W8 PPT- Physiology- Digestive, Endocrine, Lymphatic, and Immune Systems PDF

9/29/2023 Digestive System Fox Ch 18 © STANBRIDGE UNIVERSITY 2023 1 1  9/29/2023 Objectives Verbally describe the path of a b...

9/29/2023 Digestive System Fox Ch 18 © STANBRIDGE UNIVERSITY 2023 1 1  9/29/2023 Objectives Verbally describe the path of a bolus of food through the gastrointestinal tract (GI tract)/ alimentary canal Understand the digestive process in each of the areas of the GI tract Name and state the functions of the accessory organs to the GI tract Be able to articulate the neural control of the GI tract © STANBRIDGE UNIVERSITY 2023 2 2  9/29/2023 Metabolism & Cellular Metabolism Metabolism ◦ Refers to all chemical reactions in an organism Cellular Metabolism ◦ Includes all chemical reactions within cells ◦ i.e. glycolysis, Kreb’s cycle, oxidative phosphorylation ◦ Provides energy to maintain homeostasis and perform essential functions ◦ Refer to week 2 lecture for review © STANBRIDGE UNIVERSITY 2023 3 3  9/29/2023 Intro to the Digestive System Main Functions 1. Transportation through the GI tract 2.Digestion ◦ Mechanical: chewing, churning ◦ Chemical: enzymes & digestive juices 3.Absorption 4.Elimination © STANBRIDGE UNIVERSITY 2023 4 4  9/29/2023 Intro to the Digestive System Two major divisions: 1.The Digestive Tract (AKA gastrointestinal tract or alimentary canal) ◦ The tube that starts at the mouth and ends at the anus 2.The Accessory Organs ◦ Liver: Many metabolic and regulatory functions; produces bile ◦ Gallbladder: stores bile ◦ Pancreas: both an endocrine (releasing hormones into bloodstream) and exocrine gland (releases enzymes for digestion through a duct into small intestine) ◦ Salivary Glands: cleanse mouth, dissolve food chemicals for taste, moistens food to turn into bolus, contains enzyme (amylase) that begins digestion of starch © STANBRIDGE UNIVERSITY 2023 5 5  9/29/2023 Organs of the Digestive System Alimentary tract or gastrointestinal (GI) tract Mouth Pharynx Esophagus Stomach Small intestine Large intestine Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 6 6  9/29/2023 Overall Gastrointestinal Tract Activities (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 7 7  9/29/2023 Digestion Mechanical digestion ◦ Physical breakdown of food ◦ Mastication, glutination ◦ Breaking food into smaller pieces allows enzymes acids and chemicals to work © STANBRIDGE UNIVERSITY 2023 8 8  9/29/2023 Digestion Chemical digestion ◦ Breakdown of chemical bonds of food ◦ Enzymes, acid, water added ◦ Begin in mouth, pharynx and stomach ◦ Digestion occurs mostly in duodenum * All digestion of body ends after the small intestines, however bacteria in the large intestines do break things down © STANBRIDGE UNIVERSITY 2023 9 9  9/29/2023 The Mouth Also called oral cavity or buccal cavity, which processes food by: Ingestion – receiving food Mechanical Breakdown: ◦ Mastication – chewing ◦ Mixing by the tongue; combines food with saliva and amylase Digestion - salivary amylase (enzyme that begins to breakdown sugars) Propulsion – moves food into the pharynx © STANBRIDGE UNIVERSITY 2023 10 10  9/29/2023 Mouth and the Uvula (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 11 11  9/29/2023 The Pharynx Also called the throat Oropharynx Palatine tonsils Nasopharynx (only air) Laryngeal pharynx Soft palate Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 12 12  9/29/2023 The Pharynx Also called the throat Uvula ◦ Prevents food from going up into nose Epiglottis ◦ Covers trachea in presence of food to prevent food from getting into the lungs Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 13 13  9/29/2023 Basic Structure of the Alimentary Canal (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 14 14  9/29/2023 Swallowing = Deglutition Buccal phase: mouth forms a bolus (ball of food) and tongue sends bolus to pharynx (voluntary) Pharyngeal-esophageal phase is involuntary Bolus is moved to the esophagus where it is pushed down into the stomach Uvula and soft palate raise to protect the nose from up-flow of food; Tongue is raised to seal of back of mouth Epiglottis descends to cover the opening of the larynx © STANBRIDGE UNIVERSITY 2023 15 15  9/29/2023 Phases of digestion in the mouth, pharynx, and esophagus (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 16 16  9/29/2023 The Esophagus Marieb, 2019 Muscular tube ◦ Joins with stomach ◦ Lubricates food with mucus ◦ Moves food by peristalsis (in esophagus and lower parts of the pharynx) Anterior to stomach Posterior to trachea © STANBRIDGE UNIVERSITY 2023 17 17  9/29/2023 Process of Digestion in the Esophagus and Entrance into the Stomach (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 18 18  9/29/2023 Swallowing Dysphagia: difficulty swallowing. Often caused by neurological damage (strokes, cerebral palsy, brain injury) ◦ Defective swallowing process ◦ May result in food and liquids entering the larynx and going into the lungs Aspiration = food and liquids going into the lungs ◦ Often leads to aspiration pneumonia © STANBRIDGE UNIVERSITY 2023 19 19  9/29/2023 The Stomach (Marieb, 2019) ▪Fundus- the top ▪Cardiac sphincter- separates stomach from esophagus ▪Pylorus- last part of the stomach ▪Pyloric sphincter separates stomach from small intestine © STANBRIDGE UNIVERSITY 2023 20 20  9/29/2023 The Stomach: Functions ◦ Stores food and liquid and propels them with peristalsis ◦ Secretes gastric juice ◦ Secretes mucus (helps lubricate and protect stomach) ◦ Mechanical (churning) ◦ Chemical digestion: ✓ Hydrochloric acid (HCL) – breaks down proteins and destroys foreign organisms ✓ Pepsin – enzyme that digests proteins © STANBRIDGE UNIVERSITY 2023 21 21  9/29/2023 The Stomach: Functions Produces intrinsic factor that is necessary for B12 intestinal absorption Fat digestion mainly occurs in the small intestines but lipases in the acidic pH of the stomach contribute Absorption: little occurs here but alcohol and aspirin pass through the mucosa easily Chyme © STANBRIDGE UNIVERSITY 2023 22 22  9/29/2023 Peristalsis in the Stomach (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 23 23  9/29/2023 The Small Intestines Structure Duodenum – first part ◦ “12 finger lengths” in Latin ◦ most digestion (chemicals) in this part of the small intestines Jejunum – second part; middle 2/5ths - most absorption in this part of the small intestines Ileum – third part - reabsorb bile salts into the liver © STANBRIDGE UNIVERSITY 2023 24 24  9/29/2023 The Small Intestines (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 25 25  9/29/2023 Small Intestines: Functions o Secretes mucus (help neutralize acid chyme) o Secrete enzymes to break down food o Absorb digested food ◦ Villi – fingerlike projections that line the mucosa that increase surface area ◦ Microvilli – small projections on the Villi ◦ Called the brush border ◦ Brush border enzymes: complete carbohydrate and protein digestion in small intestine ◦ Blood vessels ◦ Lacteals - Specialized lymphatic capillaries that absorb fat droplets © STANBRIDGE UNIVERSITY 2023 26 26  9/29/2023 Small Intestines: Functions oBicarbonate juice from the pancreas also helps to neutralize acid chyme oMechanical break down and propulsion: mixes with enzymes for digestion and slow movement to allow for absorption oDigestion: through pancreatic enzymes and brush border enzymes oBile (produced in the liver and stored and concentrated in the gall bladder): emulsifies fat improving fat digestion and absorption of fatty acids oAbsorption of carbohydrates, proteins, lipids, nucleic acids, vitamins, electrolytes, and water *overall, the most absorption and reabsorption of water occurs in the small intestines © STANBRIDGE UNIVERSITY 2023 27 27  9/29/2023 Segmentation (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 28 28  9/29/2023 Microvilli – “tiny villi” that line the villi. They vastly increase surface area for absorption Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 29 29  9/29/2023 Absorption of Fats Lacteals absorb fat ◦ Lacteals are special lymphatic capillaries in the intestinal villi Fat/lymph mixture (chyle) drains from small intestine into the cisterna chyle (a holding pouch in the abdomen) Chyle merges with lymphatic circulation, enters blood in veins near heart Liver further processes absorbed fats © STANBRIDGE UNIVERSITY 2023 30 30  9/29/2023 The Large Intestines: Structure Cecum –Small pouch where small intestine pours through Ileocecal valve – a one-way valve that prevents backflow into the small intestine Vermiform appendix – a hanging appendage of lymph tissue Colon – Four parts 1.Ascending colon 2.Transverse colon 3.Descending colon 4.Sigmoid colon - named after the Greek letter sigma – Ʃ Rectum – temporary storage area Anal canal Anus (closes by way of the anal sphincter) © STANBRIDGE UNIVERSITY 2023 31 31  9/29/2023 The Large Intestines (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 32 32  9/29/2023 The Large Intestines: Functions ◦ Secrete mucus to ease passing of feces through colon ◦ Reabsorbs most of the remaining water ◦ Bacteria: digest some of the remaining food ◦ Bacteria in the colon produce vitamin K and some B complex vitamins ◦ Absorbs electrolytes (mostly NaCl) and the vitamins produced by bacteria ◦ Propels feces toward the rectum by mass movements ◦ Temporarily stores and concentrates feces ◦ Defection is triggered by a reflex from rectal distension © STANBRIDGE UNIVERSITY 2023 33 33  9/29/2023 Appendix Attached to posteromedial surface of cecum Contains masses of lymphoid tissue; important in immunity Stores bacteria which can be put into GI as needed Twisted structure → vulnerable to accumulation of bacteria, can be trapped by a blockage (sometimes feces) → swell and squeeze off venous drainage → ischemia and necrosis © STANBRIDGE UNIVERSITY 2023 34 34  9/29/2023 The Accessory Organs 1. Salivary glands: contains enzymes that digest carbohydrates 2. Liver: produces bile which breaks down fats in the small intestines 3. Gallbladder: stores bile 4. Pancreas: Secretes digestive enzymes into duodenum © STANBRIDGE UNIVERSITY 2023 35 35  9/29/2023 Liver, Pancreas, Gall Bladder (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 36 36  9/29/2023 Liver: Has Many Functions Makes Bile to break down fats in the small intestine Stores glucose in the form of glycogen ✓When blood sugar is low the glycogen turns back into glucose Modifies fats so that cells can use them (cholesterol) Stores some vitamins and iron Makes proteins that go into the blood plasma (albumin, globulins, and clotting factors) Detoxifies the blood – i.e. alcohol Recycles Biliruben a yellowish byproduct from the normal breakdown of RBC’s © STANBRIDGE UNIVERSITY 2023 37 37  9/29/2023 Activation of Pancreatic Proteases in the Small Intestines (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 38 38  9/29/2023 Bile and Pancreatic Juice Secretion and Release (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 39 39  9/29/2023 The Enterohepatic Circulation (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 40 40  9/29/2023 Overall Digestion and Absorption of Biological Macromolecules oCarbohydrates: Proteins: o Broken down by: ◦ Broken down by: o Salivary amylase (mouth) ◦ Pepsin with HCl (stomach) o Pancreatic amylase (small intestines) ◦ Pancreatic enzymes (trypsin, o Brush border enzymes (small intestines) chymotrypsin, carboxypeptidase in the small intestines) o Absorbed in the small intestines ◦ Absorbed in the small intestines o Transported to the liver ◦ Transported to the liver © STANBRIDGE UNIVERSITY 2023 41 41  9/29/2023 Digestion and Absorption of Biological Macromolecules oLipids: oNucleic acids: oBroken down by: ◦ Broken down by: o Lingual lipase (mouth) ◦ Pancreatic ribonuclease and o Gastric lipase (stomach) deoxyribonuclease (small intestines) o Emulsification by bile salts from the liver (small ◦ Brush border enzymes (small intestines) intestines) o Pancreatic enzymes (small intestines) ◦ Enter intestinal cells by active transport oConverted and combined with other and transported to the liver lipids and mostly absorbed by the lacteals oTransported in the lymph into the blood stream, some are absorbed and transferred to the liver © STANBRIDGE UNIVERSITY 2023 42 42  9/29/2023 Control of Digestion: Hormonal Digestive organs produce hormones ◦ Gastrin – promotes stomach secretions and movement ◦ Gastric-inhibitory peptide (GIP) – secreted by duodenum to inhibit gastric secretions ◦ Secretin – tells pancreas to secrete sodium bicarbonate to neutralize acid in the small intestine ◦ Cholecystokinin (CCK)– stimulate enzyme release from pancreas and causes gallbladder to squirt bile into duodenum © STANBRIDGE UNIVERSITY 2023 43 43  9/29/2023 Nervous System Control of the GI Tract: Enteric Nervous System The local nervous system controls are called the enteric nervous system Supply most of the nerve supply to the GI tract wall and control motility of the GI tract ◦ Intrinsic nerve plexus located in the walls of the alimentary canal ◦ Submucosal and myenteric nerve plexii © STANBRIDGE UNIVERSITY 2023 44 44  9/29/2023 Central Nervous System Control of the GI tract (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 45 45  9/29/2023 Control of Digestion Nervous System Control ◦ Parasympathetic stimulation increases activity ◦ Sympathetic stimulation decreases activity and mucus production ◦ Stress reduces mucus in GI tract which can lead to ulcers © STANBRIDGE UNIVERSITY 2023 46 46  9/29/2023 Pancreas & Associated Hormones (Marieb, 2019, Chapter 16) ά cells secrete β cells secrete glucagon insulin Sugar Breaks down Moves glucose Sugar Too Low glycogen to glucose into cells Too High Both normalize and inhibit the secretion Hyperglycemia Hypoglycemia © STANBRIDGE UNIVERSITY 2023 47 47  9/29/2023 Pancreas & Diabetes Diabetes mellitus —caused by the lack of insulin or by the inability of cells to take up glucose creates hyperglycemia (increased blood sugar levels) Type 1 diabetes —pancreas is not producing insulin Insulin dependent - insulin is not produced by the pancreas Type 2 diabetes —inability of cells to respond to insulin Most common type Non-insulin-dependent diabetes mellitus (NIDDM), or adult-onset diabetes –diet and exercise Cells do not have enough insulin receptors © STANBRIDGE UNIVERSITY 2023 14-22 48 48  9/29/2023 Negative Feedback Loop of the Pancreas and Blood Sugar (Marieb, 2019 Chapter 16) © STANBRIDGE UNIVERSITY 2023 49 49  9/29/2023 Assess Your Learning from This Lecture © STANBRIDGE UNIVERSITY 2023 50 50  9/29/2023 The Endocrine System: Endocrine Glands and Hormone Action – Chemical Messengers (Fox, Chapter 11) © Stanbridge University 2023 51 51  9/29/2023 Objectives: Name the components of the endocrine system List the various organs and each of the hormones that trigger their activation and what their response is Describe the relationship between the nervous system and the endocrine system © Stanbridge University 2023 52 52  9/29/2023 Endocrine System Works with the nervous system to coordinate and integrate activity of body cells System of hormonal communication ◦ Hormones deliver messages to various organs/tissue to turn on, or turn off a multitude of functions © Stanbridge University 2023 53 53  9/29/2023 Nervous System and Endocrine System (Marieb, 2019) © Stanbridge University 2023 54 54  9/29/2023 Glands Two kinds of glands 1. Exocrine Glands (not part of endocrine system) Release substances through ducts Secrete substances outside of blood Don’t typically secrete hormones 2. Endocrine Glands Secrete substances directly into the blood stream Secrete hormones © Stanbridge University 2023 55 55  9/29/2023 Endocrine Glands Pituitary Gland- master gland Adrenals- Cortex- corticosteroids Pineal- sleep/wake cycles Medulla- fight or flight Thyroid- metabolism Pancreatic islets- glucose metabolism Parathyroid- blood calcium levels Ovaries- menstrual cycle and sexual Thymus- T-cell growth characteristics Testes- sperm production and sexual characteristics © Stanbridge University 2023 56 56  9/29/2023 Pituitary Gland Hypothalamus controls the release of hormones from the pituitary gland Located under hypothalamus “Master Gland” Releases hormones Two parts Anterior pituitary (glandular) Posterior pituitary (neural) © Stanbridge University 2023 57 57  9/29/2023 Pituitary Gland Anterior pituitary Posterior pituitary (part of the brain) Releasing hormones produced No hormones produced and in hypothalamus stimulate only stored production of anterior *Hormones are produced in the pituitary hormones hypothalamus → * Hypothalamus releases hormones into special blood vessels → control Axons transport them to the posterior release of hormones from the anterior pituitary where they are stored in axon pituitary terminals When neuron fires and the action potential reaches the axon terminal → released into the blood © Stanbridge University 2023 58 58  9/29/2023 Hypothalamus and Anterior Pituitary (Marieb, 2019) © Stanbridge University 2023 59 59  9/29/2023 Anterior Pituitary Gland Growth Hormone (GH) Growth, lipid and carbohydrate metabolism Prolactin (PRL) Estrogen, progesterone and milk production Follicle-Stimulating Hormone (FSH) Growth of reproductive system Luteinizing Hormone (LH) Sex hormone production Adrenocorticotropic Hormone (ACTH) Metabolism Thyroid-Stimulating Hormone (TSH) Temperature, metabolism and heart rate © Stanbridge University 2023 60 60  9/29/2023 Hypothalamus and Posterior Pituitary (Marieb, 2019) © Stanbridge University 2023 61 61  9/29/2023 Posterior Pituitary Gland Hormones are produced in the hypothalamus, transported to the posterior pituitary via axons and released when an action potential moves along the neuron Anti-diuretic hormone (ADH) Prompts kidneys to increase water absorption in the blood Released in situation of dehydration Inhibited in times of hypertension, high blood volume, and alcohol intake Oxytocin Contracting the uterus during childbirth and stimulating breast milk production © Stanbridge University 2023 62 62  9/29/2023 Thyroid Gland Largest pure endocrine gland 2 iodine containing amine hormones: Triiodothyronine (T3) Thyroxine (T4) Most T3 is converted in the target tissues from T4 T4 is the major hormone secreted by thyroid follicles Named based on the number iodine atoms bonded to them Marieb, 2019 63 © Stanbridge University 2023 63 63  9/29/2023 Thyroid Gland Function: Heat production Increase metabolic rate and body Regulate tissue growth and development in skeletal and nervous systems and reproductive maturation Maintain BP (by increasing # of adrenergic receptors in the blood vessels) 64 © Stanbridge University 2023 64 64  9/29/2023 Thyroid Gland According to the Mayo clinic: Hypothyroidism: deficiency of thyroxine → slow metabolism, weight gain, water retention, coldness Hyperthyroidism: too much thyroxine → fast metabolism, increased blood pressure, bulging eyes can be a sign (ex. Grave’s disease) Goiter: enlargement of the thyroid gland (could still function normally or could not) ◦ Possible causes: iodine insufficiency, hypothyroidism, hyperthyroidism, thyroid nodule(s), hCG (human chorionic gonadotropin) inflammation, thyroid cancer © Stanbridge University 2023 65 65  9/29/2023 Parathyroid Glands Located on the posterior side of the thyroid gland Usually, 4 of them Primary regulators of blood calcium levels Secretes parathyroid hormone (PTH) ◦ ↓ blood calcium → release of PTH ◦ ↑ blood calcium → inhibits release of PTH Marieb, 2019 © Stanbridge University 2023 66 66  9/29/2023 Parathyroid Gland Function 1. Stimulates osteoclasts to digest bone → release calcium and phosphate 2. Enhances kidney reabsorption of calcium from the forming urine 3. Promotes vitamin D activation → increase calcium absorption from the intestinal mucosal cells © STANBRIDGE UNIVERSITY 2023 67 67  9/29/2023 Parathyroid Hormone’s Role in Increasing Calcium (Marieb, 2019) © Stanbridge University 2023 68 68  9/29/2023 Adrenal Glands Located on top of each kidney Two sections 1. Adrenal Cortex (outer and larger) Hormonal stimulation 2. Adrenal Medulla (inner) Neural stimulation Each division secretes different hormones Structurally and functionally two separate glands Marieb, 2019 © Stanbridge University 2023 69 69  9/29/2023 Adrenal Gland Adrenal Cortex Adrenal Medulla Long term stress via the adrenal cortex from Short term stress via the adrenal medulla from hormonal stimuli neural stimuli Hormonal Nervous tissue and neural stimulation Secretes cortisol: Secretes epinephrine and norepinephrine Stress response Inhibits immune system Fight or flight response Raises blood glucose levels Increase heart rate, increased blood pressure, Secretes aldosterone: raise blood sugar levels Regulates ion and fluid levels with kidneys Secretes androgens (corticosteroids) Sex hormones: reproductive function © Stanbridge University 2023 70 70  9/29/2023 Adrenal Glands: Structure Marieb, 2019 © Stanbridge University 2023 71 71  9/29/2023 Mechanics of Short-Term Stress Response Marieb, 2019 © Stanbridge University 2023 72 72  9/29/2023 Mechanics of Long-Term Stress Response (Marieb, 2019) © Stanbridge University 2023 73 73  9/29/2023 Pancreatic Islet Cell Pancreas is both exocrine and endocrine Two kinds of cells (endocrine cells) 1. Alpha (α) Islet Cells produce Glucagon 2. Beta (β) Islet Cells produce Insulin © Stanbridge University 2023 74 74  9/29/2023 Pancreatic Islet Cell Glucagon: Actions on the liver: 1. Glycogen → glucose (glc) 2. Synthesis of glucose from lactic acid and non-carbohydrate materials 3. Release glucose into the blood (one molecule can cause release of 100 million glucose molecules into the blood) *lowers blood amino acids (a.a.) levels (liver cells take up a.a. to make glc) © Stanbridge University 2023 75 75  9/29/2023 Pancreatic Islet Cell Insulin: lowers blood glucose 1. Allows cells to transport glucose across their plasma membranes into most body cells (esp. muscle and fat cells) (liver, kidney, and brain tissue not need insulin for this) 2. Inhibits breakdown of glycogen → glucose 3. Inhibits a.a. or fats → glucose © Stanbridge University 2023 76 76  9/29/2023 Pancreas & its Associated Hormones In its Endocrine Role (Marieb, 2019) ά cells secrete β cells secrete glucagon insulin Sugar Breaks down Moves glucose Sugar Too Low glycogen to glucose into cells Too High Both normalize and inhibit the secretion Hyperglycemia Hypoglycemia © Stanbridge University 2023 77 77  9/29/2023 Pancreas & Diabetes Diabetes mellitus —caused by the lack of insulin or by the inability of cells to take up glucose creates hyperglycemia (increased blood sugar levels). Type 1 diabetes —pancreas is not producing insulin Insulin dependent - insulin is not produced by the pancreas Type 2 diabetes —inability of cells to respond to insulin. (cells do not have enough insulin receptors) Most common type Non-insulin-dependent diabetes mellitus (NIDDM), or adult-onset diabetes –diet and exercise © Stanbridge University 2023 14-22 78 78  9/29/2023 Negative Feedback Loop of the Pancreas and Blood Sugar (Marieb, 2019) © Stanbridge University 2023 79 79  9/29/2023 Pancreas and Diabetes Why do diabetics suffer from wounds that have trouble healing? High levels of glucose in the blood ◦ Rich food source for bacteria ◦ Make the blood flow less efficient and wounds heal poorly ◦ Damage peripheral nerves over time that lead to numbness in the limbs due to poor sensation © Stanbridge University 2023 80 80  9/29/2023 Testes and Ovaries Androgens ◦ Male sex hormones produced by the testes ◦ Testosterone Estrogens ◦ Female sex hormones produced by ovaries ◦ Estrogen ◦ Secondary sexual characteristics, onset of menstruation, development of reproductive organs ◦ Progesterone ◦ Development of pregnancy (gestation) © Stanbridge University 2023 81 81  9/29/2023 Male Reproductive System (Marieb, Chapter 27) Follicle stimulating hormone (FSH) ◦ Promotes the production of sperm Luteinizing hormone (LH) ◦ Stimulates androgen secretion (testosterone) © Stanbridge University 2023 82 82  9/29/2023 Female Reproductive System Follicle-stimulating hormone (FSH) and estrogens ◦ Stimulate follicle growth and development Luteinizing hormone (LH) ◦ Triggers ovulation and development of corpus luteum © Stanbridge University 2023 83 83  9/29/2023 Female Reproductive System (Marieb, 2019) © Stanbridge University 2023 84 84  9/29/2023 Time to Assess Learning © Stanbridge University 2023 85 85  9/29/2023 Lymphatic and Immune System FOX, CHAPTER 15 © STANBRIDGE UNIVERSITY 2023 86 86  9/29/2023 Objectives: Name the various components of the lymphatic system, including the lymphatic vessels Name the functions of the lymphatic organs Name the functions of the lymphatic system © STANBRIDGE UNIVERSITY 2023 87 87  9/29/2023 Functions of the Lymphatic System 1. Takes up excess tissue fluid and returns it Marieb, 2019 to bloodstream 2. Absorb fats (from small intestines) and transports it to circulatory system (lacteals) 3. Structural basis of immune system © STANBRIDGE UNIVERSITY 2023 88 88  9/29/2023 Lymphatic System Pathway 1.Lymphatic vessels run from distal extremities toward chest eventually 2.Pour lymph into circulatory system at subclavian veins and internal jugular vein junctions 3.Lymph nodes are distributed in clusters at certain locations 4.Cisterna Chyli – pouch in upper abdominal region filled with “chyle,” a mixture of lymph and fats absorbed from small intestines Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 89 89  9/29/2023 Lymphatic System taking interstitial fluid back up to the cardiovascular system Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 90 90  9/29/2023 Right upper quadrant The rest of body’s lymph of body drains lymph is drained into left into right subclavian subclavian vein via the vein through Right Thoracic Duct Lymphatic Duct Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 91 91  9/29/2023 Right Lymphatic Duct and Thoracic Duct in the thorax Marieb, 2019 © STANBRIDGE UNIVERSITY 2023 92 92  9/29/2023 Lymphoid Organs Aggregates of lymphoid tissue in the body Lymph nodes Spleen, thymus Tissue scattered in connective tissues Mucosa-associated lymphoid tissue (MALT): tonsils, Peyer’s patches (aggregated lymphoid nodules), appendix, mucosa of respiratory tract and genitourinary organs, digestive tract © STANBRIDGE UNIVERSITY 2023 93 93  9/29/2023 Lymphoid Organs (Marieb, 2019) © STANBRIDGE UNIVERSITY 2023 94 94  9/29/2023 Spleen Largest lymphoid organ Located in the left side of the abdominal cavity just below the diaphragm, curls around the anterior stomach Functions Site for lymphatic proliferation and immune surveillance and response Extract aged and defective blood cells and platelets from the blood Macrophages remove debris and foreign matter Recycles breakdown of products of red blood cells for later Stores blood platelets and monocytes (immune system) for when needed © STANBRIDGE UNIVERSITY 2023 95 95  9/29/2023 Thymus Mainly important functions in early years of life Only lymphoid organ that does not directly fight antigens 1. site where T-lymphocyte precursors mature (happens over lifetime) 2. may be involved with development of regulatory T-cells (important in preventing auto immune response) © STANBRIDGE UNIVERSITY 2023 96 96  9/29/2023 Lymph Nodes Principle lymphoid organs The only organs that filter lymph Cluster along lymphatic vessels Functions: 1. Filtration (lymph fluid as transported to blood, macrophages in nodes) 2. Immune system activation © STANBRIDGE UNIVERSITY 2023 97 97  9/29/2023 Marieb, 2019 Lymph nodes are like mazes where immune cells lay waiting to ambush foreign bodies © STANBRIDGE UNIVERSITY 2023 98 98  9/29/2023 Tonsils Remove pathogens from the incoming food and air Palatine tonsils: either side of oral cavity in posterior end; largest and most often infected Lingual tonsil: lymphoid follicles at base of tongue Pharyngeal tonsil: (adenoids if enlarged) in posterior wall of nasopharynx Tubal tonsils: surround openings of auditory tubes into the pharynx © STANBRIDGE UNIVERSITY 2023 99 99  9/29/2023 Peyer’s Patches and Appendix Peyer’s patches: aggregated lymph nodules in wall of distal small intestines Appendix: contains a lot of lymphoid follicles 1. destroy bacteria before they can leave the intestinal wall 2. generate many “memory” lymphocytes for long-term immunity © STANBRIDGE UNIVERSITY 2023 100 100  9/29/2023 Time to assess learning © STANBRIDGE UNIVERSITY 2023 101 101  9/29/2023 White Blood Cells Marieb, 2019 © Stanbridge University 2023 102 102  9/29/2023 White Blood Cells Two categories of WBCs 1. Granulocytes Have small “grains” when stained Three kinds of cells: 1. Eosinophils 2. Basophils 3. Neutrophils -phil (attraction) © Stanbridge University 2023 103 103  9/29/2023 White Blood Cells 2. Agranulocytes Do not have “grains” Two kinds of cells: 1. Monocytes 2. Lymphocytes -cyte (cell) © Stanbridge University 2023 104 104  9/29/2023 Granulocytes Each specializes in fighting different kinds of pathogens – Neutrophils: fight bacteria and produce pus; secrete defensins (chemical in innate surface immune response); phagocyte – Eosinophils: fight parasites and involved in allergic reactions – Basophils: fight parasites and involved in allergic reactions © Stanbridge University 2023 105 105  9/29/2023 Agranulocytes Three main functions of Monocytes: 1. Phagocytosis: (“cell eating”) of foreign particles (macrophages) 2. Antigen presentation: present fragments to B-Lymphocytes so antibodies can be made 3. Produce cytokines: proteins that cause various actions in immune system © Stanbridge University 2023 106 106  9/29/2023 Two types of Lymphoytes: 1. B-Lymphocytes (“B Cells”): make antibodies 2. T-Lymphocytes (“T Cells”): target and destroy cells infected by viruses 3. (Natural Killer cells (granular lymphocyte) © STANBRIDGE UNIVERSITY 2023 107 107  9/29/2023 Marieb, 2019 First and Second Lines of Defense © Stanbridge University 2023 108 108  9/29/2023 Marieb, 2019 Third Line of Defense Adaptive © Stanbridge University 2023 109 109  9/29/2023 https://youtu.be/2DFN4IBZ3rI © STANBRIDGE UNIVERSITY 2023 110 110  9/29/2023 Two types of Immunity 1. INNATE DEFENSES 2. ADAPTIVE DEFENSES Generalized ways of Require immune system to protecting body from gather specific information infection to fight a specific invader © Stanbridge University 2023 111 111  9/29/2023 Immunity: Innate and Adaptive Defenses Marieb, 2019 © Stanbridge University 2023 112 112  9/29/2023 Innate (non-specific) Immunity: Surface Barriers Skin: keratin: resistant to most weak acids and bases, bacterial enzymes and toxins Mucous Membranes: mechanical barriers and secretions; line all body cavities open to exterior (GI, resp, urinary, reproductive) Cilia (sweep) on mucosa of upper resp tract Hairs in nose (trap) © Stanbridge University 2023 113 113  9/29/2023 Innate (non-specific) Immunity: Surface Barriers: Mucous Membrane Secretions Acid mantle: inhibits bacterial growth in skin, vagina, and stomach (sebum with sweat) Enzymes: lysozyme (saliva, resp mucus, lacrimal eye fluid) → destroys bacteria; protein-digesting enzymes in stomach → kill many microorganisms Mucin: traps microorganisms (GI, saliva, and resp), dissolves in water to form sticky mucus © Stanbridge University 2023 114 114  9/29/2023 Innate (non-specific) Immunity: Surface Barriers: Mucous Membrane Secretions Defensins: (from neutrophils) antimicrobial (mucous membranes and skin) and can pierce membrane of pathogen Sebum and dermcidin: in eccrine sweat → toxic to bacteria (skin- lipids) © Stanbridge University 2023 115 115  9/29/2023 Innate (non-specific) Immunity: Internal Defenses Phagocytes: macrophages (from monocyte); neutrophils If cannot ingest pathogen, can release chemicals into extracellular fluid Opsonization: coat bacteria with opsonins accelerates phagocytosis → makes them recognizable and phagocytes can grab them Helper T cells can enhance this process © Stanbridge University 2023 116 116  9/29/2023 Phagocytosis (Marieb, 2019) © Stanbridge University 2023 117 117  9/29/2023 Marieb, 2019 © Stanbridge University 2023 118 118  9/29/2023 Marieb, 2019 © Stanbridge University 2023 119 119  9/29/2023 Innate (non-specific) Internal Immunity: Natural Killer Cells: granular lymphocytes Recognize non-self cell surface receptors or other abnormalities Directly cause apoptosis (cell death) of target cell Secrete chemicals enhance inflammatory response Can act before adaptive immune system activated © Stanbridge University 2023 120 120  9/29/2023 Innate (non-specific) Internal Immunity 3. Inflammation: a. Prevents spread of damaging agents b. Disposes of cell debris and pathogens c. Alerts adaptive immune system d. Gets ready for repair © Stanbridge University 2023 121 121  9/29/2023 Innate (non-specific) Internal Immunity: Inflammation Mast cells → release histamine Certain boundary cells and macrophages recognize invaders → release cytokines These inflammatory chemicals: Dilate local arterioles; make leaky capillaries many attract WBCs (chemotaxis) Some have other inflammatory actions © Stanbridge University 2023 122 122  9/29/2023 Innate (non-specific) Internal Immunity Antimicrobial Proteins: Attack microorganisms Reduce reproduction of microorganisms Examples a. interferons (IFN) b. complement: 20 plasma proteins © Stanbridge University 2023 123 123  9/29/2023 Innate (non-specific) Internal Immunity Fever: WBC and macrophages detect foreign substance → release substances → hypothalamus to increase body temp above normal → Liver and spleen sequester iron and zinc → decrease support of bacterial growth Increase metabolic rate of tissue cells → speed up repair process © Stanbridge University 2023 124 124  9/29/2023 Marieb, 2019 © Stanbridge University 2023 125 125  9/29/2023 Adaptive Defenses Overall: Responsible for most complement activation Increases inflammatory response Specific to particular pathogens or substances Systemic Memory © Stanbridge University 2023 126 126  9/29/2023 Adaptive Defenses: Types Humoral Immunity (or antibody (Ab)/ immunoglobulin (Ig) mediated): B cells (lymphocytes); “in the fluid” active or passive B cells: memory B cells or plasma/effector B cells → secrete Ab (or Ig) Cellular Immunity: T cells (lymphocytes) “cell mediated” → target affected cells CD4 (helper T or memory) or CD8 (cytoxic or memory) cells © Stanbridge University 2023 127 127  9/29/2023 Lymphocytes and Lymphocyte Activation © Stanbridge University 2023 128 128  9/29/2023 Marieb, 2019 © Stanbridge University 2023 129 129  9/29/2023 Lymphocytes Immunocompetence: each lymphocyte must become “competent” to recognize its ONE specific antigen (Ag) by binding to it They display a unique receptor once competent T cells become competent and self-tolerant in thymus gland (cellular immunity) B cells become competent and self tolerant in bone marrow (humoral immunity) Called naïve before immunocompetent Once naïve cell meets its antigen, cued to differentiate (clonal selection) → effector (action) cells or memory cells © Stanbridge University 2023 130 130  9/29/2023 Humoral Immunity © Stanbridge University 2023 131 131  9/29/2023 Adaptive Defenses: Humoral Immunity: B cell activation B cell activation by T cell or Ag (less effective) Once activated becomes an effector cell (plasma cell) or memory cell Plasma cell → secretes Ab from rough endoplasmic reticulum Ab → circulate and mark Ag for destruction (B cell can switch what Ab it is making) © Stanbridge University 2023 132 132  9/29/2023 Humoral Immunity: Antigen (Ag) displayed for self vs non-self, Ab specific to an Ag (Marieb, 2019) © Stanbridge University 2023 133 133  9/29/2023 Adaptive Defenses: Humoral Immunity: Active vs Passive Active: Naturally acquired Ag from viral or bacterial infection Artificially acquired Ag from vaccines (most are dead or weakened or components of pathogens) © Stanbridge University 2023 134 134  9/29/2023 Adaptive Defenses: Humoral Immunity: Active vs Passive Passive: Ready made Ab introduced to body, so B cells not meet them, when Ab die → protection gone Naturally: mother to fetus in womb, mother to infant in breast milk Artificially: exogenous Ab (gamma globulin from immune donor) used in cases where person would be dead before active immunity is established (effect about 2-3 weeks) © Stanbridge University 2023 135 135  9/29/2023 Marieb, 2019 © Stanbridge University 2023 136 136  9/29/2023 Adaptive Defenses: Humoral Immunity: Antibodies Cannot destroy Ag They inactivate and tag Ag for destruction Work mainly on extracellular pathogens ex. bacteria, free viruses, soluble foreign materials Can hang onto virus when it goes into host cell, but less effective © Stanbridge University 2023 137 137  9/29/2023 Marieb, 2019 © Stanbridge University 2023 138 138  9/29/2023 Cellular Immunity © Stanbridge University 2023 139 139  9/29/2023 https://youtu.be/rd2cf5hValM?si=FyMXl2bqWupd4ZDF © STANBRIDGE UNIVERSITY 2023 140 140  9/29/2023 Adaptive Defenses: Cellular Immunity When activated: CD4 cells→ memory CD4 cells, most become helper T cells, some become regulatory T cells CD8→ cytoxic T cells © Stanbridge University 2023 141 141  9/29/2023 Adaptive Defenses: Cellular Immunity Helper T cells: activate B cells or other T cells and macrophages, direct adaptive immunity Cytoxic T cells: destroy cells containing foreign material (directly attack) Regulatory T cells: moderate immune response © Stanbridge University 2023 142 142  9/29/2023 Adaptive Defenses: Cellular Immunity Helper T cells (from CD-4 cells): ❖without Helper T cells, no adaptive response Help activate T and B cells to proliferate CD8 usually require helper T cells Amplify innate response (ex. macrophages and attract WBC to area) © Stanbridge University 2023 143 143  9/29/2023 Adaptive Defenses: Cellular Immunity Cytotoxic T cells (from CD-8): ❖Only T cells that directly attack and kill Perforins and granzymes secreted Bind to specific membrane receptor → stimulate apoptosis © Stanbridge University 2023 144 144  9/29/2023 Adaptive Defenses: Cellular Immunity Regulatory T cells: ❖ dampen immune system important in preventing autoimmune reactions Direct contact or release of cytokines Suppress self-reactive lymphocytes outside of lymphoid organs © Stanbridge University 2023 145 145  9/29/2023 Overview of B and T Lymphocytes Marieb, 2019 © Stanbridge University 2023 146 146  9/29/2023 Disease resulting from autoimmunity Immune system loses ability between self vs non-self and produces Ab (autoantibodies) and cytotoxic T cells that destroy its own tissues Ex. Rheumatoid arthritis Myasthenia Gravis Multiple Sclerosis Graves Disease Systemic Lupus Erythematosus Glomerulonephritis © Stanbridge University 2023 147 147  9/29/2023 Congenital or acquired condition that impairs production or function of immune cells or certain molecules (ex. complement or Ab) Examples: ◦Acquire immune deficiency syndrome (AIDS) ◦Interferes with activity of helper T cells ◦Caused by human immunodeficiency virus (HIV) ◦Hodgkin’s Lymphoma ◦Cancer of B cells can lead to immunodeficiency by depressing lymph node cells © Stanbridge University 2023 148 148