Human Body Composition and Cellular Structure
1. Levels of Organization in the Human Body
The human body is composed of several elements grouped into different levels of organization:
- Atoms: Chemical elements forming the molecules of living beings.
- Molecules: Components from which cells produce their structures.
- Cells: The basic unit of human life.
- Tissues: Sets of specialized cells working together to perform a specific function.
- Organs: Formed by different tissues and have a specific function.
- Systems: Associations of organs working together to
Oral and Maxillofacial Abnormalities: A Comprehensive Review
Oral and Maxillofacial Abnormalities
Developmental Abnormalities: These are irregularities in the normal pattern of growth and development. Some dental abnormalities are mild, causing only minor disturbances in appearance, while others are serious and devastating.
Soft Tissue Anomalies
Cleft Lip: This can be lateral, central, unilateral (left or right), or bilateral, also known as harelip.
Cleft Palate: This results from a lack of fusion and can affect the soft palate and uvula, or the entire palate.
Read MorePeriodontal Pockets: Clinical Features, Diagnosis, and Treatment
Clinical Features of Periodontal Pockets
Symptoms:
- Localized pain or sensation of pressure which diminishes with time
- Foul taste or odor
- Tendency to suck material from interproximal areas
- Radiating pain “deep in the bone”
- Urge to dig with any pointed object
- Gnawing feeling or itchy gums
Clinical Signs:
- Sulcus depth more than 3 mm
- Enlarged bluish-red margin
- Bluish-red vertical zone
- Break in the bucco-lingual continuity
- Shiny, puffy gingiva with exposed root surfaces
Histopathology of Periodontal Pockets
Soft
Read MoreHeart Function, Blood Circulation, and Kidney Filtration
Heart Function and Blood Circulation
Phases of the Cardiac Cycle
Atrial Systole
The atria contract, pumping blood into the ventricles through the atrioventricular valves.
Ventricular Systole
The ventricles contract. Blood exits into the pulmonary artery and aorta as the semilunar valves open. Simultaneously, the atrioventricular valves close.
Diastole
The heart relaxes. Blood from the vena cavae and pulmonary veins enters the atria. Blood just pumped into the arteries cannot return to the ventricles due
Cell Biology: Characteristics, Structure, and Processes
Characteristics of Living Organisms
- Nutrition: Taking in, absorbing, and assimilating nutrients (organic substances, mineral ions) containing raw materials/energy for growth and tissue repair.
- Plants: Photosynthesis – H2O, CO2, Light
- Excretion: Removal of toxic materials and waste products of metabolism and substances in excess, produced by chemical reactions in cells (respiration).
- Respiration: Breaking down food in cells to release energy.
- Sensitivity: Sensing and responding to changes in the environment
Photosynthesis: The Core of Life on Earth
What is Photosynthesis?
Photosynthesis is the chemical process by which green plants, certain algae, and some bacteria capture light energy from the sun and convert it into chemical energy. Plants contain a green pigment called chlorophyll, located in the chloroplasts of their cells. This pigment absorbs sunlight’s energy and uses it to produce carbohydrates like glucose from water and carbon dioxide. As a byproduct, photosynthesis releases oxygen into the atmosphere, crucial for life and respiration.
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