Psio Exam Block 1

Lecture: 1.1 

Objectives / Summary:

Anatomy: Study of structure, structure without function is empty

• Heart, leg, eyes, etc

Physiology: Study of function, function without structure is without mechanism

• How the functions shape the structure.

What is a structure-function relationship?

1. The link between the structure of an anatomical feature and its function.

Scenario… Dehydration Sweat Example

1. Skin

2. Sweat glands

3. Sweat comes from the blood

4. The brain tells the body to sweat to cool itself down

5. The nervous systems signals the body to sweat

5 Characteristic of living systems

1. Metabolism: the sum of all chemical processes in the body

   1. Two categories of:

      1. Catabolism: the breakdown of larger molecules into smaller ones

         1. Creates energy for vital processes

      2. Anabolism: the construction of larger molecules from smaller ones

         1. Synthesizes materials necessary for life (proteins)

            1. Storages, example life fat or glucose for later

2. Responsiveness: the ability to detect and respond to changes in the internal or external environmental (Like the Sweat Scenario Example)

3. Movement

   1. At any structural level (body, organ, cell, or cell component),

   2. A change in the position of the limb , organ, cell, o

4. Growth and Differentiation

   1. Growth= increase in number of size of cells or the material found between cells

   2. Differentiation = specialization of cells for a specific function

      1. Growth on cell size and or cell number differentiation of cells to become more specialized

5. Reproduction

   1. Formation of new cells or new individuals

Levels of Biological Organization

1. Chemical level ( Does Not have the 5 characteristics of life, so it is not the smallest loi)

   1. Atomic and molecular level, not alive, an oxygen cant respond or detect changes, or reproduce and grow.

2. Cellular level

   1. Smallest living unit of the body

3. Tissue level

   1. Group of cells and the materials surrounding them that work together on one task

   2. Less tissue allows for more flexibility, lungs, the skin has many layers which keeps everything in and protected

4. Organ level

   1. Grouping of two or more tissue types into a recognizable structure with a specific function

5. Organ System Level

   1. Collection of related organs with a common function (sometimes an organ is part of more than one system)

6. Organisms Level

   1. The living individual

Date: Jan. 22. 2025

Lecture 1.2

• Science is not a collection of facts or concepts

• Science is a way to:

  • Determine what is “fact”

  • Develop concepts 

Use the Scientific method

FIve steps of the scientific method:

1. Observation

   1. Ex: In the face of big changes in the environmental temperature, body temperature seems to be constant.

   2. Can lead to a question but should be an answer to that question. Make it more specific and more testable.

2. Hypothesis and prediction

   1. A question formed on the basis of observation.

   2. The best hypotheses are specific and testable.

   3. ‘Core body temperature in an 18 year old sitting for one hour in a 20⁰C (68⁰F) room will remain constant at 37

3. Experimental testing

   1. Gather data test your hypothesis

4. Analysis and Conclusion

   1. Was body temperature truly constant with time?

      1. It was fairly close to constant…

5. Development of a New Hypothesis

   1. Rephrase and refine, then test again

   2. Body temperature is one of many controlled conditions in our body's internal environment…

   3. Examples of other controlled conditions in the body:

      1. Glucose levels

      2. Sodium levels

      3. pH levels everywhere in the body

Homeostasis 

• Claude Bernard’s ‘relative constancy of the internal environment’

• The physical and chemical parameters of living systems (e.g., temperature, pH, concentrations of im[portant molecules) tend to remain constant over time, and this keeps organisms alive.

The definition of homeostasis 

“Homeostasis is the condition in which the body's internal environment remains relatively constant within physiological limits.”

Physiological Limits and vIability

• Living systems exist within limits of heat, moisture, pressure, chemical composition, etc.

• Picture drawn in notebook, an example of body temperatures max. and min. Physiological limit.

Maintenance of homeostasis

Negative feedback loop

Negative and Positive Feedback Loops

Negative feedback Loop:

• Original stimulus reversed 

• Most feedback loops systems in the body are negative (reinforcing)

• Used for conditions that need frequent adjustment

• Result is the opposite of the stimulus

  •  Body temperature, blood sugar levels, blood pressure, etc.

Positive feedback Loop

•             

• Seen during normal childbirth

Equilibrium vs. Steady-State

ISn't homeostasis just a fancy way of saying equilibrium?

“Homeostasis is the condition in which the body's internal environment remains relatively constant within physiological limits.”

Homeostasis is not equilibrium