Understanding Hormones and the Reproductive System
Glands are organs that produce hormones. The hypophysis is a gland that regulates all the other glands and depends on the activity of our brain.
Hormones, which are produced by glands, are chemical substances that act on the cells, changing the metabolism of the target organ.
Each hormone has a target organ, which is an organ of a group of tissues that responds to the hormone.
Types of Receptors
- Mechanoreceptors: Capture mechanical energy.
- Thermoreceptors: Capture thermal energy.
- Chemoreceptors: Capture chemical substances.
- Photoreceptors: Capture luminous energy.
- Nociceptors: Capture various kinds of energy that are dangerous for the organism.
Neurons Structure
- Body of the cell: The thickest part of the neuron.
- Axon: A large prolongation that comes out of the body of the cell and branches out at the end.
- Dendrites: Small branching prolongations of the body of the cell.
Synapse
A synapse occurs when the dendrites and the branched ends of the axon are separated by a small gap. A neuron may establish from 100 to 150,000 synapses.
Neurons
Neurons are cells that are capable of generating and transmitting nervous impulses by means of changes in their membrane. The propagation of the nervous impulse requires the collaboration of certain substances called neurotransmitters.
Nervous System Parts
- The central nervous system: Formed by the brain and the spinal cord. These organs are inside the cranium and are specially well protected.
- Peripheral nervous system: Consists of nerves made up of the axons of neurons.
Important Hormones
- Adrenaline: It favors intestinal muscular activity and prepares the organism for physical effort.
- Insulin: It decreases the level of glucose in the blood, favoring its entry into the cells.
- Glucagon: The opposite effect to insulin; it increases the level of glucose in the blood.
- TSH, LH: Act on other endocrine glands.
- Thyroxine: It activates cellular metabolism and the consumption of oxygen, producing heat.
- Growth hormone: It favors growth in general, activating cellular division, the synthesis of proteins, and the growth of bones.
Female Reproductive System
- Ovaries: Two organs the size of an almond.
- Fallopian tubes: Two channels that connect the ovaries to the uterus.
- The uterus or womb: A cavity prepared for a fertilized ovum and for housing the embryo during its development over nine months.
- The vagina: A flexible channel that connects the uterus with the exterior, opening via the vaginal orifice.
Male Reproductive System
- Testicles: Organs that produce spermatozoa and male sexual hormones.
- Epididymis: Structures located above the testicles where spermatozoa mature.
- Vas deferens: Small channels through which spermatozoa travel to the seminal vesicles.
- Seminal vesicles: Where spermatozoa are stored and mixed with a fluid that serves as a vehicle and food.
- Prostate: An organ that produces a fluid similar to that of the seminal vesicles, contributing to semen.
- Urethra: The tube that runs from the bladder and seminal vesicles to the opening at the head of the penis.
- The penis: A spongy organ whose function is to deposit spermatozoa inside the vagina; the end of the penis is the glans.
Changes During Puberty
Male
- Development and maturation of the sexual organs.
- Change in the voice.
- Development of muscles.
Female
- Development of mammary glands.
- Accumulation of fat in certain areas (hips).
- Development and maturation of the sexual organs.
During the maturation of an ovum, the uterus prepares itself for a possible pregnancy.
When the ovum is mature, it leaves the ovary and passes along the fallopian tube, having a lifespan of 24 hours. If it is not fertilized by a spermatozoon, the ovum dies. The endometrium is released 14 days after the death of the ovum. This is how menstruation occurs, which involves a loss of blood through the vagina for 4 to 5 days, after which a new cycle begins 40 days later.
- Gametes: Special cells that contain genetic information for sexual reproduction. Male gametes are spermatozoa, and female gametes are ova.
- Embryo: The stage when the zygote divides many times during its journey to the uterus.
- Fetus: The stage when the embryo develops differentiation of the organs, marking the beginning of pregnancy, which ends in birth. The embryo develops for 3 months.
- Placenta: The structure where the embryo develops, serving as the area of union between the embryo and the mother, allowing the fetus to receive oxygen and nutrients necessary for growth along the umbilical cord.
Amniotic fluid: The contractions cause the rupture of the bag of amniotic fluid, which is where the fetus develops during pregnancy.