BIOL 66 Chapter 1 The Study of Body Function

What is physiology?

The study of biological function—how the body works.

What does physiology study?

Biological function at multiple levels: molecular/cellular, tissues, organs, organ systems, and the organism.

What are mechanisms in physiology?

The processes that explain how and why something happens in the body.

What is cause and effect in physiology?

Understanding what causes a physiological change and what results from it.

How is information obtained in physiology?

Through the scientific method, including hypothesis-driven experimentation and testing.

What is the basic/fundamental unit of life?

The cell.

What is a tissue?

A group of similar or same cell types working together.

What is an organ?

A structure made of multiple tissues that perform a common function.

What is an organ system?

A group of multiple organs working together to perform functions.

What is an organism?

A complete living individual made up of multiple organ systems.

What is the hierarchy of living systems?

Cells → tissues → organs → organ systems → organism.

What does the cardiovascular/circulatory system include?

The heart and blood vessels.

What does the respiratory system include?

The lungs and air passageways.

What does the digestive/gastrointestinal system include?

The digestive tract and glands.

What does the urinary/renal system include?

The kidneys and bladder.

What does the musculoskeletal system include?

Muscles, tendons, and bones.

What does the immune system include?

White blood cells and spleen.

What does the nervous system include?

The brain, spinal cord, and sensory organs.

What does the endocrine system include?

Glands such as the pituitary gland and thyroid gland.

What does the reproductive system include?

Ovaries, uterus, testes, and other reproductive structures.

What does the integumentary system include?

The skin.

What is homeostasis?

A state of relative constancy of the internal environment.

What maintains homeostasis?

Negative feedback loops.

Is homeostasis completely unchanging?

No. Variables can change over short periods but remain relatively constant over longer periods.

What is dynamic constancy?

Physiological variables change over short periods but remain relatively constant over long periods.

What are examples of variables maintained by homeostasis?

Body temperature, sodium, glucose, pH, and oxygen.

What is negative feedback?

A response that moves a physiological variable in the direction opposite to the original change.

What happens when a physiological variable changes?

The change is detected by a sensor.

What does a sensor do?

It detects a change in a physiological variable and sends information to the integrating center.

What is the integrating center?

The part of the system that receives information and determines an appropriate response.

What does the integrating center control?

It causes an effector to produce a response.

What is an effector?

A structure that produces a response to help restore the variable toward its set point.

What is a set point?

The target or reference level around which a physiological variable is regulated.

What is the sequence of a negative feedback loop?

Change → sensor → integrating center → effector → response → variable moves toward set point.

What happens when body temperature decreases?

Shivering occurs to generate heat and raise body temperature.

What happens when body temperature increases?

Sweating occurs to help lower body temperature.

Why is negative feedback important?

It helps keep physiological variables within a relatively stable range.

What are the four primary tissues?

Muscle, nervous, epithelial, and connective tissue.

What is the main function of muscle tissue?

Contraction.

What is the main function of nervous tissue?

Generation and conduction of electrical events and related support functions.

What is epithelial tissue?

Tissue that forms membranes covering and lining body surfaces and forms glands.

What is connective tissue characterized by?

A large amount of extracellular material.

What are examples of connective tissue?

Connective tissue proper, blood, bone, and cartilage.

Which primary tissue is specialized for contraction?

Muscle tissue.

Which primary tissue conducts electrical signals?

Nervous tissue.

Which primary tissue covers and lines surfaces?

Epithelial tissue.

Which primary tissue has abundant extracellular material?

Connective tissue.