Human Digestive and Respiratory Systems: Anatomy & Function

Introduction to Nutrition and Human Body Systems

Nutrition is the life function that enables living beings to obtain matter and energy. The systems involved are:

  • Digestive System: This system transforms the food we eat into nutrients, which are absorbed and passed into the bloodstream.
  • Respiratory System: This system takes oxygen from the air and transfers it to the blood. It also takes carbon dioxide from the blood and expels it out of the body.
  • Circulatory System: This system uses blood to carry nutrients
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The Internal Environment and Circulatory System

The Internal Environment and the Circulatory System

The internal environment is the fluid surrounding the cells of an organism. Cells extract nutrients and oxygen, and necessary substances are discharged as waste and carbon dioxide. It is made up of:

  • Interstitial plasma: A liquid between the cells that functions in nutrition and defense. It originates from blood that has been filtered through the thin walls of blood capillaries.
  • Blood and lymph: Lymph is a liquid formed from interstitial plasma that
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Microorganisms: Pharmaceutical and Immunological Uses

Microorganisms in the Pharmaceutical Industry

Microorganisms play a crucial role in the pharmaceutical industry. Antibiotics, for instance, are antimicrobial chemical compounds synthesized by fungi and bacteria.

Fleming’s accidental discovery of penicillin, by contaminating a Petri dish, highlighted this. He noted that the fungus secreted a substance that destroyed bacterial colonies. Penicillin is particularly effective against Gram-positive bacteria. Later, streptomycin was discovered, proving effective

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MHC, Immunity, and Immune Response: A Comprehensive Look

Major Histocompatibility Complex (MHC)

MHC proteins are located in the plasma membrane of cells. They distinguish between foreign entities and the body’s own cells. This group of genes has high variability, making it highly improbable that two individuals will have the same set of proteins.

There are two types:

  • MHC Class I: Present in all cells of the organism. Involved in antigen presentation to cytotoxic T cells (MHC Class I).
  • MHC Class II: Present only in antigen-presenting cells (APCs) of the immune
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Essential Concepts in Biology: A Comprehensive Review

Essential Concepts in Biology

  • What is Science?

    Science is a body of knowledge and a process for generating that knowledge.
  • The Scientific Method

    The steps include:
    • Observations
    • Hypothesis: “If… then…”
    • Predictions
    • Test (Observations and Experiments)
  • Observation Defined

    A description, measurement, or record of any object or scientific phenomenon.
  • Hypothesis: Definition and Testing

    An informed, logical, and plausible explanation for observations of the natural world. It should be possible to show that
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Understanding the Central Nervous System: Structure and Function

Understanding the Central Nervous System

The central nervous system (CNS) is responsible for analyzing sensory information, storing it, and initiating specific actions.

Spinal Cord

The spinal cord processes spinal reflexes. It conducts sensory nerve impulses to the brain and motor nerve impulses from the brain to effectors.

Brain Stem

Medulla Oblongata

The medulla oblongata contains the cardiovascular center (which monitors heart rate, force, and blood vessel diameter) and the respiratory center.

Pons

The

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