Chapter 1: Introduction (Lloyd's notes) Flashcards Preview

PHYSIOLOGY - 1st Year 1st Sem Comprehensive Exam > Chapter 1: Introduction (Lloyd's notes) > Flashcards

Flashcards in Chapter 1: Introduction (Lloyd's notes) Deck (9)
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Four fundamental properties distinguished the living body from the non- living. One of the following is NOT included

living organisms operate through controlled mechanisms for optimum survival.

Notes: 4 Properties of Life
1. Exchange matter and energy with environment
2. Receive signals from environment and react accordingly
3. Life cycle of growth and reproduction
4. ADAPT to changing circumstances (not fixed)


The grand organizer – the master that controls the molecules, the cells, and the organs and the way they interact.



Which among the following is the current definition of physiology?

Physiology takes a global view of the human body where in it requires an integrated understanding of the events at the level of molecules, cells and organs.


According to French Physiologist, Claude Bernard, father of modern physiology, animals have two environments in which tissues and cells of organisms live. He supports this argument in which specific observations are stated below:

Internal environment is neither the air nor the water in which an organism lives but rather – in the case of the human body – the well-controlled liquid environment outside cells (Milieu Interieur or extracellular fluid)


Homeostatic mechanisms are responsible for
maintaining the constancy of the milieu interior. Homeostasis is currently thought of as:

the control of vital parameters.


One of the most common themes in physiology is the negative-feedback mechanisms which is responsible for homeostasis. Negative-feedback requires at least 4 key elements below, except:

a single output signal most often does not operate in isolation but rather as part of a larger network of set points.

Notes: 4 Elements
1. Sense changes in the vital parameter
2. Compare the input with a set-point
3. Multiply error and send output
4. Output signal activates effector mechanism


Homeostasis is currently to be argued to be not in equilibrium because:

Answer: all of the above

Equilibrium does not involve energy while Homeostasis does

Homeostasis is a steady-state (regulation using energy)

In homeostasis, a parameter is held constant by matching actions that lower the value, while others raise it


Physiology is and has always been the study of
homeostatic mechanisms that allows organisms to persist despite the pressures imposed by the hostile environment; therefore, in learning physiology, which one of the following should be the first and foremost principle in mind:

How do the interactions of organs in organisms and molecules in cells operate.


IDENTIFICATION: Themes of Homeostasis

1. Because the body as a whole places a HIGHER IMPORTANCE on the control of blood volume than on the control of body temperature, the system that controls the blood volume will instruct the system that controls body core temperature to reduce the production of sweat.

2. The flexibility of an organism depends on its ABILITY TO ALTER ITS RESPONSE. Indeed, many flexible feedback loops are the root of many forms of physiological variations.

3. The hypothalamus controls the anterior pituitary.

4. The MORE VITAL a parameter is, the MORE SYSTEMS that the body mobilizes to regulate it.

5. Determining the relative weights of feedback loops in ____ with one another. Ex. Insulin lowers blood glucose while glucagon increases it

1. Priority
2. Adaptability
3. Heirarchy
4. Redundancy
5. Competition