AP-2 Lab 01 Lab Report

AP-2 Lab 01 Lab Report Robert Dunfee BIOL 131-2012SP Human Anatomy and Physiology II-DL1 08 Feb 2012

1

AP-2 Lab 01 Lab Report

AP-2 Lab 01 Lab Report

Name: Robert Dunfee Section: BIOL 131-2012SP AP II-DL1

Laboratory Report: Exercise 1: The Endocrine SystemPurpose: What is the purpose of this exercise? The purpose of this lab is to identify the major endocrine structures and learn their functions. Identify how hormones help to maintain homeostasis in the body. Using prepared slides and cat dissection we will explore the structure and function of the endocrine glands, and the hormones which they produce. Is there any safety concerns associated with this exercise? If so, list what they are and what precautions should be taken. Proper care of the microscope and the related equipment needs to be observed along with a clean work environment. Sanitary measures should also be followed for the dissection of the cat. Activity 1: The Pituitary Gland Observations: Please describe in detail the structures and features you observed on the pituitary gland slide.

Acidopholis

Chromophobe

Basophil

From microscope camera

2

AP-2 Lab 01 Lab Report Data Table 1: Do some research and fill in the data table below: Hormone Adrenocorticotropic hormone (ACTH) FunctionsStress releases ACTH from the hypothalamus releasing cortisol via the anterior pituitary in the adrenal cortex regulating glucose , protein and fat metabolism ADH regulates water retention y the kidneys, reduces urine output and helps in the prevention of dehydration. FSH is secreted by the pituitary. It stimulates the sex hormone estrogen and the development of follicles in the ovaries for women and the production of sperm in men Promotes tissue mitosis and cellular differentiation. GH does not have specificity like other hormones. GH targets, bone. muscle and cartilage. In females it stimulate ovulation of eggs from the follicles developed by FSH. In males it stimulates the testes to produce testosterone. Fetal hormone determining the color of skin or hair. Released from the posterior pituitary used in positive feedback for labor contractions OT is found in both sexes for sexual arousal and orgasms. In women it aids in the contraction of the uterus and lactation. In men it's thought to propel seamen in the reproductive tract. Secreted by thyrotropes in the pituitary it stimulates growth of the pituitary gland and stimulates the release of the thyroid hormone

Antidiuretic hormone (ADH) Follicle stimulating hormone (FSH)

Growth hormone (GH)

Luteinizing hormone (LH)

Melanocyte stimulating hormone (MSH) Oxytocin Prolactin (PRL)

.Thyroid stimulating hormone (TSH)

Questions: A. Describe the function of the endocrine system. The endocrine system is a collection of specific glands, or organs that secret hormones (chemicals) into the blood to trigger action in specific cells. Hormones alter metabolic activities of specific targeted tissues and organs that can last for minutes, 3

AP-2 Lab 01 Lab Report hours, days, or longer. i.e. the hypothalamus, pituitary, pineal thalamus, pancreas, adrenal glands, testes. There other minor organs that distribute hormones such as the heart skin, liver, kidneys and the stomach with the small intestines.

B. What is a gland? A Gland is an organ in the human body that secretes particular chemical substances for use in the surrounding tissues or for release into the blood stream, usually maintaining homeostasis. Glands are classified as either endocrine or exocrine glands. Endocrine glands do not have ducts releasing their chemicals via capillaries into the bloodstream to target cells elsewhere in the body. Exocrine glands have ducts that transport their secretions to the target areas.

C. Describe how negative feedback regulates the secretion of most hormones. Most hormone secretion is governed by a "negative" feedback loop", meaning that the amount of a substance in a system regulates its own concentration. When a receptors concentration of a hormone rises to a level above its desired set point in the feedback axis, a series of steps is taken within the effector system to cause the concentration to fall. Conversely, steps are taken to increase concentration when the level is too low.

D. Why is the pituitary gland called the master endocrine gland? The pituitary gland is sometimes called the "master gland" because of its great influence on the other body organs. When the hypothalamus responds to the need for endrononic change, it signals the pituitary to release the appropriate hormone to the target areas.

4

AP-2 Lab 01 Lab Report Activity 2: The Thyroid Gland Observations: Please describe in detail the structures and features you observed on the thyroid gland slide

Colloid

C Cells

Follicular Cell

From microscope camera Questions: A. What is the overall function of the thyroid gland? The thyroid gland plays a major role in regulating the body's metabolism by extracting iodine found in foods and converting it into thyroid hormones. B. What is the function of thyroxin? Also known as T4, it has little affect until it enters the cell. Once in the cell on iodine is taken away converting it to T3. It then transcribes the DNA producing proteins for various metabolic affects. Thyroxin's principal function is to stimulate the consumption of oxygen. C. What is the function of triiodothyronine? Triiodothyronine or T3 is a hormone produced by the thyroid and is associated with almost all processes in the human body. Produced by the thyroid and its functions are associated with the body temperature, growth and heart rate. In comparison with the other thyroid hormone, T4 or thyroxin, T3 is produced in a smaller quantity and it 5

AP-2 Lab 01 Lab Report contains fewer iodine atoms. The production of both T3 and T4 are activated by the thyroid stimulating hormone (TSH). A very important function of T3 hormones is being able to increase the heart rate and its force of contraction. As a result, the systolic blood pressure is increased and the diastolic blood pressure is decreased. It is very important in the development of the growth of the central nervous system after birth and it has important effects in the growth of bones. D. What is the function of calcitonin? Calcitonin lowers the concentration of calcium in the blood when it rises above the normal value by inhibiting the activity of the osteoclasts in bone tissue and by increasing calcium excretion in the urine. E. What is hyperthyroidism? What are its effects on the body? Hyperthyroidism is a condition caused by too much thyroid hormone on tissues in the body. Because TH promotes body metabolism an increase would disrupt the body's negative feedback loop creating an imbalance. An imbalance in metabolism can cause excessive sweating, heat intolerance, increased bowel movements tremor, nervousness, agitation, rapid heart rate, weight loss, fatigue, decreased concentration Irregular heart rhythms and heart failure can occur. Untreated hyperthyroidism may result in a "thyroid storm," which is a condition involving high blood pressure, fever, and heart failure. Mental changes like confusion and delirium may also occur.

Activity 3: The Parathyroid Gland Observations: Please describe in detail the structures and features you observed on the parathyroid gland slide

Capsule

Colloid

Follicular epitheliumpathology.mc.duke.edu

6

AP-2 Lab 01 Lab Report

Questions: A. What does parathyroid hormone (PTH) do? Parathyroid hormone measures and regulates the concentration of calcium in our blood and bones and in extracellular fluid. When calcium concentrations fall below the normal range, there is an increase in secretion of PTH activating the osteoclasts in the bones to add to the depleted areas. When calcium concentrations are too high, the parathyroid shuts down and stops making PTH. B. Based on your answer to Question 1, can you live without your parathyroid glands? Why or why not? Based on the fact that the sole purpose of the parathyroid is to control calcium levels, and proper calcium concentrations are needed for proper heart and muscle functions, we need the PTH for life. Activity 4: The Thymus Gland Observations: Please describe in detail the structures and features you observed on the thymus gland slide

Lymphatic

Macrophag

Recicular

http://webpathology.com/image.asp?case=409&n=3

7

AP-2 Lab 01 Lab Report Questions: A. What does the hormone tymosin do? Tymosin is a hormone secreted by the thymus that stimulates the development of other lymphatic organs and T-Cells.

B. Based on your answer to Question 1, explain why the thymus gland shrinks as we reach adulthood. At birth and up to puberty the thymus excretes 3 hormones to promote the growth of the T cells and other glands in our body. After puberty when the growth has ceased the thymus atrophies.

Activity 5: The Adrenal Gland Observations: Please describe in detail the structures and features you observed on the adrenal gland slide

Network of cells that comprises the zona reticularis. The cells in this area produce androgens and some glucocorticoids.

From microscope camera

8

AP-2 Lab 01 Lab Report Questions: A. The adrenal glands are in part controlled by the sympathetic and parasympathetic branches of the autonomic nervous system. Name the hormones involved in this regulation and the functions of each. 1. Sympathetic Branch a. In the alarm phase i. Epinephrine ii. norepinephrine iii. Dopamine iv. Angiotensin v. Aldosterone b. In the resistance phase i. Corticotropin releasing Hormone CRH ii. ACTH iii. Cortisol iv. Glucocorticoids 2. Parasympathetic Branch During the return to a resting state the hormones decrease due to the negative feedback

B. Where in the adrenal gland are mineralocorticoids made? Zona Glomulerosa C. What are the functions of mineralocorticoids? Give an example of a mineralocorticoid hormone. Mineralocorticoids maintain salt and water balance. Aldosterone is a mineralocorticoid. D. Where in the adrenal glands are glucocorticoids made? Glucocorticoids are produced in the Zona Fasciculate and Zona Reticulate E. What are the functions of glucocorticoids? Give an example of a glucocorticoid. The function of glucocorticoids is to stimulate fat and protein catabolism, gluconeogenesis and release of fatty acids and glucose into the blood. An example of a glucocorticoid is Cortisol. Activity 6: The Pancreas Observations: Please describe in detail the structures and features you observed on the pancreas slide 9

AP-2 Lab 01 Lab Report

From microscope camera

Pancreatic islet

Exocrine acinus

Questions: A. Explain the difference between an exocrine gland and an endocrine gland. Exocrine glands are glands with ducts that excrete there chemicals via a duct into their target organ. Examples would be salivary and sweat glands that are used outside the body Endocrine glands are ductless; therefore the secreted hormones are released into the interstitial spaces that surround the cells communicating and coordinating body systems maintaining homeostasis. Endocrine glands produce hormones that can be used inside the body. The endocrine transmits the hormonal messages to the nearest capillaries and spreads the chemical throughout the body cells via the blood. The Liver and the pancreas are two glands that are both exocrine and endocrine

B. What is the exocrine function of the pancreas? Digestive enzymes that assist the absorption of nutrients and the digestion in the small intestine C. What endocrine hormones does the pancreas produce? What is the function of each? The Islets of Langerhans produce two hormones, glucose in the alpha cells and insulin in the beta cells. Insulin is used for transport of the glucose into the cells for work and glucose is used for metabolism. 10

AP-2 Lab 01 Lab Report

D. Diabetes is a serious health problem in the United States. Explain what diabetes is and the differences between the Type 1 and Type 2 forms of the disease. Blood glucose levels are controlled by a hormone from the pancreas called insulin lowering the blood glucose levels. When the blood glucose elevates, insulin is released from the pancreas to normalize the glucose level. People with diabetes have the absence or insufficient production of insulin causes hyperglycemia. Type 1 DM, known as IDDM is characterized by the pancreases inability to produce any insulin. The IDDM individual has to introduce insulin into their system in order to use the glucose for work. Type 2 DM known as NIDDM is characterized by the pancreas producing not enough insulin for the glucose to enter the cells. In some cases diet and exercise can manage type 2

Activity 7: The Gonads Observations: Please describe in detail the structures and features you observed on the testes and ovary slides

Seminiferous Tubute

Germ Cells

Sustenacular cells

Connective tissue Interstitial Cells From microscope camera

11

AP-2 Lab 01 Lab Report

Questions: A. What are the endocrine functions of the testes? The endocrine function of the testis includes the production of a hormone called testosterone for the male sex organs in response to LH B. What does testosterone do? Testosterone stimulates sperm production, and regulates secretion of pituitary hormones to prevent their overproduction. Testosterone also is responsible for the libido. C. What are the endocrine functions of the ovaries? The endocrine functions of the ovaries release two main hormones; estrogens by the ovarian follicles influence of FSH and estrogens stimulating the reproductive system and development of the secondary sex characteristics. Progesterone is also released in response to high blood levels of LH. It works with estrogens to establish the menstrual cycle. D. What do estrogen and progesterone do? Progesterone plays a role in maintaining pregnancy. The hormone is produced in the ovaries, the placenta and the adrenal glands. It helps prepare the body for conception and pregnancy and regulates the monthly menstrual cycle. It also plays a role in sexual desire. Estrogen is responsible for the growth and development of female sexual characteristics and reproduction. Estrogen is produced in the ovaries, adrenal glands and fat tissues and circulates in the bloodstream binding to estrogen receptors on cells of the breasts and uterus.. Estrogen also controls growth of the uterine lining during the first part of the menstrual cycle, causes changes in the breasts during adolescence and pregnancy. Activity 8: Cat Dissection: Endocrine System Matching: Match each structure in the left column with its correct description from the right column. C D A 1. Pancreas 2. Adrenal medulla 3. Thyroid gland A. divided into two lobes called lateral lobes B. secretes hormone that raises the number of calcium ions in the blood C. has both exocrine and endocrine functions 12

AP-2 Lab 01 Lab Report

B F E

4. Parathyroid gland 5. Ovary 6. Gonads

D. activated when body is under emotional stress E. general term for sex organs F. source of both estrogen and progesterone

Short Answer Questions A. When male cats are neutered, the testes are removed. What changes occur as a result of this procedure? With the elimination of the testes there is no production of testosterone so the ability to produce seamen is gone. In addition the sex drive is diminished

B. If a cat has not eaten all day, what would the endocrine activity of the pancreas show? If there is no food to convert to glucose and the blood glucose concentration is too low, the pancreas releases glucagon, causing the liver to convert glycogen into glucose, which then enters the blood. C. Which endocrine gland would be activated when a cat is being chased by a dog? Adrenal Gland

Activity 9: Endocrine System Review

A. Describe the effects that a malfunctioning pituitary gland would have on an individual? The pituitary is the 'Master Gland' and controls all the other glands. If it is not functioning properly, any or all of the other glands and their hormones may be affected. B. Which endocrine glands would be most affected by prolonged mental stress on the body? (i.e. work, lack of time, worrying etc.) Explain your reasoning in detail.

When confronted with stress, the hypothalamus signals the pituitary gland, stimulating it to produce adrenocorticotropic hormone (ACTH). ACTH is then released into the blood stream where it reaches the adrenal glands. ACTH stimulates 13

AP-2 Lab 01 Lab Report the adrenal cortex to produce corticoids and epinephrine allowing the body to acquire energy from energy stores in the body. It is epinephrine which causes most of the physiological changes that occur in the body to produce fast, short term high energy for the stress. The effects of stress however are meant to be short term. Once the danger passes, the body should return to its state of homeostasis through the negative feedback loop. Continued stressors do not allow the body to return to a balanced state and does not allow cortisol to decrease creating a positive feedback loop. When cortisol levels remain high due to chronic stress, norepinephrine and epinephrine production triggers more ACTH and cortisol release. High cortisol levels lead to high blood pressure, hardening of the arteries, diabetes, immune system inhibition, muscle atrophy, and osteoporosis.

Thyroid Gland, Thymus Gland, Pancreas, Kidney/Adrenal Gland, Reproductive Organs.

14

AP-2 Lab 01 Lab Report

15