Handout #1 - Cellular Function/ Water Distribution Flashcards
What three mechanisms do cells use to coordinate activity in times of health?
Electrochemical
Chemical
Mechanical
Describe electrochemical communications.
Nervous system releases chemicals called neurotransmitters, receptors on the cells sense the presence of these, causing the desired response. These responses are very quick.
How are hormonal reactions different from electrochemical?
They are very slow changes, however, generally have a longer duration of action.
What four chemicals are used in the cellular side of chemical communications?
Histamine
Serotonin
Bradykinins
Prostaglandins
What does histamine do?
Alters capillary permeability, and vasodilation
What does serotonin do?
Plays a role in homeostasis with a response similar to histamine
What do bradykinins do?
Trigger stimulation of pain receptors that warn the body of problems, and let it know of an injury
What do prostaglandins do?
Trigger cycle of changes that begin the inflammatory response
What are the six mechanical receptor cells, and what do they each detect?
Baroreceptors - pressure
Stretch receptors - changes in cell shape
Thermal - temperature
Electromagnetic - radiation levels (light)
Osmoreceptors - salt/water changes in the bloodstream, located in hypothalamus
Volume sensitive - volume depletion in the vasculature from dehydration
Where are the two most important baroreceptor sites located? Why are they important?
Carotid arteries and aortic arch
They monitor bp
What type of tissue is blood?
Hematologic - a type of connective tissue
What percent of total body weight is water in an average adult?
60%
Divide total body water into the three types.
Intracellular - 75%
Extracellular:
Interstitial - 17.5% between cells
Intravascular - 7.5% inside vessels
What percent of total body weight is water in an average neonate?
80%
What percent of total body weight is water in an average geriatric?
50%
