Lecture 1- what is physiology?

Question 1

what is physiology?

Answer 1

the study of a living organism and its component parts

Question 2

what 4 things defind when something is alive?

Answer 2

-made of 1 or more cells
-regulate its internal environment (especially when external environment changes)
-responds to stimuli/ needs a sensory system to detect stimuli
-capable of reproduction and self reproduction

Question 3

what are examples of component parts?

Answer 3

sensors
integrated circuits
capacitors

Question 4

what types of relationships defy component parts?

Answer 4

structure and function relationships
chemical and physical interactions

Question 5

living organisms have emergent properties, what does that entail?

Answer 5

an emergent property is complex and is thus just the sum of the systems individual parts.
an emergent property are properties of a system that are a result of non-linear interaction between components

Question 6

physiology covers many different topics, what are the 8 broad topics?

Answer 6

atoms
molecules
cells
tissues
organs
organ systems
organisms
populations of one species

Question 7

what are the 3 main reasons why physiology is important?

Answer 7

-helps understand how organisms (polar bears) cope with environmental stressors (climate change)

-helps answer the question, “what is life?” therefore, is the fundamental understanding of how life works

-leads to treatment of diseases in humans and other organisms

Question 8

how does physiology aide in the treatment of diseases?

Answer 8

by sequencing human genomes

Question 9

how does knowing your human genome sequence help the treatment of disease? how do they do it?

Answer 9

genomes tell us the molecular basis of evolution therefore, we know why animals are closely or further related for example.
knowing your genome helps us design drugs specifically for you.

Question 10

what are the 5 themes in physiology?

Answer 10

-structure and function are closely related
-information flow coordinates your body function (through short or long distances)
-need for energy
-evolution
-homeostasis and control systems

Question 11

what is homeostasis?

Answer 11

the ability to maintain a RELATIVELY constant internal environment even when the external environment is unpredictable/ variable.
THUS, homeostasis does NOT mean “equilibrium” or “never changing”

Question 12

how did Claud Bernard define homeostasis?

Answer 12

the constantness of the internal environment

Question 13

what are control systems?

Answer 13

internal parameters that must be regulated within a certain range to support life

Question 14

what are the 5 control systems?

Answer 14

1. temperature
2. pH
3. salinity (conc. of ions and solutes)
4. oxygen, carbon dioxide
5. nutrients

Question 15

do control systems operate over short or long distances?

Answer 15

both!

Question 16

what does short and long distances entail?

Answer 16

local communication= cells and tissue level
long distance= endocrine or nervous control “reflex control”

Question 17

what does negative feedback loop mean?

Answer 17

stabilizes the variable. occurs when you have something counteracting homeostasis so you use control systems.
homeostatic process.

Question 18

how does negative feedback loop work? (give example)

Answer 18

you eat a sugary cookie
the integrating center decides you need more insulin
glucose leaves your body through pee
glucose stabilizes

Question 19

what does a positive feedback loop do?

Answer 19

reinforces a stimulus (initial stimulus)

Question 20

what is an example of a positive feedback loop?

Answer 20

giving birth. when you give birth your oxytocin levels increase and they give you contractions. with positive feedback, it does not try to counteract that, instead, positive feedback increases oxytocin levels… until the baby pops out, then it stops increasing the levels.

Question 21

3 differences between negative and positive feedback

Answer 21

negative feedback:
1. keeps system NEAR a setpoint
2. response acts to UNDO the stimulus
3. response can RESTORE HOMEOSTASIS but cant prevent the initial stimulus
positive feedback:
1. keeps system FURTHER from a setpoint
2. response acts to REINFORCE (boost) the stimulus
3. requires an outside factor to shut off, therefore, is NOT TECHNICALLY HOMEOSTATIC, but we still consider it to be

Question 22

what is forward control?

Answer 22

allows the body to ANTICIPATE change, generate a response before a variable changes, feedforward control is NOT a loop!

Question 23

how does feedforward control work?

Answer 23

a small stimulus sets off a chain of events aimed at preventing uneasiness, therefore, change is anticipated. requires a complex “reflex” so that it can anticipate change (ex. mouth watering in anticipation of salt and vinegar chips)

Question 24

where are two places a control system may be?

Answer 24

neural
endocrine

Question 25

what is the differences between neural and endocrine control systems?

Answer 25

neural:
1. aimed at a specific target
2. fast acting
3. short lived
4. frequency of electrical signals/ action potentials is proportional to signal intensity
endocrine:
1. target determined only by receptors
2. slow acting (takes longer)
3. lasts longer
4. amount of hormone released is proportional to signal intensity