Compare and contrast exocrine and endocrine glands'

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Chapter 16

• Compare and contrast exocrine and endocrine
  glands.
• Name the major glands and their functions in the
  endocrine system.
• What is diabetes (Type 1 and 2) and how might you
  prevent Type 2?
• How does the endocrine system maintain
  homeostasis?

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Endocrine system
15.1 Endocrine glands
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Exocrine vs. endocrine glands
15.1 Endocrine glands

• Exocrine glands secrete their products into ducts
  that carry these products to other organs or
  outside the body
• Endocrine glands secrete their products directly
  into the bloodstream

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What are hormones?
15.1 Endocrine glands

• Hormones are chemical signals that promote
  communication between cells, body parts and even
  individuals
• Hormones
• Prostaglandins
• Pheromones
• Peptide hormones
• Steroid hormones

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Major glands of the endocrine system
15.2 Hypothalamus and pituitary gland

• Hypothalamus
• Posterior pituitary gland
• Anterior pituitary gland
• Thyroid gland
• Parathyroid glands
• Adrenal glands
• Pancreas
• Testes
• Ovaries
• Thymus gland
• Pineal gland

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1. Hypothalamus
15.2 Hypothalamus and pituitary gland

• Regulates internal environment through the
  autonomic nervous system
• Helps control heartbeat
• Helps control body temperature
• Helps control water balance
• Controls secretions of other endocrine glands

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2. Pineal gland
15.6 Other endocrine glands

• Located in the brain
• Secretes melatonin

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3. Posterior pituitary gland
15.2 Hypothalamus and pituitary gland

• Stores antidiuretic hormone (ADH) and oxytocin
  that are produced by the hypothalamus
• ADH
• Oxytocin

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4. Anterior pituitary gland
15.2 Hypothalamus and pituitary gland

• Hormones produced by the anterior pituitary
• Thyroid-stimulating hormone (TSH)
• Adrenocorticotropic hormone (ACTH)
• Gonadotropic hormones
• Prolactin (PRL)
• Melanocyte-stimulating hormone (MSH)
• Growth hormone (GH)

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What happens when the body produces too much or
too little GH?
15.2 Hypothalamus and pituitary gland

• Pituitary dwarfism too little GH is produced
  during childhood that results in small stature
• Gigantism too much GH is produced during
  childhood that results in poor health
• Acromegaly overproduction of GH as an adult
  that results in larger than normal feet, hands,
  and face

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What happens when GH is produced in improper
results during childhood?
15.2 Hypothalamus and pituitary gland
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What happens when GH is produced in high amounts
during adulthood?
15.2 Hypothalamus and pituitary gland
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5. Thyroid gland
15.3 Thyroid and parathyroid glands

• A large gland located below the larynx
• Iodine is needed in the diet to allow the thyroid
  gland to produce its hormones
• It produces
• Thyroid hormone (TH)
• Calcitonin

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Thyroid abnormalities
15.3 Thyroid and parathyroid glands

• Simple goiter thyroid enlarges due to lack of
  iodine in the diet
• Hypothyroidism low blood levels of thyroid
  hormones
• Congenital hypothyroidism.
• Myxedema
• Hyperthyroidism excess thyroid hormones in the
  blood
• Exophthalimic goiter
• Thyroid tumor

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Thyroid abnormalities
15.3 Thyroid and parathyroid glands
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6. Parathyroid glands
15.3 Thyroid and parathyroid glands

• Small glands embedded in the surface of the
  thyroid gland
• Produces parathyroid hormone (PTH)

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15.3 Thyroid and parathyroid glands

• Too much calcium?
• Thyroid secretes calcitonin
• Not enough calcium?
• Parathyroid secretes PTH

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7. Adrenal glands
15.4 Adrenal glands

• Glands that sit on top of the kidneys
• 2 parts of each gland
• Adrenal medulla controlled by the nervous system
• Adrenal cortex portions are controlled by ACTH
  from the anterior pituitary

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Adrenal medulla
15.4 Adrenal glands

• Inner portion of the adrenal glands
• Produces hormones that allow a short-term
  response to stress (fight or flight response)
• Epinephrine (adrenaline)
• Norepinephrine

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Adrenal cortex
15.4 Adrenal glands

• Outer portion of the adrenal glands
• Produces hormones that provide a long-term
  response to stress
• 2 major types of hormones
• Mineralocorticoids
• Glucocorticoids

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Adrenal glands can malfunction
15.4 Adrenal glands

• Addisons disease hyposecretion of
  glucocorticoids by the adrenal cortex
  characterized by bronzing of the skin

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Adrenal glands can malfunction
15.4 Adrenal glands

• Cushing syndrome hypersecretion of
  glucocorticoids by the adrenal cortex
  characterized by weight gain in the trunk of the
  body but not arms and legs

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8. Thymus gland
15.6 Other endocrine glands

• Lies beneath the sternum
• This gland is largest and most active during
  childhood
• Secretes hormones called thymosins

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9. Pancreas
15.5 Pancreas

• Located behind the stomach
• Composed of 2 tissues
• Exocrine produces and secretes digestive juices
• Endocrine (islets of Langerhans) produces and
  secretes hormones
• Insulin
• Glucagon

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15.5 Pancreas

• Too much glucose?
• Pancreas secretes insulin
• Not enough glucose?
• Pancreas secretes glucagon

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Health focus What is diabetes?
15.5 Pancreas

• Inability to control blood glucose levels
• There are two types Type 1 and Type 2
• 18 million people in the US have diabetes
• General symptoms
• Frequent urination
• Unusual hunger and/or thirst
• Unexplained change in weight
• Blurred vision
• Sores that heal slowly or not at all
• Excessive fatigue
• Long-term effects are blindness, loss of limbs,
  nerve deterioration, kidney and cardiovascular
  disease

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Diabetes Understanding the 2 types
15.5 Pancreas

• Type 1
• Usually early-onset
• Autoimmune disorder
• Pancreatic cells are attacked and cannot produce
  insulin
• Need insulin injections

• Type 2
• Usually adult-onset and most common type
• Tends to occur in obese, sedentary people
• Cells do not respond to insulin
• Diet and exercise are important for controlling
  this and may even prevent

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Sex hormones
15.6 Other endocrine glands

• Ovaries

• Testes

• Produce estrogen and progesterone

• Produce androgens (e.g. testosterone)

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Hormones from other tissues
15.6 Other endocrine glands

• Erythropoietin
• secreted by the kidney to increase red blood cell
  production
• Leptin produced by fat cells and acts on the
  hypothalamus to give a feeling of being full
• Prostaglandins
• Some cause smooth muscle contraction
• Aspirin and ibuprofen block the synthesis of these