Neurons and nervous systems and the endocrine system

Neurons and nervous systems and the endocrine system

Neurons can be divided into dendrites, cell bodies, axons, and the ends of axons are axons. When the ion channel of the neuron on the resting potential is opened, the sodium ions pour in, and the voltage exceeds the negative 50 MV to form the action potential toward the axon end conduction, and then the potassium ions flow out to form negative potential . The action potential of the axon that wraps the myelin sheath can be transmitted by jumping in the gully as a node.

Neurotransmitters are chemical substances that transmit signals through the synaptic receptor sites . Cocaine stimulates the reward system to produce more dopamine in order to give pleasure to people, and arrow venom binds the acetylcholine receptors in the muscle cells by binding to the acetylcholine receptor. Pain causes the brain to release a neuropeptide called endorphins and endorphins released by the pituitary gland, together to relieve pain and relieve pain, and a placebo can increase the level of endorphins.

Neurons receive the signals of excitement or inhibition and decide whether to produce action potentials, and the interconnected neuron group processes information in the brain to form a neural network . Neural plasticity refers to the growth of the brain in the rich environment synapse more dendrites longer.

The nervous system is divided into the CNS and peripheral nervous systems, and the myelin sheath of the peripheral nerves forms a pathway for repairing damaged nerve fibers. Peripheral nervous system is divided into somatic nervous system and autonomic nervous system, the autonomic nervous system can control heartbeat, digestion, perspiration, pupil amplification and so on. The autonomic nervous system is divided into sympathetic and parasympathetic nerves. The white matter of the spinal cord is the myelin-encapsulated axon used to connect the brain and peripheral nerves, and Reflex arc is the basis for a test-driven autonomic response.

CT (computed tomography) the scan collects X-rays from different angles and integrates them into a single graph. MRI (Magnetic resonance imaging) scans use strong magnetic fields to create a three-dimensional model of the brain or body. The ESB (for EEG stimulation) uses weak currents to activate the brain's surface, and the emotions and behaviors of people under stimulation are regulated by their personality and environment. The micro-electrode recording method can be used to observe the distribution of individual neuron action potentials. The post-traumatic behavior was observed through surgical resection or through a deep-seated damage method with strong currents. Disc-shaped small metal sheet affixed to the scalp to record an EEG . Positron emission tomography (PET) detects the release of a positron after absorption of glucose, and all brain regions of a person awake are activated. Functional magnetic resonance imaging (fMRI) enables visualization of brain activity.

The human brain weighs 1.4 kilograms and the cerebral cortex, which is 3 mm thick, contains neurons in the central nervous system 70% . The left hemisphere of the brain is responsible for information decomposition and sequential processing , and the right hemisphere mainly completes simultaneous processing of the whole . By cutting off the corpus callosum to control seizures , each hemisphere of the brain can independently perform sensory processing , conceptual organization , and behavioral stimulation .

The top of the frontal lobe has a primary motor area , and there are some mirror neurons in the motor cortex, and the surrounding joint area is responsible for processing and integrating information. Broca's Area injury will lead to exercise aphasia, the frontal lobe area is responsible for the formation of self-concept and current emotional state awareness, frontal lobe damage can lead to reasoning difficulties, improve impulsivity, more drug addiction. The parietal lobe has a primary somatosensory area. The temporal lobe has a primary auditory area , and the Werneck area damage leads to sensory aphasia. The occipital lobe has a primary visual area , and visual impairment is caused by the damage of vision combined area . Joint injury at the bottom of the occipital lobe causes face loss .

The subcortical structure is divided into the brainstem, midbrain and Forebrain, and the midbrain is the connecting part of the forebrain and brainstem. The brainstem consists of the medulla oblongata that connects the spinal cord with the brain and the cerebellum located at the base of the brain. The medulla oblongata controls the reflex of plant functions such as heart rate, respiration, swallowing, bridging the medulla oblongata and other brain regions and controlling human sleep and awakening, the cerebellum maintaining posture , balance , The degree of muscle tightness . The reticular structure located in the medulla oblongata and brainstem determines which information can activate the cerebral cortex .

The thalamus and hypothalamus are a key part of the forebrain , which is the relay station that senses the passage into the cortex, and the hypothalamus is the main control center for emotions and many basic motivations. The limbic system is composed of hypothalamus, partial thalamus, amygdala, hippocampus and other structures. The amygdala is associated with fear, and the hippocampus is associated with long-term memory and spatial localization. Animals can learn to obtain electrical stimulation of the limbic system by pressing the lever , cocaine, amphetamine, heroin, nicotine, marijuana, alcohol, etc. can activate the happy passage .

Hormones secreted by the endocrine glands are transported through blood or lymphatic circulation to the body to activate the cells at specific cell receptor sites. The pituitary gland, which is controlled by the hypothalamus, secretes growth hormone and oxytocin and regulates other glands, and melatonin secreted by the pineal gland can react to day and night, at the neck of the thyroid gland . Secretion of thyroxine regulates metabolism and makes wasting and tension. The adrenal gland is located just above the kidney and below the chest, and the adrenal medulla secretes the adrenaline associated with fear and norepinephrine, the adrenal cortex , which is associated with anger . corticosteroids are used to regulate salt balance, help the body adapt to stress, and act as a second source of sex hormones.

Left hand grip and right hand hook with right brain advantage , left hand hook and right hand straight grip with left brain superiority , left-handed hand of clumsy may come from living in right hand build world, left-handed hand people's brain function less than right hand. If the brain is a musical instrument, then the mind is the music played by the instrument.

Rain Yoko
October 17, 2015
Neurons_nervoussystem_endocrinesystem

Neurons and nervous systems and the endocrine system