36 S15 W1 1 Homeostasis Student 4perpage Essay - 818 Words

2/24/15

How to study for this course…

Chapter 1

Introduction &
Homeostasis

• Overall
– Make your own flow charts, tables, diagrams, sketches, etc to organize the material
– Watch videos & animations
– Learn prefixes & terms by making flashcards, charts or lists
– Make connections among the systems
• Lecture
– Review lecture slides & notes…within 24 hours after presentation
– Preview the material in the chapter that corresponds to the lecture
– Look at the diagrams
– Skim introductory sections and paragraphs
– Learn the bolded terms

© 2013 Pearson Education, Inc.

• Lab
– Pre-read & study background information of each lab before class
– Review post-lab questions and think about reasoning behind each procedure…within 24 hours after that lab

Table 1.2 Biology Concepts

Overview

Common Themes in Physiology
(all below excluding evolution)

• Why do we say physiology is an integrative science?

• Common themes:
– Structure => Function
– Homeostasis
– Regulation: Change => Feedback

© 2013 Pearson Education, Inc.

1

2/24/15

Figure 1.1 Levels of organization and the related fields of study

Levels of Organization
• Physiology defined
– Study of the normal functioning of a living organism and its component parts
– Our scope: Human & Normal/Ideal function
– But we will often use pathophysiology to understand and explain normal physiology
– Greek root “pathos” = suffering/disease

PHYSIOLOGY

ECOLOGY

CELL
MOLECULAR BIOLOGY
CHEMISTRY BIOLOGY
Atoms

Molecules

Cells

Tissues

Organs

Organ systems Populations of one species

Organisms

Ecosystem of different species

Biosphere

• How we define life…The cell theory!
– The cell is the basic unit of life.
– All cells originate form pre-existing cells.
– All living organisms are composed of cells.
© 2013 Pearson Education, Inc.

Table 1.1 Organ Systems of the Human Body and their Integration

Figure 1.3 Homeostasis

Homeostasis
• Regulation of the body s internal environment • Keeping internal environment stable & near a set-point or optimal level

Organism in homeostasis Internal change External change Internal change results in loss of homeostasis

Organism attempts to compensate

Compensation fails

Compensation succeeds

Illness or disease

Wellness

2

2/24/15

Figure 1.4 The body s internal and external environments

Example:
Body Fluid Compartments

Cells contain intracellular fluid (ICF)

The cell membrane separates cells from the ECF

¼ plasma
Cells

ECF

External environment Extracellular fluid (ECF)

Intracellular fluid (ICF)

Cells are surrounded by the extracellular fluid (ECF)

ECF

1/3 TBF

ICF

2/3 TBF

¾ interstitial fluid FIGURE QUESTION
Put a * on the cell membrane of the box diagram.

TBF = total body fluid
ECF =
ICF =

Figure 1.5 Mass balance in an open system

Homeostasis
Both below represent when homeostasis is achieved.
Input

To maintain constant level, output must equal input.

Input

Output

Intake through intestine, lungs, skin

Excretion by kidneys, liver, lungs, skin

BODY
LOAD

Metabolic production Metabolism to a new substance Output

Mass balance in an open system

Mass balance =

Existing + body load

Mass balance in the body

• constant input of energy is required to maintain stability (due to the use)
• Increases order & decreases entropy of that system

Equilibrium

• input is NOT continuously required (no net difference in energy input/output)
• entropy differences dissipate by balancing out

VS

Law of Mass Balance
Intake or metabolic production

Steady State
-

Excretion or metabolic removal

3

2/24/15

Figure 1.9 Steps in the response loop of a reflex control pathway

Reflex steps

Show More