General Flashcards
What are the question topics for taking a history of a presenting complaint?
S - Subject O - Onset C - Characteristics R - Radiating A - Associated Factors T - Timing E - Exacerbating Factors S - Scale I - Impact A - 'Anything else?'
- Red flags?
What are the question topics for taking a comprehensive history?
- Current General Health
- Medical History
- Medications
- Allergies
- Family History
- Social History
- Lifestyle - Use of Illicit Drugs
- Lifestyle - Alcohol
- Lifestyle - Smoking
- Lifestyle Exercise/Physical Activity
- Diet
- Red Flags
- Is there anything else?
What is the Calgary-Cambridge framework?
- Initiating Interview
- Gathering Info
- Physical Exam, then any other tests
- Explaining and Planning
- Close Session
What is the composition of fluid compartments in the body?
- Extracellular Fluid (35%) (in-between cell and capillary)
i. Interstitial Fluid (25%)
ii. Blood plasma and lymph (8%)
iii. Trans-cellular fluid (2%) (water in epithelial lined spaces) - Intracellular Fluid (65%)
What are the types of cellular communication?
- Direct:
i. Juxtacrine
ii. Gap Junctions - Via ECF:
i. Autocrine
ii. Paracrine
iii. Endocrine
iv. Neuronal
v. Neuroendocrine
What are the main constituents in the extracellular fluid and intracellular fluid?
3 Main constituents in ECF:
- Na+
- Cl-
HCO3-
3 Main constituents in ICF:
- K+
- PO43-
- Protein Anions
Describe feedforward control
An anticipatory alteration of effectors independent of feedback. There is adaptive control (I,e, system learns how to control ball throwing) and anticipatory control (or predictive homeostasis, i.e. increasing cardiac function in anticipation of exertion
Describe the Baroreceptor Reflex
- A decrease in BP result in BR in heart being stretched less. (decrease nerve impulses)
- Info sent to brain (afferent info)
- Brain increases sympathetic simulation and decreases parasympathetic (efferent info)
- Increased secretion of adrenaline and noradrenaline
- Increased heart stroke volume and heart rate (=increased cardiac output), and constriction of blood vessels (=increase in SVR).
- BP rises and homeostasis is maintaines
Describe plasma glucose in terms of homeostasis
If it is too high, pancreas will release insulin into blood and cells can use glucose as energy or convert it into glycogen, and liver will convert glucose to glycogen as well. Blood glucose levels drop and homeostasis in maintained.
If it is too low, pancreas will release glucagon into blood and so liver will convert glycogen into glucose, which raises blood glucose levels and homeostasis is maintained.
Describe the positive feedback cycle involving oxytocin in childbirth
- Head of fetus pushes against cervix
- Nerve impulses from cervix transmitted to brain
- Brain stimulates pituitary gland to secrete oxytocin
- Oxytocin carried in blood stream to uterus
- Oxytocin stimulates uterine contractions and pushes fetus toward cervix, when restarts the cycle
What are the determinants of ion diffusion across a membrane?
- membrane permeability
- concentration gradient
- voltage gradient
What causes cystic fibrosis?
A defective gated Cl- membrane transport protein (cystic fibrosis trans membrane conductance regulator (CFTR)) results in cells not being able to get rid of Cl- fast enough, so too much water is let in. The cells can’t regulate Cl- secretion and so mucus becomes excessively thick.
What are the main types of endocytosis?
- Fluid phase
- Receptor mediated
- phagocytosis
What are the main types of exocytosis?
- Constitutive (unregulated)
- Regulated
What is the rate of passive diffusion of an uncharged substance?
ΔS/Δt = -D(ΔC/Δx)
(rate of passive diffusion = proportionality constant x concentration gradient at a point).
P (permeability coefficient) = DΔx.
therefore:
Net flow of solute = -PΔC
What factors affect the permeability coefficient?
- size and shape of molecule
- lipid solubility
- electrical charge
- ability to form H-bonds (hydrophilic)
- chemical structure of molecule and cell membrane
What is the typical osmolarity of ICF and ECF in mammals?
300mOsmoles/L
What factors that need to be taken into account when determining the effective osmotic pressure difference?
- The total concentration of dissolved solutes
- Degree of dissociation of each dissolved solute
- Permeability of the membrane to each substance
What is the approximate hydrostatic pressure equivalent of 1 Osmole/L?
22.4 atmospheres = 22.4 x 760 mm Hg
What causes the different between tonicity and osmolarity?
ECF and ICF can have same osmolarity, but they may have different concentrations of different solutes. Permeability of these solutes effects tonicity, which is a measure of EFFECTIVE osmotic pressure.
What is Tonicity?
A measure of EFFECTIVE osmotic pressure.
What are the defining features of cardiac muscle?
Single nucleus, striated and involuntary.
What are the defining features of smooth muscle?
Single nucleus, NOT striated and involuntary.
What are the defining features of skeletal muscle?
Multiple nuclei, striated, voluntary
What are the different connective tissues in/around a muscle cell?
Epimysium (ensheaths entire muscle)
Perimysium (surrounds bundle of muscle fibers)
Endomysium (unsheathes cells)
What are the main sections of a sarcomere?
Whole Sarcomere = Z - Z
I Band = Z + actin and titin on either side
A Band = Myosin
H Zone = Gap between actin (i.e. just myosin)
M line = middle of H zone
Which sections of the sarcomere shorten during contraction?
I and H
What is Excitation–contraction coupling?
Excitation–contraction coupling is the process by which a muscular action potential in the muscle fiber causes the myofibrils to contract.
What is Motor unit recruitment?
Motor unit recruitment is a measure of how many motor neurons are activated in a particular muscle, and therefore is a measure of how many muscle fibers of that muscle are activated. The higher the recruitment the stronger the muscle contraction will be.
What are the 2 main skeletal muscle finer types?
- Type I – SO – Slow contracting, fatigue resistant, low strength
- Type IIa – FO – Fast contracting, fatigue resistant, high strength
- Type IIb – FG – Fast contracting, fast fatigue, highest strength, and also the largest.
What are the phases of a twitch?
- latent period
- contraction phase (ends at peak)
- relaxation phase (peak to end)
What is the difference between isometric and isotonic tension?
Isometric tension occurs when tension in muscle is equal to the opposing force. The muscle stays the same length.
Isotonic tension occurs when they are not qual, and results in either shortening or elongation of the muscle.