Introduction to Anatomy and Physiology

Introduction to Anatomy and Physiology

• Anatomy studies the structure of organisms and their parts.
• Physiology studies the function of organisms and their parts.
• Structure dictates function; the two fields are closely related.
• Understanding life processes requires studying both anatomy and physiology.

Levels of Organization

• Biological systems are organized hierarchically:
  • Chemical level: Atoms combine to form molecules.
  • Cellular level: Molecules combine to form cells.
  • Tissue level: Similar cells form tissues.
  • Organ level: Tissues combine to form organs.
  • Organ system level: Organs work together as organ systems.
  • Organism level: Organ systems make up an organism.

Homeostasis

• Homeostasis maintains a stable internal environment despite external changes.
• Factors regulated by homeostasis include temperature, pH balance, blood sugar.
• Homeostatic mechanisms use feedback loops:
  • Negative feedback: The response counteracts the initial stimulus.
  • Positive feedback: The response enhances the initial stimulus.

Tissues

• Four major tissue types in animals:
  • Epithelial tissue: Covers surfaces; lines cavities; forms glands; functions include protection, secretion, absorption, excretion.
  • Connective tissue: Connects, supports, separates tissues and organs; examples include bone, cartilage, blood, tendons.
  • Muscle tissue: Enables movement; types include skeletal, smooth, and cardiac muscle tissue.
  • Nervous tissue: Conducts electrical impulses for communication and control.

Organ Systems

• Major organ systems in animals:
  • Integumentary system: Skin; protects, regulates temperature, provides sensation.
  • Skeletal system: Bones; support, protection, movement.
  • Muscular system: Muscles; movement, posture, heat production.
  • Nervous system: Brain, spinal cord, nerves; communication, coordination, control.
  • Endocrine system: Glands secreting hormones; regulates body functions.
  • Cardiovascular system: Heart, blood vessels, blood; transports oxygen, nutrients, waste.
  • Lymphatic system: Lymph nodes, vessels; immunity, fluid balance.
  • Respiratory system: Lungs; gas exchange.
  • Digestive system: Mouth, esophagus, stomach, intestines; digestion, absorption.
  • Urinary system: Kidneys; excretion, fluid balance.
  • Reproductive system: Gonads, reproductive organs; reproduction.

Cellular Processes

• Cellular respiration: Breaks down glucose for energy.
• Photosynthesis: Plants convert light energy into chemical (glucose) energy.
• Cell division: Mitosis (growth, repair) and meiosis (reproduction).
• Membrane transport: Active and passive processes for substance exchange across cell membranes.

Basic Anatomical Terms

• Directional terms: Superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep.
• Regional terms: Describe body areas.
• Planes of section: Sagittal, frontal, transverse.

Organ Systems in Detail (Examples)

• Cardiovascular System:
  • Heart pumps blood through a closed circulatory system.
  • Blood vessels deliver blood to and from tissues.
  • Blood carries oxygen, nutrients, hormones, waste products.
• Respiratory System:
  • Lungs facilitate gas exchange.
  • Inhaling and exhaling permits oxygen uptake and carbon dioxide release.
• Digestive System:
  • Breaks down food.
  • Absorbs nutrients into the bloodstream.
  • Eliminates waste products.

Homeostatic Regulation Examples

• Blood glucose levels regulated by insulin and glucagon.
• Body temperature regulated by sweating and shivering.
• Blood pressure regulated by hormones and the nervous system.

Cell Communication

• Cells communicate through chemical signals.
• Signal transduction pathways transmit information from receptors to intracellular targets.
• Cell communication coordinates bodily functions.

Human Genetics

• Human characteristics are influenced by genetic inheritance.
• Genes encode proteins that determine traits.
• Genetic mutations can alter traits.
• Genetic disorders arise from mutations, abnormalities, or incomplete genetic information.

Niche

• A niche is a species' role in its ecosystem, including abiotic and biotic interactions (habitat, feeding, other species, nutrient cycling).
• A fundamental niche is the theoretical, ideal resource use in the absence of competition or predation.
• A realized niche is the actual resource use considering limiting factors (competition, predation).
• The competitive exclusion principle states that species with identical niches cannot coexist indefinitely. Differing niches allow coexistence.

In-depth Questions - Examples

• Factors influencing species distribution: Abiotic factors (e.g., temperature, water) limit species tolerance and distribution; biotic factors (e.g., predation, competition) influence interactions and species distribution.
• Resource partitioning: Different species use different resources to reduce competition (e.g., birds feeding at different heights).
• Character displacement: Competing species evolve different traits to minimize competition (e.g., beak size in finches).
• Symbiotic relationships:
  • Mutualism: Both benefit (e.g., bees and flowers).
  • Commensalism: One benefits, the other is neutral (e.g., barnacles on whales).
  • Parasitism: One benefits, the other is harmed (e.g., ticks on deer).
• Biodiversity and niche diversity: Higher biodiversity is associated with higher niche diversity.
• Fundamental vs. realized niches: Fundamental is theoretical potential use; realized is actual use considering limiting factors.
• Climate change and species distribution: Climate change affects temperature tolerance, precipitation, and resources, altering species ranges and interactions, potentially leading to extinction.
• Keystone species: Keystone species have a significant impact on ecosystem biodiversity disproportionate to their abundance; removal can disrupt ecosystems.
• Tropical rainforest example: Species segregation through utilizing various resources in a rainforest reduces competition allowing for rich biodiversity.