A&p Ii Ch. 16

Front 1

Includes those organs whose primary function is theproduction of hormones or paracrines

Back 1

Endocrine System

Front 2

What organs does the Endocrine System include?

Back 2

Hypothalamus, pituitary gland, thyroid gland, adrenalgland, pancreas (pancreatic islets), pineal gland,parathyroid glands

Front 3

Many other organs contain tissues that secretehormones, but endocrine function is secondary

Back 3

Heart

Thymus

Digestive tract

Kidneys

Gonads

Front 4

Back 4

Front 5

Secretes hormones involved in fluid balance, smoothmuscle contraction, control of hormone secretion byanterior pituitary gland

Back 5

Hypothalamus

Front 6

Secretes multiple hormones that regulate theendocrine activities of the adrenal cortex, thyroidgland, and reproductive organs, and a hormone thatstimulates melanin production

Back 6

Pituitary gland

Front 7

Secretes hormones affecting metabolic rate andcalcium ion levels in body fluids

Back 7

Thyroid gland

Front 8

• Secrete hormones involvedwith mineral balance, metabolic control, andresistance to stress• They also release epinephrine and norepinephrineduring sympathetic activation

Back 8

Adrenal glands

Front 9

Secretes hormones regulating rate of glucose uptake and utilization by body tissues

Back 9

Pancreas (pancreatic islets)

Front 10

Secretes melatonin, which affects reproductive function and circadian (day/night) rhythms

Back 10

Pineal gland

Front 11

Secrete hormone important to regulation of calcium ion levels in body fluids

Back 11

Parathyroid glands

Front 12

Blood volume

Back 12

Heart

Front 13

Immune response

Back 13

Thymus

Front 14

digestive function coordination,glucose metabolism, appetite

Back 14

Digestive tract

Front 15

• blood cell production

• rate of calcium andphosphorus absorption by digestive tract

• and an enzyme involved in regulating blood pressure

Back 15

Kidneys

Front 16

growth, metabolism, sexual characteristics as well as activities of organs in reproductive system

Back 16

Gonads

Front 17

To respond to a hormone, a target cell must have the appropriate protein _________.

Back 17

receptor

Without the receptor, the circulating hormone has noeffect.

Front 18

______ have receptors for many different hormones.

Back 18

Cells

Front 19

Different combinations of receptors produce differentialeffects on _______ _______.

Back 19

specific tissues

Front 20

Receptor in plasma membrane

Back 20

Extracellular receptors

Front 21

Hormones affect target cells after binding to receptors in the ___________, ___________, or ___________.

Back 21

plasma membrane

cytoplasm

nucleus

Front 22

relaying message to an intracellular intermediary (second messenger)

Back 22

first messenger

Front 23

Back 23

G protein- coupled receptors

Front 24

Examples of second messengers

Back 24

1. Cyclic AMP (cAMP)

• Derivative of ATP

• Increased levels may activate enzymes or open ionchannels, accelerating cell metabolic activity

• Decreased levels has inhibitory effect on cell

2. Calcium ions (Ca2+)

• Generally function in combination with intracellularprotein called calmodulin to activate enzymes.

Front 25

Two possible receptor locations on target cells

Back 25

1. Plasma membrane (extracellular receptors)

2. Cytoplasm or nucleus

(intracellular receptors)

Front 26

affects enzyme activity andchanges cellular metabolic reactions, exertinghormone’s effects in the cell

Back 26

Second messenger

Front 27

(enzyme complex coupled to receptor)

Back 27

G protein

Front 28

Lipid-soluble hormones diffusethrough plasma membrane

– Alter activity of specific genes

– Affect DNA transcription rate,changing pattern of protein synthesis

– Change synthesis of enzyme and structural proteins

Back 28

Steroid hormones

Front 29

•Transported across cell membrane by carrier-mediated processes

– Bind to receptors on mitochondria

• Increase rate of ATP production

•Bind to receptors in nucleus• Activate specific genes orchange rate of transcription• Affects cell’s metabolicactivity and structure

Back 29

Thyroid hormones

Front 30

Provides highest level of endocrine function byintegrating nervous and endocrine systems

Back 30

Hypothalamus

Front 31

Three mechanisms of integration

Back 31

Antidiuretic hormone (ADH)

Oxytocin (OXT)

regulatory hormones

Front 32

Synthesized by the supraoptic nuclei

Back 32

Antidiuretic hormone (ADH)

Front 33

Synthesized by the paraventricular nuclei

Back 33

Oxytocin (OXT)

Front 34

control anterior pituitary gland endocrine cells

Back 34

regulatory hormones

Front 35

Capillary networks and interconnecting vessels between the hypothalamus and the pituitary gland(hypophysis, pituitary gland)

Back 35

Hypophyseal portal system

Front 36

Regulatory hormones released from the hypothalamus at the _______ _______ of infundibulum.

Back 36

median eminence

Front 37

Move from interstitial fluid into ______________.

Back 37

fenestrated capillaries

Front 38

Carried to anterior pituitary in ______________ (portal veins).

Back 38

Portal vessels

Front 39

Allows hypothalamic hormones to reach target cellsin anterior pituitary directly, without mixing anddiluting in general circulation

Back 39

Hypophyseal portal system

Front 40

Back 40

Hypophyseal portal system

Front 41

Stimulate synthesis and secretion of one or morehormones at anterior lobe

Back 41

Releasing hormones (RH)

Front 42

Prevent synthesis and secretion of one or morehormones at anterior lobe

Back 42

Inhibiting hormones (IH)

Front 43

•Small, oval gland nestled within sella turcica ofsphenoid bone

•Releases nine peptide hormones

Seven from anterior lobe (adenohypophysis)

– Called tropic (trope, a turning) hormones because they “turn on” other endocrine glands

• Two from posterior pituitary (neurohypophysis)

• All nine bind to membrane receptors and use cAMP second messenger

Back 43

Pituitary gland, or hypophysis

Front 44

Back 44

Pituitary gland

Front 45

• Thyroid stimulating hormone (TSH)

• Adrenocorticotropic hormone (ACTH)

• Follicle-stimulating hormone

• Luteinizing hormone (LH)

• Growth hormone (GH)

• Prolactin

• Melanocyte-stimulating hormone (MSH)

Back 45

Hormones of the anterior lobe

Front 46

Hormones of the posterior lobe

Back 46

Antidiuretic hormone (ADH)

*in the kidney

Oxytocin (OXT)

*in the uterus

Front 47

• Targets the thyroid gland

• Stimulates release of steroid hormones

• Released in response to thyrotropin-releasing hormone (TRH) from hypothalamus

• Release is decreased when thyroid hormone levels rise (negative feedback)

Back 47

Thyroid-stimulating hormone (TSH)

Front 48

• Stimulates release of steroid hormones from adrenal cortex

(specifically those that affect glucose metabolism)

• Released in response to corticotropin-releasing hormones (CRH) from hypothalamus

Back 48

Adrenocorticotropic hormone (ACTH) or corticotropin

Front 49

• Regulates activity of the gonads

• Released in response to gonadotropin-releasing hormone (GnRH) from hypothalamus

Back 49

Gonadotropins

Front 50

F: promotes ovarian follicle development and (in combination w LH) stimulates secretion of estrogens

M: promotes maturation of developing sperm

Inhibited by inhibin (peptide released by gonads)

Back 50

Follicle-stimulating hormone

Front 51

F: induces ovulation, promotes secretion of estrogen and progesterone, prepares body for possible pregnancy

M: stimulates interstitial cells of testes to produce sex hormones (androgens), primarily testosterone

Back 51

Luteinizing hormone (LH)

Front 52

Stimulates cell growth and reproduction by accelerating rate of protein synthesis

– Skeletal muscle and chondrocytes are particularly sensitive to GH • Regulated by two hypothalamic hormones

• Growth hormones can be direct or indirect

Back 52

Growth hormone (GH)

Front 53

Growth hormone is regulated by two hypothalamic hormones:

Back 53

– Growth hormone–releasing hormone (GH–RH)

– Growth hormone–inhibiting hormone (GH–IH)

Front 54

Liver cells respond to GH by synthesizing and releasing ________.

Back 54

somatomedins

Front 55

What are somate

Back 55

compounds that stimulate tissue growth or insulin-like growth factors (IGFs)