What is the difference in these two chemical messengers? Neurotransmitters released by neurons Hormones release by endocrine glands endocrine gland neurotransmitter axon hormone carried by blood receptor proteins receptor proteins Lock & Key system target cell 1

Protein Hormone vs Steroid Hormone Warm Up Give 3 differences between the 2 types of hormones: protein and steroid (book pg 978-979). Structure? Examples? Reaction with target cell? Other?

Regulation & Communication Animals rely on 2 systems for regulation endocrine system (hormones) system of ductless glands secrete chemical signals directly into blood chemical travels to target tissue slow, long-lasting response nervous system (neurotransmitters) system of neurons transmits “electrical” signal & release neurotransmitters to target tissue fast, short-lasting response Hormones coordinate slower but longer–acting responses to stimuli such as stress, dehydration, and low blood glucose levels. Hormones also regulate long–term developmental processes by informing different parts of the body how fast to grow or when to develop the characteristics that distinguish male from female or juvenile from adult. Hormone–secreting organs, called endocrine glands, are referred to as ductless glands because they secrete their chemical messengers directly into extracellular fluid. From there, the chemicals diffuse into the circulation. 3

Classes of Hormones Protein-based hormones Lipid-based hormones polypeptides small proteins: insulin, ADH glycoproteins large proteins + carbohydrate: FSH, LH amines modified amino acids: epinephrine, melatonin Lipid-based hormones steroids modified cholesterol: sex hormones, aldosterone insulin 4

Action of protein hormones signal-transduction pathway Action of protein hormones 1 signal protein hormone P plasma membrane binds to receptor protein activates G-protein activates enzyme cAMP receptor protein acts as 2° messenger ATP transduction GTP transduction: the action or process of converting something and especially energy or a message into another form activates cytoplasmic signal ATP activates enzyme 2 secondary messenger system cytoplasm activates enzyme produces an action 3 response target cell 5

Benefits of a 2° messenger system 1 signal Activated adenylyl cyclase receptor protein 2 Not yet activated amplification 4 amplification 3 cAMP amplification 5 GTP G protein protein kinase 6 amplification Amplification! enzyme Cascade multiplier! 7 amplification FAST response! product 6

Action of lipid (steroid) hormones target cell blood S 1 S cross cell membrane protein carrier S 2 cytoplasm binds to receptor protein becomes transcription factor 5 mRNA read by ribosome 3 S plasma membrane 4 DNA mRNA 6 7 nucleus protein protein secreted ex: secreted protein = growth factor (hair, bone, muscle, gametes) 7

FLT Given information on hormones and feedback loops I can explain how homeostasis of glucose and temperature is accomplished through manipulatives, video, and writing

Homeostasis Animation www.brown.edu/Courses/BI0020_Miller/week/10/web-2/4-2-2007_10-21-10/Chapter_41/Present/Animations/41_A02/41_A02s.swf

Maintaining homeostasis hormone 1 gland lowers body condition high specific body condition low raises body condition gland Negative Feedback Model hormone 2 10

The pancreas Islets of Langerhans Alpha cells: •glucagon~ raises blood glucose levels Beta cells: •insulin~ lowers blood glucose levels Type I diabetes mellitus (insulin-dependent; autoimmune disorder) Type II diabetes mellitus (non-insulin-dependent; reduced responsiveness in insulin targets)

Homeostasis of Blood Glucose

Regulation of Blood Sugar Endocrine System Control Feedback Regulation of Blood Sugar islets of Langerhans beta islet cells insulin body cells take up sugar from blood liver stores glycogen reduces appetite pancreas liver high blood sugar level (90mg/100ml) low liver releases glucose triggers hunger pancreas liver islets of Langerhans alpha islet cells glucagon 13

Glucose and Glycogen—carbs Insulin and Glucagon—hormones Pancreas and Liver—organs Cells with mitochondria--target

Glucose http://bcs.whfreeman.com/thelifewire/content/chp50/5002002.html

Temperature Homeostasis http://bcs.whfreeman.com/thelifewire/content/chp41/41020.html

Positive Feedback AMPLIFICATION

positive feedback Birth

Positive Feedback in Plants Ripening Fruit—hormone ethylene One of the coolest things about ethylene is that it is released in a positive feedback loop: a little bit of ethylene causes more to be released, which causes even more to be released, and so on. A benefit of this fact is that you can take an unripe fruit (a pear, plum, or peach, for example) and put it in a paper bag with riper fruit (bananas work well for this) and ethylene will accumulate, making the unripe fruit soft and sweet.

Hormone: Animation (ADH) http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter20/animation__hormonal_communication.html

Plant Responses to Light Stress

Light Stress A plant is under light stress when it is unable to quench the light energy it is receiving either by way of photochemical or non-photochemical process. Leads to photoinhibition and possible free radical damage

Photoinhibition The reduction in capacity for photosynthesis Inhibition is primarily in photosystem II reaction center Occurs when the system becomes light-saturated Is reversible to some degree Depends on how adapted the plant is to varying light conditions

Plant Response to Water Stress

Plant Response to Water Stress

Problems with feedback loops -Diabetes -Dehydration due to less ADH

To do Practice the feedback loop related to Glucose Temperature Birth Plant Response to Dehydration (use book pg 983 as a resource)

The adrenal glands Adrenal medulla (catecholamines): •epinephrine & norepinephrine~ increase basal metabolic rate (blood glucose and pressure) Adrenal cortex (corticosteroids): •glucocorticoids (cortisol)~ raise blood glucose •mineralocorticoids (aldosterone)~ reabsorption of Na+ and K+

Chapter 45 ~ Chemical Signals in Animals Endocrine system ~Hormones

tropic hormones = target endocrine glands hypothalamus thyroid-stimulating hormone (TSH) posterior pituitary antidiuretic hormone (ADH) Thyroid gland anterior pituitary adrenocorticotropic hormone (ACTH) Kidney tubules oxytocin Muscles of uterus gonadotropic hormones: follicle- stimulating hormone (FSH) & luteinizing hormone (LH) growth hormone (GH) melanocyte-stimulating hormone (MSH) prolactin (PRL) Adrenal cortex tropins (tropic hormones) stimulate growth in target organs/cells (tropic means nourishment) When the target organ is another gland, tropic hormones cause them to produce & release their own hormones. Melanocyte in amphibian Mammary glands in mammals Bone and muscle Ovaries Testes 32

Regulatory systems Hormone~ chemical signal secreted into body fluids (blood) communicating regulatory messages Target cells~ body cells that respond to hormones Endocrine system/glands~ hormone secreting system/glands (ductless); exocrine glands secrete chemicals (sweat, mucus, enzymes) through ducts Neurosecretory cells~ actual cells that secrete hormones Feedback mechanisms ~ negative and positive

Vertebrate Endocrine System Tropic hormones ~ a hormone that has another endocrine gland as a target Hypothalamus~pituitary Pituitary gland Pineal gland Thyroid gland Parathyroid glands Thymus Adrenal glands Pancreas Gonads (ovary, testis)

Nervous & Endocrine systems linked Hypothalamus = “master nerve control center” nervous system receives information from nerves around body about internal conditions releasing hormones: regulates release of hormones from pituitary Pituitary gland = “master gland” endocrine system secretes broad range of “tropic” hormones regulating other glands in body hypothalamus posterior pituitary anterior 35

The hypothalamus & pituitary, I Releasing and inhibiting hormones Anterior pituitary: Growth (GH)~bones √gigantism/dwarfism √acromegaly Prolactin (PRL)~mammary glands; milk production Follicle-stimulating (FSH) & Luteinizing (LH)~ovaries/testes Thyroid-stimulating (TSH)~ thyroid Adrenocorticotropic (ACTH)~ adrenal cortex Melanocyte-stimulating (MSH) Endorphins~natural ‘opiates’; brain pain receptors

The pituitary, II The posterior pituitary: Oxytocin~ uterine and mammary gland cell contraction Antidiuretic (ADH)~ retention of water by kidneys

The pineal, thyroid, & parathyroid Melatonin~ pineal gland; biological rhythms Thyroid hormones: Calcitonin~ lowers blood calcium Thyroxine~ metabolic processes Parathyroid (PTH)~ raises blood calcium

Regulation of Blood Calcium Endocrine System Control Regulation of Blood Calcium Feedback calcitonin  kidney reabsorption of Ca++ thyroid Ca++ deposited in bones high  Ca++ uptake in intestines blood calcium level (10 mg/100mL) low activated Vitamin D  kidney reabsorption of Ca++ parathyroid bones release Ca++ parathyroid hormone (PTH) 39

Regulating metabolism Hypothalamus TRH = TSH-releasing hormone Anterior Pituitary TSH = thyroid stimulating hormone Thyroid produces thyroxine hormones metabolism & development bone growth mental development metabolic use of energy blood pressure & heart rate muscle tone digestion reproduction The thyroid gland produces two very similar hormones derived from the amino acid tyrosine: triiodothyronine (T3), which contains three iodine atoms, and tetraiodothyronine, or thyroxine (T4), which contains four iodine atoms. In mammals, the thyroid secretes mainly T4, but target cells convert most of it to T3 by removing one iodine atom. Although both hormones are bound by the same receptor protein located in the cell nucleus, the receptor has greater affinity for T3 than for T4. Thus, it is mostly T3 that brings about responses in target cells. tyrosine + iodine thyroxines 40

The gonads Steroid hormones: precursor is cholesterol androgens (testosterone)~ sperm formation; male secondary sex characteristics; gonadotropin estrogens (estradiol)~uterine lining growth; female secondary sex characteristics; gonadotropin progestins (progesterone)~uterine lining growth

Answer the following (74-77) Fill in reflection sheet + review area Dispatch Answer the following (74-77) Fill in reflection sheet + review area Conference with Morris cont

Mr. Anderson’s Positive and Negative Feedback Loopds