BIO 220 (exam 1)

• Anatomy


  The study of an organism's physical structure
• Physiology


  The study of how physical structures in an organism function
• There is a great amount of diversity in anatomical and physiological traits observed in animals
• Reasons for diversity in anatomy and physiology

  • Structure & Function
  • Adaptation & Acclimatization
• Adaptation


  Genetic changes that occur over long periods in a population that permit survival and reproduction in certain environments
• Adaptations


  • Increase fitness of a population
  • Depend on the alleles present in a population and the nature of existing traits
  • Involve "trade-offs": inescapable compromises between traits that cannot be optimized simultaneously
• Acclimatization


  Phenotypic changes in an individual in response to short-term changes in the environment
• Levels of correlation between structure and function

  • Molecular
  • Cellular
  • Tissue
  • Organ
  • Organ Systems
  • Organism
• Tissue


  A group of cells that function as a unit; distinct cell types that are specialized for different functions
• Adult tissue types


  • Connective tissue
  • Nervous tissue
  • Muscle tissue
  • Epithelial tissue
• Connective Tissue


  • Fluid (transport)
  • Dense (fibrous)
  • Supporting (structural; Protective)
• Connective Tissue Functions


  Energy storage; Organ protection; Structural framework for the body; Connection/compartmentalization of body tissues; Supply of hormones all over the body; Nutritional support; Site of defense reactions
• Connective Tissue Cells


  Arranged in matrices (singular: matrix) secreted by the connective tissue cells themselves
• Connective Tissue Types


  Loose (packing)
• Nervous Tissue


  Neurons and several types of supporting cells or glia
• Neuron


  Conducting cell
• Neuroglial Cell


  Support cell
• Muscle Tissue Types


  • Skeletal muscle: Voluntary/involuntary; multinucleate; striated
  • Cardiac muscle: Involuntary; uninucleate (usually); striated
  • Smooth muscle: Involuntary; uninucleate; unstriated
• Epithelial Tissue


  • Forms the interface between interior and exterior (barrier: provides protection)
  • Serves "gatekeeper" functions: regulates transfer of heat, water, nutrients, etc.
  • Typically form layers of tightly packed cells joined by tight junctions or desmosomes
• Epithelial Tissue Surfaces


  • Apical surface – faces away from other tissues, toward the environment
  • Basal (basolateral) surface – Faces interior
  • Basal lamina – connects to other tissues
• Surface Area


  The rate at which oxygen and nutrients diffuse into the cell and wastes products diffuse out depends in part on the surface area available for diffusion
• Volume


  The rate at which nutrients are used or wastes produced depends in part on the volume of the cell
• As cube side length increases, surface area and volume increase in an exponential fashion while the SVR decreases in an exponential fashion
• Metabolic rate is the overall rate of energy consumption by an individual
• Basal Metabolic Rate (BMR)


  The rate at which an animal consumes oxygen while at rest (with an empty stomach, under normal temperature and moisture conditions)
• On a per-gram basis, small animals have higher BMRs than do large animals
• As an organism's size increases, its mass-specific metabolic rate must decrease, or the surface area available for exchange of materials would fail to keep up with the metabolic demands of the organism
• Homeostasis


  Stability in the chemical and physical conditions within an animal's cells, tissues, and organs; thus, even though surrounding environmental conditions may change, internal and physical states are kept within a tolerable range
• Conformational Homeostasis


  Achieved by body's passively matching the conditions of a stable external environment
• Regulatory Homeostasis


  Achieved by active physiological processes triggered by variations in the external or internal environments
• Examples of conditions/processes that need to be regulated

  • Blood pressure
  • Blood glucose
  • Blood oxygen concentration
  • Blood pH
  • Temperature
  • Water content (osmoregulation)
• Homeostatic System


  • A sensor
  • An integrator
  • An effector
• Thermoregulation


  Heat exchange is critical in animal physiology because individuals that get too hot or too cold may die
• Ways animals exchange heat with their environment

  • Behavioral
  • Physiological
• Feedback systems work in "antagonistic pairs": One set of responses increases a parameter while another set decreases it
• Thermoregulation is an important aspect of homeostasis in humans and other mammals
• Causes of High Body Temperature

  • Infections
  • Overdose of certain medicines
  • Excessive consumption of certain stimulant drugs ex. cocaine, amphetamines, etc.
  • Overactive thyroid which increases the rate of metabolism
  • Strenuous physical activity or intensive exercise (especially among obese people)
  • Certain conditions like seizures, agitation or alcohol/drug withdrawal, etc.
• Causes of Low Body Temperature

  • Alcohol abuse (body's ability to control heat loss gets seriously affected)
  • Being under the effects of anesthesia
  • Drug abuse
  • Excessive consumption of certain medications
  • Low iodine, Hypothyroidism (low thyroid hormone levels)
  • Shock
  • Sepsis (excess bacteria in bloodstream due to widespread infection)
  • Certain other chronic conditions like anemia, hepatitis C, etc.
  • Addison's Disease (scarcity of adrenal gland hormones)
• Countercurrent Heat Exchangers


  Small differences in heat along the exchanger form a large overall temperature gradient from beginning to end. The longer the system, the greater the overall differential will be. The systems are thus often referred to as countercurrent multipliers.
• Surface Area


  The area of the surface of an object