Chapter 2 The Systems Of The Body PDF

Chapter 2 The systems of the body A diagram of a stress response Description automatically generated What Is the function of the nervous system - The nervous system: is a complex network of interconnected nerve fibers that functions to regulate many important bodily functions, including...

Chapter 2 The systems of the body A diagram of a stress response Description automatically generated What Is the function of the nervous system - The nervous system: is a complex network of interconnected nerve fibers that functions to regulate many important bodily functions, including the response to and recovery from stress - Made up of: Central nervous system and peripheral nervous system - Central nervous system: the brain and the spinal cord - Peripheral nervous system: The rest of the nerves in the body including those that connect with brain and spinal cord - where stress reaction are built, strength and timing are determined - Is made up of somatic nervous system and autonomic nervous system - Somatic (voluntary) Nervous system: connect nerve fibers to voluntary muscles and provides the brain with feedback in the form of sensory information about voluntary movement - Autonomic (involuntary) nervous system: connect central nervous system with internal organs, which people do not usually have control over - Regulation of the autonomic nervous system occurs via dynamic interplay between the sympathetic and parasympathetic nervous system - SYMPATHETIC nervous system: plan an important role in response to stress - It prepares the body to respond to potentially threatening stimuli with strong emotions ex. Fear, - While mustering energy resources for emergencies and strenuous activity - It is concerned with the mobilization and exertion of energy called **[catabolic system]** - Activation begins in brain but is often experience in the body as: increased heart rate, respiration and muscle tension - Acting in sympathy with whatever it is your attending do - Fight or flight - Parasympathetic nervous system: controls the activities of organs during non-stress circumstances and generally acts in opposite (inhibitory) manner to the catabolic actions of sympathetic nervous system - In stressful situations can assist with focused attention - Its central role is to restores the body to a steady state, when emergency has passed - Activation: during digestion; feeling relaxed and drowsy after eating large satisfying meal - The system is anabolic: concerned with the conservation of body energy - Restore equilibrium, regulates calming process in the body - Synaptic knob; tips of branches at end of axon, send messages to adjacent neurons - Axon- projection through which messages travel - Message - Motor cortex damage; numbness inability to have proper control - Spinal cord injury; paralysis happens opposite side of body - Parietal lobe: perception, correctly judge space (reach what your grabbing for, poor balance - Occipital lobe: visual - Temporal lobe sides: left side language function (left handed people it reversed) right side: creativity, aesthetics, visual spatial relationship - - Frontal lobe: sophistication, planning, for see consequences, task that involve steps together, - Damage to frontal lobe, lack of trial and error, in human functioning; can become aggressive - Lack of self-awareness, how they're coming across, cant "read the room", lose perspective taking ability, more difficult to empathize with others - Cerebellum and medulla: things are most essential for existing, make sure organs work - Limbic system; taking in sensation, emotional generation, perception of worlds arithmetic's - Right side parietal damage, difficulty getting around severe; moving in when moving in familiar place - Left Hemisphere - Spoken language, Number skills ,Right hand ,Written language, Reasoning, Scientific functions - Right - Music, Spatial orientation, Left hand, Art awareness, Creativity, Insight  A diagram of the human body Description automatically generated The Brain - Command center of the body - It receives afferent (sensory) impulses from the peripheral nerve endings and sends efferent (motor) impulses to the extremities and internal organs to carry out necessary movement - 3 Sections - The Hindbrain - The Midbrain - The Forebrain - The Hindbrain and the Midbrain - **3 main parts; The medulla, the pons and the cerebellum** - The medulla: regulation of heart rate, blood pressure and respiration, - Receives sensory information from the heart rate at which is contracting and speeds it up or slows it down as required - Also receives sensory information about blood pressure and the levels of carbon dioxide and oxygen in the body to regulate blood vessel constriction and the rate of breathing - The Pons: link between the hindbrain and the midbrain - Helps control respiration - The midbrain is the major pathway for sensory and motor impulses moving between the forebrain and the hindbrain - Responsible for the coordination of visual and auditory reflexes - Cerebellum- coordinates voluntary muscle movements - The Forebrain - 2 main sections; The diencephalon and the telencephalon - Diencephalon: thalamus and hypothalamus - Thalamus is involved in the recognition of sensory stimuli and the relay of sensory impulses to cerebral cortex - Hypothalamus helps regulate the centers in the medulla that control cardiac functioning, blood pressure and respiration - It also regulates water balance in body, regulating appetites, including hunger and sexual desire - Important transition between center between thoughts (chemical signals) generated in cerebral cortex of the brain and their impact on internal organs - Ex. Embarrassment can lead to Blushing via hypothalamus through the vasomotor center in the medulla to the blood vessels - Anxiety; may result from secretion of hydrochloric acid in the stomach via signals from the hypothalamus - Together with the pituitary gland, the hypothalamus helps regulate endocrine system - Which releases hormones, influencing functionating in target organs throughout the body - Composed of two hemisphere (left and right) of the cerebral cortex - Cerebral cortex - The largest part of the brain - Involved in higher-order intelligence, memory and personality - Sensory impulses that come from peripheral; areas of the body, up the spinal cord and through hind brain and midbrain are received and interpreted in the cerebral cortex - 4 lobes: frontal, parietal, temporal and occipital - Each lobe has its own memory storage area or areas of association - The brain is able to relate current sensation to past ones giving the cerebral cortex formidable interpretive capabilities The Limbic system (wont be asked in specific, amygdala, hippocampus, cingulate gyrus) - Borders the midline of the brain, play an important role in stress and emotional response - The amygdala and the hippocampus are involved in the detection of the threat and in emotionally charged memories - The cingulate gyrus, the septum and areas in the hypothalamus are related to emotional functioning as well - The anterior portion of the thalamus and some nuclei within the hypothalamus are important for socially relevant behaviours The role of neurotransmitters - The nervous system functions by means of chemical, called neurotransmitters - They regulate the nervous system functioning - Together they're called "CATECHOLAMINES" - Stimulation of the sympathetic nervous system prompts the secretion of large quantities of 2 neurotransmitters: EPINEPHRINE and NOREPINEPHINE - These substance enter the bloodstream and are carried throughout the body, promoting the activity of sympathetic stimulation - The release of catecholamine: heart rate increase, the heart capillaries dilate, and blood vessels constrict increasing blood pressure - Blood is diverted into muscle tissue - Respiration rate goes up and the amount of air flowing into lungs increases - Digestion and urination generally decrease - The pupils of eyes dilate - Sweat glands produce more sweat - Repeated arousal of the sympathetic nervous system may have implications of the several chronic disorders: coronary artery disease and hypertension - Efferent- away from the body out of body ( produces muscle action, hot stove, moving it away Afferent- from the periphery to the brain (affirmative message that this is hot then brain saying move away it) -relaying info from sensory organ Disorders of the nervous system - 1 in 3 Canadians will be affected by a disorder of the nervous system during their lifetime - Most forms of neurological dysfunction are epilepsy, Parkinson disease, cerebral palsy, Alzheimer diease, multiple sclerosis and huntingtions disease Epilepsy - A disease of the central nervous system affecting about 300,000 Canadians - Often Idiopathic; no specific cause for symptoms can be identified - Symptomatic epilepsy may be traced to: injury during birth, severe injury to head, infectious disease (meningitis or encephalitis) and metabolic/ nutritional disorders - It is seizures; range from noticeable staring or purposeless motor movements to violent convulsions w/ irregular breathing, drooling, loss of consciousness - Cannot be cured; but medications and behavioural interventions designed to manage stress Parkinson Disease - Progressing degeneration of basal ganglia (the group of nuclei that controls smooth motor coordination) - Results in; tremors, rigidity, and slowness of movements - 100,000 Canadians suffer- 60 + and more likely men - Although cause may not be know; depletion of the neurotransmitters dopamine may be involved Cerebral Palsy - Chronic, nonprogressive disorder - Marked by loss of muscle control, - Stems from brain damage cause by an interruption in the brains oxygen supply, usually during child birth - In older children a severe accident a=or physical abuse can produce the condition - May also have seizures, spasm, mental handicap, difficulties of sensation and perception and problems with sight, hearing or speech Dementia (including Alzheimer Disease) - Degenerative disease of the brain, dementia cause serious impairment ot thinking and memory - Alzheimer disease is most frequent cause of dementia - Women more than men Multiple sclerosis - Degenerative disease of certain brain tissue can cause paralysis and occasionally blindness, deafness and mental deterioration - Early symptoms; numbness, double vision, dragging of the feet, loss of bladder or bowel control, speech difficulties, extreme fatigue - Symptoms may appear and disappear over a period of years; after that deterioration continues - The effects of multiple sclerosis results from disintegration of myelin, a fatty membrane that surrounds the nerve fibers and facilitates proper conduction of nerve impulses - Is an autoimmune disorder, the immune system fails to recognize its own tissue and attacks the myelin sheath surrounding the nerves - Mostly women Huntington's Disease - A hereditary disorder of the central nervous system - Chronic physical and mental deterioration - Symptoms; involuntary muscle spasms, loss of motor abilities, personality changes, and other signs of mental disintegration - Sometimes mistaken for epilepsy - The gene has been isolated, and test is available if you are a carrier or not and what age they will start showing Paraplegia and Quadriplegia - Paraplegia is paralysis of lower extremities of the body; results from an injury to the lower portion of the spinal cord - Quadriplegia is paralysis of all 4 extremities and the trunk of the body - Upper portion of the spinal cord is severed - When spinal cord is severed there is complete loss of motor and sensory impulses the spinal cord injury is referred to "complete" - When it is not complete loss of function its classified as "incomplete" - The endocrine system - Complements the nervous system in controlling bodily activities - Regulated by the hypothalamus and pituitary gland - Communicates via chemical substance called hormones (adrenaline, cortisol) - The endocrine system is made up of multiple ductless glands, which secrete hormones into the blood, stimulating changes in target organ - The nervous system is chiefly responsible for fast acting, short duration responses to changes - The endocrine system mainly governs slow acting responses of long duration Pituitary gland- located at the base of the brain, it has 2 lobes - The anterior pituitary lobe - secretes hormones responsible for growth: somatotropic hormone (STH) - regulates bone, muscle and other organ developments, - Gonadotropic hormone; growth, developments and secretion of the gonads (testes and ovaries) - Thyrotropic hormone: (TSH): controls growth, development and secretion of the thyroid gland - Adrenocorticotropic (ACTH); controls the growth and secretions of the cortex region of the adrenal glands - Posterior pituitary lobe - Produce oxytocin; controls contractions during labour and lactation - And vasopressin or antidiuretic hormones (ADH) controls water absorbing ability of the kidneys - Pituitary- thyroid- thymus- adrenal- pancreas- ovary- testis Adrenal Gland - Located on top of kidney - Each adrenal gland consist of adrenal medulla and an adrenal cortex - Release hormones in response to emergencies and stress - Cortisol; helps control swelling but continued high levels can lead to high blood pressure, ulcers - Epinephrine and norepinephrine: (adrenalin and noradrenalin); produces bodily reaction for quick energy - The adrenal cortex is stimulated by adrenocorticotropic hormone - It releases hormones called steroid - Include mineralocorticoids, glucocorticoids, androgens and estrogen - Adrenal glands are critically involved in physiological and neuroendocrine reaction to stress - -both catecholamines, secreted in conjunction with sympathetic arousal and corticosteroids are implicated in biological responses to stress  Disorders of the endocrine system - Diabetes - Chronic endocrine disorder, which the body is not able to manufacture or properly Use insulin - 7.3 percent (2.3 million) Canadians have diabetes - Indigenous Canadians have 3-5 times higher rate of diabetes - Associated with the thickening of the arteries due to build up of waste in the blood - As a result show high rates of coronary heart disease - Leading cause of blindness in adults - Accounts for 50% of patients who require dialysis for kidney failure - Can produce nervous system damage, leading to pain and loss of sensation - Serve cases need amputation such as toes and feet - Type 1 diabetes (insulin dependent diabetes0 - Partially genetic in origin - Believed to be an autoimmune disorder (possibly precipitated by an earlier viral infection) - The immune system falsely identifies cells in the islets of Langerhans in the pancreas as invaders and destroys those cells, compromising or eliminating their ability to produce insulin - Type 2 diabetes - Typically occurs after age 40 - Insulin maybe produced by the body but there might not be enough of it, or the body may not be sensitive to it - Disease of lifestyle, disturbance in glucose metabolism and the delicate balance between insulin production and insulin responsiveness - Dysregulated by obesity, stress and other factors The Cardiovascular system - Composed of the heart, blood vessels and blood, - Act as a transportation system of the body - Blood carries oxygen from the lungs to the tissues and carbon dioxide, excreted as expired air - Also carries nutrients from the digestive tract to individual cells, so cells can get nutrients for growth and energy - Blood carries waste products to the kidneys, from which its extracted through urine - Also carries hormones from the endocrine glands to other organs of the body and transports heat to the surface - The arteries carry blood from the heart to other organs and tissues, where oxygen and nutrients are transported through arterioles (tiny branches of the arteries) and the capillaries (smaller vessels that branch off from the arteries) to individual cells - Veins return the deoxygenated blood to the heart - Together these vessels control peripheral circulation, dilating or constructing in response to variety of bodily events The heart - The heart function as a pump, it causes the blood to circulate throughout the body 1. The left side of the heat (left atrium and left ventricle) take in heavily oxygenated blood from the lungs and pumps it out of the aorta (major artery leaving the heart) 2. From which the blood pumps it smaller vessels (arteries, arterioles and capillaries) to reach cell tissue 3. Blood exchanges it oxygen and nutrient for the waste materials of the cells 4. then returned to the right side of the heart, which pumps it back to the lungs via pulmonary artery 5. Once oxygenated, the blood returns to the left side of the heart through the pulmonary veins Cardiac cycle; regular rhythmic phases of contraction and relaxation 2 phases in the cardiac cycle- systole and diastole - Systole: blood is pumped out of the heart and blood pressure in the blood vessels increase Heart rate: - Multiple factors that effect heart rate - During workout, emotional excitement, or stress for example the heart speeds up and the cardiac cycle is completed in a shorter time - Most of speed up comes from diastolic period, a chronically rapid heart rate reduces overall time of rest - A chronically or excessively rapid heart rate can decrease the hearts strength, which may reduce the volume of blood that is pumped - Heart rate is regulated by the amount of the blood flowing into the veins Disorders of the cardiovascular system - Defects: from birth, infection or (majority) damage over the course of life wear and tear - Lifestyle; diet, exercise, smoking and stress exposure Atherosclerosis - Caused by deposits of cholesterol and other substances on the arterial walls - Builds plaque that narrow the arteries - Reduces the flow of blood through the arteries and interferes with the passage of nutrients from the capillaries in the cells -- which can lead to tissue damage - Damaged arterial walls are also potential sites for the formation of blood clots which can completely - Obstruct a vessel and cut off the flow of blood - Lifestyle disease; poor health habits, smoking, high fat diet Atherosclerosis associated with 2 primary clinical manifestations: 1. Angina pectoris a. Or chest pain, which occurs because muscle tissue of heart must continue its activity without sufficient supply of oxygen or adequate removal of carbon dioxide and other waste products 2. Myocardial infraction (MI) b. Occurs when a clot has developed in a coronary vessel and blocks the flow of blood of the heart c. Also know as a heart attack, can cause death Other heart disorders - Arteriosclerosis: hardening of the arteries, results in calcium, salts and scar tissue react with the elastic tissue of the arteries - The decrease of elasticity of the arteries makes them rigid and hard - Blood pressure then increase because arteries cannot dilate and constrict to help blood move and hypertension (high blood pressure) may result - Aneurysm: is a bulge in a section of the wall of an artery or a vein: it is a reaction of a weak region to pressure (bleeding) and loss of blood pressure - Phlebitis: is an inflammation of a vien wall often accompanied by water retention and pain - Typically results from an infection surrounding the vein from varicose veins; from pregnancy related or pressure of a tumor on the vein - The threat posed by it is that it can encourage the production of blood clots which can blood Blood pressure - The force that blood exerts against the blood vessel walls - It is measured as a ratio of pressure as the heart contracts and pushes out (systolic) to the lower pressure when the heart rate relaxes between heart beats (diastolic) - Influenced by several factors; - Cardiac output: pressure against the arterial walls is greater as the volume of blood flow increase - Peripheral resistance: or the resistance to blood flow in the small arteries of the body (arterioles) - Blood pressure id influenced by the structure of the walls; if the walls have been damaged or if there clogged by deposits of waste, blood pressure will be higher - Chronically high blood pressure, called hypertension is a consequence of too high a cardiac output or too high a peripheral resistance - Approx; 25 percent of Canadians aged 20 and over have hyper tension - Psychosocial issues involved in the management and treatment of hypertension include diet, chronic negative affect, stress levels, and acculturation The blood - Body contain 5 liters of blood - Consist of plasma and cells - Plasma - Occupies 55 percent of blood volume - contains plasma proteins and plasma electrolytes (slats) plus the substance that are being transported by the blood (oxygen and nutrients or carbon dioxide and waste materials) - Cells: - Remaining 45 percent of blood volume is made up of cells - Which are suspended in the plasma - Blood cells are manufacture in the bone marrow - Contains 5 types of blood-forming cells: myeloblast, monoblasts - both produce specific white blood cells: lymphoblast. - Lymphoblasts produce lymphocytes; erythroblasts which produce red blood cells and megakaryocytes which produce platelets - White blood cells play an important role in healing y absorbing and removing foreign aubstance from the body - The contain granules that secret digestive enzymes that engulf and act on bacteria and other foreign particles, turning them into a form conducive to excretion - Lymphocytes: play a role in combating forgein substances - Produce antibodies agents that destroy foreign substances through antigen-antibody reaction - Important role in fight infections and disease - Red blood cells - Contain hemoglobin which is need to carry oxygen and carbon dioxide throughout body - Platelets - The clump together to block small holes that develop in the blood vessels and important in blood clotting - When injury occurs and tissue is damaged, platelets help form thromboplastin - Which in turn acts on substance in plasma known as fibrinogen, changing to fibrin - Formation of fibrin produces clotting Disorders related to white cell production - Disorders: leukemia, leukopenia, and leukocytosis - Leukemia: is a disease of the bone marrow, common form of cancer - Causes production of an excessive number of white blood cells - Thus overloading the blood plasma and reducing the number of red blood cells that can circulate the plasma - In short term anemia (shortage of red blood cells ) will result - In long term it can cause death - Exposure to chemicals such as benzene and formaldehyde and smoking are among the known risk factors - Leukopenia: deficiency of white blood cells - Accompanies diseases such as tuberculosis, measles and viral pneumonia - Leaves individual susceptible to diseases because it reduces the number of white blood cells avail to combat - Leukocytosis - Excessive number of white blood cells - Response to many infection such leukemia, appendicitis and infectious mononucleosis Disorders related to red blood cell production - Anemia - A condition where red blood cells or amount of hemoglobin is below normal - Menstruation can be a cause, bc of blood loss much vital iron is loss - Aplastic anemia; when bone marrow is unable to produce a sufficient amount of red blood cells - Decrease in blood transportation capabilities - Causing tissue to receive too little oxygen and be left with too much carbon dioxide - Anemia can cause permanent damage to nervous system and produce chronic weakness - Sickle-cell anemia - Genetically transmitted inability to produce normal red blood cells - Cells are sickle cell shaped instead of flattened spheres and contain abnormal hemoglobin protein molecules - Vulnerable to rapture, leaving individuals susceptible to anemia - Its an adaptation promoting resistance to malaria Clotting disorders - Hemophilia - Unable to produce thromboplastin and fibrin - There blood cannot clot naturally in response to injury - May bleed to death unless receive medication - Thromboses - May develop in blood vessels - Especially if arterial or venous walls have been damaged or roughened because of cholesterol - Platelets adhere to roughened area leading to formation of clots - May have serious consequences if it occurs in blood vessel leading to he heart (coronary thrombosis) or brain (cerebral thrombosis) - It will block vital glow of blood to organs - If clots occurs in vein, it may become detached form an embolus, which may be lodged in the blood vessels to the lungs, causing pulmonary obstruction What is the function of the immune system - immune system is the surveillance system of the body - implicated in infection, allergies, cancer and autoimmune disease - primary function: distinguish between "self" and what is foreign and then attack and rid the body of foreign invaders - immune system can interact with psychological and nonendocrine process to affect health Microbes that cause infection are transmitted in four ways 1. direct transmission 2. indirect transmission 3. biological transmission 4. mechanical transmission - Direct transmission involves bodily contact, such as handshaking, kissing, and sexual intercourse - HPV, genital herpes - Indirect transmission (environmental transmission):occurs when microbes are passed to an individual via airborne particles, dust, water, soil or food (covid) - Biological transmission: occurs when a transmitting agent such as mosquito, picks up microbes and changes them into a form of conducive growth in human body and passes disease to a humas - Transmission of yellow fever, Lyme disease - Mechanical transmission: passage of microbe to an individual by means of a carrier that is not directly involved in the disease process - Involve transmission of an infection by dirty hands, dirty water, rats, miles or flies - Hepatitis can be acquired through mechanical transmission - Once microbe had reached body, it can penetrate bodily tissues via several routes - Whether invading microbes gain a foothold on the body and produce infection depends on three factors - 1\. Number of organisms - The virulence of the organism - Is determined by it aggressiveness and by it toxigenicity (its ability to poison and invade other parts of the body - The body's defensive powers The course of infection - First there is an incubation period between time the infection is contracted and the time the symptom appears - Next, there is a period of nonspecific symptoms that precede the onset of disease - Such as headaches and general discomfort, low mood and fatigue - Discomfort is called sickness behaviour and is associated with immune process such as the release of cytokines - chemical messenger proteins secreted by immune cells that coordinate the immune response - microbes are actively colonizing and producing toxins - next stage ACUTE phase - symptoms are their height unless it fatal which then a period of declines follows - during this phase organisms are expelled from mouth and nose in salvia and respiratory secretion, and digestive tract and the genitor-urinary system in feces and urine - Infection may be localized, focal or systemic - Localized infection remain at their origin site and do not spread - Can still send toxins to other parts of the body causing other disruption - Systemic infection - Affect number of areas or body systems - Primary infection can lead to secondary infections - Bc body's resistance is lowered from fighting the primary infection - Pneumonia can often be send Immunity - The body's resistance to injury from invading organism - It may be developed naturally of artificially Natural immunity - Is involved in defence against various pathogens - Cells involved in innate immune process do not provide defence against a particular pathogen but rather against many pathogens - Is also gained from exposure to disease, through the process of acquired immunity - Of you have measles once its unlikely you will develop it again Artificial immunity - Acquired through vaccination and inoculations through the process of acquired process - Example: most children and adolescents receive shots for a variety of disease - Whooping cough, smallpox, poliomyelitis and hepatitis - They won't contract if exposed How does immunity work - Nonspecific and specific - Nonspecific: are general set of responses to any kind of infection or disorder - Specific which are acquired after birth, fight microorganisms and their toxins Nonspecific - Mediated 4 ways - Atomical barriers (the skin) - Phagocytosis - Antimicrobial substances - Inflammatory response - Phagocytosis - Is the process which certain white blood cells (phagocytes) ingest microbes - Are usually over produced when there is infection so that enough can be sent to the site of infection to infest foreign particles - Antimicrobial substance - Are chemicals mobilized by the body to kill invading microorganisms - Interferon, an antiviral protein secreted by cells exposed to viral antigen to protect neighbouring uninfected cells from invasion - Inflammatory response - Local reaction to infection - at site of infection, the blood capillaries first enlarge, and a chemical reaction histamine is released into the area - reaction causes increase in capillary permeability, allowing white blood cells and fluids to leave the capillaries and enter the tissue - the area becomes reddened and fluids accumulate - white blood cells attack the microbes and result in formation of pus - usually then clot forms around the inflamed areas, isolating them from spreading - example: reddening, swelling, discharge, and clotting that result when you cut your skin and the sneezing, runny nose and teary eyes result in allergic response to pollen or dust - Specific Immunity - Acquired after birth and differs from nonspecific - It protect against particular microorganisms and their toxins - Can be acquired through vaccine, - It operates through the antigen-antibody reaction - Antigens are foreign substances whose presence stimulates the production of antibodies in the cell tissue - Antibodies are protein produced in repones to stimulation by antigens, which when combined chemically with the antigens to overcome their toxic affect Humoral and cell-mediated immunity - Once microbe has passed the innate barriers, there are 2 basic immunologic reaction - Humoral and cell mediated - Humoral immunity - Is mediated by B lymphocytes in the bodily fluids, such as blood and act before cells become infected - Function of B lymphocytes; provide protection against bacteria, neutralizing toxins produced by bacteria, preventing viral reinfection - B cells confer immunity by the production and secretions of antibodies - B lymphocytes release antibodies, which bind to pathogens and their products, aiding recognition by phagocytes - Cytokines released by T cells activate the phagocytes to destroy the material they have taken up - Mononuclear phagocytes can present antigen to T-cells, thereby activating them - - A diagram of a immune system Description automatically generated When B cells are activated, they differentiate into two types - 1\) mature, antibodies- secreting plasma cells - 2\) resting, non dividng memory B cells - Differentiate into antigen-specific plasma cells only when re-exposed to the same antigen - Plasma cells reproduce antibodies or immunoglobulin - Which are the basis of antigen-specific reaction - Humoral immunity is effective in defending the body against bacterial infections and against viral infections that haven't infected the cells yet - However once cell is infected the humoral immune response can no longer detect the pathogen - This is when cell mediated immunity becomes critical Cell mediated immunity - Involving T Lymphocytes from the thymus gland - Slower-acting response - Rather than releasing antibodies into blood, it instead works on cellular level - T-cells secrete chemicals that kill invading organisms and infected cells - 3 major type of T-lymphocytes - Cytotoxic T (TC cells) - Helper T (TH cells) - Suppressor T (TS cells) - Cytotoxic cells respons to specific antigens and kill by producing toxic substances that destroy viral infected cells - Helpers (TH) echance the functioning of TC cells, B cells and macrophages by producing cytokines - Also help serve a counter-regulatory immune function, producing cytokines that suppress certain immine activites - TS cells help to end immune response after the infection is under control - Cell mediated is effective in defending the body against fungi, viral infection that have entered the cell, parasites, foreign tissue and cancer What does integrated immune response look like? 1. The first line of defence involves mechanistic maneuvers such as coughing, sneezing 2. Once invader hads penetrated the bodys surface, phagocytes (macrophages) attempt to eliminate it phagocytosis (engulfing and digesting foreign invaders) 3. Macrophages also relase interleukin-1 and display parts of the naitgen material on their surface as a signal to the Th cells 4. Then in turn, secrete Interleuking-2 which prootes the growth and differentiation of the TC cells 5. Other t helpers cells secrete substance that promote the development of antigen-specific B cells into antibody-producing plasma cells 6. Which then assist in destroying the antigen 7. TH cells also secrete gamma interferon, which enhances the capacities of the macrophages 8. Macrophages and natural killer (NK) cells also secrete various types of interferon which enhance killing potential of the NK and inhibit viral reproduction in uninfected cells 9. Macrophages NK cells and TC cells directly kill infected cells 10. During the process the TH and TS cells down-regulate and eventually turn of the immune response Lymphatic systems role in immunity - Lymphatic system; the drainage system of the body - Lymphatic capillaries, vessels and nodes - Lymphatic capillaries drain water, protein microbes and other foreign materials from spaces between cells into lymph vessels - Material is Then conducted in the lymph vessels to the lymph nodes - Which then filter out microbes and foreign materials for ingestion by lymphocytes - Drain remaining substances into blood The spleen, tonsils and thymus gland are important organs of the lymphatic system The spleen - Aids in the production of B cells and T cells and removes worn-out red blood cells from the body - The spleen also filters bacteria and is responsible for the storage and release of blood Tonsils - are patches of lymphoid tissue in the pharynx that filter out microorganisms that enter the respiratory tract Thymus gland - responsible for helping t cells mature; - also produces hormones, thymosin which appears to stimulate T cells and lymph nodes to produce the plasma cells that in turn, produce antibodies The Gut Microbiome - referred to as second brain - is an intricate ecosystem of microorganism that live withing one gastrointestinal tract - the gm has important function; food particle fermentation, pathogen management, vitamin synthesis, intestinal barrier strengthen, harmful and toxic compound removal, and immune system regulation and stimulation Disorders related to the immune system - AIDS; progressive impairment of immunity - Cancer: believed to depend heavily on immunocompromised A number of infection attack lymphatic tissue - Splenomegaly; enlargement of the spleen that may result from various infectious diseases - Hinder ability to produce phagocytes and antibodies and lymphocytes - Tonsilitis; inflammation of the tonsils that interferes with their ability to filter out bacteria - Infectious mononucleosis is a viral disorder marked by an unusually large number of monocytes. - Causes enlargement of the spleen and lymph nodes and well as fever, sore throat and general lack of energy - Lymphoma - Tumour of the lymphatic tissue - Hodgkin's disease, a malignant lymphoma involves the progressive, chronic enlargement of the lymph nodes, spleen, and other lymphatic tissues - Nodes cannot effectively produce antibodies and the phagocytic properties pf the nodes a lost The control of some infectious disorders through hygiene may have paradoxically increased the rates of disorders such as inflammatory bowel disease (IBD) - Sanitation and refrigeration, while beneficial may contribute to the development of IBD - Bc of the balance and composition of intestinal microbes Second development is that some chronic disease, once thought to be genetic in origin or unknown in origin are now being traced to infections - Ex. MS, Alzheimer's disease, schizophrenia, autism spectrum disorder, depression - Pathogens cause or activily contribute to many if not most chronic disease Finally, the development to bacterial strains that are increasing resistant to treatment - Overuse of antibiotics, is thought to be an active contributor to the development of lethal strains Autoimmunity - Specific humoral or cell-mediated immune response that attacks owns body - Certain forms of arthritis, MS is also autoimmune disorder, lupus erythematosus - Fails to recognize it own tissue, instead thinks it a foreign invader and producing antibodies to fight it - Women are more likely to be affected What the physiological systems involved in the stress response - Stress-related disease emerges, predominantly put of the fact we are often activate a physiological system that evolved for responding to acute physical emergencies - However we turn it on for months on end by worrying about human problems that are not immediate emergencies like mortgages and money problems - Stress can lead to short or long term consequences for health - The Sympathetic-adrenomedullary (SAM) system - The hypothalamic-pituitary-adrenocortical ((HPA) axis  Sympathetic activation - When we encounter stress/threatened/harmful they are labeled by the cerebral cortex - Sets of chain of reaction mediated by these appraisals - Info from cortex is transmitted to hypothalamus, which initiates one the earliest response sympathetic nervous system arousal fight or flight response - Sympathetic arousal stimulates the medulla of the adrenal glands - Secret the catecholamine epinephrine and norepinephrine - These effects result in feeling unease - Leads to increase blood pressure, increased heart rate, increased sweating and constriction of the peripheral blood vessels HPA Activation - In addition to sympathetic nervous system, HPA system is activated - Non-physiological reaction that occurs in response to stress and involves the three phases (ALARM, RESISTENCE AND EXHAUSTION) - The hypothalamus releases adrenotropin-relasing factors (CRF) - Stimulates the pituitary gland to secrete adrenocorticotropic hormone (ACTH) - Which in turn stimulates the adrenal cortex to relase glucorticoids - Cortisol is significant - It acts to conserve stores of carbohydrates and helps reduce inflammation in the case of an injury - It also allows for the body to return to it steady state flowing stress inhibiting release of CRF for the hypothalamus - Repeated activation of the HP axis can compromise ot functioning (ALLOSATIC LOAD) - When dysregulated - Daily cortisol patterns may be altered - Normal is High upon weaking, peak in the afternoon and decreases in evening - Disrupted can have high levels into the evening Effects of long term stress - Long term stress during pregnancy - Later cardiovascular and metabolic problems - Increase of adhd - Emotional difficulties and poorer cognitive development - Can lead to suppression of immune functions; produce changes such as high blood pressure and heart rate - Provoke irregular heart rhythms - Neurochemical imbalances - Lipid levels and free fatty acids Corticosteroid can compromise functioning of immune systems - prolonged secretions can lead to problems in verbal functioning, memory, and concentration because its detrimental effects on the hippocampus - high HPA= depression - socially isolated humans have higher inflammatory disease risk - chronic HPA activation is storage of fat in abdominal areas rather than hips, called (CENTRAL ADIPOSE tissue) - leads to high waist to hip ration Which response have implication fro disease - HPA and SAM both contribute to development of disease especially if chronically activated - activation of SAM is linked to inflammation - "imflammaging" long term inflammation that maintain and accelerates age -related diseases - Central process is microbiome