Class 1 Flashcards
The endocrine system regulates nearly all vital functions of the body including these 5.
- Metabolism
- Growth and Development
- Water and electrolyte balance
- reproduction
- Behavior
The endocrine system is made up of a _______ of ______. These _______ produce _________.
- Network
- Glands
- Glands
- Hormones
Endocrine disease are often caused by what?
-Abnormal amounts of hormone
Define the prefix and sufix. Endo-, -Crin, Exo-, Para-, Auto-, Neuro-
- Endo = Within
- Crin = to secrete
- Exo = outside
- Para = Near
- Auto = Self
- Neuro = Nerve
Define hormone
-Substance made by one cell that signals a response from another
Name the 4 main types of hormones.
- Peptide and protein
- Thyroid
- Catecholamine
- Steroid
Hormones act only on ______ receptors, those receptors can be found in what 2 places.
- Specific
- Inside and outside of cell
The number of hormones ________ is ________. Affecting the cells _______ to a hormone.
- Receptors
- Regulated
- Response
What maintains hormone activity?
-Negative feedback
Humans are homeothermic and maintain body temp range between what?
-36.5-37.3
What disrupts the body’s mechanisms for temperature control?
-Anesthesia
Skins and axillary temp monitoring problems.
- Skin = 3-4°C lower
- Axilla = 1° Lower
What 2 temp monitoring sites reflect brain temp?
- Nasopharynx
- External auditory meatus
What is hypothermia, hyperthermia, normothermia?
- Hypo = < 36°C
- Hyper = > 38°C
- Normo = 37°C +/- 1°
What 2 areas mediate temperature regulation for the body?**
- Anterior hypothalamus
- Preoptic Nuclei
Hypothermia effects on the vascular system?
- Vasoconstriction
- hypoperfusion
- Pulse ox difficulties
Hypothermia effects on the cardiac system?
- Shivering ↑ O2 consumption
- Myocardial ischemia
- Cardiac Morbidity
- Arrhythmias
- Osborne or J waves
At what temperature does VF occur?
-22-23°C
Defibrilation will not be successful until what temp?
30°C
Hypothermia effects on the Pulmonary system?
- ↑ PVR
- Ventilatory drive is depressed
- ↓ CO2
Hypothermia effects on the renal system?
- Cold diuresis
- Decrease plasma volume
Hypothermia effects on the hepatic system?
-Hepatic blood flow is decreased
Hypothermia effects on the CNS system?
- Cerebral O2 consumption ↓7% for every 1° decrease.
- Decrease MAC
- Delayed emergence
- Drowsiness
- Confusion
Hypothermia effects on the hematoligic system?
- Impaired / decreased platelets
- Coag factors depressed
Hypothermia effects on the metabolism system?
- Reduced by 50% @ 30° and 60% @ 25°
- Slows drug metabolism
- Prolongs NMB and inhaled agents
- Increased plasma levels of propofol and fentanyl
Hypothermia effects on healing?
- Increased infection by impairing immune system
- Poor tissue perfusion and O2
- Less ABX
How is MAC effected by hypothermia?
- For every degree drop in temp, MAC decreases 5-7%
- More gas has to come off to wake up
Colorectal study findings of normothermic patients.
- Sutures removed day earlier
- 1/3 less infections
- Discharged 2.6 days earlier
The peripheral compartment holds _____ of the body heat while the core compartment holds _____.
- 1/3
- 2/3
How is the temperature difference between the Core and Peripheral maintained?
-Vasoconstriction
Vasoconstriction is controlled by what?
-sympathetic nervous system
What is the byproduct of metabolism?
-Heat
Heat production can increase when?
- Exercise
- Shivering
- Non-shivering thermogensis
- Hypermetabolic states (sepsis, thyroid storm, MH)
- Medications
- hypothalmic lesions
Shivering can increase heat production by?
300%
If a patient was insulated enough not to lose any heat, what would happen?
-Core temp would rise 1.2°C every hour
4 main ways of heat loss
- Radiation
- Conduction
- Convection
- Evaporation
What is the major route of heat loss and how much is it?
- Radiation
- 60% of all heat loss
Define radiation heat loss
- Loss of heat to cool surroundings via electromagnetic energy
- Determined by temp difference between patient and environment
Describe convection heat loss
- Wind chill
- Layer of air next to skin carries heat away
- Can account to 25% of heat loss
Describe evaporation heat loss
- Loss of heat with skin prep and open abdominal cavities
- Respiration of gasses
Describe conduction heat loss
- Transfer of heat between adjacent surfaces (OR tables)
- < 5% of loss
- Temperature gradient
Core temperature is maintained by ____________, How does anesthesia affect this?
- Peripheral vasoconstriction
- Inhibit peripheral vasoconstriction
In the 1st hour after induction of anesthesia there is a _____ decrease in the core temp because of__________.
- 1 - 1.5°C
- peripheral vasodilatation
Basal metabolic rate decreased by ________ which decreases what?
- 20-40%
- Heat production
________ anesthesia produces similiar patterns of heat loss as _________ due to __________.
- Regional anesthesia
- General anesthesia
- Vasodilation
3 Main problems GA cause in temperature regulation.
- Vasodilation
- Decrease metabolic rate (heat production)
- Decrease hypothalamic responsiveness to hypothermia
refrigerated blood or room temp crystaloid can decrease core body temperature by?
0.25°C
Basal metabolic rate decreases ___% per year beyond age ____
- 1%
- 30
Elderly and neonatal patients have _________ which results in less _________ heat conserving mechanisms
- diminished autonomic neural functioning
- Vasocontrictive
Problems with post op shivering
- Increase in O2 consumption
- Increase in catecholamines
- 3x increase in myocardial events
Why does shivering occur?
- Cooling of the preoptic region of the hypothalamus
- Involuntary oscillatory muscular activity
Most commonly used agent for post op shivering is? and how does it work?
- Meperidine (demerol)
- Kappa opiod receptors
Causes of Hyperthermia
- MH
- Sepsis
- Thyrotoxicosis
- Pheochromocytoma
- Hypothalamic problems
- Neuroleptic malignant syndrome
- Transfusion reactions
- Meds
Most common cause of hyperthermia is what and how does it increase temp?
- Sepsis/Infection
- Pyogens release interleukin 1
- Interleukin 1 increases set point for temp in hyothalamus
- Causes shivering and vasoconstriction
MH manifest itself as what? with what symptoms?
- Hyper catabolic state
- Tachycardia
- Hypercapnia
- Muscle rigidity
- Tachy arrythmias
- Metabolicc acidosis
