Endocrine System

#3

Endocrine System

• slower responses

• long-duration responses

• act via hormones → blood (long distances)

• acts at diffuse locations → target where blood is

Nervous System

• RAPID responses

• Short-duration responses

• acts via action potentials + neurotransmitters

• acts at specific locations determined by axon pathways

• Neurons act on short distances

Exocrine Glands

• fluid that isn’t hormones

  • sweat, oil, mucus, digestive glands

Endocrine Glands

• hormones

Synergistic Hormones

• hormones that work effectively when another is there to assist

  • EPI + NOREPI

Antagonist Hormones

• Hormones that oppose the actions of other hormones

  • INSULIN & GLUCAGON

Hypothalamus

• secretes releasing and inhibiting hormones that control the release of hormones by the pituitary gland

• brain structure

Pituritary Gland

• Anterior and Posterior lobe

  • Ant = ~75%, 7 Hormones

  • Post = ~25%, 2 Hormones

Anterior Pituritary Gland

1. GH

2. TSH

3. FSH

4. LH

5. Prolactin

6. ACTH

7. MSH

Growth Hormone (GH)

• promotes growth of tissue (liver)

  • made in pit. gland, sent to liver

• stimulated: puberty & excercise

Thyroid Stimualting Hormone (TSH)

• secretes thyroid hormone & sent to thyroid gland

Follicle Stimulating Hormone (FSH)

• FEMALES: Egg, estrogen

• MALES: Testes -→ sperm

Lutemizing Hormone (LH)

• FEMALES: Estrogen, progesterone, ovulation, form corpus luteum

• MALES: testes → testosterone

Corpus Luteum

• temporary endocrine gland that forms in the ovary from the leftover ovarian follicle after an egg is released during ovulation

• egg leaves the corpus luteum behind….

Prolactin (PRL)

• milk production → mammary glands

Adrenocartitropic (ACTH)

• secrete glucuocortoids (mainly cortisol)

  • goes to zona fasciulata → binds to receptors → stim. production & release of glucuocortoids, primarily cortisol

Melancyte-stimulating hormone (MSH)

• skin color

• excess = darkening of skin

• tan = MSH increase

Posterior Pituritary Gland

• Oxytocin

• ADH

Oxytocin

• bonding hormone + childbirth

  • released when pleasured

  • responds to cervical stretch during childbirth

    • uterus: enhances contraction

    • breast: eject milk

Antidiuretic hormone (ADH)

• decreases urine output

• amount secreted varies with blood osmotic pressure

Thyroid Gland

• butterfly shaped

• inf. to larynx and ant to trachea

• Follicular Cells & Parofollicular Cells

Follicular Cells

• stimulated by TSH

• produce triiodothyrone (T3) & thyroxine (T4)

  • metabolism

Parofollicular Cells

• produces Calcitonin

  • too much calcium → thyroid gland → parofollicular cells → make calcitonin → decrease calcium levels.

Parathyroid Glands

• located: back of thyroid

• 2 glands (2 superior 2 inferior)

• contains chief and oxyphil cells

Chief cells

• produce PTH —> increase cal. levels

  • low calcium → PT GLAND → Chief Cells → make PTH → increase calcium levels

Oxyphil

• cancerous parathyroid glands → secretes excess PTH

• unknown purpose in normal PT glands

Suprarenal/Adrenal Glands

• location: on top of kidneys

• glands divided into two regions

  • outer cortex

  • inner medulla