overview Flashcards
What is Magnification?
The extent to which the image appears larger compared to the actual object.
How do you calculate magnification?
Magnification = Image size / Actual (real) size.
Define resolution in microscopy
The ability to distinguish two close points as separate; determines the image’s clarity and detail.
What is the field of view?
The visible area under the microscope.
What is the depth of field?
The extent to which the sample remains in focus at different depths.
What is an artefact in microscopy?
A structure that is not part of the specimen, often caused by processing techniques, such as drying out tissue with solvents like acetone.
What is fixation in electron microscopy?
Coating the specimen in heavy metals to prevent electrons from passing through, allowing for imaging.
What does staining do in microscopy?
Injects a resin into the specimen to preserve structures and enhance visibility.
Differentiate between light microscopes and electron microscopes
Light microscopes use visible light to view specimens, while electron microscopes use beams of electrons for higher resolution imaging.
What is the main function of the condenser lens in a light microscope?
It focuses light onto the specimen for better clarity
What are the two main types of sugars in carbohydrates?
Monosaccharides and disaccharides
Define a solute
A substance that dissolves in a solvent.
What is the primary structure of a protein?
The linear sequence of amino acids in a polypeptide chain.
Explain the term “hydrophobic”
Substances that repel water and do not mix well with it; they are non-polar.
What is a triglyceride?
A lipid made up of one glycerol and three fatty acids; commonly found in fats and oils.
What is the role of cholesterol in cell membranes?
It helps maintain fluidity and stability of the membrane by preventing fatty acid tails from packing too closely together.
Define denaturation in the context of enzymes
The disruption of the weak bonds maintaining an enzyme’s specific shape, leading to a loss of function.
describe the function of mRNA in protein synthesis
mRNA carries genetic information from DNA to the ribosome for protein synthesis.
What is the induced fit model of enzyme activity
A model suggesting that when a substrate binds to an enzyme, the enzyme undergoes a slight change in shape to better fit the substrate.
What is the genetic code?
The set of rules by which information encoded in genetic material is translated into proteins, comprising codons that specify amino acids.
What is dehydration in the context of microscopy?
Dehydration preserves structures by making cross-links in the tissue using chemicals like glutaraldehyde and osmium tetroxide.
How does embedding in resin enhance microscopy?
Embedding in resin increases contrast and improves visibility, allowing more detail to be seen.
Describe the function of the denser in a light microscope
The condenser focuses light from the light source onto the specimen for better clarity.
What is the role of the diaphragm/iris in microscopy?
The diaphragm controls the amount of light that passes through the specimen, affecting contrast and brightness.
What is the difference between coarse and fine focus knobs?
The coarse focus knob brings the specimen into general focus, while the fine focus knob adjusts the focus precisely at higher magnifications.
What is the total magnification of a microscope?
Total magnification = Objective lens magnification x Eyepiece lens magnification.
Define an atom
An atom is the smallest particle of an element.
What is a molecule?
A molecule is formed when two or more atoms are chemically bonded together.
Distinguish between solute and solvent
A solute is the substance that dissolves in a solvent, while a solvent is the substance that dissolves the solute.
What is a hydrogen bond?
A hydrogen bond is a weak interaction that occurs whenever molecules contain an electronegative atom bonded to a positively charged hydrogen atom.
List of key properties of water
Water is a universal solvent, has lower density when frozen, high specific heat capacity, cohesion and surface tension.
What are monosaccharides?
Monosaccharides are the simplest sugars, with a general formula of CnH2nOn.
What is the process of hydrolysis?
Hydrolysis is a catabolic reaction where water is used to break down larger molecules by splitting covalent bonds.
Define condensation reaction
A condensation reaction is an anabolic process where two smaller molecules combine to form a larger molecule, producing water in the process.
What is glycogen?
Glycogen is a stored form of glucose found primarily in the liver and muscles, serving as an energy reserve.
Explain the role of glucagon
Glucagon is a hormone produced by the pancreas that raises blood glucose levels by signaling the liver to break down glycogen into glucose.
define hydrophobic substances
Hydrophobic substances repel water and do not mix or dissolve in it because they are non-polar.
What are triglycerides?
Triglycerides are the most common lipids in the body, made up of one glycerol and three fatty acids.
distinguish between saturated and unsaturated fats
Saturated fats have no double bonds between carbon atoms and are usually solid at room temperature, while unsaturated fats contain one or more double bonds, making them liquid at room temperature.
What are globular proteins?
Globular proteins are compact, spherical proteins that are soluble in water and play various roles, including enzymatic activity and transport.
Describe the primary structure of proteins
The primary structure is the linear sequence of amino acids in a polypeptide chain, determining the protein’s unique characteristics.
What is the role of enzymes in proteins?
Enzymes act as catalysts to speed up biochemical reactions without being consumed in the process.
What is the function of DNA?
DNA contains genetic information that encodes the sequence of amino acids in proteins.
What is the function of RNA?
RNA acts as an intermediary that carries instructions from DNA to ribosomes for protein synthesis.
Explain the process of transcription
Transcription occurs in the nucleus where DNA is transcribed into messenger RNA (mRNA), which carries genetic information to the ribosome.
What is the genetic code?
The genetic code consists of codons, sequences of three nucleotides that correspond to specific amino acids, directing protein synthesis.
What is the function of LDL cholesterol?
LDL (Low-density lipoprotein) carries cholesterol from the liver to the cells, but excessive amounts can lead to fatty deposits in artery walls, increasing cardiovascular disease risk.
Describe HDL cholesterol
HDL (High-density lipoprotein) helps remove excess cholesterol from the bloodstream, transporting it back to the liver for excretion, thus reducing cardiovascular disease risk.
What lifestyle changes can help manage cholesterol levels?
Healthy diet, regular exercise, quitting smoking, and medications like statins can help manage cholesterol levels.
What is the function of the cell membrane?
The cell membrane regulates what enters and exits the cell, providing protection and support while maintaining homeostasis.
What are organelles?
Organelles are specialized structures within a cell that perform distinct functions, such as energy production, protein synthesis, and waste processing.
Describe the role of mitochondria
Mitochondria are the powerhouse of the cell, generating ATP (adenosine triphosphate) through cellular respiration.
What is the function of the endoplasmic reticulum (ER)?
The ER is involved in the synthesis of proteins (rough ER) and lipids (smooth ER), as well as the transport of materials within the cell.
What are ribosomes?
Ribosomes are cellular structures where protein synthesis occurs, translating mRNA into polypeptide chains.
What is the role of carbohydrates in the body?
Carbohydrates are a primary source of energy for the body, providing glucose for cellular respiration and energy production.
What are essential fatty acids?
Essential fatty acids are fats that the body cannot produce on its own, such as omega-3 and omega-6, and must be obtained from the diet.
What are the main functions of proteins?
Proteins serve structural roles, act as enzymes, transport molecules, provide immunity, and facilitate signaling within and between cells.
What is the role of insulin?
Insulin is a hormone produced by the pancreas that lowers blood glucose levels by facilitating the uptake of glucose into cells.
What are hormones?
Hormones are chemical messengers produced by glands in the endocrine system that regulate various physiological processes in the body.
What is ATP, and why is it important?
ATP (adenosine triphosphate) is the primary energy currency of the cell, providing energy for various cellular processes.
Define metabolism
Metabolism encompasses all biochemical reactions within a cell, including catabolic (breaking down) and anabolic (building up) processes.
define catabolism
Catabolism is the metabolic process that breaks down molecules into smaller units, releasing energy.
What is anabolism?
Anabolism is the metabolic process that builds up larger molecules from smaller ones, requiring energy.
Define enzyme
An enzyme is a biological catalyst that accelerates chemical reactions in the body without being consumed in the process.
What is a substrate?
A substrate is the substance on which an enzyme acts during a biochemical reaction.
Explain the difference between saturated and unsatured fats
Saturated fats have no double bonds between carbon atoms and are solid at room temperature, while unsaturated fats have one or more double bonds and are liquid at room temperature.
What do nucleic acids play in the body?
Nucleic acids, such as DNA and RNA, store and transmit genetic information, guiding the synthesis of proteins necessary for cellular functions.
What is the structure of a triglyceride, and why is it significant?
A triglyceride consists of one glycerol and three fatty acids. It is significant as it is the main form of fat storage in the body, providing energy reserves.
Describe the role of microscopy in health sciences
Microscopy allows for the examination of cells and tissues at a microscopic level, aiding in diagnosis, research, and understanding of disease processes.
What are the consequences of high levels of lipids in the blood?
High levels of lipids can lead to atherosclerosis, increasing the risk of coronary heart disease, heart attack, and stroke due to plaque buildup in arteries.
What are the main differences between prokaryotic and eukaryotic cells?
Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and organelles like mitochondria and the endoplasmic reticulum.
Give examples of prokaryotic and eukaryotic organisms
Prokaryotes include bacteria and archaea. Eukaryotes include animals, plants, fungi, and protists.
What are the key principles of cell theory?
1) All living organisms are composed of one or more cells. 2) The cell is the basic unit of life. 3) All cells arise from pre-existing cells.
What is the function of the mitochondria?
Mitochondria are the powerhouse of the cell, generating ATP through cellular respiration.
Describe the role of the endoplasmic reticulum
The rough ER is involved in protein synthesis, while the smooth ER synthesizes lipids and detoxifies chemicals.
What is the function of ribosomes?
Ribosomes are responsible for protein synthesis by translating mRNA into polypeptide chains.
What is the function of the cardiovascular system?
The cardiovascular system circulates blood to deliver oxygen, nutrients, and hormones to cells and removes waste products like carbon dioxide.
Name the main components of the cardiovascular system
Heart, blood vessels (arteries, veins, capillaries), and blood.
explain the role of red blood cells
Red blood cells transport oxygen from the lungs to tissues and remove carbon dioxide from the body by delivering it to the lungs for exhalation.
What is an ECG, and what does it measure?
An ECG (electrocardiogram) measures the electrical activity of the heart to assess heart rhythm and function.
What does a normal sinus rhythm look like on an ECG?
A normal sinus rhythm shows a regular P wave, QRS complex, and T wave, indicating a healthy heart rhythm.
What could an elevated ST segment on an ECG indicate?
An elevated ST segment may indicate a myocardial infarction (heart attack).
What are the main functions of the respiratory system?
The respiratory system allows for gas exchange, supplying oxygen to the blood and removing carbon dioxide.
Name the main organs involved in the respiratory system
The respiratory system includes the lungs, trachea, bronchi, diaphragm, and alveoli.
What role do alveoli play in respiration
Alveoli are tiny air sacs in the lungs where gas exchange (oxygen and carbon dioxide) occurs with the blood.
What is COPD?
COPD is a chronic lung disease that includes conditions like emphysema and chronic bronchitis, characterized by difficulty breathing and reduced airflow.
What are common causes of COPD?
Smoking is the primary cause, but long-term exposure to air pollutants and genetic factors can also contribute.
How is COPD diagnosed?
COPD is diagnosed using lung function tests like spirometry, which measures airflow and lung capacity.
What is coronary heart disease?
CHD is a condition where the coronary arteries become narrowed or blocked due to plaque buildup, leading to reduced blood flow to the heart.
What are the symptoms of CHD?
Symptoms include chest pain (angina), shortness of breath, and in severe cases, heart attack.
What lifestyle changes can reduce the risk of CHD?
Reducing risk factors involves maintaining a healthy diet, exercising regularly, quitting smoking, and managing conditions like hypertension and high cholesterol.
What is a stroke?
A stroke occurs when blood flow to a part of the brain is interrupted, causing brain cells to die due to a lack of oxygen.
What are the two main types of strokes?
Ischemic stroke (caused by a blood clot) and hemorrhagic stroke (caused by a burst blood vessel).
What are common symptoms of a stroke?
Symptoms include sudden numbness or weakness, confusion, trouble speaking, loss of balance, and severe headache.
How can stroke be prevented?
Strokes can be prevented by managing risk factors such as high blood pressure, smoking, diabetes, and obesity.
What is the structure and function of the nucleus?
The nucleus is a membrane-bound organelle containing the cell’s genetic material (DNA). It regulates gene expression and controls the cell’s growth, metabolism, and reproduction.
What is the role of the endoplasmic reticulum (ER)?
There are two types of ER:
Rough ER is studded with ribosomes and is involved in protein synthesis and folding.
Smooth ER synthesizes lipids, detoxifies chemicals, and stores calcium ions.
What is the function of the Golgi Apparatus?
The Golgi apparatus modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles. It is often considered the cell’s “post office.”
Describe the role of lysosomes
Lysosomes contain digestive enzymes that break down waste materials, cellular debris, and pathogens within the cell.
What is the function of mitochondria?
Mitochondria are responsible for producing energy (ATP) through cellular respiration. They are known as the powerhouses of the cell and are involved in energy metabolism.
What is the role of the cell membrane?
The cell membrane is a semi-permeable barrier that controls the movement of substances into and out of the cell, maintaining homeostasis.
What is gene expression?
Gene expression is the process by which the information in a gene is used to produce a functional product, such as a protein. It involves two main steps: transcription (DNA to mRNA) and translation (mRNA to protein).
Explain transcription
Transcription is the process by which a segment of DNA is copied into messenger RNA (mRNA) by the enzyme RNA polymerase, which then carries the genetic instructions from the DNA to the ribosome for protein synthesis.
What is translation in gene expression?
Translation is the process where the mRNA sequence is decoded by a ribosome to produce a specific protein. Transfer RNA (tRNA) helps match amino acids to the corresponding codons on the mRNA.
What is an ischemic stroke?
An ischemic stroke occurs when a blood clot or plaque blocks blood flow to part of the brain, depriving it of oxygen and nutrients, which leads to the death of brain tissue.
What is mycardial ischemia
Myocardial ischemia occurs when blood flow to the heart muscle (myocardium) is reduced, usually due to partial or complete blockage of the coronary arteries, leading to chest pain (angina) or a heart attack.
What is Atherosclerosis?
Atherosclerosis is the buildup of fatty deposits, cholesterol, and other substances (plaque) on the walls of arteries. This buildup can narrow the arteries, restrict blood flow, and lead to cardiovascular diseases like coronary heart disease and strokes.
What are the risk factors for developing atherosclerosis?
Risk factors include high cholesterol, high blood pressure, smoking, diabetes, obesity, and a sedentary lifestyle.
How does atherosclerosis lead to coronary heart disease (CHD)?
Atherosclerosis can narrow the coronary arteries, reducing blood flow to the heart muscle. This can lead to angina (chest pain), myocardial infarction (heart attack), or heart failure due to the heart not receiving enough oxygen-rich blood.
What is hypertension?
Hypertension, or high blood pressure, is a condition in which the force of the blood against the artery walls is too high, increasing the risk of heart disease, stroke, and kidney problems.
What is arrhythmia?
Arrhythmia refers to an irregular heartbeat, where the heart beats too fast, too slow, or with an abnormal rhythm. Common types include atrial fibrillation, tachycardia, and bradycardia.
Define angina
Angina is chest pain or discomfort caused by reduced blood flow to the heart muscle, often due to atherosclerosis. It can be stable (triggered by physical activity or stress) or unstable (occurring at rest).
What is chronic obstructive pulmonary disease (COPD)?
COPD is a chronic inflammatory lung disease that obstructs airflow from the lungs, making breathing difficult. It includes emphysema and chronic bronchitis.
What is emphysema?
Emphysema is a condition in which the alveoli (air sacs) in the lungs are damaged, leading to shortness of breath and reduced gas exchange.
Define bronchitis
Bronchitis is the inflammation of the lining of the bronchial tubes, which carry air to and from the lungs. Chronic bronchitis, a form of COPD, involves a persistent cough and mucus production.
What is asthma?
Asthma is a chronic respiratory condition characterized by inflamed airways that narrow, swell, and produce extra mucus, making breathing difficult. Common triggers include allergens, exercise, and stress.
What is a transient ischemic attack (TIA)?
A TIA, or mini-stroke, is a temporary blockage of blood flow to the brain, which resolves on its own within minutes to hours. It serves as a warning for future strokes.
define hemorrhagic stroke
A hemorrhagic stroke occurs when a blood vessel in the brain bursts, causing bleeding in or around the brain. This disrupts normal blood flow and leads to brain cell death.
What is spirometry and how is it used?
Spirometry is a common lung function test used to diagnose and monitor respiratory conditions like COPD and asthma. It measures how much air a person can inhale and exhale, and how quickly they can do so.
Explain how blood pressure is measured
Blood pressure is measured using a sphygmomanometer, which records two numbers:
Systolic pressure (the pressure when the heart contracts)
Diastolic pressure (the pressure when the heart relaxes between beats).
What does an ECG (electrocardiogram) measure?
An ECG measures the electrical activity of the heart to detect abnormalities in the heart’s rhythm and structure. It records the electrical impulses that trigger each heartbeat.
Name the key parts of a standard ECG waveform and their significance
P wave: Atrial depolarization (contraction of the atria).
QRS complex: Ventricular depolarization (contraction of the ventricles).
T wave: Ventricular repolarization (relaxation of the ventricles).
PR interval: Time taken for electrical activity to move from the atria to the ventricles.
ST segment: Time between ventricular depolarization and repolarization.
How would you identify a myocardial infarction (heart attack) on an ECG?
A myocardial infarction may present as ST-segment elevation (STEMI) or ST-segment depression (NSTEMI). An ST-elevation indicates a full-thickness injury to the heart muscle, while depression suggests partial injury.
what does an irregularly irregular QRS compel on an ECG indicate?
An irregularly irregular QRS complex is often associated with atrial fibrillation, a condition where the atria beat irregularly and out of sync with the ventricles.
What ECG finding is typically associated with ventricular tachycardia?
Ventricular tachycardia presents as wide, abnormal QRS complexes occurring at a rapid rate, often without visible P waves.
Explain the difference between systemic circulation and pulmonary circulation
Systemic circulation carries oxygenated blood from the left ventricle to the body and returns deoxygenated blood to the right atrium.
Pulmonary circulation carries deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atrium.
What is the function of the SA node in the heart?
The SA node (sinoatrial node) is the heart’s natural pacemaker, initiating the electrical impulses that cause the heart to beat and controlling the heart rate.
What is cardiac output and how is it calculated?
Cardiac output is the volume of blood the heart pumps per minute. It is calculated as:
Cardiac Output (CO) = Stroke Volume (SV) × Heart Rate (HR).
How does chronic bronchitis differ from emphysema in terms of COPD?
Chronic bronchitis involves inflammation and excessive mucus production in the bronchial tubes, leading to a persistent cough.
Emphysema involves the destruction of the alveoli, reducing the surface area for gas exchange, which leads to shortness of breath.
What is atherosclerosis and how does it lead to coronary heart disease (CHD)?
Atherosclerosis is the buildup of fatty deposits (plaque) in the arteries, narrowing them and reducing blood flow. When it occurs in the coronary arteries, it restricts blood flow to the heart muscle, causing CHD, which may result in angina or a heart attack.
Describe the role of LDL cholesterol in the development of atherosclerosis
Low-density lipoprotein (LDL) cholesterol is considered “bad” cholesterol. High levels of LDL can deposit in artery walls, forming plaques that contribute to the narrowing and hardening of arteries in atherosclerosis.
describe the role of ribosomes in protein synthesis
Ribosomes are the site of protein synthesis. They read mRNA sequences during translation and help assemble amino acids into polypeptides to form proteins.
what is the function of the mitochondria in cellular respiration?
Mitochondria are responsible for producing ATP through the process of cellular respiration. They convert glucose and oxygen into energy, water, and carbon dioxide.
what is the role of mRNA in gene expression?
Messenger RNA (mRNA) carries the genetic instructions from DNA to the ribosomes, where proteins are synthesized. It acts as a template for translation.
define transcription in the context of gene expression
Transcription is the process by which a segment of DNA is copied into mRNA. This mRNA carries the genetic code from the DNA in the nucleus to the ribosome for protein synthesis.
What lifestyle changes are recommended to manage and prevent CHD?
Stop smoking.
Maintain a healthy diet low in saturated fats and cholesterol.
Exercise regularly.
Manage stress.
Control blood pressure and blood sugar levels.
What medicines are commonly used to treat CHD?
Statins: Lower cholesterol levels to reduce plaque buildup in arteries.
Beta-blockers: Reduce heart rate and blood pressure, decreasing the heart’s demand for oxygen.
Aspirin or antiplatelets: Prevent blood clots by thinning the blood.
ACE inhibitors: Help relax blood vessels and reduce blood pressure.
what surgical interventions are available for severe CHD?
Angioplasty: A balloon is used to open narrowed or blocked coronary arteries, often followed by stent placement.
Coronary artery bypass graft (CABG): Healthy blood vessels from other parts of the body are used to bypass blocked coronary arteries.
What immediate treatment is recommended for an ischemic stroke?
Thrombolytic drugs like tPA (tissue plasminogen activator) are used to dissolve clots and restore blood flow to the brain, but must be administered within a few hours of symptom onset.
How are hemorrhagic strokes treated?
Surgical interventions: Procedures like craniotomy to remove blood clots or repair ruptured blood vessels.
Medications: Drugs to lower blood pressure and prevent seizures or vasospasms.
Endovascular procedures: Techniques such as coiling or clipping to prevent further bleeding.
what rehabilitation strategies are used post-stroke?
Rehabilitation often involves physical therapy, occupational therapy, speech therapy, and medications to manage symptoms such as muscle stiffness or depression.
what is the first-line treatment for managing symptoms of COPD?
Bronchodilators (e.g., salbutamol) are inhaled medications that help relax and open the airways, making it easier to breathe.
What role do inhaled corticosteroids play in the treatment of COPD?
Inhaled corticosteroids, such as budesonide, reduce inflammation in the airways, helping to prevent exacerbations in moderate to severe COPD.
What non-pharmacological treatments are recommended for COPD patients?
Pulmonary rehabilitation: A structured program of exercise, education, and support.
Oxygen therapy: For patients with low blood oxygen levels, supplemental oxygen may be prescribed.
Smoking cessation: The most important step to prevent further lung damage.
what surgical options exist for sever COPD?
Lung volume reduction surgery: Removal of damaged lung tissue to allow the remaining lung to function better.
Lung transplant: In extreme cases, a lung transplant may be considered.
How are statins used in the treatment of atherosclerosis?
Statins, such as atorvastatin, reduce LDL cholesterol levels, slowing or reversing the buildup of plaque in the arteries.
what role do antihypertensive medications play in managing atherosclerosis?
Antihypertensive drugs, like ACE inhibitors and calcium channel blockers, lower blood pressure, reducing the strain on artery walls and preventing further damage from atherosclerosis.
what surgical treatments are available for severe atherosclerosis?
Angioplasty and stenting: A catheter is inserted to open blocked arteries, often followed by the placement of a stent to keep the artery open.
Carotid endarterectomy: Surgery to remove plaque from the carotid artery in the neck to prevent strokes.
What is the immediate treatment for a heart attack?
Aspirin: To thin the blood and prevent further clotting.
Nitroglycerin: To reduce chest pain and improve blood flow to the heart.
Thrombolytics: To dissolve blood clots blocking the coronary arteries.
Percutaneous coronary intervention (PCI): Also known as angioplasty, it’s used to open blocked arteries.
What long-term treatments are recommended after a heart attack?
Beta-blockers: To reduce heart rate and blood pressure, lowering the risk of future heart attacks.
ACE inhibitors: To improve heart function and lower blood pressure.
Lifestyle changes: Similar to CHD, including quitting smoking, eating a heart-healthy diet, and regular physical activity.
what is the first-line treatment for asthma?
Short-acting beta-agonists (SABAs) like salbutamol are inhaled medications used as rescue therapy to relieve acute asthma symptoms by relaxing airway muscles.
What is the role of inhaled corticosteroids in asthma managment?
Inhaled corticosteroids (e.g., fluticasone) are used to reduce inflammation in the airways and prevent asthma attacks.
How is long-term asthma control maintained?
Long-term control is maintained using long-acting beta-agonists (LABAs), inhaled corticosteroids, and avoiding known asthma triggers (e.g., allergens, smoking).
