Extracellular Matrix: Structure, Function, and Components

TISSUE: Introduction: ECM is a complex network of macromolecules that acts as “cement” between the universal biological cells, as part of highly specialized structures: cartilage, tendons, bones, etc. This function supports the ECM’s role in regulating the behavior of cells that contact it, influencing their differentiation, development, migration, and shape. The ECM is produced by ECM-producing cells called connective tissue, connective, or supportive cells.

Supporting tissues: broadly refer to

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Infectious Diseases & Transmission: A Comprehensive Guide

Infectious Diseases

Pathogenic Microorganisms

Infectious diseases are caused by pathogenic microorganisms such as bacteria, viruses, protozoa, and fungi. While many organisms exist in nature, most are harmless. Those that cause disease are called pathogens.

Environmental Factors and Contamination

Human activities like industry, heating, and traffic contribute to air and water pollution. These pollutants can negatively impact human health.

Air Pollution

Substances that contribute to air pollution include:

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Understanding the Immune System: Innate and Adaptive Defenses

4 Types of Symbiosis. : Mutualism: both symbionts benefit from their interaction. EX: bacteria in your colon Worm describes another mutualistic relationship. Commensalism: one symbiont benefits without significantly affecting the other. EX: microscopic animals—hair follicle mites—live on your skin without causing measurable harm to you. Amensalism: one symbiont is harmed by a second symbiont, while the second is neither harmed nor helped by the first. EX: the fungus Penicillium produces penicillin,

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Morphological Differences Between Primary and Permanent Teeth: A Comprehensive Guide

Morphological Differences Between Primary and Permanent Teeth

Crown Characteristics

  • Primary teeth have wider crowns mesiodistally compared to their length.
  • Anterior primary teeth are narrower and shorter than permanent teeth.
  • Primary molars have relatively longer and more slender roots than permanent molars.

Enamel and Cervical Ridge

  • The cervical ridge of enamel is more prominent in primary teeth, especially on the labial and lingual surfaces.
  • Primary molars have more slender crowns and roots mesiodistally
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Cellular Communication, Reflexes, and Sensory Receptors: A Comprehensive Overview

Cell-to-cell communication works through synapses. Two parts: the axon terminal of the presynaptic cell and the membrane of the postsynaptic cell. Postsynaptic cells may be neurons or non-neuronal cells. Presynaptic axons are next to either the dendrites or the cell body of the postsynaptic neuron.

Electrical synapses pass signals directly from the cytoplasm of one cell to another through gap junctions. They can flow in both directions. They occur mainly in the CNS. They are found in glial cells,

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Pathogenic Substances, Infections, and Viruses: A Comprehensive Guide

Pathogenic Substances Produced by Streptococcus Pyogenes

1. What are the pathogenic substances produced by Streptococcus pyogenes?

  • Invasive &pygenic infection:
  • Streptococcal sore throat
  • Streptococcal pyoderma
  • Cellulitis
  • Subacute endocarditis
  • The most common bacterial cause of sore throat
  • Intoxication
  • Poststreptococcal sequelae.

Mechanism of Cholera Toxin

2. Explain the mechanism of cholera toxin?

  • Produce the symptoms of cholera.
  • A-B type ADP-ribosylating toxin

Sub unit A: ADP-ribosylating activity.

Sub unit

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