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Organism environment
1
Question | Answer |
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1a Organism and environment, adaptation | continuous interactions between organisms and external environment- body tries to keep constant interval environment (homeostasis) irrespective of external environment parameters via adaptation mechanisms (e.g. thermoregulatory) |
1b Organism and environment, adaptation | any change of external environment requires resetting of regulatory mechanisms to keep homeostasis- each adaptation mechanism has some capacity (limited) |
Adaptation capacity a | represents adaptability of the body- can be expressed as a range of external environment parameters within which the particular organism can keep homeostasis (survive) |
Adaptation capacity b | it is !!!very individual!!! - dependent on:- genetic disposition- age |
Adaptation capacity c | functional reserve of the body systems responsible for the adaptation to a particular change (dependent on the previous life style - nutrition, physical activity etc.) |
Adaptation capacity d | extreme (or too quick) changes of the external environment or failure of adaptation mechanism (due to failure of some organ) → change in internal environment (broken homeostasis) → disease |
Adaptation capacity e | border changes of external environment leading to survival only of individuals with best adaptation facilities are causing natural selection (Darwin theory), when Medicine does not interfere |
Adaptation capacity f | high external temperature requires thermoregulatory response based on peripheral vasodilation → ↓ BP - to keep adequate BP requires ↑ MV, people with chronic heart failure do not have |
Adaptation capacity g | sufficient heart reserve→ COLLAPSE (unconsciousness) (typical for old people) |
Factors influencing organism a | ● not-changeable - genetics, gender, ethnic, age ● changeable - nutrition, life style, personal habits |
Factors influencing organism b | ● factors from environment - viral and microbial - chemical (toxins, drugs, allergens) - physical (irradiation, temperature, sun exposure, altitude - p02)● psychological factors (family background, stress, religion etc.) |
Disease may be dependent:● exclusively on genetic factors without any possibility to influence its appearance: | - autosomal dominant (Adult polycystic kidney disease, Familial hypercholesterolemia, Osteogenesis imperfecta, Spherocytosis, von Willebrand's disease)- autosomal recessive (Color blindness, Cystic fibrosis, Phenylketonuria) |
Disease may be dependent:● exclusively on genetic factors without any possibility to influence its appearance: b | - X - linked recessive (Hemophilia, Bruton-type hypogammaglobulinemia, Duchenne's dystrophy) |
● largely dependent on environment or life style | - Colon cancer - low in developing countries (e.g. Africa), high in "westernized" populations (USA, Europe) - due to different intake of dietary fibers and fat |
● largely dependent on environment or life style | - Lung cancer - due to smoking (low in Mormons and Seventh day Adventists with code against use of tobacco – but non-smokers also can have lung cancer!!)- Skin cancer - due to ultraviolet light |
● largely dependent on environment or life style | - Malaria - only in countries with mosquitoes transmitting Plasmodium |
● dependent on combination of genetic predisposition and factors of environment or life style influencing manifestation of the disease | most frequent case- early coronary heart disease - due to predisposition to hypercholesterolemia and simultaneous high animal fat intake and/or smoking, low physical activity, stress factors etc. |
● dependent on combination of genetic predisposition and factors of environment or life style influencing manifestation of the disease b | - obesity and insulin non-dependent diabetes mellitus - combination of genetic predisposition with nutritional habits and low physical activity |