Chapter 2 - Anatomy and Physiology PDF

Chapter 2-Anatomy and Physiology ELEG 305-Introduction to Biomedical Engineering Dr. Amro Nour Chapter 2 Introduction to Biomedical 1 Engineering  Overview Introduction. Cellul...

Chapter 2-Anatomy and Physiology ELEG 305-Introduction to Biomedical Engineering Dr. Amro Nour Chapter 2 Introduction to Biomedical 1 Engineering  Overview Introduction. Cellular Organization. Tissues. Homeostasis. Major Organ Systems: 1.Circulatory System: Heart. 2. Respiratory System: Lungs. 3.Nervous System: Neuron. 4. Skeletal System: Bone. 5.Muscular System: Muscle. Chapter 2 Introduction to Biomedical 2 Engineering  FIGURE 2.1 Using the inner cell mass to form pluripotent stem cells. Courtesy of http://www.nih.gov/news/stemcell/primer.htm. Chapter 2 Introduction to Biomedical 3 Engineering  FIGURE 2.2 The Jarvik-7 artificial heart, 1985. Courtesy of http://www.smithsonianlegacies.si.edu/objectdescription.cfm?ID=172. Chapter 2 Introduction to Biomedical 4 Engineering  FIGURE 2.3 MRI scans are just one of the PPI elements available on electronic databases. Courtesy of http://images.medicinenet.com/images/SlideShow/dementia_s21_mri_doctor.jpg. Chapter 2 Introduction to Biomedical 5 Engineering  FIGURE 2.4 The purpose of the regulatory process is to conduct product review to ensure (1) device safety and effectiveness, (2) quality of design, and (3) surveillance to monitor device quality. Therefore, the review process results in verification and validation of the medical device. Chapter 2 Introduction to Biomedical 6 Engineering  FIGURE 2.5 The drug treatment process followed by clinicians. Chapter 2 Introduction to Biomedical 7 Engineering  Introduction Biomedical engineers need to exchange ideas with life scientists: – Understand basic components of the body (anatomy). – How the body functions (physiology). Physiology: – Study of the functions of the body’s structures. Chapter 2 Introduction to Biomedical 8 Engineering  Introduction Anatomy: – Internal and external structures of the body. – Physical relationships between these structures. Chapter 2 Introduction to Biomedical 9 Engineering  Cellular Organization Cell: – smallest unit in the human body. – can live and reproduce on its own (under appropriate conditions). – composed mostly of organic compounds and water (>60%). Most common elements found in human cells: – Oxygen. – Carbon. – Hydrogen. – Nitrogen. Chapter 2 Introduction to Biomedical 10 Engineering  Cellular Organization Organic compounds, which are molecules fundamental to sustaining life: – Carbohydrates: transport and store energy. – Lipids: form structural materials in cells, which are the main reservoirs of stored energy. – Proteins: the most diverse form of biological molecules. – Nucleic acids and Nucleotides: such as Cells are surrounded by a plasma DNA. membrane. They contain a membrane-based region, the – Plasma membrane: surrounds the cell, nucleus, which contains DNA. The which separates the cell’s interior from its cytoplasm lies outside of the nucleus and contains several types environment without compete isolation. of organelles that perform specialized functions. Chapter 2 Introduction to Biomedical 11 Engineering  Cellular Organization – Proteins Enzymes (specialized proteins): – Responsible for making metabolic reactions proceed at a faster rate. – Enable cells to produce the organic compounds of life. Other proteins provide structural elements in the body: – They act as transport channels. – Function as signals for changing activities. – Provide chemical weapons against disease-carrying bacteria. Chapter 2 Introduction to Biomedical 12 Engineering  Cellular Organization – Nucleotide Nucleotides are small organic compounds that contain: – five-carbon sugar (ribose or deoxyribose). – phosphate group. – nitrogen-containing base. Adenosine triphosphate (ATP): energy currency of the cell, which plays a central role in metabolism. Other nucleotides are enzyme helpers. 2 nucleic acids: – deoxyribonucleic acid (DNA). – ribonucleic acid (RNA). Chapter 2 Introduction to Biomedical 13 Engineering  Cellular Organization – DNA DNA is a unique helical molecule that contains chains of paired nucleotides that run in opposite directions. Each nucleotide contains a base with a ring structure: – pyrimidine base with a single ring: thymine (T) or cytosine (C). – or a purine base with a double ring: adenine (A) or guanine (G). In the double helix of DNA: – thymine pairs with adenine (T-A) – cytosine pairs with guanine (C-G). Chapter 2 Introduction to Biomedical 14 Engineering  Cellular Organization – DNA DNA consists of 2 chains of paired nucleotides that run in opposite directions and form a helical structure. Thymine pairs with adenine (T-A) and cytosine pairs with guanine (C-G) due to hydrogen bonding between the bases. Chapter 2 Introduction to Biomedical 15 Engineering  Cellular Organization – RNA RNA similar to DNA. Differences: – It consists of a single helical strand. – It contains ribose instead of deoxyribose. – It has uracil (U) instead of thymine (T). Chapter 2 Introduction to Biomedical 16 Engineering  Cellular Organization – Protein Transcription: the process by which DNA is copied to RNA. Translation: RNA is used to produce proteins. Chapter 2 Introduction to Biomedical 17 Engineering  Example For the following template strand, find the sequences of DNA and RNA. Chapter 2 Introduction to Biomedical 18 Engineering  Tissues Tissues: – group of cells and surrounding substances. – function together to perform a specialized activity. 4 primary types of tissue in the human body: – Epithelial – Connective – Muscle – Nervous Chapter 2 Introduction to Biomedical 19 Engineering  Tissues – Epithelial Characterized by having a free surface. Typical functions: – Absorption – Secretion – Transport – Excretion – Protection – Sensory reception Chapter 2 Introduction to Biomedical 20 Engineering  Tissues – Connective Connective tissues are the most abundant and widely distributed. Specialized connective tissue such as blood, bone and cartilage. Chapter 2 Introduction to Biomedical 21 Engineering  Tissues – Muscle Provides movement for the body. 3 types of muscle tissue: – Skeletal: attached to bones. – Smooth: found in the walls of blood vessels. – Cardiac: found only in the heart. Chapter 2 Introduction to Biomedical 22 Engineering  Tissues – Neurons Consists of: – Neurons: conduct electrical impulses. – Glial cells: protect, support and nourish neurons. Chapter 2 Introduction to Biomedical 23 Engineering  Homeostasis Process by which: – physical and chemical conditions maintained (body temperature, blood pressure, breathing rate, heart rate, …) – when external environment changes – involves several organ systems working together. Chapter 2 Introduction to Biomedical 24 Engineering  Homeostasis 3 components maintain homeostasis: sensory receptors, integrators and effectors. – Sensory receptor: detects stimuli, which then sends information to the integrator. – Integrator: pull together information from sensory receptors. – Effector: responds to the signal. Chapter 2 Introduction to Biomedical 25 Engineering  Homeostasis Positive feedback mechanism: stimulus is reinforced by the response. Negative feedback mechanism: response is opposite in direction to the initiating stimulus. An example of a negative feedback mechanism in the body involves the regulation of glucose in the bloodstream by clusters of cells. Chapter 2 Introduction to Biomedical 26 Engineering  Homeostasis-Example 2 negative feedback mechanisms control the blood level of glucose: – High glucose results in receptors producing insulin as a result glucose blood level drops. – Low glucose results in receptors producing glucagon as a result glucose blood level increases. – Glucose blood level if it’s equal to the body’s set point: Cells stop producing insulin/glucagon. Chapter 2 Introduction to Biomedical 27 Engineering  Homeostasis – Application Biomedical engineers are working on: – controlled drug delivery systems that can sense blood glucose levels and emulate the responses of the pancreatic cells. – develop an artificial pancreas that can maintain appropriate blood glucose levels. Chapter 2 Introduction to Biomedical 28 Engineering  Major Organ Systems Organs: Combinations of tissues that perform complex tasks. Organ Systems: Organs that function together. The human body has 11 major organ systems: – Integumentary – Endocrine – Lymphatic – Digestive – Urinary – Reproductive – Circulatory – Respiratory – Nervous – Skeletal – Muscular Chapter 2 Introduction to Biomedical 29 Engineering  Circulatory System Chapter 2 Introduction to Biomedical 30 Engineering  Circulatory System Delivers nutrients and hormones throughout the body. Removes waste products from tissues. Provides a mechanism for regulating temperature. Chapter 2 Introduction to Biomedical 31 Engineering  Circulatory System – The Heart The pumping station moves blood through the blood vessels. It consists of 2 pumps: right side and left side. Each side has: – one chamber (atrium) that receives blood. – another chamber (ventricle) that pumps blood away from the heart. Chapter 2 Introduction to Biomedical 32 Engineering  Circulatory System – The Heart Right side: pumps blood to the lungs (deoxygenated). Left side pumps blood to the body (oxygenated). The distance between the heart and lungs is small and the right side functions as a low- pressure pump The left side pumps blood through the entire circulatory system and functions as a high- pressure pump. Chapter 2 Introduction to Biomedical 33 Engineering  Circulatory System – The Heart Cardiac cycle: repeating pattern of contraction (systole) and relaxation (diastole) of the heart’s chambers. During each systolic interval: 𝑆𝑉 = 𝐸𝐷𝑉 − 𝐸𝑆𝑉 Where: – SV is the stroke volume (volume of blood expelled from the heart). – EDV is the end-diastolic volume (blood-filled heart). – ESV is the end-systolic volume (empty heart). 𝑆𝑉 𝐸𝑗𝑒𝑐𝑡𝑖𝑜𝑛 𝑟𝑎𝑡𝑖𝑜 = : measuring the heart’s pumping ability. 𝐸𝐷𝑉 Total cardiac output: 𝐶𝑂 = 𝐻𝑅 × 𝑆𝑉 𝑚𝑙/𝑚𝑖𝑛 Where: – HR is the heart rate in beats per minute. Chapter 2 Introduction to Biomedical 34 Engineering  Circulatory System – The Heart The cardiac cycle begins with an electrical pulse, which is defined as action potential (AP). AP spreads from one cell to another since cardiac cells are tightly linked. The sum of these ionic changes within the heart is measured through an electrocardiogram (ECG), which is an electrical measure. Chapter 2 Introduction to Biomedical 35 Engineering  Circulatory System – Application ECG non-invasive tool for cardiac disease diagnosis, which changes in amplitude and duration and is used for diagnostic information for physicians: – detect abnormal activity of the heart and certain diseases. Recording and analyzing ECGs: – Regeneration of heart muscle. – Modeling cardiac function for better diagnosis and prevention. – Generation of bio-artificial heart. Chapter 2 Introduction to Biomedical 36 Engineering  Example Question: i. Calculate the heart rate given by an ECG in which 10 R-waves occur in 6.4 s. ii. What’s the cardiac output of the heart if the stroke volume is 75 ml? Solution: i. A sequence of 10 R-waves represents 9 R-R intervals (heartbeats): ii. Cardiac output is the product of the heart rate and the stroke volume: Chapter 2 Introduction to Biomedical 37 Engineering  Respiratory System Moves air to and from the gas exchange surfaces in the body. Lung tissue engineering: Responsible for the development of lung replacement devices and tissue to treat patients with end- stage lung disease. Chapter 2 Introduction to Biomedical 38 Engineering  Respiratory System-Lungs Physical properties: compliance, elasticity, and surface tension. – Compliance: the ease with which lungs can expand under pressure. – Elasticity: the ease with which lungs and other thoracic structures return to their initial sizes after being distended, which aids in pushing air out of the lungs during expiration. – Surface tension: occurs whenever there is an air-liquid interface in which small air sacs resist collapse during expiration, and large alveoli do not over-inflate during inspiration. Chapter 2 Introduction to Biomedical 39 Engineering  Nervous System Responsible for the control of all the body’s functions: – Central nervous system (CNS): all nervous tissue enclosed by bone (brain and spinal cord). – Peripheral nervous system (PNS): nervous tissue not encased by bone. Chapter 2 Introduction to Biomedical 40 Engineering  Nervous System-Neuron Neuronal communication network: individual nerve cell. It consists of 3 major components: – cell body or soma. – receptor zone or dendrites – A long fiber called the axon, which carries electrical signals from the main body of the cell to the muscles, glands, or other neurons. Chapter 2 Introduction to Biomedical 41 Engineering  Nervous System-Neuron When an individual neuron is excited: – Electrical signal gets transmitted along its axon to many tiny branches. – Electrical pulse arrives at the synapse, which triggers the release of a tiny amount of transmitter substance. – This substance floats across the axon and the cell body, which alters the status of the receiving neuron. Chapter 2 Introduction to Biomedical 42 Engineering  Nervous System-Example Neuron in the finger senses pain when the fingertip is pricked by a pin. 1. The electrical signal travels from the neuron (sensory) to another neuron (motor) that controls muscles in the finger. 2. In response to the stimulus is contraction. 3. Remove the fingertip from the pin. Chapter 2 Introduction to Biomedical 43 Engineering  Skeletal System The skeletal system: – protects and supports the body. – helps with movement. – produces blood cells. – stores important minerals. The average adult skeleton contains 206 bones. Chapter 2 Introduction to Biomedical 44 Engineering  Skeletal System-Bone The bone is a living organ: it is constantly being remodeled. Bone transformation occurs during bone growth and to regulate calcium availability. The average skeleton is transformed about three times during a person’s lifetime. The bones of the skeletal system are attached to one another at joints. Chapter 2 Introduction to Biomedical 45 Engineering  Skeletal System – Example Biomedical engineers have helped develop artificial joints: used as replacements in diseased or injured hips, shoulders, and knees. Diseased or damaged hip and knee joints that are nonfunctional or extremely painful can be replaced by prostheses. Artificial joints can be held in place by bone ingrowth or by a special cement. Chapter 2 Introduction to Biomedical 46 Engineering  Muscular System Composed of 600 – 700 skeletal muscles. Makes up 40 percent of the body’s mass. Muscles: – maintain posture – generate heat to maintain body temperature – provide the driving force to move bones and joints of the body and the skin of the face. Chapter 2 Introduction to Biomedical 47 Engineering  Muscular System-Muscle The muscle has 4 important characteristics: – Contractility: ability to shorten. – Excitability: capacity to receive and respond to a stimulus. – Extensibility: the ability to be stretched. – Elasticity: ability to return to the original shape after being stretched or contracted. Chapter 2 Introduction to Biomedical 48 Engineering  Conclusion Define anatomy and physiology, which is highly important to biomedical engineering. Know the differences and purposes of replication, transcription, and translation. Describe the major components and functions of organ systems. Understand homeostasis and feedback mechanisms. Chapter 2 Introduction to Biomedical 49 Engineering