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Contraction of the heart muscle

The heart muscle , also known as heart or myocardium, is an involuntary contraction muscle located in the mid-thorax region. It is one of the three types of muscle of our body, in addition to the smooth, characteristic of the viscera, and the skeletal, which together with the bones constitutes the locomotor system. The cells that make up the heart muscle contain a single nucleus, unlike the two remaining muscle tissue types whose cells can have up to four. The heart muscle is responsible for pumping all existing blood through the circulatory system through

Physiology of the skin

The physiology of the skin refers to the largest organ of the body: the skin . The skin constitutes an important portion of the integumentary system, which also consists of accessory structures such as hair, nails, sweat and sebaceous glands. Together, the components of the integumentary system provide a first line of defense, either against chemical attack or microorganisms, physical impact or abrasion. This system also provides the sensory structures for the detection of touch, pressure, pain and temperature. Main layers Epidermis The epidermis is the outermost layer


Acetylcholine was the first neurotransmitter described , both in the central nervous system and in the peripheral nervous system, in humans. It is the neurotransmitter that participates in different actions at the same time , such as the circadian cycle, memory and association, and the activation phenomena of the cortex. The synthesis of acetylcholine occurs from the binding of choline plus acetyl CoA , under the participation of the enzyme choline acetyltransferase, which acts under mechanisms that regulate both synthesis and release, so that the exact amount is in the specific moments of its functions.

Anatomy of touch

Touch is a sensation on the skin that results from active or passive contact between a person's skin and an object. The pressure applied to the skin is the main stimulus for the sense of touch. Another stimulus, the vibration, emerges when there is a rapid and regular change in pressure. Tactile perception is processed through the somatosensory system. This system is composed of sensory receptors, peripheral sensory neurons and brain cells. When there is pressure on the skin, peripheral tactile receptors send information to the brain through the somatosensory pathway

Gamma-aminobutyric acid (GABA)

Gamma-aminobutyric acid (GABA) is one of the most important inhibitory neurotransmitters in our body. Neurotransmitters are substances used by the nervous system in the processes of synapses or transmission of nerve impulses. These functions are carried out by the main nerve cells, the neurons. GABA is only present in mammals and intervenes in numerous cognitive processes. As a general rule, it is obtained from the glutamate that we obtain in our diet or by its synthesis. It usually occurs in the cerebellum (GABAergic neurons), in the basal ganglia and in certain

The immune system

The human body is usually in a constant war due to the interaction with multiple agents. Specifically, the battle is waged between antigens and antibodies, which are microscopic elements that, on the one hand, try to protect the organism, while on the other, they try to spread diseases. In other words, the organism battles against external threats in order to protect itself. The main responsible for acting as a barrier or protective shield is what is known as the immune system. This is composed of a set of cells and organs that

Physiology of touch

The sense of touch is not only related to the skin , although it is true that it is the most extensive organ of the body and the most obvious. The skin has around 5 million sensory nerve receptors in the skin. This allows you to experience the sensation of pain and pressure within the body, among others. When the touch, pain or heat sensors in your skin are stimulated, they send electrical pulses to your neurons (special cells that transmit electrochemical impulses). The sensory neurons pass along the electrical pulse of the

Physiology of lactation

The physiology of breastfeeding is the set of organs, properties and functions of the same that make possible the secretion of breast milk, a fluid of vital importance for the feeding of the newborn. Physiology of lactation Milk production develops in the epithelial cells of the alveoli found in the mammary glands. In them are the stem cells that are stimulated by growth hormone and Constitution of the breast: Lactiferous sinuses: they are under the areola, milk is stored here. Nerves: its function is to send the

Physiology of the ear

The inner ear is full of fluid. It also contains the receptors for sound that convert fluid movement into electrical signals known as action potentials that are sent to the brain to allow sound perception. Therefore, sound waves carried by the air must be channeled into the inner ear and transferred for hearing to occur. The role of the outer and middle ear is to transmit the sound to the inner ear. They also help to compensate for the loss of sound energy. In addition to converting sound waves into nerve action

The cycle of krebs

The krebs cycle, also known as the citric acid cycle or tricarboxylic acid cycle, is a metabolic process of vital importance for cells that use oxygen during the process of cellular respiration, aerobic organisms. In these aerobic organisms, the krebs cycle is the binding ring of the metabolic pathways responsible for the degradation and desasimilation of carbohydrates, fats and proteins in carbon dioxide and water, thus releasing energy in a usable form as reducing power, guanosine triphosphate (GTP) and adenosine triphosphate (ATP). Where does the Krebs cycle occur? The krebs cycle can