Responsable for all communication in our body
Endocrine and Nervous Systems
1) ENDOCRINE SYSTEM
A network of hormone-secreting glands (chemical signals) that travel through the blood to regulate cells and organs.
Hypothalamus (→ Dopamine, somatostatin, vasopressin, thyrotropin releasing hormone, corticotropin releasing hormone, growth hormone releasing hormone)
Pineal gland (→ Melatonin)
Pituitary gland (→ Prolactin, oxytocin, vasopressin, growth hormone, thyroid stimulating hormone, adrenocorticotropic hormone, follicle stimulating hormone, melanocyte stimulating hormone, luteinizing hormone)
Thyroid and parathyroid (→ Calcitonin, triiodothyronine, thyroxine, parathyroid hormone)
Thymus (→ Thymopoietin)
Stomach (→ Gastrin, ghrelin, histamine, somatostatin, neuropeptide Y)
Liver (→ Insulin-like growth factor, thrombopoietin)
Pancreas (→ Insulin, glucagon, somatostatin)
Adrenal (→ Androgens, glucocorticoids, adrenaline, noradrenaline)
Kidney (→ Calcitriol, renin, erythropoietin)
Ovary and placenta (→ Progesterone, estrogen)
Uterus (→ Prolactin, relaxin)
Testes (→ Androgens, estradiol, inhibin)
2) NERVOUS SYSTEM
A network of nerves transmitting information (electrical signals) that pass through neurons throughout the body.
Central nervous system and peripheral nervous system
2.I) CENTRAL NERVOUS SYSTEM
Composed of brain and spinal cord ; The spinal cord carries information between the brain and the rest of the body.
2.II) PERIPHERAL NERVOUS SYSTEM
Made up of afferent visceral nerves (which reach the Central Nervous System), efferent visceral nerves (which leave the Central Nervous System), sensory nerves (which carry information from the sense organs : eyes, ears, skin, nose, tongue) and visceral motor nerves (which transmit information to muscles and glands).
Somatic and Autonomic Nervous System
2.II.A) SOMATIC NERVOUS SYSTEM
Conscious bodily actions; Innervations (distribution of nerves) efferent towards the skeletal muscles (biceps, quadriceps, abdominals, ...), and afferent innervations from the skin, muscles and joints.
2.II.B) AUTONOMOUS NERVOUS SYSTEM
Unconscious bodily actions; Innervations of the heart muscle, smooth muscles, blood vessels, glands, visceral organs. Afferent innervations measure blood pressure and the oxygen content of the blood. The efferent innervations modify the dilation of the bronchi and the release of digestive juices.
Sympathetic, Enteric, and Parasympathetic Nervous Systems
2.II.B.1) SYMPATHIC NERVOUS SYSTEM
Accelerator, exciter; Activates fight or flight responses (stress, danger, physical activities, etc.); Contracts muscles, accelerates heart rate, creates high blood pressure, dilates pupils and pulmonary bronchioles, contracts the bladder, reduces sexual arousal, weakens erection, creates poor digestion, etc.
2.II.B.2) ENTERIC NERVOUS SYSTEM
Controls the digestive tract.
2.II.B.3) PARASYMPATHIC NERVOUS SYSTEM
Decelerator, moderator; Activates resting and digestive responses (calms the body once the danger has passed); Relaxes the muscles, slows the heart rate, lowers blood pressure, contracts the pupils, tightens the pulmonary bronchioles, relaxes the bladder (urination) and the sphincter (defecation), induces fatigue, yawning, good sexual arousal, good erection, good digestion, etc ...