Midterms

• Human Anatomy is the scientific study of the body's structures, some of which can only be observed and analyzed with the assistance of a microscope
• Physiology explains how the structures of the body work together to maintain life
• Anatomy and Physiology are typically studied together because form and function are closely related in all living things
• Evolution provides a scientific explanation for the history of life on Earth and the mechanisms by which changes to life have occurred
• Ecosystems and Environments: all life exists within an ecosystem made up of the physicochemical environment and other biological organisms
• Causal Mechanisms: life requires information flow within and between cells and between the environment and the organisms
• Cell: the basic unit of life, where structure dictates function at each level of organization
• Levels of Organization: living organisms carry out functions at many different levels of organization simultaneously
• Matter, Energy, and Transformation: living organisms must obtain matter and energy from the external world, transforming and transferring them to build the organism and perform work
• Homeostasis maintains the internal environment in a more or less constant state compatible with life
• The Hierarchy of Complexity in the human body: from molecules to cells, tissues, organs, organ systems, and the organism
• Transport Across Cell Membrane: molecules can be moved passively through simple diffusion, facilitated diffusion, or actively through processes like the Sodium-Potassium Pump, Endocytosis, and Exocytosis
• The Cell Cycle: a sequence of events in the life of the cell from creation to division, involving phases like Interphase, Mitosis, and Cytokinesis
• Cell Cycle Control is a homeostatic mechanism that maintains proper cell function and health, preventing unwanted and excessive cell division
• Stages of Interphase: G1 Phase is the first growth phase, S Phase is the synthesis phase where the cell replicates its DNA, and G2 Phase is the second growth phase before cell division
• A combination of genetic predisposition and environmental factors lead to cancer
• STAGES OF INTERPHASE:

  • G1 Phase: 1st growth phase where the cell grows and carries out all normal metabolic functions and processes
  • S Phase: synthesis phase where the cell replicates its DNA
  • G2 Phase: 2nd gap phase where the cell continues to grow and makes preparations for mitosis
  • G0 Phase: resting phase of the cell cycle where cells have temporarily stopped dividing or have permanently ceased dividing
• STAGES OF MITOSIS:

  • Prophase: chromatin coils and condenses into visible chromosomes
  • Metaphase: sister chromatids line up along a linear plane in the middle of the cell
  • Anaphase: pairs of sister chromatids are separated, forming individual chromosomes
  • Telophase: formation of two new daughter nuclei at either end of the dividing cell
• TISSUES:

  • Aggregation of cells that are similar in structure and work together to perform a specialized function
  • Organized into four categories: epithelial, connective, muscle, nervous
  • Any disruption in tissue structure can lead to injury or disease
  • Understanding how tissues respond to damage can guide repair strategies and aging effects
• TISSUE INJURY AND REPAIR:

  • Inflammation is the body's initial response to injury, limiting the extent of injury and initiating tissue repair and regeneration
  • Acute inflammation resolves over time by tissue healing, while chronic inflammation can lead to diseased conditions like arthritis and tuberculosis
• HOMEOSTASIS:

  • Coined by Walter Cannon in 1930, homeostasis refers to processes that maintain stable conditions necessary for survival
  • Feedback loops control internal conditions through receptors, control centers, and effectors
  • Negative feedback mechanisms work to decrease deviations from the set point, maintaining variables within a normal range
• HOMEOSTASIS:

  • Positive feedback mechanisms occur when the initial stimulus further stimulates the response, increasing deviations from the set point
  • Positive feedback mechanisms are required to re-achieve homeostasis and resolve disruptions in internal balance
• CELL STRUCTURES AND FUNCTIONS:

  • Cytology is the science about the cell, the structural and functional unit of life capable of carrying out essential life processes like metabolism, growth, reproduction, and response to stimuli
  • Eukaryotic cells have a true nucleus, membrane-bound organelles, and are found in multicellular organisms like plants, animals, algae, fungi, and protists
• The three basic parts of a cell are:

  • Plasma membrane
  • Cytoplasm
  • Nucleus
• Organelles are basic cell parts that perform the physiological activities of the cell
• Cell membrane, also known as the plasma membrane, separates the cell from its external environment, covers and protects the cell, and gives shape to the cell
• The cytoplasm, also known as protoplasm, is the living substance inside the cell that contains organelles performing all the physiological properties of the cell
• The endoplasmic reticulum is a system of membranous tubules and sacs, serving as the circulatory system of the cell for internal transport
• Ribosomes are protein micro-machines, the most common organelles in almost all cells, and are sites for protein synthesis
• Mitochondria, known as the powerhouse of the cell, manufacture energy in the form of ATP through aerobic respiration
• The Golgi apparatus, also known as the Golgi complex or Golgi body, processes and packages proteins, acts as a transport agent, and is involved in the distribution of lipids around the cell
• Centrosomes/centrioles are organizing centers for microtubules, essential for cell division as they form the spindle fibers for the separation of chromosomes
• Lysosomes are tiny sacs produced by the Golgi body, acting as a digestive plant with enzymes to help in the process of digestion and keeping the cell clean by digesting excess and worn-out organelles
• Peroxisomes, formerly known as microbodies, are oxidative organelles containing enzymes that oxidize fatty acids and amino acids, overseeing reactions that neutralize free radicals causing cellular damage and cell death
• Vacuoles are storage bubbles found in cells, membrane-bound fluid sacs that store large amounts of various materials and transport needed materials into the cell via endocytosis and waste materials out of the cell via exocytosis
• The cytoskeleton is a complex network of interlinking filaments or tubules providing structural support to the cell, consisting of microfilaments, microtubules, and intermediate filaments
• Flagella and cilia are structures for cell movement, with cilia being short, hair-like, and numerous, while flagella are long, thread-like, and fewer in number
• The nucleus, normally the largest organelle, contains the nuclear envelope, nucleolus, and chromosomes housing genes (DNA) and hereditary material
• All eukaryotic cells have a nucleus, except for Red Blood Cells or Erythrocytes that lose their nuclei as they mature
• The skeletal system includes all bones and joints in the body, with the adult body made up of 206 individual bones arranged into the axial and appendicular skeleton divisions