Paper one x

Question 1

Lyme disease is caused by a bacteria called borrelia what is the structure of this bacteria ?

Answer 1

Borrelia, like other spirochetes, has a characteristic spiral shape, a cell wall composed of peptidoglycan and a thin layer of outer membrane, and unique endoflagella located in the periplasmic space.

Question 2

Outline the humeral immune response - as infected ticks can be spread to humans.

Answer 2

• Activation of B cells - stimulates production of plasma cells, and memory cells;
• Plasma cells can produce antibodies
• Antibodies are proteins which are specific to the antigen with which they bind to form an antigen - antibody complex;
• Memory cells remain in the circulation ready to divide if the same antigen is encountered again.

Question 3

Ticks are arachnids - parasite what is it gaining from the human blood ?

Answer 3

Essentially food from the blood.

Hb, present in blood erythrocytes, is a very important source of iron and amino acids for pathogenic microorganisms ranging from bacteria to eukaryotic pathogens, such as worms, protozoa, yeast, and fungi. These organisms have developed adequate mechanisms to obtain Hb or its byproducts (heme and globin) from the host.

Question 4

Describe the components of blood and their function .

Answer 4

Erythrocytes = RBC - Contains haemoglobin and transports oxygen to all cells.
Leucocytes = WBC - immune response against pathogens
Thrombocytes = Platelets - Formation of blood clots - small fragments of cells, with no nucleus and they work together with fibrin to form a clot if you are bleeding.

Question 5

Describe how EEG’s is performed and the principles of it ?

Answer 5

It is performed by a cap covered in electrodes being placed on the patients head and the electrodes measure the electrical activity of the different areas of the brain. It can be used to test waveforms to show if there is normal nerve activity in each area of the brain.

Question 6

Describe how nerve conduction studies are carried out ?

Answer 6

the test measures the speed of the nerve impulses (action potential) along a neurone using electrodes on the skin. and a nerve impulse can travel down a motor neurone at 54 m/s .It can be used to test conditions such as carpal tunnel , nerve entrapments , motor neurone disease etc.

Question 7

1.Describe the steps in synaptic transmission

Answer 7

Incoming electrical impulse that floods the presynaptic neurone. Then the neurotransmitters are released into the synaptic cleft due to exocytosis and then are absorbed into the post synaptic neurone due to the neurones receptors.

Question 8

Explain the principles of ELISA

Answer 8

Patient sample is added to a multi well plate and given time/treated to make any antigen adhere to the surface. The plate is washed with a non-reactive protein like bovine (cow) serum proteins to block any open space in the plate. An antibody (with an enzyme stuck to it) that is complimentary to the antigen you are looking for. If the patient sample has the antigen in it, the labelled antibody will bind to it. Add the substrate for the enzyme - the product of this reaction is a coloured substance.

Question 9

Describe how a calibration curve can be used to determine the level of antibodies in a patient sample.

Question 10

How does doxycycline work ? Bacteriocidal or bacteriostatic ?

Answer 10

Doxycycline is a bacteriostatic antibiotic, meaning it inhibits the growth and reproduction of bacteria rather than directly killing them.

Question 11

Some people with severe symptoms receive intravenous antibiotics - Why is IV better here ?

Answer 11

Intravenous (IV) antibiotics are often preferred for severe infections because they deliver medication directly into the bloodstream, allowing for faster and more efficient treatment.

Question 12

Paracetamol from the pharmacy can be used to help with pain and swelling in joints - treat symptoms with paracetamol - how does paracetamol work ?

Answer 12

One theory is that acetaminophen increases the pain threshold by inhibiting two isoforms of cyclooxygenase, COX-1 and COX-2, which are involved in prostaglandin (PG) synthesis. Prostaglandins are responsible for eliciting pain sensations.13 Acetaminophen does not inhibit cyclooxygenase in peripheral tissues and, therefore, has no peripheral anti-inflammatory effects. Though acetylsalicylic acid (aspirin) is an irreversible inhibitor of COX and directly blocks the active site of this enzyme, studies have shown that acetaminophen (paracetamol) blocks COX indirectly.24

Question 13

How can punnet squares be used to show the likelihood of inheriting a recessive disorder ?

Answer 13

Punnett squares are a visual tool used to predict the probability of an offspring inheriting a recessive disorder. By analyzing the possible combinations of alleles (genetic variations) from parents, they show the likelihood of offspring inheriting two copies of the recessive allele, which is required for the disorder to manifest.

Question 14

Describe protein synthesis

Answer 14

Transcription
The DNA code for a protein remains in the
nucleus, during transcription but a copy, called mRNA, moves from the nucleus to the ribosomes where proteins are synthesized during translation in the
cytoplasm. To make the mRNA the double stranded DNA unzips.
Translation
The mRNA leaves the nucleus and goes to the ribosomes.Carrier molecules bring specific amino acids
to add to the growing protein in the correct order. There are only about 20 different naturally-occurring amino acids. The protein produced depends on the template used, and if this sequence changes a different protein will be made.

Question 15

How would a mutation alter the protein being produced ?

Answer 15

A mutation, a change in the DNA sequence, can alter the protein being produced by modifying the instructions for protein synthesis. This can lead to changes in the amino acid sequence of the protein, potentially altering its structure, function, and interaction with other molecules.

Question 16

Draw and label a diagram showing the structure of the skin

Answer 16

Hair
Hair follicule
blood vessels
subcutaneous fat
dermis
epidermis
nerve
subcutaneous gland
sweat gland

Question 17

Describe the structure and function of each layer of the small intestine.

Answer 17

The duodenum

This is the first part of your small intestine. It’s a short (10-inch-long) chute that receives food from your stomach. Your duodenum is the place where your small intestine makes the digestive juices and enzymes to break down food. Your gallbladder delivers bile, and your pancreas delivers digestive enzymes to your duodenum to help it break down food.

The jejunum

This section of your small intestine is 8 feet long. It lays in many coils inside the lower abdominal cavity. The jejunum is dark red because it has many blood vessels. It has muscles that churn food back and forth and mix it with digestive juices. Peristalsis, which is an involuntary muscle movement in your digestive system, keeps food moving toward your ileum.

The ileum

This is the last and longest section of your small intestine. It absorbs nutrients from digested food for your body to use, like vitamins, minerals, carbohydrates, fats and protein. Your ileum moves food waste toward your large intestine. The ileum is where food spends the most time in the small intestine before moving to the large intestine.

Question 18

What is keratinised skin ?

Answer 18

Keratinization, also known as cornification, is the process where skin cells, called keratinocytes, undergo a series of changes and become filled with keratin, a strong protein.

Question 19

Describe the principles of spirometry

Answer 19

Spirometry is a simple test used to help diagnose and monitor certain lung conditions by measuring how much air you can breathe out in one forced breath.

It’s carried out using a device called a spirometer, which is a small machine attached by a cable to a mouthpiece.

Question 20

Describe how peak flow is carried out and what the results might mean ?

Answer 20

By measuring how fast you’re able to breathe out, your peak flow score can indicate whether your airways are narrowed. This could be a sign that you have asthma.

Question 21

Describe the structure or respiratory system

Answer 21

Nose and Mouth:
These are the initial points of entry for air, where it’s warmed, moistened, and filtered by cilia and mucus.
Pharynx (Throat):
This is a common pathway for both air and food, connecting the nasal and oral cavities to the larynx and esophagus.
Larynx (Voice Box):
Contains the vocal cords and epiglottis, which prevents food from entering the trachea during swallowing.
Trachea (Windpipe):
A tube that carries air from the larynx to the lungs, lined with cartilage to keep it open.
Bronchi:
The trachea splits into two main bronchi, one entering each lung.
Bronchioles:
Within the lungs, the bronchi divide into smaller tubes called bronchioles, which further branch into tiny air sacs called alveoli.
Lungs:
Sac-like organs where gas exchange occurs. The right lung has three lobes, and the left lung has two.
Alveoli:
Tiny air sacs in the lungs where oxygen enters the bloodstream and carbon dioxide is released.
Breathing Muscles:
The diaphragm and intercostal muscles play a crucial role in expanding and contracting the chest cavity, allowing air to flow in and out of the lungs.
Pleura:
A double-layered membrane that surrounds the lungs, providing lubrication and preventing friction during breathing.

Question 22

Histopathology method - how is a sample prepared ?

Answer 22

Fixation
Processing - Dehydration, Clearing,Embedding
Sectioning
Mounting and Staining
Mounting and Microscopy

Question 23

Amniocentesis – Amplified by PCR and analysed by Gel Electrophoresis – describe these techniques ?

Answer 23

PCR (Polymerase Chain Reaction) is used to amplify specific DNA sequences from these fetal cells, creating millions of copies. The amplified DNA is then separated and visualized using gel electrophoresis, a technique that separates DNA fragments based on size.

Question 24

What are the benefits of topical treatments ?

Answer 24

Alternative to oral medication. Some people struggle with oral medication, especially children. …
Reduces risk of gastrointestinal issues. …
Fewer risk of drug abuse. …
Easy to use. …
Better compliance. …
Easy termination. …
Takeaway. …
Reach Out Today.

Question 25

How could a team of specialists impact the NHS financially ?

Answer 25

As many specialists require to be paid lots of money due tother extensive research in their field.

Question 26

How do cannabinoids work ?

Answer 26

Cannabinoids, like THC and CBD, exert their effects primarily by interacting with the body's endocannabinoid system (ECS). The ECS is a complex network of receptors and chemicals that play a role in regulating various bodily functions. Cannabinoids, both those produced naturally by the body and those found in cannabis, bind to these receptors, influencing how cells communicate and impacting various aspects of the nervous system.

Question 27

Research - ethical consideration , trials , sampling methods and research methods for cannabinoids.

Question 28

Define nominal data

Answer 28

Nominal data, also known as categorical data, is a type of qualitative data used to label or classify variables.

Question 29

suggest what statistical test is most appropriate for analysing nominal data

Answer 29

Chi squared

Question 30

Identify the organs of the digestive system, with an explanation of the role of each

Answer 30

1. Mouth: Function: The mouth starts the digestive process with mechanical digestion (chewing) and chemical digestion (saliva breaking down starches). Structures: Teeth, tongue, and salivary glands. Role: Chewing, mixing food with saliva, and swallowing. 2. Pharynx: Function: A passageway that transports food and liquids from the mouth to the esophagus. Role: Facilitates swallowing and prevents food from entering the trachea. 3. Esophagus: Function: A muscular tube that connects the pharynx to the stomach. Role: Peristaltic waves (muscular contractions) push food down to the stomach. 4. Stomach: Function: A muscular pouch that churns and mixes food with gastric juices. Role: Further breaks down food, kills bacteria, and releases enzymes. 5. Small Intestine: Function: The primary site for nutrient absorption. Role: Completes the breakdown of food and absorbs nutrients into the bloodstream. 6. Large Intestine: Function: Absorbs water and minerals. Role: Stores and compacts waste, forming stool. 7. Rectum: Function: Stores stool before it is eliminated. Role: Signals the need for bowel movements. 8. Anus: Function: The opening through which stool is expelled.Accessory Organs: Pancreas: Secretes enzymes that break down carbohydrates, fats, and proteins. Liver: Produces bile, which helps digest fats, and processes nutrients absorbed by the small intestine. Gallbladder: Stores and concentrates bile.

Question 31

What is the formula for calculating BMI ?

Answer 31

The formula for calculating Body Mass Index (BMI) is: BMI = weight (kg) / height (m)².

Question 32

How do osmotic laxatives work ?

Answer 32

Osmotic laxatives work by increasing the water content in the large bowel, which softens the stool and makes it easier to pass. They do this by drawing water from the body into the bowel through a process called osmosis. This process helps to restore the balance of water in the stool, preventing it from becoming hard and dry.

Question 33

Describe the principles of blood pressure monitoring

Question 34

Describe the principles of ECG monitoring

Question 35

What are the causes and symptoms of scurvy ?

Answer 35

Scurvy is caused by a severe deficiency of vitamin C in the diet, typically for several months. Symptoms include fatigue, weakness, swollen and bleeding gums, easy bruising, and red or blue spots on the skin.

Question 36

What are the causes and symptoms of rickets?

Answer 36

Rickets is a bone disease that affects infants and young children. The child's growing bones fail to develop properly due to a lack of vitamin D. This can result in soft and weakened bones, fractures, bone and muscle pain, and bone deformities.

Question 37

What are the causes and symptoms of anaemia ?

Answer 37

Anaemia, a condition where the blood doesn't carry enough oxygen, can be caused by various factors including iron deficiency, blood loss, or issues with red blood cell production. Common symptoms include fatigue, shortness of breath, pale skin, and weakness.

Question 38

Describe the electrical control of a heart beat

Answer 38

The heart controls its electrical activity through a specialized system called the cardiac conduction system, which ensures coordinated contractions and pumping of blood. This system begins with the sinoatrial (SA) node, the heart's natural pacemaker, which generates electrical signals that spread through the atria, causing them to contract. The signals then travel to the atrioventricular (AV) node, where they are briefly delayed before being passed to the bundle of His and Purkinje fibers, which stimulate the ventricles to contract.

Question 39

Describe the structure and function of all 3 main types of blood vessels

Answer 39

The three main types of blood vessels are arteries, veins, and capillaries. Arteries carry blood away from the heart, veins return blood to the heart, and capillaries facilitate gas exchange between blood and tissues. Arteries: Structure: Arteries have thick, elastic, muscular walls with a narrow lumen (internal space). Their walls contain a layer of smooth muscle, elastic fibers, and connective tissue to withstand high blood pressure. Function: They carry oxygenated blood away from the heart to the body's tissues. The elastic fibers help maintain blood pressure and smooth blood flow. Veins: Structure: Veins have thinner, less elastic, muscular walls with a wider lumen than arteries. They also contain valves to prevent backflow of blood. Function: Veins carry deoxygenated blood back to the heart. The valves ensure blood flows in one direction, towards the heart. Capillaries: Structure: Capillaries are tiny, thin-walled blood vessels that connect arteries and veins. They are made up of a single layer of endothelial cells. Function: Capillaries facilitate the exchange of oxygen, nutrients, and waste products between the blood and body cells. The thin walls allow for rapid diffusion of substances across the capillary walls.

Question 40

Describe the formation of tissue fluid in the lymphatic system

Answer 40

Tissue fluid, a crucial component of the lymphatic system, is formed from blood plasma by a process called filtration, driven by hydrostatic pressure. At the arteriole end of capillaries, high blood pressure forces fluid, along with small molecules and some nutrients, out of the blood and into the spaces surrounding body cells, creating tissue fluid. While a significant portion of this fluid is reabsorbed at the venule end back into the bloodstream, some remains in the tissues and is eventually collected by the lymphatic vessels, forming lymph, which returns to the circulation.

Question 41

Draw and label a motor neurone

Question 42

Describe the passage of information across a synapse

Answer 42

Information passes across a synapse through a process of chemical and electrical signals being converted and transmitted between neurons. The sending neuron, the presynaptic neuron, releases neurotransmitters into the synapse, which then bind to receptors on the receiving neuron, the postsynaptic neuron. This binding triggers a response in the postsynaptic neuron, which can be either excitatory (increasing the likelihood of firing an action potential) or inhibitory (decreasing the likelihood).

Question 43

Describe how a nerve impulse travels along a neurone

Question 44

Describe the formation of urine (ultrafiltration) in the nephron of a kidney ?

Question 45

What is urodynamic testing ?

Answer 45

Urodynamic testing is a series of tests that assesses the function of the bladder, urethra, and associated muscles. It helps diagnose and understand various urinary issues like incontinence, urgency, and difficulty emptying the bladder. The tests analyze how the bladder fills and empties, providing valuable information to determine the cause of the problem and guide treatment.

Question 46

Describe the structure of haemoglobin

Answer 46

Haemoglobin, a globular protein, is composed of four polypeptide chains, two alpha and two beta, with each chain associated with a heme group. The heme group contains an iron ion (Fe2+) that can reversibly bind with oxygen, enabling haemoglobin to transport four oxygen molecules.

Question 47

Describe the non - specific immune response

Question 48

Describe the specific immune response

Question 49

What is the integumentary system ?

Answer 49

The integumentary system is an organ system consisting of the skin , hair, nails and exocrine glands. The skin is only a few millimetres thick yet is by far the largest organ in the body.

Question 50

What are the three functions of skin ?

Answer 50

1. Protects us from infection 2. Keeps our body at the right temperature 3. Covered in receptors so we can feel things.

Question 51

What do mechanoreceptors do ?

Answer 51

Mechanoreceptors they tell you about sensations of pushing, pulling or movement.

Question 52

What do thermoreceptors do ?

Answer 52

Thermoreceptors they tell you about sensations of temperature.

Question 53

How does the skin protect against invasions ?

Answer 53

The skin covers the whole body and protects it from physical damage, microbe infection and dehydration. It is difficult for microbes to penetrate the skin's dry, dead outer cells. The sebaceous glands produce oils which also help to kill microbes.

Question 54

What is adipose fat and what does it do ?

Answer 54

Beneath the dermis is a fat layer. You can survive, perhaps for only about one day on stored glycogen. With fat, you can survive for weeks. Fat is made when excess food is eaten. Stored fat is used for energy when food is lacking.

Question 55

How does skin synthesise vitamin D ?

Answer 55

The human skin can make large amounts of vitamin D when your bare skin is exposed to sunlight. The part of the sun's rays that is important is ultraviolet B (UVB). OR you can vitamin D from your diet.

Question 56

What does too much exposure to the sun result in ?

Answer 56

Exposure to too much UVA and B can cause skin cancer. UVB = Burns, UVA = Tans.

Question 57

What is thermoregulation ?

Answer 57

Too hot = hyperthermia too cold = hypothermia The hypothalamus of the brain brings about a number of changes in the body .

Question 58

What does the hypothalamus do ?

Answer 58

Your hypothalamus is a section of your brain that controls thermoregulation. When it senses your internal temperature becoming too low or high, it sends signals to your muscles, organs, glands and nervous system.

Question 59

What are the functions of bones and joints ?

Answer 59

- shape - movement - protection - support - blood cell production

Question 60

Describe the function (shape) for the skeleton

Answer 60

The skeleton gives us our shape and determines our size .

Question 61

Describe the function of (support) for the skeleton

Answer 61

The skeleton supports muscles and organs.

Question 62

Describe the function of (protection) for the skeleton

Answer 62

The skeleton protects delicate parts of the body like the brain and lungs.

Question 63

Describe the function of (movement) for the skeleton

Answer 63

The skeleton allows us to move. Muscles are attached to the bones and move them as levers.

Question 64

Describe the function of (blood cell production) for the skeleton

Answer 64

Blood cells are made in the bone marrow.

Question 65

Describe the spine

Answer 65

Spinal column - vertebral column A series of bones, separated by cartilage discs This allows for locomotion.

Question 66

Describe the intervertebral discs

Answer 66

These are the 'cushions' between your vertebrae that work as the shock absorbers for your spine. There is an annulus fibrosus, the tough outer section, then there is the nucleus pulposus, the softer, gel - like centre.

Question 67

Describe fibrous joints ?

Answer 67

Fibrous joints are connected by dense connective tissue = collagen. These joints are also called fixed or immovable joints because they do not move. Skull bones are connected by fibrous joints called sutures.

Question 68

Describe cartilaginous joints ?

Answer 68

Cartilaginous joints are connected entirely by cartilage. Cartilaginous joints allow more movement between bones than a fibrous joint but less than the highly mobile synovial joint.

Question 69

Describe synovial joints

Answer 69

- Synovial joints allow for movement. - where the bones meet to form a synovial joint, the bones' surfaces are covered with a thin layer of strong, smooth articular cartilage. - A very thin layer of slippery, viscous joint fluid, called synovial fluid, separates and lubricates the two cartilage - covered bone surfaces. A healthy knee joint has up to 4 ml of synovial fluid. - A synovial membrane encapsulates the joint surfaces and synovial fluid. The synovial membrane is very thin, often just a few cells thick and produces synovial fluid. The synovial membrane is backed by a slightly thicker sub synovial membrane.

Question 70

Name different types of joints.

Answer 70

- Pivot joints - hinge joint - saddle joint - plane joint - condyloid joint - ball and socket joint

Question 71

Describe a ligament

Answer 71

Connects bone to bone i.e., ACL

Question 72

Describe a tendon

Answer 72

Connect muscle to bone.

Question 73

What is the nervous system ?

Answer 73

The nervous system is specialised network of cells in the human body and is our primary internal communication system.

Question 74

What are the two main functions of the nervous system ?

Answer 74

1. To collect, process and respond to information in the environment. 2. To co-ordinate the working of different organs and cells.

Question 75

Describe the CNS ?

Answer 75

The CNS is made up of the brain and the spinal cord. - the brain is the centre of all conscious awareness. - The spinal cord is an extension of the brain. It is responsible for reflex actions.

Question 76

Describe the PNS ?

Answer 76

The PNS transmits messages via millions of neurons, to and from the central nervous system . The PNS is further sub divided into : - The somatic nervous system (SNS) - The autonomic nervous system (ANS)

Question 77

Describe the somatic nervous system ?

Answer 77

The part of the nervous system that is under voluntary control, it allows you to do things like move your arms and legs .

Question 78

Describe the ANS ?

Answer 78

This governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses. These are not under conscious control.

Question 79

Describe a neuron ?

Answer 79

Cells that conduct nerve impulses are called neurones.

Question 80

Describe the nucleus of a neurone ?

Answer 80

The control centre of a cell, which contains the cell's chromosomal DNA.

Question 81

Describe a dendrite of a neurone ?

Answer 81

Receives the nerve impulse or signal from adjacent neurone.

Question 82

Describe an axon of a neurone ?

Answer 82

Where the electrical signals pass along .

Question 83

Describe a myelin sheath of neurone ?

Answer 83

Insulates / protects the axon from external influences that might affect the transmission of the nerve impulse down the axon.

Question 84

Describe the node of ranvier of a neuron ?

Answer 84

Small gaps in the myelin sheath that let the electrical impulse travel quicker.

Question 85

Describe axon terminals/ synaptic knob of neurone ?

Answer 85

Synaptic knob sends signals to an adjacent cell by releasing or detecting chemical signals.

Question 86

Describe reflexes ?

Answer 86

Produce fast response to stimulus. Information relays between sensor and effector in the spinal cord .

Question 87

Describe the reflex arc ?

Answer 87

1. Receptors detect stimulus 2. Sensory neurones conduct impulse to the CNS. 3. Sensory neurones enter the spinal cord 4. Sensory neurone synapses with relay neurone 5. Relay neurone synapses with motor neurone. 6. Motor neurone carries impulse to effector.

Question 88

Describe the difference between the structure of arteries , veins and capillaries ?

Answer 88

arteries - Tough collagen outer coat to prevent overstretching. Small lumen surrounded by smooth endothelium to prevent friction. Thick layer of smooth muscle that can stretch as blood pumped in and recoils to maintain pressure. Vein - Larger lumen as blood is under lower pressure. Less muscle and elastic fibres. Instead, veins contain semilunar valves to prevent backflow of blood. Capillaries - A single layer of endothelium allowing movement of substances between blood and cells.

Question 89

What does the superior vena cava do ?

Answer 89

Returns deoxygenated blood to the heart.

Question 90

What does the right atrium do ?

Answer 90

Contracts and pumps deoxygenated blood into the ventricle.

Question 91

What does the tricuspid valve do ?

Answer 91

Pressure of the contraction of the atrium opens this value which then closes, preventing back flow.

Question 92

What does the right ventricle do ?

Answer 92

Thinner muscular wall compared to the left ventricle as less pressure is produced on contraction. This prevents of blood into the left ventricle after it contracts.

Question 93

What does the septum do ?

Answer 93

It is a wall diving oxygenated blood (left) and deoxygenated blood (right) side of the heart.

Question 94

What does the left ventricle do ?

Answer 94

Comparatively thicker muscular wall to produce a higher pressure to push oxygenated blood rapidly around the body .

Question 95

What does the bicuspid (mitral) valve do ?

Answer 95

Behind which is the left atrium - it prevents back flow of blood into the atrium.

Question 96

What does the Pulmonary veins do ?

Answer 96

They return oxygenated blood from lungs to the right atrium.

Question 97

What does the pulmonary (semi lunar) valve do ?

Answer 97

There is a similar valve in the aorta. They prevent blood flowing back into the heart between heart beats.

Question 98

What does the pulmonary artery do ?

Answer 98

Takes deoxygenated blood to the lungs from the right ventricle.

Question 99

What does the aorta do ?

Answer 99

carries oxygenated blood from the left ventricle to the body.

Question 100

What happens during atrial systole ?

Answer 100

Atrial contract. Pressure opens atrio-ventricular valves. Blood flows into ventricles.

Question 101

What happens during ventricular systole ?

Answer 101

Ventricles contract. Atrio-ventricular valves close due to pressure in ventricles. Semilunar valves in aorta and pulmonary artery open. Blood flows into arteries.

Question 102

What happens during ventricular diastole ?

Answer 102

Ventricle muscle relaxes. Semilunar valves close to prevent back flow of blood.

Question 103

What happens during diastole ?

Answer 103

Heart muscle relaxes and atria begin to fill from vena cava and pulmonary veins.

Question 104

Describe how the heart initiates heartbeats ?

Answer 104

- The heartbeat is myogenic; imitation comes from the heart itself. - The Sino-atrial node acts a pacemaker sending waves of excitation across the atria causing them to contract simultaneously. - A layer of connective tissue prevents the wave of excitation passing down to the ventricles. - The atrioventricular node transmits impulses down the bundle of His to the apex of the heart. - The impulse then travels up the branched Purkinje fibres stimulating ventricles to contract from the bottom up ensuring all the blood is pumped out.

Question 105

Describe the ECG ? - not method ?

Answer 105

The electrical activity that spreads through the heart during the cardia cycle can be detected using electrodes placed on the skin and shown on a cathode ray oscilloscope.

Question 106

What is a P wave on an ECG ?

Answer 106

Depolarisation of the atria corresponding to atrial systole.

Question 107

What is a QRS wave on an ECG ?

Answer 107

Spread of depolarisation through the ventricles resulting in ventricular systole.

Question 108

What is a T wave on an ECG ?

Answer 108

Depolarisation of the ventricles resulting in ventricular diastole.

Question 109

Describe the formation of tissue fluid ?

Answer 109

A link between blood and cells. Important as plasma transports nutrients, hormones, excretory products and distributes heat. 1. At the arterial end of the capillary bed, hydrostatic pressure is higher than osmotic pressure. 2. Water and small soluble molecules are forced through the capillary walls, forming tissue fluid between the cells. 3. Proteins and cells in the plasma are too large to be forced out. 4. Due to reduced volume of blood and friction, blood pressure falls and it moves through the capillary. 5. At the venous end of the capillary bed osmotic pressure of the blood is higher than the hydrostatic pressure. 6. Most of the water from tissue fluid moves back into blood capillaries. The remainder of the tissue fluid is returned to the blood, via lymph vessels.

Question 110

Describe a RIA ?

Answer 110

Radioimmunoassay (RIA) is a very sensitive technique that can be used to measure low levels of antigens by use of antibodies. It is a commonly used technique and a relatively low -cost technique in clinical labatories. In a RIA a known quantity of an antigen is made radioactive, and mixed with a known quantity of antibody and the two specifically bind together. A sample from a patient containing an unknown quantity of the same antigen is added. This causes the unlabelled antigen from the patient sample to compete with the labeled antigen for antibody binding sites . A higher concentration of unlabelled, patient antigen, displaces more labelled antigen from the antigen - antibody complex. Bound antigens are separated from unbound antigens and the radioactivity of the bound antigen remaining is measured by a gamma counter.

Question 111

What does RIA stand for ?

Answer 111

Radioimmunoassay

Question 112

What are RIA's used for ?

Answer 112

Detecting antigens in bodily fluid.

Question 113

What is the radioactive part in a RIA ?

Answer 113

A radioactively labelled antigen

Question 114

Why is the RIA made radioactive ?

Answer 114

So we can detect how much of it binds to an antibody.

Question 115

What two substances have known quantities for RIA ?

Answer 115

The antibody and the radioactive antigen.

Question 116

What is added that has a unknown quantity - RIA?

Answer 116

The patients antigens in their bodily fluid.

Question 117

How is the unknown quantity worked out - RIA ?

Answer 117

How much of the radioactive antigen is displaced by the patients antigen.

Question 118

What does ELISA stand for ?

Answer 118

Enzyme linked immunosorbent assay

Question 119

What are the three types of ELISA ?

Answer 119

- Direct ELISA - looks for a specific antigen in a patient. - Indirect ELISA - tests if a patient had antibodies in their sample. - ELISA'S are usually carried out in a 96 well micro titre plate.

Question 120

Describe a direct ELISA ?

Answer 120

Patient sample is added to a multi-well plate and given time/treated to make any antigen adhere to the surface. The plate is washed with a non reactive protein like bovine (cow) serum proteins to block any open space in the plate. An antibody (with an enzyme stuck to it) that is complimentary to the antigen you are looking for is added. If the patient sample has the antigen in it, the labelled antibody will bind to it. Add the substrate for the enzyme - the product of this reaction is a coloured substance.

Question 121

Limitations of Direct ELISA ?

Answer 121

- The direct ELISA is not very sensitive, with a small amount of antigen present the colour change may be so small that it is hard to detect.

Question 122

What does an indirect ELISA test do ?

Answer 122

- Indirect ELISAs are more sensitive tests than direct ELISAs because more secondary antibodies give a stronger signal.

Question 123

Steps of ELISA ?

Answer 123

Antigens we want to test for in a patient sample are attached to a surface (multi well plate ), a solution containing enzyme labelled antibodies is added to the plate , a substance containing the enzymes substrate is added. The subsequent reaction produces a detectable signal, most commonly a colour change. The higher the concentration of antigen, the stronger the colour change, which can then be detected by a spectrometer.

Question 124

Limitations for ELISA ?

Answer 124

sensitivity - Greater than 90% specificity - 95% interfering agents - typically caused by interactions between antibodies within the assay itself and other antibodies present in a patient's sample. Any type of interference can cause an assay to report a false result.

Question 125

What are the different topical administration routes ?

Answer 125

Transdermal - applied directly to the skin Inhalable - Breathed in Buccal - held inside the cheek ophthalmic - given in the eye , usually drops otic - given in to the ear , usually drops nasal - given in to the nose , usually spray.

Question 126

What are the different parental administration routes ?

Answer 126

Infused - delivered into the blood stream over a period of time (IV) intrathecal - injected into the spinal cord intramuscular - injected into the muscle intravenous - injected into a vein subcutaneous - injected under the skin

Question 127

What factors do doctors need to consider when they are choosing an administration route ?

Answer 127

- If a healthcare professional has to administer it - if it would be broken down by the digestive system - any side effects due to the method - how predictable the dosing/absorption is - where the drug is needed - patient preference - how easy it is to do - how fast the drug can have its effect once administered.

Question 128

What are the advantages of oral administration routes ?

Answer 128

- easy - preferred by patients - 'slow release' preparations may be available to extend duration of action - drugs can be formulated in such a way as to protect them from digestive enzymes , acid , etc . - patient administered.

Question 129

What are the advantages of Sublingual administration routes ?

Answer 129

- absorbed in to the blood but avoids first pass metabolism - good for patients who are vomiting - rapid absorption and onset - patient administered.

Question 130

What are the advantages of rectal administration routes ?

Answer 130

- good absorption - avoids first pass metabolism

Question 131

What are the advantages of parental administration routes ?

Answer 131

- Good absorption - onset is rapid - depending on formulation can have a very long duration of action - dependable and reproducible effects - entire administered dose reaches the circulation immediately - the dose can be accurately adjusted against response.

Question 132

What are the advantages of topical administration routes ?

Answer 132

- easy - non invasive - high levels of patient satisfaction - patient administered.

Question 133

What are the disadvantages of oral administration routes ?

Answer 133

- unsuitable in patients who are uncooperative, strictly 'nil by mouth', are vomiting profusely or have ileus - most are absorbed slowly - unpredictable absorption due to degradation by stomach acid and enzymes.

Question 134

What are the disadvantages of sublingual administrations routes ?

Answer 134

- Does not work for slow release medications. - can be hard to keep the medication under the tongue for long enough.

Question 135

What are the disadvantages of rectal administration route ?

Answer 135

- may not be suitable after rectal or anal surgery - some patients dislike suppositories - may need a medical professionals to carry out

Question 136

What are disadvantages of parental administration routes ?

Answer 136

- injections hurt, causes bruises and frighten children and people who have phobias of needles . - more expensive and labour intensive than other routes. - Most need a medical professional to carry out - cannulation is distressing to some patients, especially children. - cannula are prone to infection.

Question 137

What are the disadvantages of topical administration routes ?

Answer 137

- most drugs ave high molecular weight and are poorly lipid soluble, so are not absorbed via skin or mucous membranes - very slow absorption - unpredictable dosage.

Question 138

Example of an oral drug ?

Answer 138

- beta blockers for hypertension

Question 139

Example of sublingual drug ?

Answer 139

Nitroglycerine to treat angina

Question 140

Example of a rectal drug ?

Answer 140

Methimazole to treat hyperthyroidism

Question 141

Example of parental drug ?

Answer 141

Depot medications - haperidol to treat schizophrenia insulin to treat type 1 diabetics

Question 142

Example of a topical drug ?

Answer 142

Bactroban antibiotic to treat bacterial infection