Photosynthesis

1
(No Transcript)
2
Outline

• Endocrine Glands
• Pheromones
• Steroid Hormones
• Peptide Hormones
• Hypothalamus and Pituitary Gland
• Other Endocrine Glands and Hormones
• Thyroid
• Parathyroid
• Adrenal
• Pancreas
• Gonads

3
The Human Endocrine System
4
Chemical Signals

• Pheromones
• Chemical signals that work at a distance between
  individuals
• A womans axillary extract can alter another
  womans menstrual cycle
• Hormones
• Chemical signals that work
• At a distance between organs, or
• Locally between adjacent cells

5
Target Cell Concept
6
Action of Hormones

• Hormones
• Chemical signals produced by one cell that
  regulate the metabolism of other cells
• Steroid Hormones
• Can cross cell membranes
• Peptide Hormones
• Most bind to receptor in plasma membrane
• First Messenger
• Causes internal release of cAMP
• Second Messenger

7
Peptide Hormone
8
Steroid Hormone
9
Human Endocrine System

• Endocrine glands
• Ductless glands that secrete hormones directly
  into the bloodstream
• Most endocrine hormones are peptides
• Only gonads and adrenal cortex produce steroid
  hormones
• Effects of hormones are moderated in two ways
• Negative feedback opposes release
• Antagonistic hormones oppose each others actions

10
Hypothalamus and Pituitary Gland

• Hypothalamus regulates internal environment
• Acts through autonomic system
• Also controls glandular secretions of pituitary
  gland
• Posterior Pituitary
• Antidiuretic Hormone (ADH)
• Controlled by negative feedback
• Oxytocin
• Controlled by positive feedback
• Anterior Pituitary
• Hypothalamus controls by producing
• Hypothalamic-releasing hormones, and
• Hypothalamic-inhibiting hormones

11
Hypothalamus and the Pituitary
12
Anterior Pituitary Hormones

• Anterior pituitary hormones that affect other
  glands
• Thyroid-Stimulating Hormone (TSH)
• Adrenocorticotropic Hormone (ACTH)
• Gonadotropic Hormones
• Anterior pituitary hormones that do NOT affect
  other glands
• Prolactin (PRL)
• Melanocyte-Stimulating Hormone (MSH)
• Growth Hormone (GH)

13
Effect of Growth Hormone
14
Acromegaly
15
Thyroid Glands

• Composed of large number of follicles filled with
• Triiodothyronine (T3), and
• Thyroxine (T4)
• Thyroid hormones increase metabolic rate
• Thyroid-induced abnormalities
• Simple goiter - Poor hormone production
• Cretinism - Poor thyroid development
• Myxedema - Hypothyroidism
• Exophthalmic goiter - Hyperthyroidism

16
Simple Goiter
17
Cretinism
18
Calcitonin

• Regulates blood calcium level (in part)
• Secreted by thyroid gland when blood calcium
  level rises
• Brings about deposit of calcium in the bones
• Low calcium level in blood stimulates the release
  of parathyroid hormone (PTH)
• Parathyroid hormone causes
• Phosphate level in blood to decrease, and
• Calcium level in blood to increase
• Insufficient production of parathyroid hormone
  leads to tetany

19
Regulation of Blood Calcium Level
20
Adrenal Glands

• Paired One sits atop each kidney (ad-renal)
• Each consists of outer cortex and inner medulla
• Inner portion, the adrenal medulla
• Produces
• Epinephrine, and
• Norepinephrine
• Short-term response to stress (fight or flight)
• Outer portion, adrenal cortex
• Produces
• Mineralocorticoids, and
• Glucocorticoids
• Long-term response to stress

21
Adrenal Glands
22
Glucocorticoids

• Cortisol
• Raises blood glucose level
• Promotes breakdown of muscle proteins to amino
  acids
• Promotes metabolism of fatty acids
• Counteracts inflammatory response

23
Mineralocorticoids

• Aldosterone
• Promotes two renal functions
• Absorption of sodium, and
• Excretion of potassium
• Renin-angiotensin-aldosterone system
• Raises blood pressure
• Angiotensin II constricts arterioles
• Aldosterone causes kidneys to reabsorb sodium
  (causing water retention)
• Atrial natriuretic hormone (ANH) is antagonistic
  to aldosterone

24
Regulation ofBlood Pressure and Volume
25
Addison Disease
26
Cushing Syndrome
27
Pancreas

• Made up up exocrine and endocrine tissue
• Endocrine Portion of the Pancreas
• Consists of pancreatic islets
• Produce and secrete
• Insulin
• Secreted during high blood glucose level
• Stimulates uptake of glucose by cells
• Glucagon
• Secreted during low blood glucose level
• Stimulates liver to break down glycogen
• Exocrine Portion of the Pancreas
• Secretes enzymes and buffers into intestine

28
Regulation of Blood Glucose Level
29
Other Endocrine Glands

• Gonads
• Testes
• Produce testosterone
• Secondary sex characteristics
• Ovaries
• Produce estrogen and progesterone
• Reproduction
• Secondary sex characteristics

30
The Effects of Anabolic Steroid Use
31
Other Endocrine Glands

• Pineal Gland
• Produces melatonin
• Involved in Circadian rhythms
• Thymus Gland
• Secrete thymosins
• Aid in differentiation of lymphocytes
• Prostaglandins
• Produced within cells
• Not distributed in blood

32
Melatonin Production
33
Review

• Endocrine Glands
• Pheromones
• Steroid Hormones
• Peptide Hormones
• Hypothalamus and Pituitary Gland
• Other Endocrine Glands and Hormones
• Thyroid
• Parathyroid
• Adrenal
• Pancreas
• Gonads

34
(No Transcript)