PHS 201 General Physiology & Body Fluids Flashcards
(34 cards)
Who has a higher % of body water male or female and why?
Men 60%
Woman 55% because of more adipose fat tissues
Who has a higher % of body water old/young and why?
Young, because adipose tissue increases with age, therefore water content decreases
Significance of body fluids
In homeostasis: body cells survive in the fluid medium called internal environment, it consists of substances essential for growth and functioning of the cell. Water also plays a role in homeostasis.
In transport mechanism
In metabolic reactions
In texture of tissues
In temperature regulation
How many L of water in a 70kg male
42L
Intracellular fluid % and L
Extracellular fluid % and L
40% and 28L
20% and 14L
Marker measure total body water
3H2O Tritium
2H2O Deuterium
Antipyrine
Marker to measure extracellular fluid
Radioactive sodium
Chloride
Bromide
Sulphate
Thiosulphate
Marker to measure plasma
Evans blue
Radioactive iodine (T-1824) : injecting serum albumin labeled with iodine
It can also be measure indirectly by measuring rbc volume
Properties of an ideal marker
Non toxic
Not alter volume
Not be excreted
Easy to measure
Not be metabolized by the body during a period of time
Not change color of body fluid
Where do gametes descend from?
Primordial germ cells in the walk of the yolk sac at 4th week of development
Definition of physiology
Physiology is the study of processes and functions of living things
definition of homeostasis
Homeostasis Is the Maintenance of Steady States in the Body by Coordinated Physiological Mechanisms.
Who was the first to formulate the concept of the internal environment (milieu intérieur)
The nineteenth-century French physiologist Claude Bernard
What was Claude Bernard’s ideology
He pointed out that an external environment surrounds multicellular organisms (air or water), but the cells live in a liquid internal environment (extracellular fluid)
Who introduced the concept of homeostasis?
In the first half of the twentieth century, the American physiologist Walter B. Cannon
what happens if blood glucose concentration is too low?
if blood glucose concentration is too low, the hormone glucagon, from alpha cells of the pancreas, and epinephrine, from the adrenal medulla, will increase it.
what happens if blood glucose concentration is too high?
If blood glucose concentration is too high, insulin from the beta cells of the pancreas will lower it by enhancing the cellular uptake, storage, and metabolism of glucose.
Disease or death is often the result of_
dysfunction of homeostatic mechanisms.
cycle of self regulating devices (4)
- Sensors or detectors, which recognize the deviation.
- Transmission of this message to a control center.
- Transmission of information from the control center to the effectors for correcting the deviation (either electrically through nerve impulses or .chemically through hormones in blood and body fluids)
- Effectors, which correct the deviation
What are feedback signals?
Feedback is a process in which some proportion of the output signal of a system is fed back to the input
What is negative feedback?
Negative feedback is the one to which the system reacts in such a way as to reverse the direction of change
What is positive feedback?
Positive feedback is the one to which the system reacts in such a way as to increase the intensity of the change in the same direction (a progressive change in one direction).
What is adaptive control system and where is it typically seen?
Adaptive control system refers to a delayed type of negative feedback mechanism. This is seen in the nervous system
resting membrane potential
The resting membrane potential of a neuron is the electrical potential across the neural membrane of an unstimulated nerve cell. It is around -70 mV
