Cell Theory, Biology, and Human Body Processes
Key Figures and Discoveries in Biology
Schleiden and Schwann authored the cell theory. Jansen is associated with the microscope, while Knoll and Ruska developed the electron microscope. The scientific method is based on facts, logic, and order. Carolus Linnaeus developed Systema Naturae and is a key figure in taxonomy.
Branches of Biology
- Anatomy: The study of the structure of living things.
- Physiology: Studies the functioning of organisms.
- Genetics: Deals with the study of the transmission of hereditary
Understanding Your Body’s Defenses: Immunity Explained
1. Body’s Defense Mechanisms
1.1 External Barriers
1.1.1 Physical Barriers
Skin: Infectious organisms can only penetrate the body when the skin is injured. Therefore, it is important to clean and disinfect any wound with soap and iodine solution.
1.1.2 Chemical Barriers
There are different parts of our body where there is no skin, such as the mouth, nostrils, eyes, anus, urethra, and vagina. The mucous lining of these parts secretes substances that kill microorganisms, such as lysozyme.
Lysozyme is an
Read MoreSensory Transduction: Olfactory, Gustatory, and Visual Systems
Sensory Transduction Mechanisms
Vestibular System
- Head movements cause stereocilia to move in the opposite direction of head rotation.
- Neurotransmitter release at the synapse between vestibular hair cells and the afferent neuron involves glutamate.
- Afferent nerve fibers in the inner ear converge to form the vestibulocochlear nerve.
- Meniere’s disease can cause dizziness.
Olfactory System
- The olfactory membrane is located within the nasal conchae.
- Odorant receptors are G-protein coupled receptors.
- Olfactory
Nutrition and Nutrients: Essential Guide to a Balanced Diet
Nutrition and Nutrients
Nutrition: A set of processes through which the body receives, transforms, and incorporates needed nutrients.
Nutrients: Chemical compounds contained in foods that cells need to live.
Duties of Nutrients:
- Energy: Invigorating.
- Plastic and Reconstructive: Contributing components to growth.
- Regulator: Substances that control chemical reactions.
Types of Nutrients
- Carbohydrates: They provide a lot of energy. Some are simple and easy to digest, while others are more complex.
- Lipids: Develop.
Human Biology: Blood, Excretion, Nutrition, and More
Human Biology: An Overview
Blood Composition and Function
Blood is composed of plasma and three types of cells:
- Erythrocytes: Red blood cells without a nucleus, responsible for oxygen transport.
- Leukocytes: White blood cells that defend the body against infections.
- Platelets: Involved in blood coagulation.
Diastole refers to the relaxation of the heart chambers, while systole refers to their contraction.
Excretion and the Kidneys
Excretion is the process of eliminating waste substances from the blood.
The
Read MoreDarwinian Evolution: Natural Selection, Speciation, and Mechanisms
Lesson 1: Darwin and Natural Selection
Evidence for Evolution:
- Selection is a plausible mechanism for species change.
- The fossil record shows species change over time (e.g., whale hind legs).
- Homology of forelimb structure and comparative embryology suggest common ancestry.
- Biogeography showed patterns of distribution of organisms consistent with ancestor-descendant relationships (e.g., beak sizes).
Evolution of drug resistance and viruses is important to our health and society.
The State of Knowledge
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