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Relationship of Form and Function

(Sample Lesson)

Principle

There is a direct relationship between the form (shape) of a human body part (molecule, cell, tissue, organ, or organ system) and the way it functions. The relationship between the two features is often expressed as ….

  • Form follows function: a body part can perform its function only if it is a certain shape, or
  • Form determines function: the shape of a body part directly affects what it can do.

When this relationship principle is continuously applied to the study of anatomy and physiology, it helps make the material easier to understand.

Examples

(A) The unique form (shape) of the thumb carpometacarpal joint increases the flexibility of the thumb and makes it possible for the hand to grasp and manipulate objects (function).

To do so, the thumb moves forward (anteriorly) from the palm and sideways (medially) toward the tips of the other fingers. This motion is called opposition.

Form: the shape of the thumb carpometacarpal joint
Form: the thumb carpometacarpal joint shape allows thumb opposition.
Function: thumb opposition.
Function: objects are grasped and manipulated using thumb opposition.

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Terms of Use

(B) The hemoglobin molecule is a complex protein consisting of four, globular subunits. Each subunit is composed of a long and unique sequence of linked amino acid molecules. The sequence of amino acids controls the 3-D conformation or folding of each subunit and the way in which the subunits are bonded together. In turn, the form (shape) of the hemoglobin molecule determines its ability to bind oxygen (function).

Hemoglobin form: The sequence of amino acids controls the 3-D conformation of a hemoglobin molecule.
Form: The sequence of amino acids controls the 3-D conformation of a hemoglobin molecule.
Hemoglobin function: the 3D conformation (shape) of a hemoglobin molecule determines its ability to bind with oxygen.
Function: the 3D conformation (shape) of a hemoglobin molecule determines its ability to bind with oxygen.

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Terms of Use

Terms for Using Human Bio Media Materials

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Acknowledgments

OpenStax College, Anatomy and Physiology

Reference: Overview of Anatomy and Physiology


LibreTexts

Access for free at: bio.libretexts.org

Reference 1: “Structure & Function – Proteins I

Reference 2: “Hemoglobin: Oxygen transport in mammals