endocrine system

• Endocrine system exerts chemical control over the human body.
• Maintenance of homeostasis is shared by the Endocrine and Nervous System.
• The Hypothalamus of the Brain sends signals to the Pituitary Gland.
• Endocrine Glands are ductless glands that secrete the hormones into the bloodstream.
• Hormones are chemical substances that affect the activity of another part of the body.
• Hormones serve as messengers, controlling and coordinating activities throughout the body.
• Cellular respiration, growth and reproduction (Growth Hormone)
• Fluids in the body (Vasopressin)
• Secretion of other hormones (Thyrotropin)
• Behaviour pattern (Serotonin)
• reproductive cycles of men & women (Testosterone and Estrogen)
• MODIFIED AMINO ACIDS: Adrenal Medulla and Posterior Pituitary Gland
• Epinephrine (Fight-or-Flight)
• Norepinephrine (Stress Hormone)
• Oxytocin (Love Hormone)
• Vasopressin (Water Retention and Increase Blood Pressure)
• PROTEIN HORMONES: Pancreatic Islets and Anterior Pituitary Gland
• Classification of Hormones: Modified amino acids, Protein hormones, and Steroid hormones
• HYPOTHALAMUS OF THE BRAIN

  ✔ Inferior part of the diencephalon

  ✔ Controls secretions from the pituitary gland

  ✔ Sends neural and chemical signals to the pituitary gland
• INFUNDIBULUM

  ✔ Funnel-shaped stalk

  ✔ Extends from the floor of the hypothalamus connecting it to the pituitary gland
• Neurosecretions- Chemical signals that nerve cells in the hypothalamus produce.
• Pituitary Glands

  ● Hypophysis

  ● A small gland (about a size of pea)

  ● Its hormones affect other endocrine glands such as testes, ovaries, the adrenal cortex,

  and the thyroid gland.
• Pituitary glands is divided into two lobes: Anterior and Posterior
• ANTERIOR PITUITARY GLAND

  ▪ Adenohypophysis

  ▪ Produces seven hormones
• Growth Hormone

  o Stimulates cell metabolism causing cells to divide and increase in size.

  o Influenced by nutrition, genetics, and sex hormones
• Too little growth hormone results Dwarfism
• Too much growth hormone results Gigantism
• HORMONES Control the internal environment of the body.
• Hormone helps to control the concentrations of a number of hormones in our bodies.
• Hormone production and release are primarily controlled by negative feedback.
• Thyroid stimulating hormone - Stimulates the thyroid gland to produce its hormone
• Thyroid stimulating hormone - o Its secretion rate is regulated by the hypothalamus
• Thyroid stimulating hormone - Thyrotropin-releasing hormone (TRH)
• Adrenocorticotropic hormone - Stimulates the adrenal cortex to secrete its hormone

  called CORTISOL.

  o Regulated by corticotropin-releasing hormone (CRH)

  produced by the hypothalamus.
• Melanocyte stimulating hormone - Increases the production of melanin

  o Causes deepening pigmentation
• Follicle stimulating hormone

  o In females, it stimulates development of the follicles in the ovaries.

  o In males, it stimulated the production of sperm cells.
• Luteinizing Hormone

  o In females, it stimulates ovulation in the ovary and production of progesterone.

  o It helps maintain pregnancy.

  o In males, it stimulates the synthesis of testosterone. o It helps maintain sperm cell production.
• ● Lactogenic Hormone

  o Stimulates milk production in the mammary glands o In females, it maintains progesterone levels.

  o In males, it appears to increase sensitivity

  o It may cause a decrease in male sex hormones

  o Prolactin
• POSTERIOR PITUITARY GLAND

  ▪ Consists primarily of nerve fibers and neuroglial cells that support the nerve fibers.
• Special neurons in the hypothalamus produce its hormones.