Psycho-Babble Students Thread 634956

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I can't study!!!

Posted by Deneb on April 19, 2006, at 20:34:23

I have an exam tomorrow and I can't get studying today!!

This always happens. The closer I get to the exam, the less I can study and concentrate.

Aaaah! I hope I already studied enough to pass!

Argh, I hate this. I'm avoiding things. Aaaahhh!

Someone test me on animal physiology!!

Quick, test me on the vertebrate kidney!

Test me on the respiratory systems and the circulatory systems in fish, reptiles, birds and mammals!

Electrical conduction in the heart....
Control of blood pressure, chronic and acute mechanisms...
Carbon dioxide excretion in mammals, teleost fish and dogfish...
Oxygen equilibrium curve, shifts, P50...
Loops of Henle, proximal, distal tubules, ascending and descending limbs, countercurrent, gradients...
Thermoregulation...
Osmoregulation in marine and freshwater fish...
Alpha and beta 1 and 2 adrenoreceptors...

I wish someone was here to test me on this stuff...

I gotta study! Look at the big picture! I keep memorizing the small details...I need to study the big picture...that is why I did poorly last time...

Structure and function relationships...

Okay, I'm freaking out just a tad...

Aaaahhh! :-) Don't mind me.

Deneb

Me either... summer has set in (nm) » Deneb

Posted by Gee on April 19, 2006, at 20:34:24

In reply to I can't study!!!, posted by Deneb on April 19, 2006, at 13:59:55

Review and circulatory system

Posted by Deneb on April 19, 2006, at 20:34:24

In reply to Me either... summer has set in (nm) » Deneb, posted by Gee on April 19, 2006, at 15:06:14

Okay, I'm desperate...

I'm going to write my study notes here. I need some incentive to study efficiently. I'm going to teach people here what I know. Here I go!

Please tell me if I'm incorrect in something!
----------------------------------------------
The hypothalamus links the nervous and endocrine system.

In the sympathetic system there are adrenergic fibres that release noradrenaline.

In the parasympathetic system there are cholinergic fibres that release ACh.

The adrenal gland is made up of the adrenal medulla, and the adrenal cortex. In the adrenal medulla there are chromaffin cells.

Stimulation of alpha adrenoreceptors cause vasoconstriction.

Stimulation of beta1 adrenoreceptors increase heart contraction rate and strength. ( ve chronotrophic and inotropic)

Stim. of beta2 receptors cause vasodilation.

Steroids and thyroid hormones are lipid soluble, are transcription factors, cause long lasting effects.

Peptides/proteins and catecholamines are lipid insoluble. Involve a 2nd messenger and amplificatiion. Rapid, short lived responses.

Hypothalamo-Hypohyseal complex
- hypothalamus
- pituitary gland
- infundibular stalk

-------------------------------------------
Circulation

Circulatory system functions
- transport of materials and heat
- production of force

Design of circulatory systems
- pump, vessels, circulating fluid
- kinds of pumps...positive and negative pressure pumps...chamber, persistalic

Open vs Closed systems
- open...incomplete vessels...haemolymph, high vol, low pressure, limited capacity to alter velocity and distribution of blood flow
- closed...high pressure, differential distribution of blood flow possible

Undivided vs Divided systems
- undivided...one circulation, no separation of oxygenated and deoxygenated blood

Fish
- single circulation
- 2 resistance beds, gills and tissues
- gills must withstand high pressure

Birds/Mammals
- separate systemic and pulmonary circulations
- equal blood flow in separate circuits
- lungs need low pressure, otherwise edema

Intermittent Air Breathers
- single circulation
- selective distribution of blood flow to lungs, skin and body
- eg. Lungfish...oxy blood to branchial arches 3 and 4 to tissues...deoxy blood to arches 5 and 6 (gills)...bypasses lungs via ductus

Heart
- atrioventricular, aortic and pulmonary valves
- sinoatrial node, atrioventricular nodes, atrialventricular bundle, Purkinje fibres

Action Potentials spread via gap junctions

Neurogenic vs myogenic hearts

Pacemaker potential is unstable b/c of Na leak

Chronotropic effects
- Parasym innervation...ACh increase k conductance of pacemaker cells
- Symp innervation and catecholamines...increase Na and Ca2 conductance...decrease K conductance

Cardiac Action Potential
- open voltage-gated Na channels
- slow opening of voltage-gated Ca2 channels
- closure of voltage-gated K channels

Electrocardiogram
- atrial depolarization - P
- atrial repolarization - lost in QRS
- Ventricular depolarization - QRS
- Ventricular repolarization - T

Tension is proportional to [Ca2 ]

Cardiac output = (stroke vol)(heart rate)
Q = SV*HR

Frank-Starling Relationship
- SV is proportional to diastolic filling

Delta P = QR

R is proportional to L*n/delta P

compliance = deltaV/deltaP

Windkessel vessels
- aorta, arteries
- large r, low R
- little P drop
- compliant elastic walls dampen pressure oscillations to maintain continuous flow

Precapillary resistance vessels
- small arterties, arterioles
- small r, high R, great P drop

Precapillary sphincters

Capillaries
- low velocity

Post-capillary resistance vessels
- venules, small veins
- r can be adjusted
- adjustment of P across capillary beds

Capacitance Vessels
- veins
- 50% of total blood vol

Fainting
- blood pools in veins
- decrease venous return
- decrease cardiac output
- decrease arterial pressure
- decrease blood flow to brain

Capillaries
- 1 mm long, 3-10 micrometer diameter
- endothelial cells, basement membrane
- Fick equation
Amount transferred = (gradient)(permeability)SA/T
- continuous capillary
- fenestrated capillary (kidney)- pores
- sinusoidal capillary - paracelluar gap

Fluid exchange
- Hydrostatic P
- Osmotic P

Starling-Landis Hypothesis
- arterial side - net filtration
- venous side- net absorption
Filtraion > Absorption
- Net fluid loss...need lympatic system

Oedema
- increased BP
- lympathatic failure
- reduced proteins

Blood
- Plasma...albumins, globulins, fibrinogens
- RBC, WBCs
- Haematocrite = %RBCs/vol

Blood Pressure
- Acute
deltaP = QR
- adjust heart rate and R

Baroreceptors
- respond to pressure as stretch of vessel walls
- located in carotid sinus and aortic arch
- increase BP...increase baroreceptor firing
- at normal BP, there is tonic baroreceptor firing

Decrease Arterial BP
- decreased baroreceptor firing
- decrease parasymp activity (vagus)... ve chronotropic, increase cardiac output
- increase symp activity... ve chronotropic, ve inotropic...increase cardiac output
- increase symp activity...vasoconstriction...increase peripheral R

Regional Circulation
- ischemia, hyperemia...active and reactive

Controlled by...
- local, neural and hormonal
- arterioles, pre-capillary sphincters

Sympathetic nerves (adrenergic fibres)
- norad
- alpha receptors...vasoconstriction
- brain, heart lact alpha receptors

Catecholamines (adrenaline) from adrenal medulla
- beta receptors
- beta2 vs beta1 in heart

Local control
- heat, nitric oxide, histamine
- metabolic activity...decrease O2, increase CO2, increase [H ], increase heat

Exercise
- increase O2 consumption 5-10x
- increase heat dissipation
- increase blood flow up to 7x

1. Hyperemia in muscles
- symp. cholinergic stim
- local metabolic changes

2.Increase cardiac output
- ve inotropic, ve chronotropic
= venous vasoconstriction...increase venous return

3. Peripheral vasoconstriction
- alpha1 receptors on gut, kidney, etc.

Constant BP
- muscle vasodilation > vasoconstriction therefore decrease R
- increase cardiac output

Exercise
- increase symp activity
- ACh and metabolic factors
- vasodilation in skeletal muscles
- Norad...gut and kidney..vasoconstriction
...heart...increase Q
...veins...increase venous return, increase cardiac output (Q)

Re: I can't study!!!

Posted by Deneb on April 19, 2006, at 20:34:24

In reply to I can't study!!!, posted by Deneb on April 19, 2006, at 13:59:55

Aaaahh!

I just studied the circulatory system, but I still need to study respiration, osmoregulation and thermoregulation!!

I can't study!

Maybe I need a break.

Deneb*

Re: I can't study!!! » Deneb

Posted by muffled on April 19, 2006, at 20:34:24

In reply to Re: I can't study!!!, posted by Deneb on April 19, 2006, at 16:30:27

WHAT is thermo and osm regulation anyways!!!!!!!!!!!!??????????????
LOL!
muffled

Re: I can't study!!!

Posted by Deneb on April 19, 2006, at 20:34:24

In reply to Re: I can't study!!!, posted by Deneb on April 19, 2006, at 16:30:27

Okay, I just studied respiration. Now I have to study osmoregulation and thermoregulation.

Brain...can't take in more info...must squeeze info in...LOL

I'm not studying this stuff for the first time of course. I just gotta refresh everything.

Deneb*

Re: I can't study!!! » Deneb

Posted by Phillipa on April 19, 2006, at 20:34:24

In reply to Re: I can't study!!!, posted by Deneb on April 19, 2006, at 18:35:42

Deneb I have no idea what you're talking about. Pretend I'm your proffessor. Class Deneb gets an Aplus. Love Phillipa

Re: I can't study!!! poss. trig

Posted by Deneb on April 19, 2006, at 21:50:21

In reply to Re: I can't study!!! » Deneb, posted by Phillipa on April 19, 2006, at 19:33:18

I can't wait until my exams are over! I have to study until the 27th!

I just want to pass 2 out of 3 classes. I'm not looking to do well. I've skipped too many quizzes and classes to do well. I'm just looking to pass 2 out of 3 classes. I've given up on one of my classes. I'm just too behind in that class. I'm not going to do anything crazy to get a deferral. I'm just going to have to fail that class.

After this is over and if I pass 2 classes, I will have 4 more classes to complete before getting my degree. I'm really behind. I've dropped a LOT of classes in the past. I basically took a year off.

I'm 2 years behind. It's okay though. I don't handle stress very well, and if it takes me 6 years to finish my degree with some sanity left, so be it. I'm not in any rush. My family is supportive. I'll make it up to them when I get a job.

I think I'll live at home for a while, to save up some money. My Mom doesn't want me to leave home. She's afraid I'm not ready for the world. She has fears of me getting stressed out in the real world and committing suicide.

I'm going to try to live as stress-free a life as possible. I'm not looking to make a lot of money. If I don't get bored, I think it would be okay to not be challenged all the time at work.

I want to have free time to do whatever I want. I want a job where the working stays at work.

I still have to study a bit. I'm procrastinating...

Deneb*

Re: I can't study!!!

Posted by Deneb on April 20, 2006, at 12:35:19

In reply to Re: I can't study!!! poss. trig, posted by Deneb on April 19, 2006, at 21:50:21

I'm done with animal physiology!!

Woohoo!

The weather is super nice today. Argh, still must study for environmental science...

Gotta study really hard. I have until the 27th to study. Study, study, study.

I gotta find a job...

No time for job right now, must focus on studying.

How often do you take breaks when you study? I take them every 2 hours or so.

Deneb

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