Human Nervous and Endocrine Systems: A Comprehensive Study
Coordination Systems
Receiver: It perceives structures capable of receiving stimuli and transmitting them to the nerve centers. Any stimulus is called a change, both from the exterior and the interior of the body, capable of eliciting a response from the organism.
Nerve Centers: It is the organ in charge of receiving the information that the receptors collect, processing it, drawing up, and transmitting the appropriate responses to the effector organs.
Effectors: It is the organ in charge of carrying out the response. It can be a muscle or a gland.
Components of the Nervous System
The neuron is the cell specialized in nerve coordination. It represents the aforementioned functional anatomical unit of the human brain; its function consists of sending messages, that is, nerve impulses. There are around 100 billion neurons; these do not regenerate. Neurons are composed of a cell body and extensions called axons and dendrites.
- Sensory or afferent neurons (inward) are sensitive to various stimuli: temperature change, touch, etc. They send information from the tissues and sensory organs to the interior of the spinal cord and the brain.
- Motor neurons or efferents (outward). They transmit information from the brain and spinal cord to the muscles and glands.
- Interneurons. They collect nerve impulses from sensory neurons and transmit them to motor neurons.
Glial cells: Among them are intercalated neurons that protect and nourish them.
The Nervous System
Central Nervous System (CNS): It is in charge of controlling the body and its activities.
Peripheral Nervous System (PNS): It transmits impulses from the receptors to the CNS, and from the CNS to the effectors.
The Endocrine System
- Adrenal Glands > Adrenaline > It favors intense body activity and prepares for situations by acting as a stimulant.
- Pancreas > Insulin > It decreases blood glucose. Glucagon > It increases blood glucose.
- Testicles > Testosterone > It acts on the development of the main sexual organs, and also on the secondary ones and the production of sperm.
- Ovaries > Estrogens > It acts on the development of the main sexual organs, and also on the secondary ones. > Progesterone > It regulates the ovarian cycle and prepares for pregnancy.
Functioning of the Nervous System
Reflex Acts: They are automatic self-protection acts. They are involuntary and cannot be controlled. The brain does not intervene; therefore, the path is shorter and much faster.
Functioning of the Hormone System
Excess or defect can lead to diseases. The mechanism of feedback or regulation is called feedback and is controlled by the central nervous system through the pituitary and the hypothalamus.
Mental Health
Schizophrenia: A very serious brain disorder, in which the affected person hears internal voices telling them what to do or not to do. It is said to be due to the lack of gray matter.
Obsessive-Compulsive Disorder: It is an obsession or compulsiveness to do things in a certain order, repeat them, perform rituals, repetitive behaviors, etc.
Diseases of the Endocrine System
Diabetes: It is due to a shortage of insulin and high concentrations of glucose in the blood. There are two variants:
- Type 1: It is insulin-dependent, requires daily injections of insulin, and is incurable.
- Type 2: It is not insulin-dependent, which means that the cells do not use glucose properly, and there are high concentrations in the blood.