Overview of Acute Inflammation

Inflammatory Cells

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nflammation is complex. It forms part of the innate immune system and has acute and active chronic stages, but today we’ll just be focusing on ACUTE inflammation. Then there’s the fluid/vascular and cellular phases of the acute inflammatory response. It can get confusing – I was certainly drowning in confusion when I was learning this in my Introduction to Veterinary Pathogenesis unit in second year bachelors. Let's ease into it with a brief overview! Hope it helps…

Anatomy of a Kidney

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he kidneys are part of the urinary system, serving as the starting point from which urine is collected and delivered to the bladder via the ureters. However, it has other functions as well, including controlling levels of water, electrolytes, and metabolic substances in bodily fluids. Let’s explore the anatomical features of this important organ…

All the reptiles, one tree!

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riting this article made me realise just how complicated classification can be in the animal kingdom. The class Reptilia is certainly diverse and at times, a bit unclear. But that’s the nature of biology – we’re constantly finding new evidence for evolutionary relationships which continuously modifies our current understanding of phylogenies. But with what I’ve learnt from my lectures in Australian Wildlife Biology, I’ve put together a diagram of reptile diversity which will give us the big-picture of where reptiles sit in and amongst each other!

Cell Signaling

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ow do cells send signals? Who receives those signals? What response comes about from this communication? Cell signaling is not straightforward, but then again, nothing in physiology ever is. In this article, I’ll try to give you a basic overview of cell signaling, if basic is even a word in this unit!

Scales or Scutes?

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o lizards have scales or scutes? How about crocodiles? Turtles? Let’s discuss the difference between scales and scutes in reptiles…

What are the reptiles?

Turtles, crocodiles, alligators, tuataras, snakes, and lizards are all reptiles. They have a keratinised bony outer layer of skin made of epidermal plates/scales or scutes.

What are scales?

Scales and plates are structures of the outer skin of some reptiles. They…

- Start growing from the epidermis. This is the topmost layer of the three skin layers (epidermis, dermis, hypodermis).

- Overlap

- Shed and are replaced. This also helps get rid of parasites on the superficial layer of skin.

- Prevents moisture loss

- Makes it easier for reptiles to move through their environment, for example, by providing friction

A plate is basically a larger, bonier scale.  

Reptiles with scales include snakes, tuataras, and lizards.

What are scutes?

Scutes (pronounced ‘skewts’) are the shells or body armour in certain reptiles. They…

- Start growing from deeper within the dermis

- Do not overlap as they are individualised

- Shed off in some species or have new keratin perpetually growing from beneath each scute in other species. If shed, the scutes break off section by section, not all in one go like in snakes.

- Prevents moisture loss

- Are like defensive armour

Reptiles with scutes include turtles, crocodiles, and alligators.

So, what are osteoderms?

Osteoderms are hard, bony protective structures at the skin. If the reptile has osteoderms, it would lie underneath the scale or the scute. Whilst scales and scutes are composed of alpha and beta keratins, osteoderms are made of bone.

These explanations are simplistic but hopefully it’s useful! Remember to always check with journal articles and reputable sources for specific and up-to-date information pertaining to your research topics and assignments for uni! I guess the main difference between scales and scutes are that scales overlap and scutes grow out from deeper in the dermis.

Next time you see a crocodile, you’ll know to say scutes not scales!

See you in my next article Xx

Sources:

Thompson, E 2019, BIOL2032 Australian Wildlife Biology, lecture: Reptiles: Introduction, lecture PowerPoint slides, Taronga Institute of Science and Learning, The University of Sydney