Introduction to the Body: Physiology, Homeostasis, and Feedback Control

Vocabulary flashcards covering key terms from the lecture notes (Pages 1-22).

Physiology

The study of how cells, tissues, and organs function; emphasizes function and cause-and-effect relationships, with overlap into chemistry and physics.

Anatomy

The study of the structure of the body; the counterpart to physiology focused on form.

Homeostasis

Dynamic consistency of the internal environment in a living being, maintained by physiological processes.

Negative feedback

A regulatory mechanism that counteracts a change to return the system to its original state (e.g., thermostat maintains temperature).

Positive feedback

A regulatory mechanism that reinforces the initial change; less common in humans (e.g., birth).

Receptor

A sensor that detects changes from the set point in a feedback loop.

Integrating center

The control center that processes input from receptors and coordinates a response (also called control center).

Effector

An organ or tissue that carries out the response to restore homeostasis.

Germ layers

Three primary tissue layers from which the four tissue types derive: ectoderm, endoderm, and mesoderm.

Ectoderm

Outer germ layer that contributes to tissues such as skin and nervous system.

Endoderm

Inner germ layer that forms internal linings and associated organs.

Mesoderm

Middle germ layer that gives rise to connective tissue, muscle, and other structures.

Connective tissue

One of the four primary tissue types; provides support, binding, and protection.

Muscle tissue

One of the four primary tissue types; enables movement through contraction.

Nervous tissue

One of the four primary tissue types; transmits nerve impulses.

Epithelial tissue

One of the four primary tissue types; forms coverings and linings of surfaces and cavities.

Zygote

Fertilized egg; the first stage after conception.

Morulla

Early solid ball of cells formed after zygote division.

Blastula

Early hollow ball of cells in embryonic development.

Embryo

Developing organism from early stage through the first weeks of life (up to about the 8th week).

Fetus

Developing organism after the embryonic stage, later prenatal development.

Life begins at conception

Physiological life begins at conception with fertilization (zygote formation).

Death criteria

Legal/medical determination of death: flat EKG (no heart function), flat EEG (no brain function), and no vital signs.

pH range (blood)

Normal arterial blood pH: 7.35–7.45.

Blood pressure

Normal blood pressure: about 120/80 mmHg.

Blood glucose

Normal blood glucose range: 70–140 mg/dL.

Body temperature

Normal body temperature: approximately 98.6°F (37°C).

Baroreceptors

Sensors in blood vessels that detect changes in blood pressure and help regulate it.

Chemoreceptors

Sensors that detect chemical changes (e.g., in blood) and contribute to regulatory responses.

Pancreas

Gland that regulates blood glucose through hormones (e.g., glucagon and insulin).

Glucagon

Hormone produced by the pancreas that raises blood glucose levels.

Endocrine system

Regulates homeostasis through hormones; can be involved in processes like birth.

Nervous system

Regulatory system that uses rapid electrical signals; includes sensory and motor components.

Pathology

Study of disease processes.

Pathophysiology

Study of how disease disrupts normal physiological function.

Delivery loop

A positive feedback mechanism during birth where uterine stretch increases contractions.