Basic Sciences Flashcards
What are the transition points of first and second order neurons?
Cranial nuclei and anterior horn cells
A lesion of this will lead to LMN signs, same as a 2nd order neuron lesion
In which lobe is the hippocampus?
Temporal lobe
Where is the primary motor cortex located?
Frontal lobe
Where is the sensory motor cortex location?
Parietal lobe
Where is the primary auditory cortex located?
Temporal lobe
Where does the corticospinal tract decussate?
Lower medulla
Which part of the brain is the terminal for all sensory nerves?
Thalamus
Within the thalamus, what do the anterior, lateral, medial and posterior nuclei do?
Anterior - language and memory function
Lateral - motor and sensory function
Medial - arousal and memory
Posterior - visual function
What are the 4 medial structures of the brainstem?
Motor pathway
Medial lemniscus
Medial longitudinal fasciculus
Motor nucleus
What are the 4 side structures of the brainstem?
Spinocerebellar pathways
Spinothalamic pathways
Sensory nucleus of the 5th CN
Sympathetic tract
Note - all begin with S
What is Frank-Starling’s law of the heart?
The stroke volume of the heart increases in response to an increase in the volume of blood in the ventricles before contraction (i.e. preload) when all other factors remain constant.
What is the modified Bernoulli equation for echo assessment of systolic PA pressure?
PASP = 4V^2 + RAP
Assuming no RVOT obstruction
Which part of an antibody do immune cells bind to?
Fc region
What is the function of a peroxisome?
Catabolism of very long chain fatty acids and amino acids
Results in the formation of hydrogen peroxide
What is the function of a proteosome?
Along with the lysosome pathway involved in degradation of protein molecules that have been tagged with ubiquitin
What is the function of a ribosome?
Translation of RNA into proteins
What is the function of a lysosome?
Breakdown of large molecules such as proteins and polysaccharides
What is the function of a nucleolus?
Ribosome production
What is the function of Golgi apparatus?
Modifies, sorts, and packages molecules that are destined for cell secretion
Site of O-linked glycosylation
What is the function of smooth endoplasmic reticulum?
Steroid and lipid synthesis
Examples of cells which have extensive SER includes those in the testes, ovaries, adrenal cortex and hepatocytes
What is the function of rough endoplasmic reticulum?
Translation and folding of new proteins
Manufacture of lysosomal enzymes
Site of N-linked glycosylation
Cells with extensive RER include pancreatic cells, goblet cells, plasma cells
What is p53, where is it located and what is its function?
p53 is a tumour suppressor gene on chromosome 17p
Prevents entry into S phase of cell cycle until DNA has been checked and repaired
Implicated in breast, colon and lung cancer, among others
What is the main source of IL-1, and what are its functions?
Macrophages
Acute inflammation and induction of fever
What is the main source of IL-2, and what is its function?
Th1 cells
Stimulates growth and differentiation of T cell response
What is the main source of IL-3, and what is its function?
Activated T helper cells
Stimulates differentiation and proliferation of myeloid progenitor cells
What is the main source of IL-4, and what is its function?
Th2 cells
Stimulates proliferation and differentiation of B cells
What is the main source of IL-5, and what is its function?
Th2 cells
Stimulate production of eosinophils
What are the main sources of IL-6, and what are its functions?
Macrophages, Th2 cells
Stimulates differentiation of B cells, induces fever
What is the main source of IL-8, and what is its function?
Macrophages
Neutrophil chemotaxis
What is the main source of IL-10, and what are its functions?
Th2 cells
Inhibits Th1 cytokine production
Also known as human cytokine synthesis inhibitory factor and is an “anti-inflammatory” cytokine
What are the main sources of IL-12, and what are its functions?
Dendritic cells, macrophages, B cells
Activates NK cells and stimulates differentiation if naive T cells into Th1 cells
What is the main source of TNFa, and what is its function?
Macrophages
Induces fever and neutrophil chemotaxis
What is the main source of IFNy, and what is its function?
Th1 cells
Activates macrophages
What is the role of hepcidin in regulation of the body’s iron stores?
Binds to ferroportin on basolateral surface of gut enterocytes and plasma membrane of reticuloendothelial cells (macrophages)
Causes internalisation and degradation of ferroportin
Iron is trapped in enterocyte/reticular endothelial cell
What are the subunits of HbA, HbA2 and HbF?
HbA - a2b2
HbA2 - a2d2
HbF - a2y2
Name 6 causes of microcytic anaemia
Iron
Thalassaemia
Anaemia of inflammation/chronic disease
Hyperthyroidism
Lead poisoning
Congenital sideroblastic anaemia
What are common self surface markers for B cells? Name 4.
CD19
CD20
Kappa
Lambda
An individual B cell can only express either kappa or lambda light chains.
What are the common cell surface markers for T-cells? Name 4.
CD3
CD4
CD8
CD5
What is the cell surface marker for stem cells?
CD34
What are the cell surface markers for granulocytes? Name 3.
CD33
CD13
CD15
What are the cell surface markers for monocytes? Name 2.
CD14
CD64
Which factors does prothrombin complex concentrate contain?
Factor II
Factor VIIa
Factor VIII
Factor IX
Factor X
Name 4 mechanisms of metastatic spread in malignancies.
Haematogenous spread
Lymphatic spread
Transcoelomic spread
- direct seeding of peritoneal/pleural cavity
Transplantation
Name the phases of the cell cycle and what happens during each.
G1 - cellular contents, excluding chromosomes, are duplicated
S - each of the 46 chromosomes are duplicated by the cell
G2 - chromosome errors are checked for, with repairs made if necessary
Mitosis - cell divides
Name 4 types of monoclonal antibodies, and associated nomenclature.
Mouse - -omab
Chimeric (34% mouse protein) - -uximab
Humanised (10% mouse protein) - uzumab
Fully human - umumab
What does a phase one study aim to do?
Dose defining study - find out maximum tolerated dose
Given in population with target disease
What does a phase two study aim to do?
Look for signal of efficacy.
What does a phase three study aim to do?
Comparing experimental with standard i.e. effectiveness.
In the context of antibiotic resistance, what is conjugation?
Direct cell-to-cell contact, considered main mode of horizontal gene transfer of antibiotic resistance genes
Plasmid exchange via a bacterial pilus
In the context of antibiotic resistance, what is transduction?
Transduction is the transfer to genetic material from one bacterium to another using a viral vector (i.e. a bacteriophage)
In the context of antibiotic resistance, what is transformation?
Transformation is when free short fragments of DNA (through death and lysis of another bacterium) are taken up by naturally transferable bacteria
How does GFR change in pregnancy?
GFR increased by 50% within 6 weeks - maximal 12-20 weeks
Equal afferent and efferent arteriolar dilatation maintains glomerular hydrostatic pressure
How does hyperkalaemia impact upon blood pH?
Increases pH
What is the main site of potassium absorption in the nephron?
Proximal convoluted tubule
In normal conditions, what makes the concentration of bicarbonate ions in the urine small?
Reabsorption of bicarbonate ions by type A and B intercalated cells in the proximal tubule
How does angiotensin II impact upon renal blood flow?
Renal blood flow is reduced by elevated plasma concentrations of angiotensin II and vice versa.
How does renal sympathetic activity impact upon renal blood flow?
Renal sympathetic activity = renal afferent arteriolar constriction = reduced renal blood flow
How does partial compression/occlusion of the renal artery impact upon renin secretion, urine output and arterial blood pressure?
Reduction in renal arterial pressure results in reduced GFR, and thus the NaCl in the macula densa, which then stimulates renin secretion from the juxtaglomerular apparatus.
What are the 3 functions of vasopressin?
Increasing water permeability of initial and cortical collecting tubules via insertion of aquaporin-2 channels - effect mediated by V2 receptors
Augmenting urea absorption in the inner medullary collecting ducts
Acute increase of sodium absorption across the ascending loop of Henle
What is the role of the alpha intercalated cells in the kidney?
The alpha intercalated cells are responsible for secreting excess acid and reabsorbing base.
Alpha = secrete Acid
What is the role of the alpha intercalated cells in the kidney?
The beta intercalated cells are responsible for secreting excess base (bicarbonate) and reabsorbing acid.
Beta = secrete Base
What compound does a healthy liver convert ammonia to?
Glutamine
