Chapter 10: Taste and Smell

I. Overview The gustatory and olfactory systems are probably the oldest of the senses in evolutionary terms. Both systems allow us to detect chemicals in the external environment and, thus, are usually grouped together. In practice, however, they represent two very different sensory modalities that complement but cannot replace each other. Taste cells are modified […]

Chapter 11: Motor Control Systems

I. Overview The neural pathways that control muscle activity in humans were developed during early evolutionary history to facilitate directed locomotion. Coordination of muscle groups that move the limbs was accomplished initially using simple neural feedback loops, but, as body complexity and the difficulty of the tasks that it was required to perform increased, so […]

Unit II Study Questions

Study Questions Choose the ONE best answer. II.1. Autoimmune diseases such as multiple sclerosis cause neurological impairment by affecting axon conduction velocity. Which of the following would slow axonal signal propagation to the greatest extent? A. Increasing axon diameter B. Increasing axon length C. Increasing myelin thickness D. Decreasing leak-channel density E. Decreasing depolarization rate […]

Chapter 12: Skeletal Muscle

I. Overview The various organs of the body are housed within compartments (the thorax and abdomen) that are framed and carried by a bony skeleton (bone structure and function is discussed in Chapter 15). Bones also define the limbs, which are used to manipulate objects and for locomotion. Bone movement is facilitated by skeletal muscles, […]

Chapter 13: Cardiac Muscle

I. Overview Cardiac muscle shares much in common with skeletal muscle. Skeletal and cardiac muscle sarcomeres are organized similarly, so the two muscle types give similar banding patterns when viewed under polarized light (Figure 13.1). The essential principles and molecular components of contraction are the same also. There are some key differences, however, because the […]

Chapter 14: Smooth Muscle

I. Overview Skeletal and cardiac muscle are both designed to contract rapidly. Rapid kinetics facilitate locomotion (skeletal muscle) and sustain a cardiac output (cardiac muscle) that supports flow to dependent organs, even at rest. However, the human body performs many other functions that require muscular involvement on a less urgent time scale. The tasks are […]

Chapter 15: Bone

I. Overview The brain and many other soft tissues of the body are enclosed within a protective framework made of bone. Bone also fashions limbs that, together with skeletal muscles, facilitate locomotion and allow objects to be manipulated. The 206 bones that make up the human skeleton work in conjunction with cartilage, ligaments, tendons, and […]

Chapter 16: Skin

I. Overview Individual cells erect a membrane around their periphery to create a barrier between the extracellular and intracellular environments, which allows them to regulate their cytoplasmic composition. The body similarly encloses its tissues within skin, a multilayered covering comprising epidermis, dermis, and a functionally linked hypodermis (Figure 16.1). Skin forms a physical barrier that […]

Unit III Study Questions

Study Questions Choose the ONE best answer. III.1. Which of the following cytoskeletal proteins functions like a spring, limiting the extent to which the sarcomere can be stretched? A. α-Actinin B. Dystrophin C. Nebulin D. Titin E. Z disk Best answer = D. Titin is a massive, thick filament–associated structural protein that limits sarcomere length […]

Chapter 17: Cardiac Excitation

I. Overview The cardiovascular system is responsible for making oxygen and nutrients available to every cell in the body. It also carries away metabolic waste products, including heat. The principal components of the cardiovascular system are blood, blood vessels, and the heart (Figure 17.1). Blood carries materials to and from the tissues, blood vessels are […]