Chapter 01 Lecture Outline PDF

Chapter 01 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 1.1 Anatomy and...

Chapter 01 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 1.1 Anatomy and 1. Describe the science of Physiology anatomy. Compared 2. List the subdivisions in Learning both microscopic and Objectives: gross anatomy. 3. Describe the science of physiology. 4. List the subdivisions of - physiology. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 2 1.1 Anatomy and Physiology Compared Anatomy studies the form and structure of the body Anatomy = Study form and structure of the body Anatomist = a person study form and structure of organism ex. Study blood capillaries will say compost of thin wall Physiology examines how the body functionsPhysiology = study function of the body parts Physiologit = Examine how organs and body systems function ex) Study blood capillaries and explan how the thin wall allow nutrient bxchange between the blood Form and function are interrelated Interrelated = If some disease effect the organ(Anatomy) then the function(Physiology) will also be affected 3  1.1 Anatomy and Physiology Compared Scientific method refers to a systematic and rigorous process by which scientists – Examine natural events through observation ↳ – Develop a hypothesis for explaining phenomenon – Experiment and test hypothesis by collecting data – Determine if the data support the hypothesis, or if the hypothesis should be rejected or modified 4 1.1a Anatomy: Details of Structure and Form Microscopic anatomy = only see under microscope, can't be seen with eyes. - Cytology (Cellular anatomy): Study of body cell and Microscopic anatomy sturcture - Histology: Study of tissue – Examines structures that cannot be observed by unaided eye – Specimens examined under microscope Gross anatomy, or macroscopic anatomy – Investigates structures visible to the unaided eye Gross anatomy (macroscopic anatomy) = Investigate structure that is visible to an eye like heart, intestine, liver, kidney. Gross anatomy can be approaces in many ways – Specimens dissected for examination - Systematic anatomy: Study each function of the system ex) urinary system may involve in kidney, Ureters, urethra, urinary bladder - Reginal anatomy: Examine all sturcturs in that region ex) study axillary (armpit) region we may study axillary artery and vein, nerves, lymph nodes, musculature, connective tissue, skin in that area. - Superficial anatomy: Focus on superficial anatomic marking and internal body structures that underkneath the skin that cover that part. Ex) paulse locations, Where to CPR. - Comparative anatomy: Examines the similartities and differences in anatomy of different species. Ex) compare human brain to cat brain - Embryology: Concerned with developmental changes occuring from conception to birth ex) study from fetus to baby born 5 1.1a Anatomy: Details of Structure and Form Divisions of microscopic anatomy ̶ Cytology—study of body cells and their internal structure Deal with cell. How they look, inside structure ̶ Histology—study of tissues 6  1.1a Anatomy: Details of Structure and Form Divisions of gross anatomy ̶ Systemic anatomy studies anatomy of each functional body system Individual system ̶ Regional anatomy examines all of the structures in a particular region of the body ̶ Surface anatomy focuses on superficial anatomic markings and internal body structures ̶ Comparative anatomy examines anatomical similarities and differences in different species ̶ Embryology studies developmental changes from conception to birth From single cell to fetus to baby born 7  1.1a Anatomy: Details of Structure and Form Diagnostic anatomical procedures Several specialized brancehes of anatomy focus on the diagnosis of medical conditions ̶ Pathologic anatomy examines macroscopic and microscopic anatomic changes resulting from disease scanning procedure to understand diff structure ̶ Radiographic anatomy investigates internal structures visualized by scanning procedures Investigates the relationships among internal sturctures that may be visualizaed by specific scanning procedures like X-ray, ultrasound, MRI 8  1.1b Physiology: Details of Function Function Physiologists examine the following organ systems, focusing on the molecular and cellular level ̶ Cardiovascular, functioning of the heart, blood vessels, and blood how the heart pumps the blood, what are the parameters for healthy blood pressure ect.. ̶ Neurophysiology, functioning of nerves and nervous system organs ̶ Respiratory physiology, functioning of respiratory organs Study how respiratory gases are transferred by gas exchange between the lungs and the blood vessels ̶ Reproductive physiology, functioning of reproductive hormones and the reproductive cycle ̶ Pathophysiology, relationship between the function of an organ system and disease or injury to the system Ex) examine how contractile force of the heart,blood pressure and both gas and nutrient exchange is affected from heart disease 9  What subdiscipline of What did you anatomy may explore how the learn? lower limb differs between humans and chimpanzees? Comparative ? What subdiscipline of anatomy focuses on cells? What subdiscipline of physiology focuses on disease? Pathologic? Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 10 1.2 Anatomy and Physiology Integrated Learning 1. Explain how the studies Objectives: of form and function are interrelated. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 11  1.2 Anatomy and Physiology Integrated Form (anatomy) and function (physiology) are interrelated ̶ Integrating these disciplines is the easiest way to learn about both ̶ Both disciplines must use information from the other field ̶ Form follows function (anatomical structures are designed to perform their specific function) ̶ Without a thorough knowledge of anatomical structures, the physiologist can not truly understand the structure’s function You can't describe and understand the anatomic form of an organ without learning the function. It's the most effective to learn both fields. Ex) you can't fully understand how the small intestine propels food and digest or absorbs nutrients unless you understand about the structure of the small intestine wall 12 1.3 The Body’s 1. List the characteristics Levels of common to all living things. Organization Learning 2. Describe the levels of Objectives: organization in the human body. 3. Compare the organ systems of the human body. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 13  1.3a Characteristics That Describe Living Things Properties common to all organisms Organization simple to complex ̶ All organisms exhibit a complex structure and order Metabolism—the sum of all chemical reactions that occur within the body Chemical reaction that produces energy Annabel = raising up ̶ Anabolism—small molecules joined to form larger ones Using absorbed nutrient to form larger molecule like cell ̶ Catabolism—large molecules broken down into smaller ones when we eat food then it gets broken down into smaller pcs of nutrition Growth and development ̶ Organisms assimilate materials from environment; grow and develop 14  1.3a Characteristics that Describe Living Things Properties common to all organisms (continued) Responsiveness—ability to sense and react to stimuli Ex) When your hand touches hot surface can cause you to withdraw your and right away to Regulation prevent further injury ordamage ̶ Ability to adjust internal bodily function to accommodate environment changes Ex) When body temp raise, more blood is circulated near surface to facilitate heat loss, and thus can return back to normal range ̶ Homeostasis—ability to maintain body structure and function Reproduction Not only about produce off spring, but also, cell damage healing/reproduce with healthy cells. ̶ Produce new cells for growth, maintenance, and repair ̶ With sex cells (gametes), can develop into new organisms Somatic cells (body cells) > Divided by mitosis> It can produce new cells for growth, maintenance, repair Gametes cess (sex cell) > Divided by meiosis > produce offspring 15  1.3b The View from Simplest to Most Complex Levels of organization from simplest to most complex ̶ Chemical level ̶ Cellular level ̶ Tissue level ̶ Organ level ̶ Organ system level ̶ Organismal level 16 1.3b The View from Simplest to Most Complex Chemical level This is the simplest level -units of matter ̶ Atoms—smallest ̶ Molecules—one or more Using combined atoms hydrogen bond/iconicbond/any kind of bond to o E.g., sugar, water, vitamincombined atoms together ̶ Macromolecules—more complex molecules o E.g., proteins and deoxyribonucleic acid (DNA) o Organelles—microscopic structures within cells There’s no life over here at this stage yet 17 1.3b The View from Simplest to Most Complex Cellular level ̶ Cells—the smallest living structures o Basic units of structure and function in organisms Cells and their components are forms by atoms and molecule from the chemical level o Formed from molecules from the chemical level o Vary widely in structure, reflecting specialized functions Each cells has different structure depending on its function ex)muscle cell is long, redblood cell is round flat 18 1.3b The View from Simplest to Most Complex Tissue level Tissue = group of similar cells that perform common functions – Groups of similar cells performing common functions * – Four main categories of tissues เอป-ปะ -ตีล-เลียล o Epithelial tissue covers exposed surfaces and lines body cavities 2o Connective tissue protects, supports, and binds structures and organs > o Muscle tissue produces movement o Nervous tissue conducts nerve impulses 19 1.3b The View from Simplest to Most Complex Organ level Organ = two or more tissue types to perform specific functions – Two or more tissue types performing specific functions o E.g., the small intestine composed of all four tissue types, working to process and absorb digested nutrients Contain multiple related organs that work together to coordinate activities and achieve the common function Organ system level Diff organ comes together to make a system ex. Cardiovascular system, nervous system – Related organs working together to achieve a common function One specific doctor will specialize in each organ system o E.g., organs of the digestive system working together to digest food, absorb nutrients, and expel waste products Organismal level A human being, a cat This is the highest level of structural organization in the body. All systems function interdependently in an organism, which is a living person. – Highest level of structural organization – All body systems function interdependently 20  Levels of Organization in the Human Body One system fail may affect another system as it’s inter independence Figure 1.2 21  1.3c Introduction to Organ Systems All organisms must exchange nutrients, wastes, and gases to carry on metabolism Multicellular organisms require organ systems to perform multiple activities In humans, 11 organ systems, each composed of interrelated organs, work together to perform specific functions 22  1.3c Introduction to Organ Systems 11 organ systems of the human body - Integumentary system =provides protection, prevents water loss and gain, synthesizes vitamin D, release secretions, regulates 1. Integumentary system body temp, and houses sensory receptors skin and associated glands (sweat gland, oil gland hair nails Usually it’s muscular skeletal system. Bone, joints, Ligament and connected tissue that hold bones or joints. 2. Skeletal system 1. compact bone : steady, not degenerated like dinosaur bones 2. Cancourse bone or called spongy bone: Not that steady so it can dissappear quickly 3 types of muscle 3. Muscular system Neurons cells. Transmit impause from receptor found on the skin (heat/cold/ 4. Nervous system bla) then send to brain. Brin get process and send response to appropriate organ. Main = process and produce respond to appropriate system 5. Endocrine system Your hormone producing Glands Adrenal gland/ Thyroid gland/Pancreas/ Pituitary/ Parathyroid/ Pineal gland/ Hypothalamus /Ovary/ Testic 6. Cardiovascular system Heart and blood vessel 23  1.3c Introduction to Organ Systems 11 organ systems of the human body (continued ) 7. Lymphatic system Collect excess fluid in the cell and dump back in the cell. When nutirne are given to tissue some of the fluid remain in the tissue. The lamp will put them back? 8. Respiratory system For creating. Need oxygen to product ATP 9. Urinary system Kidneys, Bladder, Urinary filtering waste and maintaining blood PH and volume 10. Digestive system Break down food, link to nervouse 11. Male and female reproductive systems Producing hormone and off spring 24  Organ Systems Figure 1.3 25  Organ Systems Figure 1.3 (continued) 26  Organ Systems Figure 1.3 (continued) 27  What characteristics are common What did you to all life? learn? Organization, Metabolism (Anabolism, Catabolism) Growth and development, Responsiveness Regulate, Reproduction List the levels of organization within the body, starting with the most complex? Organismal > Organ system > Organ > Tissue > Cellular > Chemical Which organ system is responsible for filtering waste products from the blood and excreting them in urine? Urinary system Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 28 1.4 The Language 1. Describe the anatomic of Anatomy and position and its importance in Physiology the study of anatomy. 2. Describe the anatomic Learning sections and planes through Objectives: the body. 3. Define the different anatomic directional terms. 4. Identify the major regions of the body, using proper anatomic terminology. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 29 1.4 The Language of Anatomy and 5. Describe the body cavities Physiology and their subdivisions. (continued) 6. Explain the role of serous Learning membranes in the ventral Objectives: cavities. 7. Compare the terms used to subdivide the abdominopelvic region into nine regions or four quadrants. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 30 1.4 The Language of Anatomy and Physiology This is important because we need to ensure that we’re discussing about the same features and function Ex) if we say arm then somebody may feel like arm = the whole thing from shoulder to hand. In anatomy arm = only from shoulder to elbow. A precise, common language is required to describe body position, direction, regions, and cavities Most terms are derived from Greek or Latin 31  1.4a Anatomic Position Important when you write report ex on the left forearm (of the patient not of you) To describe any body region or part require a common initial point of reference. Common reference position Characteristics of anatomic position – Upright stance – Feet parallel and flat on the floor Lie on belly – Upper limbs at the sides of the body – Palms face anteriorly (toward the front) – Head is level – Eyes look forward Lie on the back 32  1.4b Sections and Planes “Slices” of body called sections or planes ̶ Section—actual cut or slice that exposes internal anatomy ̶ Plane—imaginary flat surface passing through body; 3 types Front half = Anterior Back half = posterior Coronal plane or frontal plane 1o Coronal (or frontal ) plane ˗ Vertical plane dividing the body into anterior (front) and plane = แบ่งร่างกายเป็น 2 ส่วนคือส่วนหน้า (Anterior)กับ หลัง posterior (back) parts Coronal (posterior) Transverse plane or cross-sectional plane or horizontal plane 2o Transverse (or cross-sectional) plane ˗ Horizontal plane dividing the body into superior (top) and inferior (bottom) parts Upper Lower Transverse = Upper and lower body 33  1.4b Sections and Planes ̶ Plane (continued ) 3 o Midsagittal (or median) planeMid sagittal · Cut in the middle get qual left and right Sagittal that is ˗ Vertical plane dividing the body into equal left and right parasagittal. Left is not equal to right one is more than the other. halves Divide to Mid sagittal o Sagittal plane Parasagittal (not mention here) It can only have 1 midsagittal plane, but it can have millions of sagittal plane. ˗ Parallel to midsagittal, but left or right of midsagittal; divides structure into unequal portions อ่านว่า โอบลีค o Oblique plane ˗ Passes through structure at an angle Oblique = cut at an angle ตัดเฉียง 34  why is it important? For imaging Figure 1.4 35  A person is standing, face forward, What did you with palms turned backward. Is learn? he/she in anatomic position? So, 3 important planes What type of plane separates the 1. Coronal plane = Front and back of the body 2. Transverse = Upper and lower of the body nose and mouth into superior and 3. Sagittal - Midsagittal = Cut in the middle left = right inferior structures? - Parasagittal = Cut not in the middle left not equal to right 4. Oblique = Cut at angle What abdominal region lies lateral to the hypogastric? Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 36  1.4c Anatomic Directions In anatomic position, specific directional terms are used to describe relative positions Presented in opposing pairs ̶ E.g., anterior/posterior; dorsal/ventral; proximal/distal Medial = Lateral = going to going Another name another Superior = Inferior = the away from for anterior = name for toward the toward the middle the mid ventral posterior = head foot dorsal 37  Your shoulder is proximal to your elbow Directional Terms in Anatomy Your wrist is Distal to your elbow Ex. Your nose is anterior to your back Your spine is posterior to your intestine & Your sternum is medial to your lung Your arms are lateral to your torso (main part of the body) Or ears are Your eyes are superior to your nose lateral to your nose Your abdomen is inferior to your chin Only use in limbs (แขน ขา) Proximal = Distal = Toward the Away from point of point of attachment attachment Deep = going inside of Superficial = going toward the skin the body away from the skin Your skin is superficial to your muscle Figure 1.6 38 39 40 What did you learn? The elbow is ________ to the wrist? The liver is ________ to the skin? The mouth is ________ to the ear? Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 41  1.4d Regional Anatomy Human body is partitioned into two main regions ̶ Axial region o Head, neck, and trunk o Forms the main vertical axis of the body ̶ Appendicular region o Upper and lower limbs Several more regions within these two main ones 42  · · Figure 1.7a 43 Figure 1.7b 44  The term antebrachial refers to What did you which body region? Arm learn? The term crural refers to which body region? Front leg The term antecubital refers to which body region? Front elbow If a physician makes an incision into the abdomen superior to the umbilicus and just inferior to the diaphragm, what abdominopelvic region was incised? If a patient is complaining of lower back pain, what regions could be involved? Lumbar Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 45  1.4e Body Cavities and Membranes Internal organs are housed within enclosed spaces or G cavities Empty space Body cavities are named according to surrounding structures Body cavities are grouped into a – Posterior aspect – Ventral cavity 46  1.4e Body Cavities and Membranes Posterior aspect – Completely encased in bone – Physically and developmentally distinct from ventral cavities – Subdivided into o Cranial cavity (endocranium) is formed by bones of the cranium – Houses the brain Cranial cavity = Hold your brain o Vertebral canal is formed by the bones of the vertebral column – Houses the spinal cord Vertebral canal = hold your spinal cord 47  1.4e Body Cavities and Membranes Divide Thoracic and Abdominopelvic Or Anterior [ Thoracic cavity divided into 1. mediastinum (Heart + Major blood vessel) Ventral cavity 2. Pulmonary = lung – Larger than posterior cavity – Anteriorly placed in the body Abdominopelvic cavity – Does not completely encase organs in bone 1. Abdominal = digestive organs (intestine, stomach, liver) 2. Pelvic = Bladder, – Partitioned into a reproductive organs, Rectum o Superior thoracic cavity o Inferior abdominopelvic cavity 48  1.4e Body Cavities and Membranes Significant difference between posterior aspect and ventral cavity—subdivisions of ventral cavity are lined with serous membranes Two layers of serous membranes ̶ Parietal layer lines internal surface of body wall Parietal = Doesn’t move with the organ. Attached to the body’s wall ̶ Visceral layer covers external surface of organs (viscera) Visceral layer = Attached to the organ and Move with organ o Serous cavity—space between membranes Serous fluid Fluid in serous cavity that act like lubricant reduces friction – Liquid secreted by cells in serous membrane – Acts as lubricant – Reduces friction caused by movement of organs against body wall 49  Body Cavities It’s important because when we do imaging we know exactly where we’re looking for Each organs should be in their specific region Organs are moving such as intestine or lungs. What happen when they move is creating friction, and that create heat. We don’t want heat because the cell are going to die. To prevent friction we put them in double layered membrane. Between layer we have fluid to prevent the layer to create friction among themselves. First layer = doesn’t move Second layer that close to the organ move along with the organ Figure 1.8 50  1.4e Body Cavities and Membranes Visualizing the serous membrane layers Fist represents body organ Balloon represents serous membrane Stay put 8Organ - Fluid filled between 2 membrane Move with organ. If you move your hand it moves with you 51  1.4e Body Cavities and Membranes Thoracic cavity Mediastinum—median space in the thoracic cavity – Contains heart, thymus, esophagus, trachea, and major blood vessels that connect to the heart Pericardium—two-layered serous membrane – Parietal pericardium o Outer layer, which forms the sac around the heart – Visceral pericardium o Forms the heart’s external surface – Pericardial cavity o Space between parietal and visceral layers containing serous fluid 52  1.4e Body Cavities and Membranes Pleura—two-layered serous membrane associated with lungs – Parietal pleura o Outer layer lines internal surface of thoracic wall – Visceral pleura o Inner layer covers external surface of lungs – Pleural cavity o Space between parietal and visceral layers containing serous fluid 53 Serous Membranes in the Thoracic and Abdominopelvic Body Cavities Figure 1.9 b-c 54  1.4e Body Cavities and Membranes Abdominopelvic cavity Abdominal cavity – Superior area – Contains most of the digestive system organs, kidneys, and most of the ureters Pelvic cavity – Inferior area, between hip bones – Contains distal part of large intestine, remainder of ureters and urinary bladder, and internal reproductive organs 55  1.4e Body Cavities and Membranes Abdominopelvic cavity (continued ) Peritoneum—two-layered serous membrane lining the abdominopelvic cavity – Parietal peritoneum o Outer layer, which lines the internal walls of the abdominopelvic cavity – Visceral peritoneum o Inner layer, which covers the external surface of most abdominal and pelvic organs – Peritoneal cavity o Potential space between parietal and visceral layers containing serous fluid 56 Serous Membranes in the Thoracic and Abdominopelvic Body Cavities Figure 1.9d 57  Which body cavity is associated with the lungs, and what are the What did you names of its serous membranes? learn? Which body cavity is associated with the heart, and what are the names of its serous membranes? What serous membrane lines the abdominopelvic cavity, and what are the names of its two layers? Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 58  1.4f Abdominopelvic Regions and Quadrants Stomach are large so we need to identify which organ are hurting. So we know which area contain which regions. *** Left / right of the patient ***** You can now narrow it down. Abdominopelvic cavity 4. Hypo = below Condor = Cartilage 2. Eli = above Gastro = stomach 5. Left side is partitioned into nine (Rib cartilage) compartments Umbilical region 7. Left lumbar 1.Start here 6. Light lumbar – Middle region, named for the umbilicus (navel) that lies in its 8. Right 3. Hypo = below Gastro = stomach 9. Left center Iliac wehre inguinal Epigastric region canal are located – Superior to umbilical Hypogastric region – Inferior to umbilical Figure 1.10a 59  1.4f Abdominopelvic Regions and Quadrants Abdominopelvic cavity compartments (continued) Right and left hypochondriac regions – Inferior to costal cartilages and lateral to epigastric Right and left lumbar regions – Lateral to umbilical Right and left iliac regions – Lateral to hypogastric Figure 1.10a 60  1.4f Abdominopelvic Regions and Quadrants Abdominopelvic cavity can also be divided into four compartments with transverse and midsagittal planes through the umbilicus – Right and left upper quadrant – Right and left lower quadrant Figure 1.10b 61 1.5 Homeostasis: Keeping Internal 1. Define the components of a Conditions Stable homeostatic system. Learning 2. Be able to recognize each of Objectives: the components in representative systems. 3. Define negative feedback. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 62 1.5 Homeostasis: 4. Explain how homeostatic Keeping Internal mechanisms regulated by Conditions Stable negative feedback detect and (continued) respond to environmental changes. Learning Objectives: 5. Define positive feedback. 6. Describe the actions of a positive feedback loop. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 63  1.5 Homeostasis: Keeping Internal Conditions Stable Cells require stable environment so it can function normally. It is called Homeostasis It’s steady state (change constantly but always come back to normal). Eat food sugar level then blood sugar goes up > produce insulin > Blood sugar goes down. Hundreds of anatomic structures and physiologic processes are continuously monitored and adjusted Homeostasis—the ability of an organism to maintain consistent internal environment, or “steady state,” in response to changing internal or external conditions If homeostasis are not well then it could lead to diseases 64  1.5a Components of Homeostatic Systems Three components of homeostatic systems 7 Receptor detects changes in a variable Located both inside and outside of the body ̶ Stimulus (e.g., change in temperature sensed by skin) Inside: maintain pH, temperature, pressure of blood vessels Out side like temperature that is detected by skin 2 Control center interprets input from receptor and The receptor send signal to the control center (brain initiates changes through effector or spinal cord) ̶ Nervous system can provide a quicker response o E.g., regulation of blood pressure upon rising ̶ Endocrine response is more sustained o E.g., parathyroid hormone regulating calcium levels 3 Effector is the structure that brings about changes to alter the stimulus Brain send back to the effector organs like glans or muscle and they basically produce protein or hormone or whatever to make it normal again. Not all homeostasis follow this 1 2 3. 65  1.5b Homeostatic Systems Regulated by Negative Feedback Negative feedback ̶ Controls most processes in the body ̶ Variable fluctuates within a normal range around a set point ̶ If a stimulus increases a variable, receptor informs homeostatic control system, which activates effector to decrease variable back into normal range ̶ If a stimulus decreases a variable, receptor informs homeostatic control system, which activates effector to increase variable back into normal range ̶ So, in negative feedback, homeostatic control responds to move variable in opposite direction to bring it into normal range 66  1.5b Homeostatic Systems Regulated by Negative Feedback Example: Temperature regulation 1. Body temperature drops 2. Sensory receptors detect this and signal hypothalamus in the brain 3. Hypothalamus sends nerve impulses to smooth muscle in blood vessels in skin, causing them to contract, called vasoconstriction, which decreases internal passageway, or lumen, of vessels 4. This decreases blood flow to the surface of the body 5. Thus, less heat is released through skin 6. Also, nerve impulses are sent to skeletal muscles, causing shivering to warm body 7. Also, nerve impulses are sent to piloerector muscles attached to hair follicles in skin, causing them to contract (goosebumps) to warm the body 67  1.5b Homeostatic Systems Regulated by Negative Feedback Example: Temperature regulation (continued) 1. Body temperature rises 2. Sensory receptors detect rise and signal hypothalamus 3. Hypothalamus sends nerve impulses to smooth muscle in blood vessels in the skin, causing relaxation or vasodilation, which increases size of lumen 4. Increases blood flow to body surface 5. So, more heat is released through skin 68 Components of a Homeostatic Control Mechanism Figure 1.11 69  Negative machanism from too cold back to normal stage 1. Sense the cold 2. Send to brain 3. Muscle needs to move and make you shrive to generate the heat Figure 1.13a 70 Negative feedback Sense the heat because it was too high then Brough back to normal Brain/nerve said needs to cool down Create sweat Figure 1.13b 71  1.5b Homeostatic Systems Regulated by Negative Feedback Other examples of homeostatic regulation – Withdrawal reflex in response to injury – Regulating heart rate and blood pressure during exercise – Changing breathing rate in response to increased carbon dioxide – Parathyroid hormone release in response to decreased calcium – Release of insulin by the pancreas in response to increased blood glucose 72  List and describe the three What did you components of a homeostatic learn? system? On a cold day, what are some of the strategies the body uses to conserve heat? Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 73  1.5c Homeostatic Systems Regulated by Positive Feedback Positive feedback ̶ Occurs much less frequently than negative feedback ̶ Stimulus reinforced to continue moving variable in same direction until a climactic event occurs, then body returns to homeostatis Only 3 that we can think of Breast feeding Blood clotting Uterine contraction of labor Positive feedback = Stimulies then stimulus again in cycle 74  1.5c Homeostatic Systems Regulated by Positive Feedback Positive feedback during breastfeeding 1. Sensory detectors detect baby suckling 2. Message is transmitted to the hypothalamus 3. Hypothalamus signals posterior pituitary to release the hormone oxytocin 4. Oxytocin stimulates the mammary gland to eject breast milk 5. Cycle repeats as long as the baby suckles Other examples of positive feedback – Blood clotting cascade – Uterine contractions of labor 75  Positive Feedback Figure 1.15 76 1.6 Homeostasis, Health, and Disease 1. Explain the general relationship of Learning maintaining homeostasis Objectives: to health and disease. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 77  When homeostatsis not working well then we have disease 1.6 Homeostasis, Health, and Disease Summary of homeostatic system characteristics – Dynamic – Control center is generally nervous system or endocrine system – 3 components o Receptor o Control center o Effector – Regulated through negative feedback – If systems fails, homeostatic imbalance or disease results 78  Clinical View: Establishing Normal Ranges for Clinical Practice Normal ranges for homeostatic variables – Body temperature 98.6ºF – Blood glucose 80–110 mg/dL – Blood pressure 90–120/60-80 mm Hg – Determined by sampling healthy individuals in a population – Normal range is value for 95% of individuals sampled – 5% of healthy population have values outside normal range 79  1.6 Homeostasis, Health, and Disease Diabetes is an example of homeostatic imbalance – Occurs when homeostatic mechanisms for regulating blood glucose are not functioning normally – Blood glucose fluctuations and high glucose readings Treating patients involves finding a diagnosis, a specific cause of the homeostatic imbalance Most medications have benefits and side effects – Many can be explained by examining homeostatic mechanisms 80  Clinical View: Clinicians’ Use of Scientific Method Doctor need to asks questions to get data to create hypothesis diagnosis to order test. Then confirm, Developing a diagnosis reject or modify the diagnosis – Follow scientific method – Examine patient and gather data o E.g., patient health history, complaints, current vital signs such as weight and blood pressure – Initial hypothetical diagnosis – Order tests – Confirm, modify, or reject initial diagnosis – Definitive diagnosis 81  1.6 Homeostasis, Health, and Disease Drugs may affect normal homeostatic control mechanisms (e.g., SSRIs) Patients with depression may have lower levels of serotonin in their brains SSRI drugs block reuptake of serotonin into nerve cells in brain, thus prolonging its effects; SSRIs help elevate mood of patients with depression Side effects of SSRIs due to – Serotonin also used in nerve cells of digestive system – Digestive system becomes more excitable due to SSRI – Symptoms include nausea and upset stomach 82  Clinical View: Medical Imaging Magnetic Computed Tomography (CT) Resonance Radiography Imaging (MRI) Digital Subtraction Positron Emission Sonography Angiography (DSA) Tomography (PET) 83  Clinical View: Medical Imaging Magnetic Computed Tomography (CT) Resonance Radiography Imaging (MRI) Digital Subtraction Positron Emission Sonography Angiography (DSA) Tomography (PET) 83