Endocrine System PDF

# Unit 4: Human Body ## Chapter 5: Endocrine System and Adolescence ### Syllabus - Endocrine System: - Two types of glands: exocrine, endocrine (basic concept and difference) - Hormone (definition) - Hormonal glands: (thyroid, adrenal, pancreas, pituitary): location and function of ea...

# Unit 4: Human Body ## Chapter 5: Endocrine System and Adolescence ### Syllabus - Endocrine System: - Two types of glands: exocrine, endocrine (basic concept and difference) - Hormone (definition) - Hormonal glands: (thyroid, adrenal, pancreas, pituitary): location and function of each. - Study the following in tabular form: name of gland, location in body, secretion, function - Adolescence and accompanying changes: - Physical and emotional changes in the body during adolescence - Importance of personal hygiene. - Stress Management: (meaning of stress) - Ways to tackle stress: yoga, meditation, time management, sports, hobbies, rational thinking, etc. ### Introduction - Our body has two types of glands: the exocrine glands and the endocrine glands. - **Exocrine glands**: secrete enzymes through ducts to the target organs. (Examples: salivary glands, pancreas) - **Endocrine glands**: ductless glands that secrete **hormones** directly into the blood, which are then carried by blood to the target organs. ### Types of Glands - **Exocrine Glands**: (Gland with duct) - Secrete enzymes - Have ducts - Examples: Salivary glands - **Endocrine Glands**: (Ductless gland) - Secrete hormones - No ducts - Examples: Thyroid gland ### Endocrine Glands - **Hormone-producing glands** - **No ducts**, secrete hormones directly into the blood - Also called **ductless glands**. - Secrete **hormones** in small quantities. - Vital and carried to all parts of the body. - Each hormone has a specific function and its effect is produced in one or more specific parts only. ### Hormone - Chemical substance secreted by an endocrine gland, which is directly poured into the bloodstream and acts on a target organ or cell. ### Thyroid Gland - Bilobed gland situated on either side of the windpipe, just below the larynx. - Secretes **thyroxine,** an iodine-containing protein hormone. - **Functions**: - Speeds up the rate of most of the activities of the body. - Stimulates growth in infants. - **Insufficient Secretion of Thyroxine**: - Causes three ailments: - **Simple Goitre**: enlargement of the thyroid gland, appears as a swelling in the neck. Occurs due to insufficient iodine in the daily food. - **Cretinism**: abnormal development in an infant. Results in mental retardation. - **Myxoedema**: occurs in adults where insufficient thyroxine is produced. Causes sluggishness with sweating of the hands. - **Over-secretion of thyroxine**: - Increased metabolic rate - Increased heart beat - Weight loss - General Nervousness ### Adrenal Glands - Consists of two parts: - **Cortex**(peripheral) - **Medulla**(central) - Adrenal cortex secretes many hormones, but the well-known hormone is **cortisone**. - **Cortisone**: - Influences carbohydrate, fat and protein metabolism. - Regulates salt and water balance in the body. - Adapts the body to "stresses" such as extreme heat, cold, infections, etc. - Adrenal medulla secretes **adrenaline** or **epinephrine**, the **emergency hormone**. - **Adrenaline**: - Secreted when severe stress (physical or emotional), fearful or angry. - Prepares the body to meet any emergency situation. - Called the "fight or flight or fright hormone". - Provides extra energy and strength to the body in any adverse situation. - Increases heart beat, blood pressure, increased blood supply to the muscles, and release of more glucose into the blood by the liver. ### Pancreas - Situated behind the stomach. - **Digestive gland** - Contains **Islets of Langerhans** - Secretes two principal hormones: **insulin** and **glucagon**. - **Insulin**: - Lowers glucose from the blood stream. - Converts extra glucose to glycogen, which is ultimately stored in the liver and muscles. - Induces the cells to burn extra glucose to produce heat and energy for the body. - Causes the cells to convert extra glucose into fat. - **Insufficient secretion of insulin**: - Causes **diabetes mellitu**. - High concentration of sugar (glucose) in blood. - Excessive urination. - Feeling of thirst. - Loss of weight. - Weakness. - **Over-secretion of insulin**: - Causes **hypoglycemia**. - Glucose level comes down. - Harmful and may have serious consequences. - **Glucagon**: - Stimulates the breakdown of glycogen in the liver to glucose. - Raises the sugar level in the blood ### Pituitary Gland - Pea-sized gland located below the brain. - Secretes several hormones, some of which regulate the activity of other endocrine glands. - Also called the **"master gland"**. - **Functions**: - **Growth hormone**: regulates growth, especially in the adolescent individual (Insufficient amount of growth hormone causes dwarfism, and excess secretion results in gigantism) - **Thyroid-stimulating hormone**: stimulates the thyroid gland to produce thyroxine - **Follicle-stimulating hormone**: - Influences the production of sperms in males - Influences the production of ova or eggs in females. - **Prolactin**: stimulates the breast to produce milk after child birth. | Gland | Location | Hormone | Function | |---|---|---|---| | Thyroid | On either side of the windpipe, just below the larynx. | Thyroxine | Controls the metabolic rate. | | Adrenal | Like a cap over the kidneys. | Adrenaline | Prepares the body for any emergency situation. | | Pancreas | Behind the stomach. | Insulin | Regulates the amount of sugar in blood. | | Pancreas | Behind the stomach. | Glucagon | Releases sugar from the liver. | | Pituitary | Below the brain. | Growth hormone (GH) | Speeds up growth | | Pituitary | Below the brain. | Thyroid-stimulating hormone (TSH) | Stimulates the thyroid gland to secrete thyroxine | | Pituitary | Below the brain. | Follicle-stimulating hormone (FSH) | Stimulates the production of sex cells (gametes) in males and females | ### Adolescence - Begins from the day an individual is born. - A new-born baby has a complete set of sex organs. - The testes of a baby boy are not yet able to leak sperms, and the ovaries of a baby girl already have hundreds of immature eggs. - Growth is a natural process. - **Adolescence**: a transitional stage of physical and mental development that occurs between childhood and adulthood. - Also called **"puberty"**. - **Adolescent period**: between 10-19 years of age, normally begins around 12 and lasts upto 18 or 19 years of age. - May vary, girls typically begin a year or two earlier than boys. ### Physical Changes During Adolescence 1. **Increase in Height**: Most visible and conspicuous change during adolescence. Bones of the arms and legs elongate, weight of the body also increases. Initially, girls grow faster than boys. 2. **Change in Body Shape**: Boys- longer bones, more muscles, broader shoulders, narrow hips. Girls- broader hips due to the enlargement of hip bones. 3. **Change in Voice**: Larynx (voice box) begins to grow during adolescence. Boys develop larger voice boxes. Protruding part of the throat called **"Adam's apple"**. Girls, voice box is smaller in size, generally, girls have a high pitched voice, whereas boys have a deeper, hoarse voice. 4. **Increased activity of sweat and sebaceous glands**: The secretion of sweat glands and sebaceous glands (oil glands) increases. Acne and pimples on the face due to increased activity of these glands. ### Development of Sexual and Secondary Sexual Characters - During the adolescent period, the sex organs become active. - Testes start producing sperms, and the ovaries start producing eggs. This indicates that the individual is becoming capable of producing children. - **Puberty**: the period during which the reproductive systems of boys and girls mature. - **Girls**: starts at 12, first sign is the development of breasts. - **Boys**: starts at 13, the enlargement of the testes is the first sign. - Puberty is brought on by **sex hormones**, which start getting produced by the testes and ovaries. - **Male sex hormones**: called **androgens** (main one being **testosterone**). - **Female sex hormones**: called **estrogens** (produced by the ovaries, activated by **FSH,** Follicle-stimulating hormone). - **Secondary Sexual characteristics**: - **Boys**: hair growth on legs, chest and face, voice breaks. - **Girls**: breast development, fat is laid down in the thighs, giving the characteristic curves of the female body. ### Importance of Personal Hygiene - Personal hygiene plays a very important role in maintaining one's own health during adolescence. - **Recommended Practices**: - **Proper and Safe Food**: - Adolescence is a stage of rapid growth and development, therefore a balanced diet is necessary. Eat proteins, carbohydrates, fats, vitamins and minerals. - Milk is good for bones. - Fruits and fresh vegetables also provide nourishment. - Take freshly prepared food and avoid stale food. - Store cooked food and milk, butter, fish, meat and other perishable food items properly in a refrigerator. - Avoid excessive consumption of fast foods. - **Proper Life Style**: - Get adequate sleep and exercise. - Avoid long hours of continuous table work. - Avoid watching television or playing games on the computer for long hours. - Avoid smoking and consumption of alcohol and drugs. - **Cleanliness**: - Always wash your hands with soap before and after taking meals. - Clean your teeth after each meal and before going to bed. - Take bath regularly with clean water and good soap. - Change clothes, especially undergarments, daily. - Avoid wearing very tight clothes. - Adopt regular toilet habits. - Clean your hands after defecation. - Clean and protect your feet everyday. - Wash your hair regularly. - Use a clean comb. - Wash your eyes daily with clean and cold water. - Avoid rubbing your eyes with your hands. - Girls should take special care of cleanliness during their menstrual cycle. - **Physical Exercise**: - Walk, exercise, and play outdoor games with your peers regularly. - Physical activity is important to combat the stress and strain of adolescence. ### Stress - **Stress**: state of mental or emotional strain. - **Body's way of responding to any kind of demand**. - Can be caused by both good and bad experiences. - When people feel stressed, their bodies release certain hormones into the blood. - **Managing Stress**: - **Time Management**: Getting organized and planning to manage your work and have a better sense of what needs to be done. - **Hobbies**: Do something that you enjoy. - **Deep Breathing**: Relax and sit in a quiet place for about 15-20 minutes every day, eyes closed, focus on your breathing, clearing your mind of negative or stressful thoughts. - **Meditation**: Relax, sit in a quiet place for about 15-20 minutes every day, with your hands in a comfortable position, eyes closed, and focus on your breathing, working on clearing your mind of negative or stressful thoughts and simultaneously concentrate on your inhaled and exhaled breath. - **Yoga**: - Mind-body practice - Combines physical poses, controlled breathing, and meditation or relaxation. - Increased flexibility - Increased muscle strength and tone - Improved respiration, energy and vitality - Weight reduction - Improved athletic performance. - **Exercise**: 30 to 45 minutes of exercise at least three times a week can make you feel much healthier and in control of your life. You playing a team sports/jogging, swimming, football, hockey, etc. - **Proper Sleep Schedule**: Improves your sleep schedule. - **Reading**: Calm your mind and gain knowledge. - **Thinking Positively**: Be a positive thinker and take more pleasure in your everyday interactions. - **Laughing**: Improves your mood and makes you feel happier. ### Objective Type Questions 1. (a) Cortisone hormone is secreted by: (ii) Cortex of adrenal 2. (b) Which one of the following hormones stimulates the breakdown of glycogen in the liver into glucose ? (ii) Adrenaline 3. (c) Which one of the following hormones converts excess of glucose into glycogen ? (i) Insulin 4. (d) Which one of the following glands is also called the master gland ? (i) Pituitary gland 5. (e) The emergency hormone to face the danger or to fight is secreted by: (iv) Adrenal medulla 6. (f) Which one of the following endocrine glands produces its hormone in large quantities as a result of emotional stimulation ? (ii) Islets of Langerhans 7. (g) In humans, increased thyroxine production results in: (i) Increased metabolism ### Matching | Column A | Column B | |---|---| | (a) Cretinism | (ii) Abnormal development of infant | | (b) Diabetes mellitus | (v) Insufficient insulin in blood | | (c) Increased metabolic rate | (iii) Oversecretion of thyroxine | | (d) Simple goitre | (iv) Insufficient iodine in food. | | (e) Growth hormone | (i) Pituitary gland | ### Short Answer Questions 1. **Define the terms:** - a) **Endocrine glands**: Ductless glands that secrete hormones directly into the bloodstream. - c) **Glucagon**: A hormone secreted by the pancreas that stimulates the liver to release glucose into the bloodstream, raising blood sugar levels *This is a hormone secreted by the pancreas that increases blood glucose levels.* - e) **Puberty**: The period of sexual development during which the reproductive system matures. 2. **Fill in the blanks**: | S .No | Name of the gland | Hormone produced | Function | |---|---|---|---| | 1 | Thyroid | Thyroxine | Controls the metabolic rate. | | 2 | Pancreas | Insulin | Regulates the amount of sugar in the blood. | | 3 | Adrenal | Adrenaline | Prepares the body for any emergency situation. | | 4 | Pituitary | Growth hormone | Speeds up growth.| 3. **Locations of the following glands**: - a) Thyroid gland: On either side of the windpipe, just below the larynx. - c) Pancreas: Behind the stomach. - b) Adrenal gland: Like a cap over the kidneys. - d) Pituitary gland: Below the brain. - e) Adam's apple: Protruding part of the throat in boys ### Long Answer Questions 1. **Distinguish between the following pairs on the basis of the words indicated in the brackets:** - **(a) Exocrine and Endocrine glands (secretion):** *Exocrine glands*: secrete substances through ducts, such as enzymes. *Endocrine glands*: secrete hormones directly into the bloodstream. - **(b) Cretinism and Myxoedema (symptoms):** *Cretinism*: abnormal development in an infant. Results in mental retardation. *Myxoedema*: occurs in adults where insufficient thyroxine is produced. Causes sluggishness with sweating of the hands. - **c) Insulin and Glucagon (function):** *Insulin*: Lowers glucose from the blood stream. Converts extra glucose to glycogen, which is ultimately stored in the liver and muscles. Induces the cells to burn extra glucose to produce heat and energy for the body. Causes the cells to convert extra glucose into fat. *Glucagon*: Stimulates the breakdown of glycogen in the liver to glucose. Raises the sugar level in the blood. - **(d) Thyroxine and adrenaline (source):** *Thyroxine*: produced by the thyroid gland. *Adrenaline*: produced by the adrenal gland. - **(e) Human male and female hormone (one example of each):** *Male hormone*: Testosterone *Female hormone*: Estrogen 2. **Give reason/explain:** - **(a) Pituitary gland is considered as the "master gland"**: The pituitary gland controls the activities of many other endocrine glands such as the thyroid gland and the adrenal gland, making it the "master gland". - **(b) Epinephrine is also called as the 'emergency hormone'**: Epinephrine (adrenaline) is a hormone secreted by the adrenal glands that prepares the body for the "fight or flight" response in stressful situations, thus it is considered the emergency hormone. 3. **Draw neat and labelled diagrams of the thyroid gland showing its:** - **(a) Front view**: You can draw a simple diagram of the thyroid gland. - **(b) Back view**: You can draw a simple diagram of the thyroid gland. 4. **Briefly write about the importance of physical hygiene during adolescence.**: Adolescence is a crucial time as physical and emotional changes occur at a rapid pace. It is important to maintain proper physical hygiene during this time for overall health and well-being. - It helps prevent diseases and infections. - It boosts confidence and self-esteem. - It allows for proper growth and development. 5. **Briefly discuss any four activities which can be practised to overcome stress.**: Adolescence is a period of rapid growth and change, which can be quite stressful. There are many activities people can utilize to help manage their stress. - **Exercise**: Physical activity can release endorphins, which have mood-boosting effects. - **Yoga, meditation, and relaxation techniques**: Practice relaxation, exercise, and meditation to manage stress. - **Hobbies**: Enjoy your hobbies to divert attention from stressful thoughts. - **Social support and connecting with others**: Connect with friends and family for support and to enhance your emotional well-being. ### Source and Function of Hormones | Hormone | Source | Function | |---|---|---| | (a) Glucagon | Pancreas | Increases blood glucose levels by stimulating the liver to release stored glucose. | | (b) Thyroxine | Thyroid gland | Controls the metabolic rate, regulates growth and development. | | (c) Adrenaline | Adrenal medulla | Prepares the body for "fight or flight" response in stressful situations. Increases heart rate, blood pressure, and blood sugar levels. | | (d) Insulin | Pancreas | Regulates blood glucose levels by allowing glucose to enter cells for energy. | | (e) Cortisone | Adrenal cortex | Regulates salt and water balance in the body, influences carbohydrate, fat, and protein metabolism. |