Switch to Dark theme

The immune system: basis of so much health and disease: 1. overview of immunity and the immune system

From Volume 44, Issue 2, February 2017 | Pages 151-156

Authors

Crispian Scully

CBE, DSc, DChD, DMed (HC), Dhc(multi), MD, PhD, PhD (HC), FMedSci, MDS, MRCS, BSc, FDS RCS, FDS RCPS, FFD RCSI, FDS RCSEd, FRCPath, FHEA

Bristol Dental Hospital, Lower Maudlin Street, Bristol BS1 2LY, UK

Articles by Crispian Scully

Eleni A Georgakopoulou

PhD, MD, MSc, DDS

Research Fellow, University of Athens and Dental Practitioner, 4 Fokaias Str, 14232 N Ionia, Greece

Articles by Eleni A Georgakopoulou

Yazan Hassona

BDS, FFD RCSI, PhD

Assistant Professor and Consultant in Oral Medicine and Special Needs Dentistry, The University of Jordan, Amman

Articles by Yazan Hassona

Abstract

The immune system is the body's primary defence mechanism against infections, and disturbances in the system can cause disease if the system fails in defence functions (in immunocompromised people), or if the activity is detrimental to the host (as in auto-immune and auto-inflammatory states). A healthy immune system is also essential to normal health of dental and oral tissues. This series presents the basics for the understanding of the immune system, this article covering an overview of immunity and the immune system.

Clinical Relevance: Modern dental clinicians need a basic understanding of the immune system as it underlies health and disease.

Article

We inhabit a world dominated by microbes and toxins, many of which can cause harm to humans (ie they are pathogens). Some pathogens are exogenous but others, such as some bacteria, viruses, and fungi, share their lives with us (ie they are commensals or endogenous), often usually in harmony though, under certain conditions, some may become opportunistic pathogens. Humans are colonized, for example, by over 1,000 different types of micro-organisms. Immunity is the state of having sufficient biological defences to avoid infections (Figure 1).

The immune system – the body's primary defence mechanism against diseases caused by pathogens – is made up of various interacting cells (sometimes termed immunocytes), soluble substances, and proteins designed to identify and destroy pathogens.

The main primary organs of the immune system are lymphoid – the thymus and bone marrow (Figure 2) and secondary tissues such as spleen, tonsils, lymph vessels, lymph nodes, adenoids, skin and liver (‘lymphoreticular system’) (Figure 3).

Register now to continue reading

Thank you for visiting Dental Update and reading some of our resources. To read more, please register today. You’ll enjoy the following great benefits:

What's included

  • Up to 2 free articles per month
  • New content available

Already have an account? Sign in here