Mammalian Physiology Chapter 1

What is physiology?

Physiology is the study of the normal functioning of a living organism and its component parts, including all its chemical and physical processes. The term physiology literally means “knowledge of nature”

Who described physiology as the functioning of all living organisms, not just of the human body?

Aristotle (384-322 bce)

Who described physiology to mean "the healing power of nature"

Hippocrates (ca. 460–377 bce)

What is the current term of physiology?

Refer to the study of animals and plants.

What are emergent properties?

Are properties that cannot be predicted to exist based only on knowledge of the system’s individual components.

What are emergent properties a result of?

Results from complex, nonlinear interactions of the different components.

What are proteomics?

The study of proteins in living organisms.

What is integration of function?

A special focus of physiology. (To integrate means to bring varied elements together to create a unified whole.)

What does "ome" stand for?

A collection of items that make up a whole, such as a genome.

What is a genome?

Is a collection of all the genetic material of an organism

What is a physiome?

Describes the organism’s coordinated molecular, cellular, and physiological functioning.

What are cells?

The smallest unit of structure capable of carrying out all life processes

What is a cell membrane?

Lipid and protein barrier (also called the plasma membrane) separates cells from their external environment

What are tissues?

Collections of cells that carry out related functions.

What are organs, and what do they form?

Tissues form structural and functional units known as organs {organon, tool}, and groups of organs integrate their functions to create organ systems

What is the integumentary system?

The integumentary system {integumentum, covering}, composed of the skin, forms a protective boundary that separates the body’s internal environment from the external environment

What is the musculoskeletal system?

Provides support and body movement.

What does the respiratory system do?

The respiratory (pulmonary) system exchanges gases.

What does the digestive system do?

The digestive (gastrointestinal) system takes up nutrients and water and eliminates wastes.

What does the urinary system do?

The urinary (renal) system removes excess water and waste material.

What does the reproductive system do?

Produces eggs or sperm.

What does the circulatory system do?

Distributes materials by pumping blood through vessels.

What does the nervous and endocrine system do?

The nervous and endocrine systems coordinate body functions.

What does the immune system do?

Includes but is not limited to the anatomical structures known as the lymphatic system. The specialized cells of the immune system are scattered throughout the body. They protect the internal environment from foreign substances by intercepting material that enters through the intestines and lungs or through a break in the skin

What is the function of a physiological system?

The “why” of the system or event.

What is teleological approach to science?

Thinking about a physiological event in terms of its adaptive significance.

What are mechanisms?

The “how” of a system

What is the mechanistic approach?

Examines process.

What is translational research?

translational research, an approach sometimes described as “bench to bedside.” Translational research uses the insights and results gained from basic biomedical research on mechanisms to develop treatments and strategies for preventing human diseases.

What are the four themes related to physiology?

Structure-function relationships, biological energy use, information flow within an organism, and homeostasis and the control systems that maintain it.

What are molecular interactions?

The ability of individual molecules to bind to or react with other molecules is essential for biological function

Compliance

Ability to stretch.

Elastance

Stiffness or the ability to return to the unstretched state.

Fluidity

Viscosity.

What is compartmentation?

The division of space into separate compartments. Compartments allow a cell, a tissue, or an organ to specialize and isolate functions.

Theme 1: Structure and Function Are Closely Related

Molecular interactions, and compartmentation.

Theme 2: Living Organisms Need Energy

Growth, reproduction, movement, homeostasis—these and all other processes that take place in an organism require the continuous input of energy.

Theme 3: Information Flow Coordinates Body Function

Information flow in living systems ranges from the transfer of information stored in DNA from generation to generation (genetics) to the flow of information within the body of a single organism.

Theme 4: Homeostasis Maintains Internal Stability

And what is homeostasis?

Organisms that survive in challenging habitats cope with external variability by keeping their internal environment relatively stable, an ability known as homeostasis

French physician Claude Bernard did what?

Created the concept of relatively stable internal environment.

What does homeostasis do?

Body monitors its internal state and takes action to correct disruptions that threaten its normal function.

Canon divided his variables into?

Environmental factors that affect cells (osmolarity, temperature, and pH) and “materials for cell needs” (nutrients, water, sodium, calcium, other inorganic ions, oxygen, as well as “internal secretions having general and continuous effects”). Cannon’s “internal secretions” are the hormones and other chemicals that our cells use to communicate with one another.

What happens if the body fails to maintain homeostasis?

The normal function is disrupted and a disease state, or pathological condition {pathos, suffering}, may result.

What is pathophysiology?

The study of body functions in a disease state?

What is diabetes mellitus?

A metabolic disorder characterized by abnormally high blood glucose concentrations.

What is extracellular fluid?

Watery internal environment that surrounds the cells, a “sea within” the body.

What is the fluid inside cells called?

Intracellular fluid (ICF)

What does the law of mass balance say?

That if the amount of a substance in the body is to remain constant, any gain must be offset by an equal loss

What is a load?

The amount of a substance in the body.

What is excretion?

The elimination of material from the body, usually through the urine, feces, lungs, or skin

What is mass flow?

The rate of transport of a substance x as it moves through body fluids or into and out of the body.

What is plasma?

plasma, the fluid component, plus the heavier blood cells.

What is dynamic steady state?

In a state of homeostasis, the composition of both body compartments is relatively stable. This condition is a dynamic steady state.

How does the body maintain homeostasis?

These important regulated variables are kept within their acceptable (normal) range by physiological control mechanisms that kick in if the variable ever strays too far from its setpoint, or optimum value.

What is an example of local control?

Can be observed when oxygen concentration in a tissue decreases.

What is a response loop?

a response loop has three primary components: an input signal, an integrating center to integrate the signal, and an output signal.

What does the sensor do?

Monitors the variable.

What is a feedback loop?

feedback loop, where the response “feeds back” to influence the input portion of the pathway.

What is negative feedback?

A pathway in which the response opposes or removes the signal is known as negative feedback

What is feedforward control?

A few reflexes have evolved that enable the body to predict that a change is about to occur and start the response loop in anticipation of the change. These anticipatory responses are called feedforward control.

What is a circadian rhythm?

For example, all animals exhibit some form of daily biological rhythm, called a circadian rhythm