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
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
Read MoreMHC, 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
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
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
Read MoreAnimal and Plant Nutrition: Processes and Systems
Nutrition encompasses the substances that living organisms use and convert into energy and matter through their own processes. These substances, found in living foods, are composed of single units.
Nutrients
Nutrients are direct and simple substances that reach the cells.
Animal Nutrition
Digestive Processes
This involves breaking down food substances into simpler forms that the body can use and transport to cells via the blood.
Gas Exchange
This is the process of taking in oxygen for metabolism and expelling
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