Endocrine System Major Hormone Secreting Structures The Endocrine

Endocrine System

Major Hormone Secreting Structures

The Endocrine System • A system containing many glands that secrete hormones that send messages in order to maintain homeostasis • A group of glands that work together with the nervous system to coordinate all body functions.

General Information § Integrates and coordinates activities of § body cells. Maintains homeostasis by regulating: 1. 2. 3. 4. metabolism and energy balance water, electrolyte & nutrient balance reproduction, growth and development mobilization of body against stressors § Hormones are secreted into interstitial § fluid diffusing into blood or lymph fluid. Hormones act upon specific target cells.

An Overview of the functions of the Endocrine Glands

§ Pituitary Gland – the master gland. Called this b/c it controls all other endocrine glands and b/c it produces the highest number of different hormones compared to all other endocrine glands. § Hypothalamus – senses the hormone levels in the blood, then tells the pituitary what to do with either hormones it produces or by direct nerve stimulation.

§ Pineal Gland – produces a hormone (melatonin) that helps you go to sleep. § Thyroid Gland – produces hormones that influence metabolic rate, decrease blood calcium and increase bone calcium levels. § Parathyroid Glands – produces a hormone that increases blood and decreases bone calcium levels. § Thymus Gland – produces a hormone that stimulates the immune response in children.

§ Adrenal Glands – produces hormones help prepare the body for stress and control blood pressure. § Pancreas – produces hormones that control BSL (blood sugar level). § Ovaries – produces hormones that control female characteristics and menstrual cycle. § Testes – produces a hormone that control male characteristics and sperm production.

Todays Agenda § Lab- Tagxedo, word cloud § Class Pick up crash course homework due wed 12/16 Take out note packet Objectives: List all the glands in the endocrine system Explain how hormones work with target cells. Distinguish the difference between endocrine glands/ exocrine glands List the 4 different types of hormones

Checkpoint 1. List the functions of the endocrine 2. 3. system. List the major glands in the endocrine system What is the endocrine system and how does it interact with the nervous system?

Functions § Maintain homeostasis § Regulate metabolic rate § Regulate growth and onset of puberty § § and menopause Regulate gametogenesis Regulate pregnancy, childbirth, and milk production

Endocrine Glands vs. Exocrine Glands Endocrine Gland Exocrine Gland

Exocrine gland: § a gland that dumps molecules (ex. enzymes or tears - not hormones) into ducts that generally lead out of the body or into another organ. It is a ducted gland (has tubes). Exocrine glands are NOT part of the endocrine system Examples: salivary, milk, and sweat gland, tear gland, stomach acid,

Sketch the diagram in your notes Basic Structure of an exocrine gland:

The Endocrine System Endocrine gland: § a group of cells organized into a ductless gland (no tubes) that secretes molecular messengers (hormones) directly into the bloodstream. Glands secrete into blood or interstitial fluid Examples: pituitary, adrenal and thyroid ***Horomones

Sketch the diagram in your notes Basic Structure of an endocrine gland:

The Pancreas § The pancreas is a gland that is part endocrine and part exocrine. § The endocrine part of the pancreas secretes hormones. § The exocrine part of the pancreas secretes digestive juices including enzymes.

Regulation & Communication § Two systems for regulation: u endocrine system § ductless glandular epithelium a. secrete hormones directly into blood w chemical travels to target tissue w target cells have receptor proteins b. slow, long-lasting response c. Affects metabolic rate of cells

Regulation & Communication § Two systems for regulation: u nervous system § system of neurons a. transmits “electrical” signal & release neurotransmitters to target tissue (action potentials) b. fast, short-lasting response c. Affects: 3 types of muscles and glands

Regulation by chemical messengers § Neurotransmitters released by neurons § Hormones release by endocrine glands endocrine gland neurotransmitter axon hormone carried by blood receptor proteins target cell Lock & Key system

Hormone § A chemical that acts like a messenger; § § § a protein or steroid that causes a response in a target cell or organ About 50 hormones in the human body. Powerful chemicals that work at low concentrations Produced by endocrine glands, NOT exocrine glands. Basal level =lowest level of hormones Examples: ADH (Antidiuretic hormone), testosterone, thyroxin

Classes of Hormones § Steroids ex. § Protein ex. § Biogenic amine ex. § Flcosonoids ex. insulin

Agenda 12 -16 § Check point § Quiz § Grade Quiz § Notes on target cells and negative feedback

Check Point 1. Explain the main difference between the endocrine and exocrine glands 2. List the major difference between the nervous system and the endocrine system 3. What is a hormone?

12 -17 § Finish looking up hormones action- 10 mins § 20 minutes of notes on target cells and negative feedback § 10 mins for chart activity § LAB: you may use your extra time to finish any of the tasks above § Finish Tagxedo, concussion testing Turn in HW Crash Course

Activity § Using page 322 -323 in your text book § Fill out the information of chemistry of hormones and steroid hormones and non steroid hormones (10 mins)

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

Steroid Hormones § Lipid soluble § § (hydrophobic) Synthesized from cholesterol Transported by a protein in bloodstream. Diffuses inside, binds with DNA to transcribe gene. Full effect could be minutes to days. Animation – Intracellular Receptor Model

Protein Hormones § Water soluble (hydrophilic) § Binds to receptors on target § § cell membranes. No diffusion! Causes second messengers (c. AMP) to be activated inside cell. Cascading effect: a single molecule can activate hundreds of second messengers each which activates thousands of reactions. Rapid response Multiplier effect! Animation – Second Messenger c. AMP

Target Cell § Virtually all cells in the body are exposed to circulating hormones but only certain cells respond to a given hormone § A cell that a hormone is specifically directed towards. Example: ADH works on the collecting tube in the nephron. § Target cells contain molecules on their surface called receptors, to which hormones can bind. Target cells do their job when hormones are bound to their receptors.

Target Cells § Located on surface of cell membranes § Inside target cells § Ex. Increases/decreases rate of cell division § Ex. Increases/ decreases synthesis and secretion of material

Target Cells § Responsiveness can depend on: 1. Hormone concentration 2. Amount of receptors a. up-regulation (increasing # of receptors) b. down-regulation (decreasing # of receptors) 3. Influence of other hormones Synergistic effect vs. Antagonistic effect (Glucagon + epinephrine) (Insulin and Glucagon)

Target Cells § In order for a hormone to cause a response, its’ shape must match the shape of its’ target cell’s receptors. § If the hormone and the cell’s receptors do not match, the cell will not be affected and no response by the cell will occur. § It’s like the lock and key model

Target Cells § Target cell receptors locations: § Example: http: //www. ftmguide. org/images/receptors. gif

Control of Hormone Secretion

Hormone Regulation § Hormone secretion is controlled by: § 1. Neural stimuli 2. Humoral stimuli (blood chemistry) 3. Hormonal stimuli Process used to regulate: FEEDBACK LOOPS!

Negative Feedback § Negative Feedback – is when an activity alters a condition in the body, and this triggers a series of events that reverses the altered condition Ex. Body temperature - When body temp. goes up, we sweat - When body temp. goes down, we shiver

Negative Feedback Ex. Blood sugar levels - When blood sugar goes up, insulin lowers blood sugar - When blood sugar goes down, glucagon raises blood sugar

Homeostasis of Blood Glucose

Gland A secretes a hormone that stimulates gland B to increase secretion of another hormone. The hormone from gland B alters its target cells and inhibits activity of gland A.

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

Agenda 12 -18 § Check Point § Chart Activity (4 people) § Group Work (4 People) § LAB: Work on your Poster Presentation

Check Point § What is a target cell, and how do they § § work? How does negative feedback work? Explain the difference between steroid hormone action and protein horomone action

Agenda 12 -22 § Period 3/4 Waffle Day House Episode Secret Santa Exchange Period 2 Quiz Grade quiz Chart activity time/ project time

Agenda 12/23 Happy Holidays Time to work on your poster presentations use this time to your advantage!

1 -4 -16 Happy New Year § Take out note packet pick up group work activity, Gland list, endocrine system lab § Notes on endocrine glands § Group work activity § Lab- Time to work on your poster presentation Check Point: Meet with the person (Shoulder to Shoulder) next to you take 5 mins to discuss what we have learned about the endocrine system

Endocrine Glands Section 39 -1 Hypothalamus The hypothalamus makes hormones that control the pituitary gland. In addition, it makes hormones that are stored in the pituitary gland. Pituitary gland The pituitary gland produces hormones that regulate many of the other endocrine glands. Parathyroid glands These four glands release parathyroid hormone, which regulate the level of calcium in the blood. Thymus During childhood, the thymus releases thymosin, which stimulates Tcell development. Adrenal glands The adrenal glands release epinephrine and nonepinephrine, which help the body deal with stress. Pineal gland The pineal gland releases melatonin, which is involved in rhythmic activities, such as daily sleep-wake cycles. Thyroid The thyroid produces thyroxine, which regulates metabolism. Pancreas The pancreas produces insulin and glucagon, which regulate the level of glucose in the blood. Ovary The ovaries produce estrogen and progesterone. Estrogen is required for the development of secondary sex characteristics and for the development of eggs. Progesterone prepares the uterus for a fertilized egg. Testis The testes produce testosterone, which is responsible for sperm production and the development of male secondary sex characteristics

Hypothalamus § Part of brain and attached to pituitary § Controls pituitary secretions § Secretes several hormones control the release of other hormones known as releasing hormones

Anterior Pituitary Gland § nickname: Master gland u u Controls the other endocrine glands Secretes 7 hormones § Growth Hormone (GH) – increases metabolic rate u Too much – gigantism u Too little – dwarfism u Prolactin: initiate milk production during pregnancy

Posterior Pituitary Gland § Comprises 25 % of gland § Neurons secrete these hormones (2) § Oxytocin: allows milk secretion and contractions in uterus § Antidiuretic hormone (ADH): decreases urine production

THYROID GLAND (Butterfly Shaped) § Located anterior to the neck just § anterior to the larynx and trachea Regulates Metabolism and energy balance u Secretes 2 hormones: u thyroxine: regulates metabolism u Calcitonin: Decreases Ca in the blood u

1 -5 -16 § Take out note packet and pick up lab from front desk § Notes on parathyroid to Pancreas § Check Point: 1. Which gland is butterflied shape and produces calcitonin? 1. Which gland releases growth releasing hormone? 2. If you drink alcohol which hormone will be inhibited?

Parathyroid Gland - Embedded in the back of the thyroid Secretes parathyroid hormone which controls metabolism of calcium and phosphate

Adrenal Gland § Releases hormones to deal with stress - Located on top of the kidneys Secrete adrenaline which helps deal with stress and accelerates the heart and breathing rates

Adrenal Gland Cont. § Cortex u u Produces more than 2 dozen steroid hormones Aldosterone Cortisol corticosteriods § Medulla u u u “fight or flight” Made up of postganglionic neurons Epinephrine and

Pancreas § Located in abdominal cavity § Secretes 4 hormones § Insulin § glucagon

Ovaries Female gonads are called ovaries produce gametes via meiosis - Located in the pelvic region - Secrete estrogen and progesterone which regulate female secondary sex characteristics -

Testes Male gonads are called testes - Secrete 2 hormones - Located in the scrotum - Secrete testosterone which regulates male secondary sex characteristics - Inhibin- inhibits the release of Menstrual cycle hormones -

Pineal § Rounded gland in midbrain region § Secretes 1 hormone- Melatonin: Controls the body’s internal clock affects: jet lag, insomnia

Thymus § Small mass located anterior to the heart. § Secretes 4 hormones § Thymosin- promotes maturity of T cells: destroys microbes

Heart § Secretes 1 hormone § Atrial matriuretic peptide (ANP)decreases blood pressure

Kidneys § Secretes 2 hormones § Renin: combines w/ other hormones § Regulates BP Erythropoietin (EPO): new blood cells

Hormone Disorders § Most involve the HYPOSECRETION or HYPERSECRETION of a hormone. § Hypersecretion most likely due to a tumor on the gland. § Few cases involve faulty hormone receptors or reduction of receptors.

Diabetes § § § D. Insipidus “tasteless” Hyposecretion of ADH Extreme thirst Dehydration Excessive urination § § § D. Mellitus “Sweet tasting” Hyposecretion of insulin (type 1) Blood glucose build up Weight loss Excessive urination Sweet smelling breath

Diabetes Mellitus § Group of related disorders that result in hyperglycemia

Type I § Juvenile § Insulin cells are destroyed by own immune system

Type II § Adult § Loose ability to respond to insulin

Diabetes Insipidus § Under secretion of ADH § Symptoms: lots of urine, thirst, dehydration § Bed wetting in children § Treatment: Injection/ nasal spray

Grave’s Disease Hyperthyroidism Symptoms: Intolerance to heat Heart palpitations Sensitivity to light Weight loss Appetite increase Easily agitated Protruding eyes

Hypothyroidism or Myxedema Early symptoms: Being more sensitive to cold Constipation Depression Fatigue or feeling slowed down Heavier menstrual periods Joint or muscle pain Paleness or dry skin Thin, brittle hair or fingernails Weakness Weight gain (unintentional) Cretinism – lack of thyroxine during fetal life Late symptoms, if left untreated: Decreased taste and smell Hoarseness Puffy face, hands, and feet Slow speech Thickening of the skin Thinning of eyebrows

Acromegaly § hypersecretion of GH during adulthood, usually a pituitary tumor. Only certain bony regions in face, feet and hands are affected by excessive bone deposition.

Goiter Iodine deficiency causes thyroid to enlarge as it tries to produce thyroxine + ✗ tyrosine + iodine AP Biology thyroxines ✗

Gigantism Hypersecretion of GH during childhood If left untreated, acromegaly will occur.

Pituitary Dwarfism § Hyposecretion of § § GH, can be corrected by giving GH hormone Must be diagnosed before growth plates have closed. Can be tumor related

Gigantism vs. Dwarfism

Adrenal Gland Disorders § § § Cushing’s Excess Cortisol Weight gain Rounded moon face Fatty hump on back Fatigue § § § Addison’s Hyposecretion of glucocorticoids and mineralcorticoids Mouth lesions Hypoglycemia Strange skin pigmentation Salt craving

Adipose and Leptin § Leptin is hormone that § causes you to feel full. Obesity may be due to no leptin or not enough or hypothalamus becomes leptin resistant.