6Endocrine SystemEndocrine glands release more than 20 major hormones directly into the bloodstream without the use of ductsor by diffusion into surrounding tissue where it affects the target cells-Discusses the various glands and their functions
7Endocrine System Hypothalamus Pituitary gland Pineal body Thyroid ParathyroidPancreasAdrenalsOvaries and Testes
8HypothalamusPresent in the brain and produces releasing hormones and inhibitory hormones and controls information to the pituitary
9Pituitary glanda small pea sizes gland located in the center of the skull, acting as the Master Gland controllingReleases a number of hormone that activate other glandsList some of them in Journal noted in this videoPituitary gland video medline plus
10Pineal BodyA structure of the diencephalon produces several hormones including Melatonin to influence sleep-wake cycles and sexual development.Connects the endocrine system with the Nervous system by converting nerve signals from PNS to hormone signals
11Thyroid Gland Located in the neck , Secretes T3 and Thyroxine (T4) that regulates metabolism where food is broken down and converted to heat or energySecretes Calcitonin that plays a role in calcium balance
12Thyroid Feedback Loop hypothalamus senses low levels of T3 and T4- Sends message of Thyrotropin-releasing hormone(TRH) to Pituitary gland to produce TSHPituitary send message to Thyroid of TSHThyroid get message increases production and release of T3, T4Blood levels rise.Hypothalamus receives Info of increase levelsCommunicates this to PituitaryPituitary sends message to thyroid to slow production CYCLE CONTINUES
13Parathyroid 4 pea-sized glands on the thyroid gland in the neck. name is similar to thyroid but glands are completely different.Produce parathyroid hormone (PTH), helps balance calcium and phosphorous. Which play an important role in muscle contraction and nerve impulse
14PancreasLong narrow gland located in the abdomen behind the stomach and in front of the spineSecretes insulin, glucagon to help regulate the body's use of sugar
15Adrenal glands 2 small glands located on the top of each kidney SOME Hormones ReleasedAREcorticosteroids- Cortisol and Catecholamine's such as dopamine, epinephrine to increase HR and BP during stress and norepinephrineAldostrone that affects kidney function by controlling levels of salt and water in the bloodAlso small amounts of Androgens
16Thymus2 lobes Lies in the lower part of the neck or upper chest behind the sternumSecretes thymus hormone which plays an important role in the immune system
17Ovaries and TestesTestes Male sex glands that secrets androgens that contribute to production of sperm and the development of male characteristicsOvaries release hormone estrogen and contribute to the female characteristics and regulate menstrual cycle
19What does the Endocrine System Do??? Once a hormone is secreted, it travels from the endocrine gland that produced it through the bloodstream to the cells designed to receive its message called target cells.
20Target Cellstarget cells have receptors that latch onto only specific hormones, and that hormone will communicate only with the target cell that have receptors for that hormoneWhen the hormone reaches its target cell, it locks onto the cell's specific receptorsThe hormone-receptor combinations transmit chemical instructions to the inner workings of the cell.
21Hormone ReceptorsHormone receptors are found either exposed on the surface of the cell or within the cell, depending on the type of hormone. Three actions of hormonesEndocrine action: the hormone is distributed in blood and binds to distant target cells.Paracrine action: the hormone acts locally by diffusing from its source to target cells in the neighborhood.Autocrine action: the hormone acts on the same cell that produced it.
22Hormone Levels Thyroid Hormone Feedback Loop. When hormone levels reach a certain normal amount, the endocrine system helps the body to keep that level of hormone in the blood.Example,Thyroid Hormone Feedback Loop.
23Disorders related to Hormones Give examples of disorders involving hormones.HypothyroidismHyperthyroidismCushing's SyndromeAddison’s diseaseGrowth Hormone Deficiency- GHD
24Hypothyroidism Thyroid does not produce enough thyroid hormone. Symptoms include: feeling tired and weak; cold intolerance; dry skin and brittle nails; and constipation.Can raise your cholesterol levels and can make you more likely to have a stroke or heart attack.It can be treated with thyroid hormone pills.
25Hyperthyroidism Thyroid is producing too much thyroid hormone. Common symptoms include:excessive sweating; heatintolerance; increasedbowel movements;nervousness or agitation;and weight loss withincreased appetite.Treatments includeantithyroid drugs; ablationwith radioactive iodine; orsurgery to partially removethe thyroid.
26Cushing's SyndromeResults from excessive production of Cortisol from adrenal gland .Can be the result of tumor or drug therapy.Symptoms include fat deposition in face and around shoulders. (Buffalo hump)Decreased Vit D activity=bone lossEmotional frailty.Hirsuitism-hair growth on face in females
27Addison’s disease Result from a deficiency in Cortisol production. Can be genetic or the result of illness or injury.Symptoms include low blood pressure, muscle weakness, weight loss, and hyperpigmentation of skin.JFK suffered from this.
28Growth Hormone Deficiency- GHD Different effects depending on the age of onset.In infants and children- hypoglycemia and growth failure.Rarely happens in adults, but may manifest as bone loss, loss of muscle mass and strength.Treated by intramuscular injections of HGHGary Coleman Little Rascals and Different Strokes and more
29Activity 2.3.1 The Hormone Connection Use Inspiration to create a concept map for Chemical Communication describing the basic mechanism of hormone action in the human body.Share concept maps with class
30Feedback Mechanism(1) A loop system in which the system responds to perturbation either in the same direction (positive feedback) or in the opposite direction (negative feedback).(2) A process in which the level of one substance influences the level of another substance.(3) A mechanism or a signal that tends to initiate (or accelerate) or to inhibit (or slow down) a process.https://www.youtube.com/watch?feature=player_detailpage&v=_QbD92p_EVs -feedback loop
31Essential Questions 2. How do hormones interact with target cells? 3. What are examples of endocrine glands and exocrine glands in the human body?
32Essential Questions4. How do feedback loops help regulate the action of hormones?5. How can too little or too much of a hormone lead to disease?
33Activity 2.3.2 Hormones Gone Wild Part 1 Activity Part 1 onlyNeed:White Poster BoardMarkersWhat are his SymptomsWhat organs and glands are effectedWhen your team thinks they have the correct diagnosis- Get Part 2 from your teacher
34Activity 2.3.2 Hormones Gone Wild Part 2 Build the Pituitary Gland on your ManikinWhat is the connection between the Pituitary Gland and the HypothalamusBuild the Thyroid Gland on your Manikin
36HypothalamusThe hypothalamus is part of the brain that lies just above the pituitary gland. It releases hormones that start and stop the release of pituitary hormones. The hypothalamus controls hormone production in the pituitary gland through several "releasing" hormones. It functions in maintaining homeostasis, especially in coordinating the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors, which regulate the anterior pituitary.These include:Growth hormone-releasing hormone, or GHRH (controls GH release)Thyrotropin-releasing hormone, or TRH (controls TSH release)Corticoptropin-releasing hormone, or CRH (controls ACTH release)Another hormone made by the hypothalamus is gonadotropin-releasing hormone (GnRH). It tells the pituitary gland to make luteinizing hormone (LH) and follicle-stimulating hormone(FSH), which are important for normal puberty and reproduction.
37Pituitary GlandThe pituitary gland is sometimes called the "master gland" because of its great influence on the other body organs. Its function is complex and important for overall well-being. It produces hormones that act directly on the body and that stimulate other endocrine glands to produce their own hormones. The anterior pituitary (the front part of the pituitary) produces several types of hormones:Prolactin: stimulates milk production from a woman's breasts after childbirth. In pregnant and breastfeeding women, prolactin helps prevent ovulation (the release of eggs from the ovaries).Growth hormone (GH): GH stimulates growth in childhood and is important for maintaining a healthy body composition. In adults it is also important for maintaining muscle mass and bone mass. GH also affects fat distribution in the body.Adrenocorticotropin (ACTH): ACTH stimulates production of cortisol by the adrenal glands. Cortisol, a so-called "stress hormone," is vital to survival. It helps maintain blood pressure and blood glucose levels, among other effects.
38Pituitary GlandThyroid-stimulating hormone (TSH): TSH stimulates the thyroid gland to make thyroid hormones, which, in turn, control (regulate) the body's metabolism, energy, growth and development, and nervous system activity.Luteinizing hormone (LH): LH regulates testosterone in men and estrogen in women.Follicle-stimulating hormone (FSH): FSH stimulates the ovaries to release eggs (ovulate) in women. LH and FSH work together to allow normal function of the ovaries or testes, including sperm production.The posterior pituitary (back part of the pituitary) produces two hormones:Oxytocin: Oxytocin causes milk to be released in nursing mothers and contractions during childbirth.Antidiuretic hormone (ADH): ADH, also called vasopressin, regulates water balance. If ADH is not secreted in the right amount, this can lead to too much or too little sodium (salt) and water in the bloodstream.
42Key Terms Endocrine Gland A gland (as the thyroid or the pituitary) that produces an endocrine secretion -- called also ductless gland, gland of internal secretion.Endocrine SystemThe glands and parts of glands that produce endocrine secretions, help to integrate and control bodily metabolic activity, and include especially the pituitary, thyroid, parathyroid, adrenals, islets of Langerhans, ovaries, and testes.Exocrine GlandA gland (as a sweat gland, a salivary gland, or a kidney) that releases a secretion external to or at the surface of an organ by means of a canal or duct.GlandA cell, group of cells, or organ of endothelial origin that selectively removes materials from the blood, concentrates or alters them, and secretes them for further use in the body or for elimination from the body.GlucagonA protein hormone that is produced especially by the pancreatic islets of Langerhans and that promotes an increase in the sugar content of the blood by increasing the rate of breakdown of glycogen in the liver.HormoneAny one of the many circulating chemical signals found in all multicellular organisms that are formed in specialized cells, travel in body fluids, and coordinate the various parts of the organism by interacting with target cells.HypothalamusThe ventral part of the vertebrate forebrain; functions in maintaining homeostasis, especially in coordinating the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors, which regulate the anterior pituitary.InsulinA vertebrate hormone that lowers blood glucose levels by promoting the uptake of glucose by most body cells and the synthesis and storage of glycogen in the liver.
43Lesson 2.4 Communication with the Outside World Essential Question1.How do humans communicate with the world around them?
44Communication with the Outside World How does the Nervous System and Endocrine System Communicate.The hypothalamus connects these two important communication systems.The hypothalamus is a tiny collection of nuclei that is responsible for controlling an astonishing amount of behavior.Hypothalamus located at the base of the forebrain, regulates basic needs such as sleep, hunger, thirst and sex in addition to emotional and stress responses.hypothalamus controls the pituitary glands, which controls the release of hormones from other glands in the endocrine system
45Essential Questions2. How does the power of sight allow humans to communicate with the outside world?
46Optical Illusions caused by the eye or by the brain
48A Person with perfect vision is still susceptible to optical illusions A dissociation between physical reality and subjective perceptionthe visual illusion is one of the most important tools used by neuroscientists to understand how the brain creates its sense of reality.
49Terms to know about the EYE Optic NerveScleraCorneaAnterior CavityPosterior CavityTapetumChoriodOptic Disc or Blind SpotPupilAqueous HumorVitreous HumorIrisCiliary BodySuspensory LigamentsLens
52Structures of the EyeCornea: the clear front window of the eye. The cornea transmits and focuses light into the eye.Iris: the colored part of the eye. The iris helps regulate the amount of light that enters the eye.Lens: the transparent structure inside the eye that focuses light rays onto the retina.Macula: a small area in the retina that contains special light-sensitive cells. The macula allows us to see fine details clearly.Optic Nerve: the nerve that connects the eye to the brain. The optic nerve carries the impulses formed by the retina to the brain, which interprets them as images.Pupil: the dark center in the middle of the iris. The pupil determines how much light is let into the eye. It changes sizes to accommodate for the amount of light that is available.Retina: the nerve layer that lines the back of the eye. The retina senses light and creates impulses that are sent through the optic nerve to the brain.Vitreous: the clear, jelly-like substance that fills the middle of the eye.
53Essential Questions 3. How is light focused by the eye? 4. How do the eye and the brain work together to process what we see?5. How does what we see impact other human body systems?
54Key Terms Accommodation The automatic adjustment of the eye for seeing at different distances affected chiefly by changes in the convexity of the crystalline lens.AstigmatismA defect of an optical system (as a lens) causing rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image.Blind spotThe small circular area in the retina where the optic nerve enters the eye that is devoid of rods and cones and is insensitive to light.ConeAny of the conical photosensitive receptor cells of the vertebrate retina that function in color vision.CorneaThe transparent part of the coat of the eyeball that covers the iris and pupil and admits light to the interior.Depth PerceptionThe ability to judge the distance of objects and the spatial relationship of objects at different distances.
55Key TermsHyperopiaA condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects -- called also farsightedness.IrisThe opaque muscular contractile diaphragm that is suspended in the aqueous humor in front of the lens of the eye, is perforated by the pupil and is continuous peripherally with the ciliary body, has a deeply pigmented posterior surface which excludes the entrance of light except through the pupil and a colored anterior surface which determines the color of the eyes.LensA curved piece of glass or plastic used singly or combined in eyeglasses or an optical instrument (as a microscope) for forming an image by focusing rays of light.MyopiaA condition in which the visual images come to a focus in front of the retina of the eye because of defects in the refractive media of the eye or of abnormal length of the eyeball resulting especially in defective vision of distant objects -- called also nearsightedness.Optic nerveEither of the pair of sensory nerves that comprise the second pair of cranial nerves, arise from the ventral part of the diencephalon, form an optic chiasma before passing to the eye and spreading over the anterior surface of the retina, and conduct visual stimuli to the brain.
56Key TermsPupilThe opening in the iris, which admits light into the interior of the vertebrate eye; muscles in the iris regulate its size.RefractionThe deflection from a straight path undergone by a light ray or a wave of energy in passing obliquely from one medium (as air) into another (as water or glass) in which its velocity is different.RetinaThe sensory membrane that lines most of the large posterior chamber of the vertebrate eye, is composed of several layers including one containing the rods and cones, and functions as the immediate instrument of vision by receiving the image formed by the lens and converting it into chemical and nervous signals which reach the brain by way of the optic nerve.RodAny of the long rod-shaped photosensitive receptors in the retina responsive to faint light.
57Visual PerceptionIt is the ability to interpret the surrounding environment by processing information that is contained in visible light. The resulting perception is also known as eyesight, sight, or vision
58Visual PerceptionPredict your dominant eye. Which eye do you think is your dominant. Next, locate an object 8-10 feet away. Keep both eyes open and hold your thumb up at arms length. “Cover” the object with your thumb. Now, close the right eye. If the thumb appeared to move to the right, the right eye is dominant. If the thumb did not seem to move, the left eye is dominant. Poll the class to see how the result matched their prediction.Introduce optical illusions and depth perception by showing hidden image stereograms. You can either bring in books or have them view the online example at the Magic Eye® site
59Activity 2.4.2 Visual Perception Show DVD: Human Body: Pushing the Limits DVD series. Chapter 2 – 1.11 on the Sight DVD
60Activity 2.4.2 Visual Perception In pairs make your way through the eleven stations.Only spend about 10 minutes in each stationYou will need Activity 2.4.2: Student Response Sheet
61Color VisionThe retina of the eye possesses two special types of nerve cells known as photoreceptors.Rods function in dim light and perceive shades of gray.Cones function in bright light and provide sharp, colorful images.Impulses from rods and cones pass through nerve cells to the optic nerve.
62Color Vision There are three different types of cones: Red conesBlue conesGreen conesEach type of cone is sensitive to a different range of wavelengths of light.Different types of cones function together to interpret colors other than blue, red, and green.If any of the cones malfunction, color deficiency or color blindness occurs.
63Depth PerceptionDepth perception is the ability to judge the relative distances between objects in three dimensions.With one eye, the field of vision appears two-dimensional.With two eyes, the eyes see and the brain processes different views of the same object.
64AccommodationTwo parts of the eye – the cornea and the lens – focus light on the retina.The cornea does most of the work, but it cannot change shape. Fine adjustments are carried out by the lens.Accommodation is the combination of reflex actions by which the lens of the eye changes to keep the focal length, the distance between the center of the lens and its focal point, constant.Ciliary muscles in the eye assist adjustment of the lens.
65AstigmatismAstigmatism is a condition in which the cornea or the lens is irregularly shaped.This shape change causes incoming light rays to refract and converge improperly.The light rays do not focus at a specific point on the retina, resulting in a blurry or distorted image.Astigmatism may be corrected with eyeglasses, contact lenses, or refractive surgery.
66Blind SpotThe optic nerve exits the eye at the retina on its way to the brain.Since this area of the retina does not have receptors that respond to light, it is referred to as the blind spot. An image that falls on this area can not be seen.Normally people do not recognize the blind spot because the eyes are always on the move and the brain ignores this “hole” in visual input.
67Peripheral VisionPeripheral vision is the ability to see things that fall outside of the direct line of vision.Due to their proximity to the edge of the retina, rods are responsible for this aspect of vision.Peripheral vision is better for detecting movement than for processing sharp images, and is most often stronger in the dark.
68Optical IllusionsOptical illusions are visual tricks that actually take place in the brain rather than the eye.The visual cortex of the brain deciphers images sent from the eye, however surrounding objects, intense colors, distortions of expected patterns, and preconceptions can cause the mind to “see” and interpret an image differently.
69AfterimagesAfterimages are optical illusions that occur when looking away after staring intently at a fixed image or color.The constant light stimulating the retina causes the cones in that area to become fatigued.After looking away from the image, the less-stimulated cones, which are not fatigued, still function.The resulting image lasts briefly and because it comes only from the less-fatigued cones, is perceived as a negative image.
70Essential Questions 6. What is visual perception? 7. What does it mean to have 20/20 vision?
71Essential Questions8.How can corrective lenses be used to refocus light and resolve myopia and hyperopia?9. How does the eye perceive depth, color and optical illusions?
73Disorders of the Eye RETINITIS PIGMENTOSA MYOPIA HYPEROPIA GLAUCOMA REVIEW QUESTIONS
74RETINIS PIGMENTOSARefers to a group of inherited disorders that slowly lead to blindness due to abnormalities of the photoreceptors in the retina.
75MYOPIA near- sightedness short-sightedness A vision condition in which close objects are seen clearly, but objects farther away appear blurred.Myopia occurs if the eyeball is too long or the cornea, the clear front cover of the eye, has too much curvature. As a result, the light entering the eye isn’t focused correctly and distant objects look blurred.
76HYPEROPIA (farsightedness) A defect of vision caused by an imperfection in the eye (often when the eyeball is too short lengthwise or when the lens can’t become round enough causing inability to focus on near objects)As an object approaches the eye, the eye must increase its power to keep the image in focus on the retina.In hyperopia the power of the cornea and lens is insufficient so the image appears blurred.
77GLAUCOMAGlaucoma is an eye disease that affects the pressure of the eye, resulting in optic nerve damage. The aqueous and vitreous humor expand, which then covers the optic nerve, which leads to vision loss. Glaucoma is the second leading cause of blindness.
78Essential Question10. How does an error in the structure or function of the eye relate to disease or dysfunction?11. How is life impacted by a vision disorder?
79Essential Question12. What are the tests and procedures in a routine eye exam?
80Activity 2.4.4 Eye Care Professionals Part 1Create a handout titled “What You Need to Know about an Eye Exam”.
81Activity 2.4.4 Eye Care Professionals Career Journal:OpthamologistOptometristOpticianDescribe a Scenario of why a a patient would see this type of eye doctor in addition to the information listed on your Career Journal Rubric.