|
Testosteroni (film)
Testosterone is the primary male sex hormone and androgen in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testicles and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. It is associated with increased aggression, sex drive, dominance, courtship display, and a wide range of behavioral characteristics. In addition, testosterone in both sexes is involved in health and well-being, where it has a significant effect on overall mood, cognition, social and sexual behavior, metabolism and energy output, the cardiovascular system, and in the prevention of osteoporosis. Insufficient levels of testosterone in men may lead to abnormalities including frailty, accumulation of adipose fat tissue within the body, anxiety and depression, sexual performance issues, and bone loss. Excessive levels of testosterone in men may be associated with hyperandroge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Press
The CRC Press, LLC is an American publishing group that specializes in producing technical books. Many of their books relate to engineering, science and mathematics. Their scope also includes books on business, forensics and information technology. CRC Press is now a division of Taylor & Francis, itself a subsidiary of Informa. History The CRC Press was founded as the Chemical Rubber Company (CRC) in 1903 by brothers Arthur, Leo and Emanuel Friedman in Cleveland, Ohio, based on an earlier enterprise by Arthur, who had begun selling rubber laboratory aprons in 1900. The company gradually expanded to include sales of laboratory equipment to chemists. In 1913 the CRC offered a short (116-page) manual called the ''Rubber Handbook'' as an incentive for any purchase of a dozen aprons. Since then the ''Rubber Handbook'' has evolved into the CRC's flagship book, the '' CRC Handbook of Chemistry and Physics''. In 1964, Chemical Rubber decided to focus on its publishing ventures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjugation (biochemistry)
Bioconjugation is a chemical strategy to form a stable covalent link between two molecules, at least one of which is a biomolecule. Function Recent advances in the understanding of biomolecules enabled their application to numerous fields like medicine and materials. Synthetically modified biomolecules can have diverse functionalities, such as tracking cellular events, revealing enzyme function, determining protein biodistribution, imaging specific biomarkers, and delivering drugs to targeted cells. Bioconjugation is a crucial strategy that links these modified biomolecules with different substrates. Synthesis Synthesis of bioconjugates involves a variety of challenges, ranging from the simple and nonspecific use of a fluorescent dye marker to the complex design of antibody drug conjugates. As a result, various bioconjugation reactions – chemical reactions connecting two biomolecules together – have been developed to chemically modify proteins. Common types of bioconjug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Drive
Libido (; colloquial: sex drive) is a person's overall sexual drive or desire for sexual activity. Libido is influenced by biological, psychological, and social factors. Biologically, the sex hormones and associated neurotransmitters that act upon the nucleus accumbens (primarily testosterone and dopamine, respectively) regulate libido in humans. Social factors, such as work and family, and internal psychological factors, such as personality and stress, can affect libido. Libido can also be affected by medical conditions, medications, lifestyle and relationship issues, and age (e.g., puberty). A person who has extremely frequent sexual urges, or a suddenly increased sex drive may be experiencing hypersexuality, while the opposite condition is hyposexuality. In psychoanalytic theory, libido is psychic drive or energy, particularly associated with sexual instinct, but also present in other instinctive desires and drives. A person may have a desire for sex, but not have the opportun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggression
Aggression is overt or covert, often harmful, social interaction with the intention of inflicting damage or other harm upon another individual; although it can be channeled into creative and practical outlets for some. It may occur either reactively or without provocation. In humans, aggression can be caused by various triggers, from frustration due to blocked goals to feeling disrespected. Human aggression can be classified into direct and indirect aggression; whilst the former is characterized by physical or verbal behavior intended to cause harm to someone, the latter is characterized by behavior intended to harm the social relations of an individual or group. In definitions commonly used in the social sciences and behavioral sciences, aggression is an action or response by an individual that delivers something unpleasant to another person. Some definitions include that the individual must intend to harm another person. In an interdisciplinary perspective, aggression is rega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androgenic Hair
Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty. It is differentiated from the head hair and less visible vellus hair, which is much finer and lighter in color. The growth of androgenic hair is related to the level of androgens (often referred to as male hormones) and the density of androgen receptors in the dermal papillae. Both must reach a threshold for the proliferation of hair follicle cells. From childhood onward, regardless of sex, vellus hair covers almost the entire area of the human body. Exceptions include the lips, the backs of the ears, palms of hands, soles of the feet, certain external genital areas, the navel, and scar tissue. The density of hair – i.e. the number of hair follicles per unit area of skin – varies from person to person. In many cases, areas on the human body that contain vellus hair will begin to produce darker and thicker body hair during puberty, such as the first growth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone
A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provide structure and support for the body, and enable animal locomotion, mobility. Bones come in a variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple Function (biology), functions. Bone tissue (osseous tissue), which is also called bone in the mass noun, uncountable sense of that word, is hard tissue, a type of specialized connective tissue. It has a honeycomb-like matrix (biology), matrix internally, which helps to give the bone rigidity. Bone tissue is made up of different types of bone cells. Osteoblasts and osteocytes are involved in the formation and mineralization (biology), mineralization of bone; osteoclasts are involved in the bone resorption, resor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle tissue, and are often known as muscle fibers. The muscle tissue of a skeletal muscle is striated – having a striped appearance due to the arrangement of the sarcomeres. Skeletal muscles are voluntary muscles under the control of the somatic nervous system. The other types of muscle are cardiac muscle which is also striated and smooth muscle which is non-striated; both of these types of muscle tissue are classified as involuntary, or, under the control of the autonomic nervous system. A skeletal muscle contains multiple fascicles – bundles of muscle fibers. Each individual fiber, and each muscle is surrounded by a type of connective tissue layer of fascia. Muscle fibers are formed from the fusion of developmental myoblasts in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Sexual Characteristic
Secondary sex characteristics are features that appear during puberty in humans, and at sexual maturity in other animals. These characteristics are particularly evident in the sexual dimorphism, sexually dimorphic phenotypic traits that distinguish the sexes of a species, but unlike the sex organs (primary sex characteristics), are not directly part of the reproductive system. Secondary sex characteristics are believed to be the product of sexual selection for traits which display fitness (biology), fitness, giving an organism an advantage over its rivals in courtship and in aggression, aggressive interactions. Secondary sex characteristics include, for example, the manes of male lions, the bright facial and rump coloration of male mandrills, and horns in many goats and antelopes. These characteristics are believed to be produced by a positive feedback loop known as the Fisherian runaway produced by the secondary characteristic in one sex and the desire for that characteristic in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostate
The prostate is both an Male accessory gland, accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, chemically, and physiologically. Anatomically, the prostate is found below the Urinary bladder, bladder, with the urethra passing through it. It is described in gross anatomy as consisting of lobes and in microanatomy by zone. It is surrounded by an elastic, fibromuscular capsule and contains glandular tissue as well as connective tissue. The prostate glands produce and contain fluid that forms part of semen, the substance emitted during ejaculation as part of the male Human sexual response cycle, sexual response. This prostatic fluid is slightly alkaline, milky or white in appearance. The alkalinity of semen helps neutralize the acidity of the vagina, vaginal tract, prolonging the lifespan of sperm. The prostatic fluid is expelled in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testicle
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosterone. Testosterone release is controlled by the anterior pituitary luteinizing hormone, whereas sperm production is controlled both by the anterior pituitary follicle-stimulating hormone and gonadal testosterone. Structure Appearance Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Scrotal asymmetry, in which one testicle extends farther down into the scrotum than the other, is common. This is because of the differences in the vasculature's anatomy. For 85% of men, the right testis hangs lower than the left one. Measurement and volume The volume of the testicle can be estimated by palpating it and comparing it to ellipsoids of known sizes. Another method is to use caliper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Male Reproductive System
The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the body and within the pelvis. The main male sex organs are the penis and the testicles which produce semen and sperm, which, as part of sexual intercourse, fertilize an ovum in the female's body; the fertilized ovum (zygote) develops into a fetus, which is later born as an infant. The corresponding system in females is the female reproductive system. External genital organs Penis The penis is the male intromittent organ. It has a long shaft and an enlarged bulbous-shaped tip called the glans penis, which supports and is protected by the foreskin. When the male becomes sexually aroused, the penis becomes erect and ready for sexual activity. Erection occurs because sinuses within the erectile tissue of the penis become filled with blood. The arteries of the penis are dilated while the veins are compressed so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Males
Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male organism cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually. Most male mammals, including male humans, have a Y chromosome, which codes for the production of larger amounts of testosterone to develop male reproductive organs. Not all species share a common sex-determination system. In most animals, including humans, sex is determined genetically; however, species such as ''Cymothoa exigua'' change sex depending on the number of females present in the vicinity. In humans, the word ''male'' can also be used to refer to gender in the social sense of gender role or gender identity. Overview The existence of separate sexes has evolved independently at different times and in different lineages, an example o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Sex Drive")
_young_males_eyeballing.jpg "Click for more on -> Aggression")
