Introduction To Human Physiology and Homeostasis in Health and Disease

Question 1

What is human physiology?

Answer 1

The study of the normal function of the human body and the integrative mechanisms that control them at the level of:
The cells
The tissues
The organs
The body systems
The whole body

Question 2

What is our body fundamentally made up of?

Answer 2

Cells

Question 3

What do cells form when joined together?

Answer 3

They make up tissues (a group of cells with a similar structure and specialised function): e.g. muscle tissue, nervous tissue, epithelial tissue or connective tissue.

Question 4

What are our body organs composed of?

Answer 4

They are made up of two or more types of primary tissues that function together to perform a particular function(s).

Question 5

What is the definition of a body system, e.g. the cardiovascular system, gastrointestinal system?

Answer 5

Body systems are made up of groups of organs that perform related functions and work together to achieve a common goal(s).

Question 6

How do we maintain a healthy body through our body systems?

Answer 6

Normally, our body systems work in harmony as a highly sophisticated integrated unit to maintain a healthy boy.

Question 7

What does normal body function require?

Answer 7

It requires the coordination of function from molecular and cellular to whole body function.

Question 8

What must our bodies maintain to remain healthy?

Answer 8

To remain healthy, our bodies must maintain highly regulated optimum physiological conditions within them.

Question 9

What are seven examples of components of our bodie’s environment that must be maintained within narrow ranges?

Answer 9

Concentration of water and electrolytes within and outside the cells.
Pressures and volumes.
pH
Body temperature
Concentration of nutrients e.. glucose
Concentration of O2 and CO2.
Concentration of waste products e.g. urea.

Question 10

What is homeostasis essential for?

Answer 10

Normal cell and body function and survival of cells.

The body cells and systems contribute to the maintenance of homeostasis.

Question 11

What is the definition of homeostasis?

Answer 11

The maintenance of steady states within our bodies by coordinated physiological mechanisms.

Question 12

What can be the result of a disruption in homeostasis?

Answer 12

It may result in disease or death.

Many diseases are caused by deficient, inappropriate, or excessive homeostatic mechanisms.

Question 13

Why is the application of physiological knowledge essential for the understanding of patient conditions?

Answer 13

It often provides a rational for patient investigations, treatment, and health promotion.

Question 14

at what level does much of the physiological control occur?

Answer 14

The level of the cell membrane

Question 15

What is the chane in cell membrane potential (voltage across the membrane between inside and outside a cell) is central to what?

Answer 15

The functionality of nerve and muscle cells.

Question 16

Many pharmacological agents act at what level to produce their therapeutic effect?

Answer 16

The level of the cell membrane.

Question 17

Why are physiological control systems important?

Answer 17

They are important for the maintenance of homeostasis within our bodies.

Question 18

In order to maintain homeostasis, a control sytem must be able to do what 3 things?

Answer 18

Sense deviations from normal in the internal environment that need to be held within narrow limits.
Integrate this information with other relevant information.
Make appropriate adjustments in order to restore a controlled variable to it’s desired value.

Question 19

Homeostatic control systems are grouped into what two classes?

Answer 19

Intrinsic controls

Extrinsic controls

Question 20

What is the role of intrinsic controls?

Answer 20

These are local controls that are inherent in an organ.

Question 21

What is the role of extrinsic controls?

Answer 21

They are regulatory mechanisms initiated outside an organ.

They are accomplished by nervous and endocrine systems.

Question 22

What are two homeostatic control systems?

Answer 22

Feedforward and Feedback

Question 23

What is feedforward and what is it’s role?

Answer 23

Fedforward is the term used for responses mde in anticipation of a change.
Feedforward usually act in combination with negative feedback (negative feedback is the main type of homeostatic control in the body) - e.g. in physical exercise.

Question 24

What is feedback and what are the types of feedback systems?

Answer 24

Feedback refers to responses made after change has been detected.
The types of feedback systems are
Positive feedback systems and Negative feedback systems (the main type of homeostatic control).
Feedback systems ten to kick in when something has already changed.

Question 25

Do positive feedback and negative feedback occur as often as each other?

Answer 25

No positive feedback doesn’t occur as often as negative feedback.

Question 26

What does positive feedback do to the initial change?

Answer 26

Positive feedback amplifies the initial change.

Question 27

What is the primary type of homeostatic control system?

Answer 27

Negative feedback systems.

Question 28

What type of homeostatic control system opposes initial change?

Answer 28

Negative feedback system.

Question 29

What is an example of a negative feedback system?

Answer 29

Control of blood pressure, Regulation of body temperature.

Question 30

What is an example of positive feedback control?

Answer 30

Uterine contractions during labour become increasingly stronger until the birth of baby.

Question 31

What are the components of negative feedback systems?

Answer 31

Sensor
Control Centre
Effector(s)

Question 32

What is the role of the sensor in negative feedback systems?

Answer 32

It monitors the magnitude of a controlled variable.

Question 33

What is the role of the control centre in negative feedback systems?

Answer 33

It compares the sensor’s input with a set point.

Question 34

What is the role of the effector in negative feedback systems?

Answer 34

The effector makes a response to produce the desired effect.

Question 35

What is the role of Negative feedback?

Answer 35

Negative feedback promotes stability by regulation of a controlled variable through a flow of information along a closed loop.