Book 1 Flashcards
What are the functions of the 3 main structures of the brain??
Cerebrum - higher function skills, like speech, higher intellectual function and fine control of movement
Cerebellum- balance and co ordination
Brain stem- autonomic processes, control of bp, blood volume, heart rate, respiration, arousal
What two hemispheres are the cerebrum divided into?? How do they communicate?
What 4 lobes are there of the cerebral cortex??
Left cerebral hemisphere and right cerebral hemisphere, communicate via corpus callosum
Temporal- speech, lanugae, hearing, smell
Occipital- passt visual experience and vision
Parietal - sensory
Frontal- motor, emotions, personality
What is the cerebral cortex for??
Concious thought and perception
Outermost 20mm of cerebral hemispheres
What is the sensory and motor cortex?
Sensory - parietal lobe. Sensory neurons from sensory organs like ears, eyes, arrive at sensory cortex
Motor - in frontal lobe responsible for planning, control and voluntary movement. gets info from cerebellum. And messages sent via motor neurons to initiate voluntary movement
What are the 3 parts of the brain stem and their functions?
Midbrain - upper part containing auditory and visual reflex centres, and contains cranial reflect activities like blinking and ducking head
Pons- middle part relays info between cerebrum and cerebellum. Helps coordinate breathing with medulla oblongata
Medulla oblongata - respiratory, vasomotor centre and cardiac centre for controlling breathing and cardiovascular system, also reflex systems like vomiting and swalloing
What are the meninges, blood brain barrier and cerebrospinal fluid csf
Meninges- membranes around cns for protection. Outter dura mater- strong thick. Arachnoid mater- transparent thin pia mater - delicate inner layer
Blood brain barrier - tight junctions between capillaries and astrocytes . Foot processes which encircle capillaries and create semi permeable layer separating blood from neurones in brain.
Cerebrospinal fluid- fluid made from ependymal cells in canal of spinal cord. Transparent fluid containing urea, protein, glucose, lactic acid. Contributes to intra cranial pressure, supports the weight of cranium, allows exchange of substances by medium, keeps structures moist, protection
What organ systems involved in intake of nutrients, oxygen and removal lf waste products
Oxygen- muscular system, nervous system and respiratory system
Nuritients - digestive system, muscular, endocrine, nervous
Removal of waste products - renal, urinary, respiratory system
Functions of cell membrane?!
Encloses cell contents Barrier Communication Cell movement Chemical reactions Celluar identity
Two types of endocytosis
Phagocytosis
Pinocytosis - cell drinking, vesicles allow small droplets inside the cell
How do hormones produce changes in target cells?
Changes in permeability of cell membrane, activation or deactivation of enzymes, stimulation of cell division, stimulation of synthesis of proteins or regulatory molecules
What 3 ways are endocrine cells, tissues and organs controlles
Neural, ions and hormonal (pituitary gland or hypothalamus)
Definition of homeostatis ?
Keeping the levels of interal environment eithin narrow defined limits regardless of what enters the body or how the external environment differs, by autocorrective self adjusting mechanisms.
Comtrolloed by neural and hormonal systems
Negative feedback reverses any shift away from optimum state, automatic response involving a corrective mechanism,
Effects of the sympathetic nervous system, part of the autonomic nervous system in PNS
Pupils dilate, promotes ejaculation, bronchi relax, increased breathing rate, rate increases in heart, noadrenaline adrenaline produced. Gi tract inhibited.
Skeletal muscle vaso dilation
Example of the antagonisitic relationship of para and sympathetic responses?
How does this effect meds to give
The heart
Para - neurones release chemical acetyl choline
Sympathetic- neurone release noradrenaline or adrenaline on target tissue
Meds- if panicky give acetyl choline meds to activate para. Or meds to block action or adrenaline (prazosin)
What is REM and non REM sleep?
REM- rapid eye movement, associated with dreaming and skeletal muscles are paralysed. Occurs 80-100 minutes after start of sleep. And then every 90 momutes, lastig 5-30 minutes each cycle. Rapid movement of eyes, and the heart and respiratory rate is irregular. 4-5 cycles a night of rem. If woken up during rem dreams are remembered.
Non REM- 4 stages of sleep, most of our sleep at night, reduction of physiological activity, and brain waves measured by ecg slower, and breathing and heart rate decrease.
What is circadian rhythms??
Bodily changes in 24 hours. The normal fluctuations of the body like hormone secretion, temperatures and other physiological factors.
Can be effected by to a certain extent by external factors like meal times and work patterns.
Changes occur with regular increases and decreases of cellular activities that occur in 24 hours.
What is the pineal gland what does it do?
Serotonin / melatonin
Pineal gland indirectly responds to light.
Suprachiasmatic nucleus is the biological clock and influences pineal gland.
Together they control secretion of hormone melatonin from pineal gland. Darkness stimulates melatonin, light inhibits melatonin.
Melatonin is made from serotonin, both from the amino acid tryptophan, rich in foods like milk, chocolate. Serotonin is associatied with feeling good and relaxation, and melotonin is sleepiness and secreted at night.
Why do we need sleep?
Restoration - rest and repair
Energy conservation - save calories
Brain processing - synaptic processing
What is erythropoiesis?
Formation of new red blood cells from red bone marrow. When dead or lost. As they grow they exclude their nucleus as they fill with haemoglobin. Squeeze in to red reticulocytes to begin circulating around the body.
When less oxygen levels hypoxia. Kidney (receptor) then releases erythropoietin which stimulates red bone marrow (effector) to make erythropoietin (controller) which increases rbc count, increases 02 carrying ability of blood
What is plasma and the functions of plasma proteins??
Steaw coloured sticky fluid made of 91% water and 7% plasma proteins of albumins, a globulins, y globulins and beta globulins
Functions are
Clotting blood
Antibodies are y globulins
Transport substances are carried in blood eg calcium by albumins
Plasma proteins contribute to viscosity of blood helping with resistance in blood vessels increasing bp
What is haemostasis and what are the 3 stages??
Haemostasis is the stemming of blood following damage to the blood vessel.
Vascular spasm
Formation of a temporary platelet plug formation
Co agulation
What is vascular spasm in heamostasis?
Vascular spasm is when the smooth muscle fibres contract in the damages walls of blood vessels. Reducing blood flow to damage. Mimmediate protection
What is platelet plug formation in haemostasis?
Im a damaged blood vessel, collagen fibres are exposed to blood. Platelets stick to the collagen causing a platelet plug which blocks minor bleeding,
Thromboxane makes platelets sticky allowing the plug to form
What is the co agulation phase of haemostasis?
Last but most effective method,
Goal is to convert fibrinogen to fibrin,which then entraps platelets and blood cells and seal the cut. Requires clotting factors that was normally in active.
Substances released from damaged tissues results in prothrombin activator, which activates coagulation.
This causes prothrombin to be converted to thrombin, with calcium present
Thrombin convets soluble fibrinogen to insoluble firbin
Fibrin forms a network of threads which traps platelets and blood cells to form a clot halting bleeding.
Calcium always needs to be present
What is firbinolysis?
Process that breaks down the fibrin clot by firbinolytic agents
What are anti-platelet drugs?? In haemotology
They reduce the risk of clots forming in the blood. Reducing stokes and heart attacks.
Aspirin is an anti platelet drug as it prevents the formation of thromboxane by binding to an exxyme cyclooxegenase (cox) which prevents platelets being able to stick together.
What are anticoagulant? In haemotology like antiplatelet drugs
Anti coagulant drugs reduce ability of blood to clot. Like heparin (what mast cells make) and warfarin which interferes with the action of vitamin K it is a coenzyme of prothrombin
What cofactor is needed in the liver as a clotting factor to produce prothrombin??
Vitamin K
Deficiency leads to bleeding,
What are the cells in muscle tissue and what are their characteristics??
Cardiomyocytes
Lots of mitochondria, need calcium for contraction
Striated mononucleated
Y shaped
Joined by intercalated discs which contain gap junctions which allows ions to move from cell to cell allowing depolarisation,
What are the 3 stages in cardiac cycle?
Atrial systole - contraction of the atrium after SA node depolarises it
Ventricular systole- ventricular contraction after AV node depolarises it
Complete diastole - relaxation of heart where blood is passively filling from atrium in to ventricles (passive ventricular filling)
What dos ECG stand for? And what does it all show?? What is sinus rhythm?
Electrocardiogram
Sinus rhythm is the natural rhythm of the heart,
P wave- depolarisation of atrium
QRS- depolarisation of ventricles
T - repolarisation of ventricles before diastole
What is digoxin?
Glycoside from foxglove plant,used to treat heart problems like atrial fibrillation, effects like able to slow down heart, and help it beat more regularly by distributing concentration of ions in cardiomyocytes and reduces conductivity in av node.
What is blood pressure and what 3factors effect it?
Blood pressure is the force exerted by blood on the inner walls of blood vessels.
Heart rate, blood volume and viscosity, blood vessels in relation to their diameter
What is the equation to calculate blood pressure?
Blood pressure = cardiac output x total peripheral resistance
What is the equation to find out cardiac output?
Co = stoke volume x heart rate
Total volume of blood pumped out of ventricles during a minute
Stroke volume is volume ejected from left ventricle per 1 contraction
What is peripheral resistance?
Peripheral resistance is the resistance to blood flow which is mainly created by the diameter of blood vessels
Controlled by short term nervous system and long term hormones
How can heart rate be controlled?
Baroreceptors (receptor) in aortic arch and internal carotid arteries. Send info to cardiac centre in medulla (in brain stem which is the controller) which is controlled by autonomic PNS parasympathetic and sympathetic nervous systems, heart is the effector by neurones exciting the SA node, AV node and cardiac muscle, increasing heart rate in sympathetic.
How is peripheral resistance regulated?
Baroreceptors in aprtic arch and internal carotid ateries detect lower blood pressure, nerve impulses sent to neurones in the medulla in the vasomotor centre. Which is the controller of the diameter of arterioles. Vasomotor tone in blood vessels is controlled by vasomotor centre, and sympathetic impulses lead to vasoconstriction of smooth muscle. Increases peripheral resistance
What are baroreceptors?
Pressure sensitive receptors which detect changes in the stretch in the artery walls due to blood pressure changes, which sends impulses to vasomotor centre and cardiac centre in medulla
Found in aortic arch and internal carotid arteries
What are antihypertensives? Pharmacology of heart rate
Class of medicines that help to control high blood pressure. Diuretics try and reduce volume of fluid,
Beta - blockers work by blocking effect on adrenaline on the heart, decreasing heart rate and force of contraction
Calcium channel blockers work by blocking the cardiomyocytes from having calcium for contraction. So will dilate blood vessels and reduce the force of contraction
Some try to suppress sympathetic nervous system
What is amygdala hijack and allostatic load?
Amygdala hijack occurs when a threat overwhelms the brain involving emotional distress, anger, impulse and fear taking actions which may later be regretted
Allostatic load- chronic stress with repeated reactions from amygdala leads to wear and tear of the brain and body.
What is the long term stress response? HPA axis (hypothalamic-pituitary-adrenal axis)
Danger detected by amygdala via eyes or ears
Distress signals sent to hypothalamus who is in charge of the stress response stimulates sympathetic system, activating pituitary gland and adrenal gland
Adrenal medulla in adrenal cortex produces adrenaline
CRF is send to Pituitary gland from hypothalamus which makes the pit gland release ACTH
ACTH activates the adrenal cortex to produce cortisol into blood which increases energy availability by increasing glucose and fatty acids in blood. Suppressed immune system and is an anti-inflammatory
What 4 ways can the respiratory system by divided?
Upper respiratory tract- from nose is larynx
Lower respiratory tract- trachea to alveoli
Conduction zones- function of getting air in and out of lungs, warms and filters air. Eg nose pharynx, larynx, trachea, bronchi
Respiratory zone- gas exchange at alveoli, alveolar duct
Functions of respiratory system?
Filter, humidy and warm air Gas exchange Get air in and out of lungs Expel waste products Speech Smell
What are the lungs like?
Two cone shaped organs protected by ribs, sternum and vertebrae.
Divided into regions of lobes, left 2 right 3 lobes
Protected by double layered protective membrane. Called the pleurae. One layer covering the lungs is visceral pleurae, and one covering walls of thorax is the parietal pleurae.
Thin layer between there is pleural fluid
What is the equation of respiration and what is internal respiration?
Glucose + oxygen = atp co2 and water
C6h12o6 + 6o2 = 2900kj 6h2o 6co2
Internal respiration is the process where oxygen is unloaded by the tissue capillaries and taken up by tissue cells and the reverse happens with co2
External respiration - gaseous exchsange in lungs
Pulmonary ventilation - action of breathing inspiration and expiration
Co2 carried as carbonic acid in blood (co2 and h2o)
What helps diffusionim alveoli
Large s a
Thin permeable membrane over short distance
High conc diff
Extensive blood supply surrounding alveoli
Describe the alveoli and linings of the airways
Sac like alveoli has 2 types of cells, simple squamous epithelial, thin, and cuboidal epithelial which secrete pulmonary surfactant, which is made from phospholipids and proteins, lowers surface tension allowing them to inflate after exhalation, and prevents them collapsing
Alveolar gas exchange occurs
From nose to larynx theres pseudostratified columnar, cilitated epithelial,
Bronchioles have cuboidal epithelial with cilla, taking mucus to larynx.
Goblet cells- mucus
Larynx- epiglottis
Trachea bronchi- c shaped cartilage rings
The process of inspiration and expiration?
Inspiration is active , ribs move up and out, diaphragm curves down.
Expiration is passive and relies on muscle relaxation and elastin recoil. Diaphragm relaxes and intercostal muscles relax. Down and in.
Due to pressure and volume changes.
Nerve supply of the muscles in respiration
Intercostal muscles- intercostal nerves
Diaphragm - phrenic nerves
How is breathing respiration regulated?
Central chemoreceptors in the medulla respond to lowering of PH due to co2 increase in cerebrospinal fluid, which gets in through blood brain barrier. As a rise in Co2, lower the PH.
Peripheral chemoreceptors in aorta and carotid bodies detect change in co2 and falls in o2 in blood.
Both chemoreceptors Stimulate respiratory centre in medulla oblongata and pons, they increase depth and rate of breathing, which lowers co2 level.
What happens in brain stem respiratory centre?
Chemoreceptors to respiratory centre to lungs
Areas referred to as medullary rhythmicity area
1- dorsal respiratory group in medulla integrates chemoreceptor info and signals VRG
2 - ventral respiratory group in medulla is the basic rhythm generator
3- apneustic centre - in pons helps regulate depth and rate of inspiration
4- pneumotaxic respiratory group - involved in regulation of apneustic centre and medullary rhythmicity area
What is lung compliance and lung surfactant?
Lung compliance is a measure of how easy it is to inflate the lungs due to elastic
Surfactant- in alveoli allow the walls to be separated and stretch. Acts as a detergent in lowering surfactant tension. Increases lung compliance
What 3 ways can airway resistance be increased b
Inflammation, mucus in excess, bronchi constriction
What drugs can cause the respiratory system to be depressed?
Opoids, eg anthistamines may cause sneezing, congestion and mucus
What are macronutrients??
Macronutrients are nutritional components that are required in large amounts and provide energy
Carbs energy
fats energy
fatty acids proteins energy and growth and repair
What are micronutrients ?
What are fat soluble and water soluble vitamins?
Dietary components required in small amounts like minerals and vitamins. Not produced in the body.
Fat soluble vitamins (ADEK)
Can be stored in liver
Water soluble vitamins include vitamin B complex and vitamin C
What are the function of fat soluble ( ADEK)
And water soluble (B C)
A- important roles in embroyonic development, organ formation, eye development
D- absorption of calcium and healthy bones
E- antioxidant which protects cell membrane helps to maintain healthy skin, eyes and strengthens immune system.
K- synthesis of blood clotting proteins
B complex- metabolism and energy production from carbohydrates fat and protein. Role in cell division and growth
C- cofactor in enzyme controlled reactions, important for collagen synthesis and healthy connective tissue, helps wound heal
Clinical manifestations of dehydration? 3 ways
Fall in blood pressure - reduction in cardiac output
Fall in capillary refill time- rate at which blood refills capillaries is slower than norm. Less fluid in blood means the time it takes for pad to return to normal colour following release of pressure is longer.
Reduction in skin turgor- lack of water in dermis so fold of skin will take longer to come back to normal position when pinched
Identify the two sources the kidney gets blood from?
Receives 1.5 litres of blood every minute from hepatic portal vein from the gut, and hepatic artery
Definition of digestion?
The process where large, complex substances are broken down in to small, simple substances that can be easily absorbed
What two things is the digestive system made up of?
The digestive tract - stomach, intestines, rectum, mouth, oesophagus,
Accessory organs - liver, pancreus, gall bladder, salivary glands
What organ location in abdominal cavity??
Right upper-liver, pancreas, gall bladder, transverse colon
Left upper- stomach, transverse colon, pancreas, spleen
Right lower- ascending colon, small intestine
Left lower- descending colon, small intestine, sigmoid colon
What is ingestion,propulsion, elimination?
Ingestion- mouth
Propulsion- movement by peristalsis, oesophagus, stomach, small i
Elimination - anus and rectum
What are the functions of saliva from salivary glands, and what enzyme is in saliva
Amylase enzyme that initiates starch digestion
Saliva has an antibacterial effect as the enzyme lysozyme destroys bacteria
Saliva washes away food that can be a source of bacteria
Saliva acts as a buffer as it contains bicarbonate which neutralises acid preventing dental cavities
What are the four layers of the gi tract wall lumen?
Mucosa
Submucosa
Muscularis
Serosa
What is a bolus? And process of swallowing?
A bolus is a ball of food formed during mastication, and directed around the mouth by the toungue until swallowed, where it moves from the mouth to the pharynx into the oesophagus. Epiglottis is important to prevent food entering trachea
What is the inner lining of the gi tract called and its function?
Mucosa- inner layer made from epithelial tissue. Subjected to wear and tear as in direct contact with food. Its thick epithelial in places like the rectum, mouth
The second layer of gi tract and its characteristic?
Sub mucosa - loose connective tissue contains nerves, blood and lymph vessel, blood supply enables nourishment of tissues and serves for transport products of digestion.
What two things is the digestive system made up of?
The digestive tract - stomach, intestines, rectum, mouth, oesophagus,
Accessory organs - liver, pancreus, gall bladder, salivary glands
What organ location in abdominal cavity??
Right upper-liver, pancreas, gall bladder, transverse colon
Left upper- stomach, transverse colon, pancreas, spleen
Right lower- ascending colon, small intestine
Left lower- descending colon, small intestine, sigmoid colon
What is ingestion,propulsion, elimination?
Ingestion- mouth
Propulsion- movement by peristalsis, oesophagus, stomach, small i
Elimination - anus and rectum
What is the inner lining of the gi tract called and its function?
Mucosa- inner layer made from epithelial tissue. Subjected to wear and tear as in direct contact with food. Its thick epithelial in places like the rectum, mouth
What is a bolus? And process of swallowing?
A bolus is a ball of food formed during mastication, and directed around the mouth by the toungue until swallowed, where it moves from the mouth to the pharynx into the oesophagus. Epiglottis is important to prevent food entering trachea
What are the four layers of the gi tract wall lumen?
Mucosa
Submucosa
Muscularis
Serosa
What are the functions of saliva from salivary glands, and what enzyme is in saliva
Amylase enzyme that initiates starch digestion
Saliva has an antibacterial effect as the enzyme lysozyme destroys bacteria
Saliva washes away food that can be a source of bacteria
Saliva acts as a buffer as it contains bicarbonate which neutralises acid preventing dental cavities
The second layer of gi tract and its characteristic?
Sub mucosa - loose connective tissue comtaines nevres, blood and lymph vessel, blood supply enables nourishment of tissues and serves for transport products of digestion.
3rd and 4th layer of gi tract?
Muscularis- 2 layers of muscular layer smooth muscle.
Circular and longitudinal muscle with nerves In-between.co ordinated contraction allows for peristalsis. In mouth, pharynx and upper part of oesophagus contains skeletal muscle involved in voluntary swallowing.
Serosa- outer coat for protection. Loose fibrous tissue containing blood vessels, nerves and lymph vessels.
What is the oesophagus and characteristics?
Connects the pharynx to the stomach.
Mucus cells in mucosa allow to line airways.
Circular and longitudinal muscle in muscularis layer allows for peristalsis for bolus
Oesophagus has upward curve as it goes through diaphragm to prevent food going back into oesophagus once it has entered the stomach. Also there is a cadiac spincter which opens and closes to prevent reflux.
What is the 3 parts of the stomach?
Fundus by the cardiac sphincter
The body middle part
Antrum lower part by the pyloric sphincter
Characteristics of stomach?
Folds in mucosa and submucosa allow it to expand, also has gastric pits that secrete diff substances in to the stomach.
Eg goblet cells mucus to coat lining of stomach
G cells produce gastrin hormone for gastric juices
Patietal cells produce hydrochloric acid and intrinsic factors for absorption of vit B
Muscle longitudal and circular muscle in muscularis layer allows it to churn and mix the food with gastric juices producing chyme.
Small amounts of chyme are squirted through the pyloric sphincter into small intestine
Parts of the small intestine??
Duodenum - contains glands which secrete alkaline mucus which neutralises acidic chyme. Also large ducts from major accessory organs
Jejunum- follow duodenum its 2.5 metres long
Ileum - 3.5 metres long attached to large intestine at the ileocaecal sphincter
Simple sugars, amino acids and fatty acids absorbed by diffusion and active transport.
What happens at large intestine??
From ileocaecal valve to rectum prevents back flow to small i Absorption of water and electrolytes Storage and elimination of faeces Bacteria produce vitamins Bacteria digest some polysaccharides
No villi and food no longer in a chyme
Mucus cells in mucosa layer to facilitate passage of faeces and protect the walls.
Flatus is produced from bacterial fermentation of carbs
What is the functions of the liver, and how this contributes to homeostasis?
Storage - iron, glycogen (glycogenesis) fat soluble vitamins (ADEK)
Regulation, synthesis and secretion - bile, cholesterol, clotting factors (prothrombin) and plasma proteins
Purification - red blood cells, transformation of drugs in to water soluble, and breakdown of amino acids into co2’ water, energy and ammonia, but that is toxic so turns in to urea which is then transported to kidney to be eliminated
Fighting infections - kupffer cells. That destroy any bacteria
What is the liver made up from?
Liver lobules cylindrical 2mm diameter
Hepatocytes which carry out metabolic functions
Sinusoids
Stellate cells involved in fibrosis and formation of scar tissue in response to liver damage
Central vein in the centre of lobule, with cords of hepatocytes radiating out. In spaces between hepatocytes there are cells of sinusoids which are think walled blood vessels lined with epithelial and kupffer cells (macrophages which remove ages red blood cells, bacteria and debris)
3 vessels around the edge of each lobule, bile duct, hepatic portal vein and hepatic artery.
Function of bile produced by kidney?
Emulsifies fat particles, large s a allows lipase enzymes secreted in pancreatic juice to digest lipids
Waste products from haemoglobin, like bilirubin and excess cholesterol are excreted in bile.
What is the composition of bile?
Water, mineral salts, mucus, bile salts, cholesterol
What is the functions of the liver, and how this contributes to homeostasis?
Storage - iron, glycogen (glycogenesis) fat soluble vitamins (ADEK)
Regulation, synthesis and secretion - bile, cholesterol, clotting factors (prothrombin) and plasma proteins
Purification - red blood cells, transformation of drugs in to water soluble, and breakdown of amino acids into co2’ water, energy and ammonia, but that is toxic so turns in to urea which is then transported to kidney to be eliminated
Fighting infections - kupffer cells. That destroy any bacteria
What is the liver made up from?
Liver lobules cylindrical 2mm diameter
Hepatocytes which carry out metabolic functions
Sinusoids
Stellate cells involved in fibrosis and formation of scar tissue in response to liver damage
Central vein in the centre of lobule, with cords of hepatocytes radiating out. In spaces between hepatocytes there are cells of sinusoids which are think walled blood vessels lined with epithelial and kupffer cells (macrophages which remove ages red blood cells, bacteria and debris)
3 vessels around the edge of each lobule, bile duct, hepatic portal vein and hepatic artery.
Function of bile produced by kidney?
Emulsifies fat particles, large s a allows lipase enzymes secreted in pancreatic juice to digest lipids. Has bile salts made from cholesterol which act like detergents and break down the bile
Waste products from haemoglobin, like bilirubin and excess cholesterol are excreted in bile.
What is the composition of bile?
Water, mineral salts, mucus, bile salts, cholesterol
What is the process in to the small intestine??
Bile is concentrated and stored in the gall bladder
After a meal is eaten fatty acids in duodenum stimulate endocrine cells to release hormone cholecystokinin (CCK)
CCK produced in the walls of duodenum stimulates the smooth muscle of the gall bladder to contract allowing bile to be released in to the duodenum
Definition of a drug?
And define pharmacokinetics?
A drug is any substances used for treatment (antibiotics), relief, diagnosis (barium) or as a preventative of disease. (Warfarin)
How the body deals with the drug
What are the two types of administration?
Enteral refers to anything involving the gi tract from mouth to rectum, oral, rectal,
Parenteral means to avoid the gut, any other method away from the gi tract eg injections, topical ,vaginal
What are the 4 processes of pharmacokinetics?
Administration
Distribution
Metabolism
Elimination
What is drug absorption?
The process from administration through till the time it reaches the tissues and is available for use
Maybe involve having to get in to circulation but not in cases of topical, inhalation. Drugs must be converted to soluble state through dissolution
What factors effect drug absorption?
Drug prep - how quick it disintegrates, tablets, capsules
Interactions - ph, stomach contents
Physiological factors - individual factors as to how quick the drug moves through digestive system. Due to age, diarrhoea
Administration route, dosage and drug
What is distrubtion of drug and what is meant by unbound free drug?
Distribution is when drug absorbed in blood stream is distributed to its site of action
Only unbound drug molcules and freely diffusible can diffuse out of capillaries in to tissues. This drug are carried in blood ina simple solution, - free drug
Mot free drug are bound to plasma albumins so cant exert its effects
The conc of bound drug depends on ph, presence of other drugs, conc of plasma proteins and drug
What is drug metabolism?
Transforming the drug so it is more water soluble and can be excreted , at the liver mainly, or can be kidneys, lungs and plasma
The liver attempts to break the drugs down in to parts so it can be eliminated. Metabolised in to inactive metabolites
What is the first pass effect in the metabolism of drug in liver?
First pass effect is the effect liver metabolism has upon the drug during its first passage through the liver, and how much is inactive
Determines the half life, amount of drug reaching general circulation and whether it undergoes bio transformation. Which is the conversion of molecules from one form to another within an organism
What is bio transformation?
Conversion of molecules from one form to another within an organism. Pro drugs go from inactive to active during bio transformation
What is excretion of drugs?)
Active or inactive drugs removal from site of action, by kidneys, skin, lungs, bladder , liver
What is bioavailability?
The fraction of am administered dose of the drug that reaches the systemic circulation
What is modified release drugs and its benefits?
Modified release preps are designed to slowly release drug into the gi tract over a period of time ,
Dose frequency is reduced
Less peaks and troughs in plasma levels so more sustained therapeutic effect
Peak plasma level is reduced so less side effects
In what proteins do drugs exert their effects??
Receptors, enzymes, ions and carrier transport molecules
What 4 ways do drugs tend to work??
Replace missing chemicals or act as their substitutes
Stimulate particular cell activities
Slow down or inhibit cell activities
Interfere with the function of foreign cells
What is a ligand?
Collective name for a chemical that binds to a receptor eg hormones, neurotransmitters
What are the drugs that target receptors classified as??
Antagonists and agonists
What is drug affinity ?
Interaction between the drug and the binding site, the closer the fit and greater number of bonds , the higher the affinity for the drug for the receptor
What are agonists?
When The drug has the same effect on the receptor as the natural substance that normally binds to receptor. Can increase or decrease cell activity
What is an antagonist? What are the two types?
When the bound drug blocks the binding sites of the natural substance and so prevent its effects. Get competitive (irreversible and reversible) and non competitive
What two sorts of drugs work by enzyme??
NSAIDS - non steroidal anti inflammatory drugs , inhibit enzyme COX cyclooxygenase , responsible for making chemical mediators including prostaglandins, which play a key role in inflammation and pain
Acteylcholinesterase inhibitors - Alzheimer’s
Acetylcholine is a neurotransmitter that improves memory , inhibit acetylcholinesterase enzyme that breaks down acetylcholine in synaptic cleft so more acetylcholine left for memory
What drug is used as an example of how drugs affect transport carriers?
Selective serotonin re-uptake inhibitors (SSRI) which prevent re uptake of serotonin from synaptic cleft back in to ore synaptic cleft - so more chance of the serotonin receptor being activated - mood enhancement
What examples of drugs that effect ion channels?
Calcium channel blocker - vasodilator reducing peripheral resistance
Sodium channels for propagation of the action potential along axon
Potassium channel - prolong repolarisation
GABA -reduces excitability in the cns
