Chapter 1 Flashcards
The number of cells in the body
100 trillion
The number of red blood cells in the body
25 trillion
What is homeostasis?
The maintenance of nearly constant conditions in the body
What is disease?
The state of disrupted homeostasis
What is Cell theory?
Cells are the basic functional and structural unit of the body
Cells arise from pre-existing cells
Omnis cellula e cellula
Functional activity of cell depends on specific structural proteins in the cell
Cells are building blocks of the body
The body is made up of how much fluid ?
60% of body is made up of fluid
Out of this 60%, 40% is ICF and 20% is in ECF
Out of this 20%, 5% fluid is plasma and 15% is interstitial fluid
Majority of ions in the ECF?
Sodium, chloride and bicarbonate
Majority of ions in the ICF?
Potassium, phosphate and magnesium
The term homeostasis was introduced by?
Walter Cannon in 1929
Circulation of blood when the body is at rest?
One cycle each minute
Circulation of blood when the body is in the state of exercise?
Six cycles per minute
Which thing cannot pass through a capillary wall?
Plasma proteins
The origin of nutrients in the ECF is due to?
Lungs of respiratory system
Gastrointestinal tract
Liver, kidneys and endocrine glands
Musculoskeletal system
Which organs are responsible for the removal of metabolic and products from the body?
Lungs of respiratory system
Liver
Kidneys
Gastrointestinal tract
Regulation of body systems is caused by which systems?
Nervous system:
As it contains a sensory input portion, central nervous system and motor output portion.
The most important part is played by the autonomic nervous system
Hormone system:
As it contains eight major endocrine glands that secrete hormones in the ECF to transport to the target tissues
Which systems are responsible for the protection of body?
Immune system:
As it is responsible for the identification and destruction of foreign particles in the body
Integumentary system:
As it acts as a barrier between the body and the environment
How much body weight is covered by the skin?
The skin takes up 12 to 15% of the body weight
What are the examples of control systems in the body?
The regulation of arterial blood pressure by the baroreceptor system
The regulation of oxygen and carbon dioxide concentration in the ECF
What are the characteristics of control systems?
Most of these are negative feedback type
The gain of control system is higher
What is the gain of a control system?
It tells us the effectiveness with which a control system maintains the constant conditions
Gain= Correction/Error
Why positive feedback causes vicious cycle?
In case of 1 L of blood loss, the body can compensate it by the negative feedback system
But in case of 2 L of blood loss, the body cannot compensate it, and the pumping of heart further decreases due to which the death occurs.
In which cases positive feedback is helpful for the body?
Blood clotting
Childbirth
Transmission of nerve signals
How positive feedback is part of a negative feedback?
As in case of blood clotting, this process is part of the process to stop the bleeding and it turn prevent the blood loss
As in case of nerve impulse generation, impulse can in turn be part of a negative feedback overall
What is adaptive control?
It is delayed negative feedback
The body performs the function and send signal to the brain for its correction in the future responses by the feed forward control.
