BIO 3200Human Physiology

Dr. David Njus(313) 577-2783

0162 Biological Sciences (lab)dnjus@wayne.edu

August 30, 2012

What Is Physiology?

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Study of organ systems

How these systems work together to make or bodies function

How diseases or drugs alter these systems

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Physiology connects molecular mechanisms to behavior of the

organism

Does evolution select for good genes?

• Natural selection selects for good physiology

• Genes coding for good physiology are preserved as a consequence

• Physiology connects genetics and evolution

Text• Human Physiology:

An Integrated Approach, 6th Ed., by D.U. Silverthorn

Prerequisites • Introductory Microbiology (BIO 2200)• Introduction to Cell Biology (BIO 2600)

About the Course

Blackboard

Material now available on Blackboard:• Syllabus

Material to be added:• Announcements• Handouts• Powerpoints of lectures

Stay Engaged

• Come to class – Powerpoint lectures are not enough

• Read the textbook• Ask questions when you need

clarification• Answer clicker questions – Don’t just

wait for the answer

Clickers• You will need an iClicker• We will begin using the

clickers right away• You will get two points per

lecture for answering clicker questions beginning Sept. 13

• Clicker questions are intended to help you see whether or not you understand the physiological concept

GradingExam I 240 Tuesay, September 25Exam II 240 Thursday, October 18Exam III 240 Tuesday, November 13Final Exam 240 Thursday, December 13Clicker points 40 Total 1000 points

Grading

• All hour exam scores will count

• There will be no make up exams

• Grades will be based on a straight scale as listed on the syllabus

Lectures and Reading

• Tuesday’s lecture (9/4) will cover Chapter 6: Communication, Integration and Homeostasis

• We will skip Chapters 1 – 5. These cover material you should have learned in earlier classes.

• You may want to review Chapters 1 - 5 to be sure that you remember this material, and read Chapter 6.

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Themes in Physiology:1. Structure and Function are Closely Related2. Living Organisms Need Energy3. Information Flow Coordinates Body Functions4. Homeostasis Maintains Internal Stability

Ch. 1: Introduction to Physiology

Homeostasis: The ability of the body to maintain a relatively constant internal environment

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Ch. 1: Introduction to Physiology

Ch. 2: Molecular Interactions

• Molecules and bonds– Hydrocarbons are non polar– Carbohydrates are polar– Ions are charged

• Noncovalent interactions– Water and pH– Hydrophilic interactions– Hydrophobic interactions

• Protein interactions

C) Glucose

C) Hexane

Which of these is not soluble in water?

A) Na+

B) Glutamate

Ch. 3: Compartmentation: Cells and Tissues

• Functional Compartments of the Body• Biological Membranes• Intracellular Compartments• Tissues of the Body• Tissue Remodeling• Organs

Ch. 4: Energy and Cellular Metabolism

• Energy in Biological Systems• Chemical Reactions• Enzymes• Metabolism

Ch. 5: Membrane Dynamics

• Osmosis and Tonicity• Transport Processes• Diffusion• Protein-Mediated Transport• Vesicular Transport• Epithelial Transport• The Resting Membrane Potential• Integrated Membrane Processes: Insulin

Membrane PotentialIn animal cells, the cytoplasm has an electrical potential more negative than the outside of the cell

There is more negative charge inside of the cell and more positive charge outside

Why is the membrane potential negative in animal cells?

A) The Na+/K+ ATPase pumps more Na+ out of the cell than it pumps K+ in

B) Membranes have more negative charge on their inside surface than on their outside

C) Animal cell membranes are more permeable to K+ than to Na+

D) Animal cells contain a lot of negative charges

Diffusion

• K+ is more concentrated inside the cell than outside

• K+ diffusion carries positive charge out of the cell

150 mM

15 mM

Which way will Na+ diffuse?

What would the membrane potential be if the membrane were more permeable to Na+ than to K+?

Into the cell

Positive (About +60 mV)

EnzymesEnzymes bind substrates selectively

The Na+/K+ ATPase hydrolyzes ATP and transports 3 Na+ out and 2 K+ in

It creates a higher K+ concentration and a lower Na+ concentration inside the cell

Active Transport

Enzymes catalyze chemical reactions

Reactions go in the direction of decreasing free energy

When is active transport required?

A) To transport material from a region of lower concentration to a region of higher concentration

B) To increase the rate at which material is transported across a biological membrane

C) To move material through the viscous interior of the membrane

D) To transport ions and charged molecules across the membrane

Active Transport

Which involves a greater change in free energy?

ATP hydrolysis or

transport of Na+ and K+

ATP hydrolysis

Next Time

• Communication, Integration and Homeostasis (Chapter 6)