2. CT specialized : + minerals - bone, cartillage, teeth.
what’s amorphous ground substance ?
everything else in the EM (between fibres, resists compressive forces)
what are elastic fibre useful for ? what’s it 2 units of construction ?
- what makes the blood vessel retrack (and other organs)
- made of microfibrils and elastin
mast cells
cells waiting for allergens and release histamine/heparin/leukocyte chemotactic factors
lysosome role
membranous vesicules of hydrolitic enzymes used for the controlled degradation of macromolecules
mesenchymal cells
stem cells that lie in the EM, adult stem cell (can make anything tissue)
endosome
deliver their contents to lysosomes via the endocytic pathway
peroxisomes
produce hydrogen peroxide and then use it to oxidaze a variety of other substrate such as alcohol and other toxic molecules that enter the bloodstream
what do fibroblast make ?
collagen and elastic fibers
roles of binding and connective tissue
- connects tissues and provide a flexible support
- nutritive and excretory role
- role in the defense of the body against infection
cells of connective tissue
- mesenchyme
- fibroblast/fibrocyte
- macrophage
- mast cell
- plasma cell
- adipocyte
plasma cells
specialized in synthesis of proteins as antibodies
where do the nerves of parasympathetic systems are ?
cranio-sacral
where do the nerves of sympathetic systems are ?
thoraco-lumbar
are the parasympathetic ganglia closer of further from target that sympathetic ?
closer
what is the main post-ganglionic neurotransmitter for the PNS
acetylcholine (Ach)
what is the main pré-ganglionic neurotransmitter for the PNS
Ach
what is the main pré-ganglionic neurotransmitter for the SNS
Ach
what is the main post-ganglionic neurotransmitter for the SNS
norepinephrine ou epinephrine ou noradrenaline ou adrenaline
what are the 3 main structures that control the ANS ?
- insular cortex
- hypothalamus
- nucleus of the tractus solitarius
how do you call all the ganglions of the sympathetoc system ?
sympathetic chain
A first-order sympathetic neuron in the hypothalamus synapses on a second order neuron in the intermediolateral cell column of the spinal cord. The second order neuron does 1 of 3 things
- the first synapse on a «third order» neuron in the sympathetic chain (para-vertebral ganglia) that will then innervate a target organ
- synapsing on a third-order neuron in one of 4 pre-vertebral ganglia
- directly innervate the neuro-endocrine cells of the adrenal medulla
when the adrenal medulla is stimulated, what does it secretes ?
epinephrine and norepinephrine directly into the bloodstream (as hormones)
what arepostural vital signs ? how can it help you diagnose ?
Check BP and HR while lying down
• Have the patient stand and check them again
• Normally there is a small postural drop in blood pressure compensated by tachycardia, before both return to normal
• An excessive* or prolonged drop in BP, or an absence of a compensatory tachycardia, are abnormal
what senses the change in BP ?
baroreceptors in the carotids sinus
how does the brainstem responds to increases in BP ?
by increasing parasympathetic outputs (diminuer le HR et le contractibility
how does the brainstem responds to a decrease in BP ?
by increasing sympathetic outputs (augmenter le HR, la contractibility et la PVR (peripheral vascular resistance))
what structures aren’t innerved by the parasympathetic . system ?
blood vessels and sweat glands
adrenergic receptors
receptors for catecholamines (adrenaline + epinephrine) in the sympathetic
muscarinique et nicotinic receptors
Ach (para)
is there innervation of the bronchial smooth muscle by the sympathetic nervous system ?
No, done by release of epinephrine by adrenal glands
in the case of asthma, what kind of medication can be used ?
- first line of treatment is inhaled beta-agonist (to dilate the bronches)
- anticholinergic medications are also used (to block the parasympathetic nervous system which constrict the airways
what can happen if the beta-blockers and alpha-blocker used to treat chronic hypertension are too strong ?
they can prevent the compensation for postural hypotension
what happens with blood when you after you give it ?
- filtered to removes lymphocytes
- tested for multiple infectious diseases (HIV, HEPA and B, syphillys, etc.)
- centrifuged to separate into packed RBCs, platelets and plasma
what is the utility of frozen plasma ?
coagulation factors and usually used for people with significant bleeding problems
what are factor concentrates ?
manifactured by fractionnation from large pools of human plasma and used for replacement of specific factors in a patient.
what’s cryoprecipitate ?
manifactured by freezing plasma and collecting the precipitate, used a lot in patient having massive traumas
what are the neutrophils useful for ?
bacterial and fungal immunity
what are the eosinophils useful for ?
parasites and allergies
what are the lymphocytes useful for ?
viral infections
where do platelets arise from ?
megakaryocytes in bone marrow
what are platelets useful for ?
they interact with proteins from coagulation cascade and lead to blood clotting
when fully oxygenated, hemoglobin form _______. Once deoxygenated, they form ______
a) relax state
b) tense state
at higher pressure of O2, is more of less Hgb oxygenatted ? where is this kinda pressure then ?
more. In the lungs (versus less in the capillaries to relâche oxygen)
what’s a CBC?
complete blood count (includes white blood cells, red blood cells and platelets count)
why is the hemoglobin higher in men ?
because of testosterone levels
normal CBC for white cells ?
4 - 11 x 10^9
normal CBC for hemoglobin
120-160
normal CBC for platelets
150-400 x 10^9
define anemia
red blood cell number, hemoglobin or hematocrit below the normal range
de quoi est constituée l’hemoglobin
oxygen carrying protein in red blood cells (2 alpha and 2 beta chains with 4 heme groups)
what’s the etiology of sickle cell anemia ?
mutation in beta chain (hemoglobin)
what’s the etiology of thalassemia ?
defect in production of alpha of beta chains (hemoglobin)
hematocrit
% of red blood cells in known blood volume
reticuocytes
immature red blood cells which still contain ribosomal RNA. These normally circulate in the peripheral blood.
MCV
mean blood cell volume; average SIZE of red blood cells (should be between 80-95 fl)
microcytosis
MCV<80 = small blood cells
macrocytosis
MCV >95 red blood cells larges
erythropoiesis
formation of new red blood cells
under what is the control of erythropoiesis ?
the level of erythropoiesis is under the control of erythropoietin, a hormone produced by the renal tubule cells which sense the O2 levels in blood. The kidney will then make more erythropoietin to tell the bone marrow to make more blood cells (more reticulocytes in blood then)
possible cause of anemia
- Deficiency of “building blocks” for red blood cells
- Congenital abnormality of the content of red blood cells
- Abnormality in the production site of red blood cells
- Loss of red blood cells: Bleeding
- Decreased lifespan of red blood cells in the circulation (<120 days): Hemolysis
- Chronic illness: Suppressed erythropoiesis
what are the different building block that you can lacks in anemia ?
- iron, stored in the form of ferritin
- vitamin B12
- folate
name 2 congenital abnormality of Hgb in red blood cells
- thalassemia
2. sickle cells
what are the different abnormality that can happen in the production site of red blood cells leading to anemia ?
- empty bone marrow
2. bone marrow filled with other elements (leukemia, lymphooma, cancer)
what hemolysis
decreased lifespan of red blood cells in corps (usually leads to anemia). Increased breakdown of red blood cells. An elevated reticulocyte count is often first clue.
signs of anemia (physical exam)
- pallor, nails changes (koilonichia), smooth tongue
- bleeding
- infection/bruising (indicate bone marrow failure)
- jaundice
how is jaundince and red blood cells linked ?
When red blood cells are broken down in the circulation, hemoglobin is released. The heme portion is then broken down into bilirubin. If the rate of RBC destruction is rapid, bilirubin may build up in the blood leading to jaundice.
what are the best laboratory investigation for anemia ?
- CBC
- reticulocyte count
- MCV
what does anemia and high reticulocyte count mean ?
bone marrow working fine (souvent bleeding of hemolysis or nutritional deficiency on replacement)
what does anemia and normal or low retic number mean ?
abnormal erythropoiesis or bone marrow disfunction
anemia + microcytosis mean ?
- iron deficiency (heme)
- thalassemia
- chronic disease
anemia + macrocytosis SUPER high (megalocytosis) mean ?
- abnormality in SNA synthesis
- vitamin B12 deficiency
- folate deficiency
- drugs (chemotherapy
anemia + macrocytosis high (macrocytosis) mean ?
- reticulocytosis
- liver disease
- thyroid disease
cause of hemolysis ?
- extracorpular
- red blood cell membrane
- hemoglobin
- enzyme defects
what are the extracorpular cause of hemolysis ?
either
- AUTOIMMUNE : AIHA (the body makes anti-body against own red blood cells
- NON-IMMUNE : mechanical (heart valves that break red blood cells when it sends them to circulation)
what are the red cell membrane cause of hemolysis ?
- hereditary elliptocytosis
2. hereditary spherocytosis
what are the hemoglobin cause of hemolysis ?
- sickle cell anemia
2. thalassemia major
Coomb’s test
mesures IgG on surface of red blood cells = autoimmune
haptoglobin
carries hemoglobin in the circulation. When you mesure it in somebody with hemolysis, it’s low because it’s bound to your hemoglobin
