A Serum That Signals Macrophages To Alter In The Spleen and Promote Red Blood Cell Production During Anemic Stress

Source: https://www.thoughtco.com/red-blood-cells-373487 Anemic stress promotes an emergency production of red blood cells. It is best understood in mice where it occurs in the spleen. However, emergency red blood cell production in both human and mouse utilize signals and precursor cells that are different from regular red blood cell production. These precursor cells are capable of … Continue reading A Serum That Signals Macrophages To Alter In The Spleen and Promote Red Blood Cell Production During Anemic Stress

The Bacterial Conjunctivitis

Acute, purulent, bacterial conjunctivitis causes swelling and redness in the conjunctiva, the membrane lining the whites of the eyes and the inner eyelids. It is often accompanied by a yellow, green, or white discharge, which can dry and become encrusted on the eyelashes. (credit: “Tanalai”/Wikimedia Commons) OpenStax Microbiology Like the skin, the surface of the … Continue reading The Bacterial Conjunctivitis

What is Anthrax?

(a) Cutaneous anthrax is an infection of the skin by B. anthracis, which produces tissue-damaging exotoxins. Dead tissues accumulating in this nodule have produced a small black eschar. (b) Colonies of B. anthracis grown on sheep’s blood agar. (credit a, b: modification of work by Centers for Disease Control and Prevention) OpenStax Microbiology The zoonotic disease anthrax is caused … Continue reading What is Anthrax?

The Acne

(a) Acne is characterized by whitehead and blackhead comedones that result from clogged hair follicles. (b) Blackheads, visible as black spots on the skin, have a dark appearance due to the oxidation of lipids in sebum via exposure to the air. (credit a: modification of work by Bruce Blaus) OpenStax Microbiology One of the most … Continue reading The Acne

The Necrotizing Fasciitis

(a) The left leg of this patient shows the clinical features of necrotizing fasciitis. (b) The same patient’s leg is surgically debrided to remove the infection. (credit a, b: modification of work by Piotr Smuszkiewicz, Iwona Trojanowska, and Hanna Tomczak) OpenStax Microbiology Streptococcal infections that start in the skin can sometimes spread elsewhere, resulting in … Continue reading The Necrotizing Fasciitis

Cellulitis, Erysipelas, and Erythema Nosodum

S. pyogenes can cause a variety of skin conditions once it breaches the skin barrier through a cut or wound. (a) Cellulitis presents as a painful, red rash. (b) Erysipelas presents as a raised rash, usually with clear borders. (c) Erythema nodosum is characterized by red lumps or nodules, typically on the lower legs. (credit a: … Continue reading Cellulitis, Erysipelas, and Erythema Nosodum

The Streptococcal Infections of the Skin

Streptococcus pyogenes forms chains of cocci. (credit: modification of work by Centers for Disease Control and Prevention) OpenStax Microbiology Streptococcus are gram-positive cocci with a microscopic morphology that resembles chains of bacteria. Colonies are typically small (1–2 mm in diameter), translucent, entire edge, with a slightly raised elevation that can be either nonhemolytic, alpha-hemolytic, or beta-hemolytic when … Continue reading The Streptococcal Infections of the Skin

The Superficial Staphylococcal Infections

Furuncles (boils) and carbuncles are infections of the skin often caused by Staphylococcus bacteria. (a) A furuncle contains pus and exhibits swelling. (b) A carbuncle is a pus-filled lesion that is typically deeper than the furuncle. It often forms from multiple furuncles. (credit a: modification of work by “Mahdouch”/Wikimedia Commons; credit b: modification of work … Continue reading The Superficial Staphylococcal Infections