HS Final-2 PDF - Human Biology

Importance of O2 ​ Oxygen (O2) is crucial for the body to generate energy ​ It is used in the process of cellular respiration to metabolize macromolecules and produce ATP How does the body obtain energy? ​ Carbohydrates, fats, and proteins can be metabolized to make ATP throu...

Importance of O2 ​ Oxygen (O2) is crucial for the body to generate energy ​ It is used in the process of cellular respiration to metabolize macromolecules and produce ATP How does the body obtain energy? ​ Carbohydrates, fats, and proteins can be metabolized to make ATP through cellular respiration ​ ATP is the chemical energy form that body cells need to drive their many activities Cellular Respiration ​ Cellular respiration is the process of metabolizing macromolecules to store energy in the form of ATP ​ It requires oxygen and releases carbon dioxide Respiratory System ​ The respiratory system is responsible for obtaining oxygen and releasing carbon dioxide through the process of respiration ​ It is made up of several parts including the nose, nasal passages, pharynx, epiglottis, larynx, trachea, bronchi, lungs, bronchioles, alveoli, and diaphragm Respiration ​ Respiration, also known as breathing, is the process of gas exchange in humans  ​ There are four main phases of gas exchange in humans: breathing, external respiration, respiratory gas transport, and internal respiration Respiratory Surface ​ The respiratory surface is the part of an animal where oxygen diffuses into the animal and carbon dioxide diffuses to the surrounding environment Respiratory System ​ Emphysema causes alveoli to rupture, while pneumonia causes alveoli to collect mucous material ​ Both conditions result in reduced surface area for gas exchange ​ For gases to dissolve, the respiratory system must be moist How Breathing Happens ​ Volume changes lead to pressure changes, which lead to the flow of gases to equalize the pressure ​ The brain detects the rate of breathing by responding to internal stimuli that indicate how much oxygen the body needs (high carbon dioxide and low oxygen = increased breathing rate) ​ The diaphragm contracts (moves down) ​ Chest cavity expands, which causes the lungs to expand (increase in volume; decrease in pressure) ​ Air moves into the lungs ​ Passive process ​ Diaphragm relaxes (moves up) ​ Decreases size of chest cavity, which causes the lungs to recoil (decrease in volume; increase in pressure) ​ Air flows out of the lungs ​ Gases take the shape of their container  ​ If the volume is large, the pressure of the gas will be lower (because more room for gas molecules to move) ​ If the volume is decreased, the pressure will rise ​ As the chest cavity expands, the lungs expand due to the pleura being stuck together ​ Exhalation is normally a passive process, unless respiratory passages are narrowed (asthma) then intercostal muscles (between ribs) and abdominal muscles must actively work to decrease the size of the chest cavity Nonrespiratory Air Movements ​ Many situations other than breathing move air into and out of the lungs and may modify normal respiratory ​ Note: we use the term ventilation to refer to any mechanism that increases contact between surrounding air and the respiratory surface; hence the term "ventilator" The Circulatory System ​ The body's transport system ​ Transports oxygen, nutrients, cell wastes, hormones, and other substances ​ Heart ​ Blood Vessels ​ Blood ​ Lymphatic system The Heart ​ Surrounded by a double-walled sac (pericardium) ​ Two atria (superior to two ventricles, separated by septums)  ​ Atria involved in receiving blood from the body/lungs ​ Ventricles involved in propelling blood out of the heart to the body/lungs ​ Tricuspid ​ Pulmonary ​ Mitral (bicuspid) ​ Aortic ​ Heart contraction is regulated by two systems: the autonomic nervous system and the nodal system ​ Atria contract (filling ventricles with blood) ​ Ventricles contract (pumping blood to the body) ​ A group of cells in the right atrium (SA node or pacemaker) controls the contraction of the atrium (atria contract simultaneously) and sends a signal to the AV node which causes the ventricles to contract when the atria are beginning to relax ​ Blood enters the heart through the superior and inferior venae cavae into the right atrium ​ Blood is pumped into the right ventricle ​ Blood is pumped into the pulmonary trunk (which splits into the pulmonary arteries) to travel to the lungs for oxygenation (pulmonary circuit) ​ Blood returns to the heart through the pulmonary veins into the left atrium ​ Blood is pumped into the left ventricle ​ Blood is pumped into the aorta to be pumped to the body cells (systemic circuit) ​ Cardiac or Coronary Circuit (the travel of blood within the heart) ​ Pulmonary Circuit (the path of blood from the heart to the lungs) ​ Systemic Circuit (the path of blood from the heart to the rest of the body) Anatomy of the Heart  ​ The heart contains coronary arteries that branch from the base of the aorta and encircle the heart, while coronary veins empty into the right ventricle. ​ The left side of the heart receives and pumps only oxygen-rich blood, while the right side receives and pumps only oxygen-poor blood. Blood Pressure ​ Blood pressure is the force the blood exerts against the walls of our blood vessels, created by the pumping of our heart. ​ The cardiac cycle refers to the events that occur in one complete heart beat, with both atria and ventricles contracting and relaxing. ​ Systole is the contraction of the ventricles, while diastole is the relaxation of the ventricles. Electrocardiography ​ An electrocardiograph (ECG) is a representation of the heart's electrical activity recorded from electrodes on the body surface. ​ A typical ECG contains three recognizable waves: P wave, QRS Complex, and T Wave. ​ The ECG helps evaluate the heart's function and identify any problems that might exist, such as the rate and regularity of heartbeats, the size and position of the heart's chambers, and whether there is any damage present. Blood Vessels (Vascular System) ​ Blood vessels are the freeways, roads, and alleys that move blood throughout our bodies. ​ Arteries carry blood away from the heart, have a thick layer of smooth muscle, and are capable of withstanding high pressures.  ​ Capillaries are thin-walled and consist of a single layer of endothelial cells, and are the location of gas, nutrient, and waste exchange. ​ Veins are the largest blood vessels and carry blood toward the heart, and have valves that prevent back flow of blood. Imaging the Heart ​ Positron Emission Tomography (PET) is a type of nuclear medicine that involves injecting a radioactive tracer molecule to diagnose differences in biological activity in the body. ​ Echocardiography is a type of ultrasound test that uses high-pitched sound waves sent through a device called a transducer to produce images of the heart. Arteries are red and veins are blue, but for the lungs, there's an exception of two. Arteries divide into smaller arteries eventually leading into smaller branches called arterioles which then lead to the capillaries. Capillaries intertwine among body cells. Veins have valves that prevent back flow of blood. Positron Emission Tomography (PET) is a type of functional or physiological imaging to diagnose differences in biological activity in the body. Echocardiography is a type of ultrasound test that uses high-pitched sound waves sent through a device called a transducer to produce images of the heart. Positron Emission Tomography (PET) Scan  ​ Used to measure body functions such as blood flow, oxygen use, and metabolic rates ​ Images produced can be in color or black and white ​ In color, hot spots (areas of high chemical activity) are indicated by red and orange colors ​ In black and white, hot spots are indicated by darker areas How does it work? ​ Step 1: A radioactive isotope is injected into the body ​ Step 2: The radioactive tracer that is injected into the body continually decays producing gamma radiation (an electromagnetic wave) that can be detected by a PET scanner ​ Step 3: A computer takes this data and converts it into an image ​ Step 4: The image is projected on the screen and read by physicians ​ NOTE: Gamma rays are a type of ionizing radiation Patient Procedure ​ Fasting is required for at least 4 hours before the procedure ​ Patient must also refrain from alcohol, tobacco and caffeine for 24 hours before the test ​ Street clothes and jewelry must be removed ​ Test must be started with an empty bladder ​ One or two intravenous (IV) lines will be started to inject the tracer into the patient (you will then wait for 30-60 minutes) ​ Patient will need to lie still for the length of the test. You will move into the scanner slowly as the cross sectional images are taken. PET/CT Fusion ​ CT scans and PET scans both have strengths and weaknesses  ​ Newest machines are now able to perform a fused PET and CT scan and overlay the results on top of each other ​ This allows for directly seeing what area in the chest or abdomen is lighting up on PET Echocardiography ​ A type of ultrasound that utilizes ultrasonic sound waves that travel at a high frequency to produce an electronic image ​ When sound waves hit something at an angle, a certain amount of the sound is transmitted through it and the rest bounces off. This reflected wave is called an echo. ​ M-Mode Echo: simple line tracing image; used for size of chambers, thickness of walls or size of heart ​ Doppler Echo: measures and assessed the flow of blood through the hearts valves and chambers (can be done in color to designate the direction of flow) ​ 2D Echo: produces "real-time" motion of the heart's structures (can see how they work) ​ 3D Echo: produces "real-time" motion of the heart in greater depth than 2D Image obtained from http://www.fetal.com/ FetalEcho/ 05%20Color.html ​ This illustrates the use of color Doppler to identify the flow of blood into the ventricles. In this example blood flow is only observed flowing into the left ventricle. Single Positron Emission Computed Tomography (SPECT) ​ Isotopes with longer half lives are used ​ The way gamma radiation is produced is different  ​ The resolution produced is lower ​ The detector used is less expensive Echocardiography ​ A non-invasive imaging technique used to assess the heart's structure and function ​ Uses sound waves to create images of the heart How it works: ​ A transducer emits sound waves that travel into the body and create echoes when they reach the boundaries between substances ​ Echoes are received by the transducer and converted back into electrical energy which can be interpreted by a computer to create an image ​ Different ultrasound frequencies are used depending on the type of scan being done; higher frequency provides greater resolution but less penetration ​ The speed at which sound waves are returned to the transducer, as well as how much of the sound wave returns, is translated by the transducer as different types of tissue ​ White indicates a dense substance like bone ​ Greyscale indicates a medium dense substance like fat or muscle ​ Black indicates fluid reflectors like blood Patient Procedure: ​ Street clothes from the waist up must be removed ​ ECG electrodes may be attached to the chest ​ The patient will need to lie down for the procedure  ​ The technician will apply clear gel to the patient's chest, which allows a medium for the sound waves to travel from the transducer to the patient ​ The test can take anywhere from 30-45 minutes Risks and Benefits: ​ Like all diagnostic tools, echocardiography has its own risks and benefits ​ Benefits include providing valuable information about the heart's structure and function, and it is non-invasive and does not use radiation ​ Risks are minimal and may include discomfort from the application of the transducer and the use of gel Blood: ​ The main component of blood is plasma, which makes up about 54-55% of blood ​ Plasma is 90% water and contains dissolved molecules, plasma transport proteins, and antibodies (immunoglobins) ​ Erythrocytes (Red Blood Cells) are the most numerous of the blood cells and are responsible for the transport of oxygen ​ Thrombocytes (Platelets) are cell fragments that are responsible for clotting ​ Leukocytes (White Blood Cells) are produced in bone marrow and in lymph nodes, thymus and spleen and are an important component of a body's immune system Components and functions of white blood cells (Leukocytes) ​ White blood cells (Leukocytes) are colorless cells that are part of the immune system ​ They can squeeze through capillary walls and in between body cells  ​ Types of Leukocytes include: Lymphocytes, Neutrophils, Monocytes, and Basophils ​ Lymphocytes recognize disease-causing organisms and alert the body ​ Neutrophils surround and kill invaders using phagocytosis ​ Monocytes become macrophages, which are the long-term clean-up crew ​ Basophils release histamine and an anticoagulant ​ Leukocytes contain nuclei and can live for months or years ​ The number of Leukocytes fluctuates when fighting an infection Human Blood Groups ​ Blood groups are based on the presence or absence of antigens (A, B, and Rh) on the plasma membranes of RBCs ​ Antibodies are found in the plasma and bind to specific antigens ​ Introduction of foreign antigens in the blood can be fatal (transfusion reactions) ​ Blood is generally classified into 4 main groups: A, B, AB, and O. Each can be Rh+ or Rh-, giving 8 groups in all. Blood Type Testing ​ To determine an individual's blood type, blood is placed in serums with specific antibodies ​ If a reaction (clumping) occurs, the antigen specific for that antibody is present ​ Serums used include: Anti-A Serum, Anti-B Serum, and Anti-Rh Serum Complications ​ Blood donation and pregnancy can lead to transfusion reactions if blood types are not compatible  ​ Pregnancy can lead to hemolytic disease of the newborn if an Rh- mother is carrying an Rh+ child and does not receive an injection of anti-Rh+ antibodies shortly after childbirth Immunity and the Lymphatic System ​ The immune system protects the body from foreign substances and pathogens ​ The lymphatic system is a part of the immune system and helps to protect the body from infection ​ The lymphatic system includes the spleen, thymus, lymph nodes, and lymphatic vessels Pathologies and Immunity ​ Disease can be caused by pathogenic or deficiency factors ​ Hereditary factors can also play a role in the development of disease Types of Immunity ​ Active immunity is when the body produces its own antibodies in response to an antigen ​ Passive immunity is when the body receives antibodies from an external source Cellular Immunity ​ Cellular immunity is when the immune system uses cells to fight off pathogens ​ Cells involved in cellular immunity include T cells and macrophages Humoral Immunity  ​ Humoral immunity is when the immune system uses antibodies to fight off pathogens ​ Antibodies are proteins produced by B cells in response to an antigen Immunity and Aging ​ Immunity can decline with age, making older adults more susceptible to infections ​ Vaccinations can help to boost immunity in older adults Immunity and Vaccinations ​ Vaccinations expose the body to a weakened or dead form of a pathogen, allowing the body to produce antibodies ​ Vaccinations can provide active immunity to a pathogen Immunity and Public Health ​ Immunity plays a role in public health by protecting populations from the spread of infectious diseases ​ Vaccinations can help to control the spread of infectious diseases Immunity and Global Health ​ Immunity plays a role in global health by protecting populations from the spread of infectious diseases ​ Global immunization efforts can help to reduce the burden of infectious diseases in low- and middle-income countries Understanding Disease and Immunity ​ Disease: an impairment of the normal state of the living animal body or one of its parts that interrupts or modifies the performance of the vital functions, is typically manifested by distinguishable and predictable signs and symptoms. It can be cured. ​ Examples of diseases include various physiological diseases, illnesses, disorders, medical conditions, and syndromes.