Fungi. A fungus (singular) is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms (Figure 1). Fungi are classified as a kingdom that is separate from plants, animals, and bacteria.One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose.he discipline of biology devoted to the study of fungi is known as mycology, which is often regarded as a branch of botany, even though genetic studies have shown that fungi are more closely related to animals than to plants. Pathogenic fungi are fungi that cause disease in humans or other organisms.
Erectile Dysfunction Causes and Symptoms. There are many causes of erectile dysfunction (impotence) and some include: 1  blood vessel diseases (such as peripheral vascular disease and others), 2  systemic disease, 3  hormonal imbalance, and. 4  medications (such as blood pressure and heart medications).
Causes. Male sexual arousal is a complex process that involves the brain, hormones, emotions, nerves, muscles and blood vessels. Erectile dysfunction can result from a problem with any of these. Likewise, stress and mental health concerns can cause or worsen erectile dysfunction.Sometimes a combination of physical and psychological issues causes erectile dysfunction.For instance, a minor physical condition that slows your sexual response might cause anxiety about maintaining an erection.rectile dysfunction can result from a problem with any of these. Likewise, stress and mental health concerns can cause or worsen erectile dysfunction. Sometimes a combination of physical and psychological issues causes erectile dysfunction.