Chapter 1: Cell and Membrane Physiology

Overview The human body comprises several distinct organs, each of which has a unique role in supporting the life and well-being of the individual. Organs are, in turn, composed of tissues. Tissues are collections of cells specialized to perform specific tasks that are required of the organ. Although cells from any two organs may appear […]

Chapter 2: Membrane Excitability

I. Overview All cells selectively modify the ionic composition of their internal environment to support the biochemistry of life (see 1?II) as shown in Figure 2.1. Moving ions into or out of a cell creates a charge imbalance between the intracellular fluid (ICF) and the extracellular fluid (ECF) and thereby allows a voltage difference to […]

Chapter 3: Osmosis and Body Fluids

I. Overview One of the more memorable quotes from the popular television series Star Trek: The Next Generation came from a silicon-based alien life form that referred to the intrepid Captain Picard as an “ugly bag of mostly water.” The average human body comprises 50%–60% water by weight, depending on body composition, gender, and age […]

Chapter 4: Epithelial and Connective Tissue

I. Overview The human body comprises a diverse assemblage of cells that can be placed in one of four groups based on structural and functional similarities. These groups are known as tissues: epithelial tissue, nervous tissue, muscle tissue, and connective tissue. The four tissue types associate with and work in close cooperation with each other. […]

Unit I Study Questions

Study Questions Choose the ONE best answer. I.1. A fluid that is composed of 120 mmol/L K+, 12 mmol/L Na+, and 15 mmol/L Cl− but is virtually Ca2+ free (<1 μmol/L) would best approximate which body fluid compartment? A. Transcellular B. Plasma C. Interstitial D. Intracellular E. Extracellular Best answer = D. Intracellular fluid should […]

Chapter 5: Nervous System Organization

I. Overview To a casual observer, a microscopic pond organism such as Paramecium behaves with apparent intent and coordination that suggests the involvement of a sophisticated nervous system. If it bumps into an object, it stops, swims backward, and then moves off in a new direction (Figure 5.1). This simple behavior minimally requires a sensory […]

Chapter 6: Central Nervous System

I. Overview The central nervous system (CNS) comprises the spinal cord and brain (Figure 6.1). The spinal cord is a thick communications tract that relays sensory and motor signals between the peripheral nervous system (PNS) and the brain. The cord also contains intrinsic circuits that support certain muscle reflexes. The brain is a highly sophisticated […]

Chapter 7: Autonomic Nervous System

I. Overview Cells erect a barrier around themselves (the plasma membrane) to create and maintain an internal environment that is optimized to suit their metabolic needs. The body similarly is covered with the skin to establish an internal environment whose temperature, pH, and electrolyte levels are optimized for tissue function. Maintaining a stable internal environment […]

Chapter 8: Vision

I. Overview The ability to detect light is common to most organisms, including bacteria, reflecting the importance of the visual sense. Designs for visual organs have arisen multiple times and many remain extant. In humans, photoreception is the purview of the eyes. Each eye comprises a sheet of photoreceptive cells (the retina) housed within an […]

Chapter 9: Hearing and Balance

I. Overview Modern day aquatic vertebrates possess lateral-line sensory systems that detect vibrations and movements in their watery surrounds. Lateral lines comprise lines of pits running down both sides of the body. Movements are transduced by clusters of sensory hair cells embedded in a gelatinous dome that protrudes from each lateral-line pit. When the dome […]