In this animated object, learners read a brief description of the roles of the hypothalamus, emotions, and adrenal secretions during the stress response.

In this video you'll study the structure of the cell membrane and construct it using the correct molecules.

In this animated object, learners examine the eight cranial bones, the fourteen facial bones, and the ribs.

In this animated object, learners examine the major events that occur at the neuromuscular junction.

In this animated and interactive object, learners examine how blood flows through the heart and lungs. A brief quiz completes the activity.

In this animated activity, learners examine muscle cell contraction and relaxation and consider the role of calcium ions.

Learners examine the function of each part of a microscope and follow step-by-step instructions on how to focus on a specimen. They also review the proper use and care of a microscope and test their knowledge in two drag-and-drop exercises.

In this animated and interactive object, learners examine ABO blood antigens and Rh antigens and their compatibility.

In this interactive object, learners examine the structure and function of the sense of taste.

In this animated and interactive object, learners examine the structure and functions of granulocytes and agranulocytes. Two exercises complete the activity.

In this animated object, learners examine neutral fats, phospholipids, and cholesterol. The molecular formula and general function for each are shown.

In this learning activity you'll review the structure and function of the different tissues of the human body.

In this animated object, learners examine synthesis, decomposition, exchange, and reversible reactions.

In this animated object, learners examine processes that do not use ATP directly including hydrostatic pressure and facilitated diffusion with carrier proteins.

In this animated object, learners compare the mode of action of steroids with the action of amino acid-based hormones.

Explore what proteins are, their structure, and their functions.

In this animated object, learners examine the mechanisms for gas exchange among the lungs, blood, and tissues.

In this animated object, learners trace the olfactory pathway from the nasal cavity to the olfactory cortex.

In this learning activity you'll review information on the neural synapse.

In this animated object, learners examine the different types of joints and their movements.

In this animated object, learners examine the various connective tissue layers of the muscle organ. The terms "prime mover," "synergist," "antagonist," "origin," and "insertion" are defined.

In this video, learners view the parts of an animal cell and its organelles.

This animated object illustrates the events leading to the migration of phagocytes into areas of tissue damage and/or bacterial presence. Learners view bacterial cell phagocytosis, its subsequent enzymatic digestion, and exocytosis.

Learners read about the mutations that occurred in plants for the successful transition from an aquatic to a terrestrial existence. The classification of plants is based on these adaptive structures.

In this animated object, learners examine the major descending tracts of the nervous system. A matching exercise completes the activity.