Week 1 Flashcards
(52 cards)
Intracellular fluid
- AKA ICF
- Fluid within cells
Extracellular fluid
- AKA ECF
- fluid outside the cells
- precisely regulated fluid
- internal environment of the body
Normal core body temperature
37 degrees C
Normal pH range in the body
7.35 - 7.45
Normal potassium [K+] range in body
3.5-5.0mmol/L
Normal calcium [Ca+] range in body
2.2-2.7mmol/L
Normal blood glucose range in body
70-100 mg/dl
Normal blood volume in body
5 L
Normal mean arterial pressure in body
93 mmHg
Normal arterial oxygen levels
75-100 mmHg
Normal arterial carbon dioxide levels
34-45mmHg
Consequences of homeostatic failure
- values of physiological parameters drift outside normal ranges
- disease, changes throughout body, death
Types of homeostatic feedback control
negative feedback and positive feedback
Negative feedback
- Reverses effect on original stimulus
- Maintains conditions that require frequent monitoring; long term
- temperature regulation
Positive feedback
- Amplifies effect of original stimulus
- Associated with infrequent, short term processes
- minor role
- blood clotting
Components of a homeostatic feedback system
- stimulus produces change in variable
- change detected by receptor
- information sent by receptor to control centre
- control centre compares information from receptor with monitored value with acceptable range. Information sent to effector
- Response of effector returns monitored value within limits of normal range
Matter
Anything that occupies space and has mass
What is matter composed of
Elements
Elements are…
- unique substances
- composed of atoms
- can not be broken down into simpler substances by chemical means
- 92 naturally occurring
How are elements arranged in the periodic table?
By their atomic numbers
Major chemical elements in the body
- oxygen (96%)
- Carbon (65%)
- Hydrogen (9.5%)
- Nitrogen (3.2%)
Significance of oxygen in body
- part of water and many organic molecules
- used to generate ATP
Significance of carbon in body
- forms backbone chains and rings of all organic molecules, carbohydrates, lipid, proteins and nucleic acids (DNA, RNA)
Significance of hydrogen in body
- constituent of water and most organic molecules
- ionised form makes body fluids more acidic