Examide 5mg Medical Background
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Transcript of Examide 5mg Medical Background
Prepared ByGeorge Shafik
Product Manager
Examide 5mg
Medical Background
Agenda
The Hypertension 4
The Cardiovascular System 1
Arterial Blood Pressure 2
The Urinary System 3
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1The Heart
2
The Vessels
3Endothelium
The heart is a hollow cone-shaped muscle located between the lungs and behind the sternum.The heart is a double pump organ.It contains 4 chambers:(2 atria + 2 ventricles).The right side receives deoxygenated blood from the tissues & pumps it to the lung.The left side receives oxygenated blood from the lung & pumps it to the body.
1The Heart
The heart has three layers.
1The Heart
• The smooth, inside lining of the heart.
Endocardium.
• The middle layer of heart muscle.Myocardium.
• The sac filled with a fluid Surrounding the heart
Pericardium.
The Heart has 2 Ventricles & 2 Atria.
1The Heart
• 2 Chamber at the upper part of the heart (right & left).
2
Atria
• 2 Chamber at the lower part of the heart (right & left).
2
Ventricles
Each chamber has a sort of one-way valve at its exit that prevents blood from flowing backwards.
When each chamber contracts, the valve at its exit opens.When it is finished contracting, the valve closes so that
blood does not flow backwards.
1The Heart
•The pulmonary valve The exit of the right ventricle. •The mitral bicuspid valve The exit of the left atrium.
•The aortic valve The exit of the left ventricle.•The tricuspid valve The exit of the right atrium.
The Heart Beats
1The Heart
When the heart muscle contracts (Systole)Then the heart muscle relaxes (Diastole)
The heart contracts in two stages:
1. The 2 atria contract at the same time, pumping blood to the ventricles.
2. Then the 2 ventricles contract together to pump the blood out of the heart.
The Cardiac Cycle
1The Heart
The Cardiac Cycle
The Cardiac Cycle
1The Heart
1. Blood returns to the heart → fills the atria → pressure against atrioventricular valves→ forced to be open.
2. Blood fills the ventricles (ventricular filling) [Mid diastole].
3. Atria contract → forcing additional blood into ventricles [late diastole].
The Cardiac Cycle
1The Heart
4. Blood returns to the heart → fills the atria Ventricles contract (ventricular systole) → forcing the blood against AV valves → AV valves close [Isovolumetric ejection phase] → papillary muscles contract & cordae tendinae tighten preventing valves from everting into atria → intraventricular pressure rises →blood is pushed against semiluner valves (aortic, pulmonary) →forced to be open [Ventricular ejection phase]
5. As ventricles relax → intraventricular pressure falls → semilunar valves close [Early diastole].
The Cardiac Electrophysiology
1The Heart
• Heart beats 60-80 times / min.• Alternative contractions (systole) & relaxation (diastole).• This is due to 3 fundamental electrophysiological properties:
Automotricity.Excitability (SA node, AV node)Conductivity (AV bundle, bundle branches,
Purkinje fibers).• The cardiac muscle has an intrinsic ability to depolarize &
contract.• Nodal system initiates and distributes impulses through the
heart, so that the myocardium depolarizes and contracts in an orderly sequential manner
The Cardiac Electrophysiology
1The Heart
The proper function of the cardiac muscle requires oxygen & nutrients.
The Coronary Circulation
• A very high flow• Filling up occur during diastole.• Any blockage of coronary arteries can be
serious & in some cases fatal
Nutrition of the heart
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Sympathetic innervations• Its stimulation lead to Positive actions
(frequency, contraction, excitability & conduction)Parasympathetic innervations
• Its stimulation lead to Negative actions (frequency, contraction, excitability & conduction)
Innervations of the heart
1The Heart
The blood vessels (Arteries, Veins & capillaries).
2
The Vessels
The Structure:• Tunica Intima.• Tunica Media.• Tunica Adventitia.
2
The Vessels
• Form a selective barrier.• Are metabolically active.• Contain converting enzyme.• Release vasoactive substances.
3Endothelium
Agenda
The Hypertension 4
The Cardiovascular System 1
Arterial Blood Pressure 2
The Urinary System 3
• The force of the blood against the walls of the artery.
• The force applied against the walls of the arteries as the
heart pumps blood through the body.
• The pressure is determined by the force and amount of
blood pumped and the size and flexibility of the arteries.
1Definition
Peripheral resistance The force applied against the walls of the arteries
Blood Pressure= Cardiac Output X Peripheral Resistance
Cardiac Output = Heart rate X Stroke Volume
Blood Pressure = Heart Rate X Stroke Volume X Peripheral Resistance
Craniological Concepts2
Blood pressure in arteries is greater than in veins & systemic blood pressure is higher than pulmonary blood pressure.
When we talk about blood pressure we mean systemic arterial blood pressure.
Systolic blood pressure refers to the pressure of blood in the artery when the heart contracts. It is the top (and higher) number in a blood pressure reading and it ranged between (90 – 140 mmHg).
Diastolic blood pressure refers to the pressure of blood in the artery when the heart relaxes between beats. It is the bottom (and lower) number in a blood pressure reading and it ranged between (60 – 90 mmHg).
3 Physiological variation of arterial blood pressure
Normal blood pressure is not fixed figure , there is normal variability between different individuals & varies in the same person under different circumstances
3 Physiological variation of arterial blood pressure
B.P. variation depends upon some factors:1. Age: blood pressure increase by age (New born
80/40), (4 years 100/65),(adult 120/80) .
2. Sex: (males more than females) before age 45 years old.
3. Emotions: stress & Anxiety increases blood pressure.
4. Exercise: increase blood pressure.
5. Salts, Smoking, Coffee, Alcohol
3 Physiological variation of arterial blood pressure
4 Physiological control of blood pressure
Hormones.
RAAS.
Bradykinin.
HumoralRegulation
Sympathetic (Hypertensive action).
Parasympathetic (Hypotensive action).
Baroreceptors
NervousRegulation
Baroreceptor
They are stretch-sensitive mechanoreceptors that form a part of the afferent arm of the baroreflex, which acts as a short-term regulator of heart rate and blood pressure.
Baroreceptor in the human body detect the pressure of blood flowing through them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output.
4 Physiological control of high blood pressure
4 Physiological control of high blood pressure
Agenda
The Hypertension 4
The Cardiovascular System 1
Arterial Blood Pressure 2
The Urinary System 3
The kidneys are two bean-shaped organs located in the posterior part of the abdomen
filter wastes (such as urea) from the blood and excrete them, along with water, as urine.
Above each kidney is an adrenal gland (also called the suprarenal gland)
1The Kidney
The Nephron is the basic functional unit of the kidney ,there are more than a million within the cortex and medulla.
Nephrons regulate water & solute (especially electrolyte).
Nephrons reabsorb some necessary fluid and molecules back into the blood while secreting other.
The Nephron2
The Nephron2
Glomerular Capsule. Proximal tubule.
• Proximal convoluted tubule.• Proximal straight (Descending)
Loop of Henle.• Descending limb (Thin segment).• Ascending limb (Thick segment).
Distal convoluted tubule.
The Nephron2
Responsible for re-absorption of:o2/3 Salts and water.oGlucose and organic acids 100%.oPotassium 65%.oUrea 50%.
Proximal Tubule
The Nephron2
Responsible for re-absorption of:oWater.oPotassium.oNa.oCl.
Distal Tubule
The Nephron2
Is the portion of the Nephron that leads from the proximal convoluted tubule to the distal convoluted tubule.
The main function of this structure is to reabsorb water and ions from urine.
To do this, it uses a countercurrent multiplier mechanism in the medulla.
The loop of Henle
The Nephron2
Divided into 4 parts:1. Descending limb. 2. Thin ascending limb.3. Thick ascending limb.4. Cortical thick ascending
limb.
The loop of Henle
The Nephron2
The loop of Henle Thin ascending limb
not permeable to water, but it is permeable to ions.
Descending limb has low permeability to
ions and urea, highly permeable to water.
Thick ascending (Na+), (K+) and (Cl-) ions are reabsorbed from the urine by
active transport. The electrical gradient drives more Reabsorption of Na+, as well as (Mg2+) and importantly
calcium Ca2+.
Cortical thick as. limbdrains urine into the distal
convoluted tubule.
Agenda
The Hypertension 4
The Cardiovascular System 1
Arterial Blood Pressure 2
The Urinary System 3
Hypertension:defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHga systolic pressure above 140 with a diastolic pressure above 90.
The two major types are: •Primary or essential
hypertension, that has no known cause, is diagnosed in the majority of people.
•Secondary hypertension ,is often caused by reversible factors, and is sometimes curable.
1 Definition &Types of Hypertension
The other types include: •Malignant Hypertension.
•Pulmonary hypertension (hypertension
occurring in the heart-lung arteries).
•Gastrointestinal hypertension (early stages
of high blood pressure during pregnancy).
•Isolated Systolic Hypertension .
•White Coat Hypertension.
•Resistant Hypertension
1Types of Hypertension
Essential hypertension:it is by far the most common type of hypertension, and is diagnosed in about 95 % of cases.Essential hypertension has no obvious or yet identifiable cause.
1Types of Hypertension
Primary Hypertension
Due to:• Kidney damage or impaired function (This
accounts for most secondary forms of hypertension.)
• Tumors or over activity of the adrenal gland • Thyroid dysfunction • Coarctation* of the aorta • Pregnancy-related conditions
1Types of Hypertension
Secondary Hypertension
• The most severe and progressive form of hypertension,. It rapidly leads to organ damage.
• Malignant hypertension is becoming relatively rare, and is not caused by cancer or malignancy.
• Unless properly treated, it is fatal within five years for the majority of patients.
• Death usually comes from heart failure, kidney damage or brain hemorrhage.
1Types of Hypertension
Malignant Hypertension
Hypertension occurring in the heart-lung arteries.
1Types of Hypertension
Pulmonary hypertension
• In this case the systolic blood pressure, (the top number), is consistently above 160 mm Hg, and the diastolic below 90 mm Hg.
• This may occur in older people, and results from the age-related stiffening of the arteries. The loss of elasticity in arteries, like the aorta, is mostly due to arteriosclerosis.
• Treatment starts with lifestyle modification, and if needed, added drugs.
1Types of Hypertension
Isolated Systolic Hypertension
• Anxiety-induced hypertension, it means blood pressure is only high when tested by a health professional. it does not need to be treated. However, regular follow- up is recommended to ensure that persistent hypertension has not developed.
• Lifestyle changes like more exercise, less salt and alcohol, no nicotine and weight loss, would be wise. A low fat, high fibre diet, with increased fruit and vegetable intake, will be beneficial.
1Types of Hypertension
White Coat Hypertension
If blood pressure cannot be reduced to below 140/90 mmHg, despite a triple-drug regime, resistant hypertension is considered.
1Types of Hypertension
Resistant Hypertension
1.Symptoms:• Most people with high blood pressure don't have
any symptoms.• People with severe high blood pressure or a rapid
rise in blood pressure may also experience headaches, blurred or impaired vision, fits or black-outs.
2.Complications:• People with high blood pressure have an increased
risk of major illnesses including:• cardiovascular disease such as angina, stroke, heart
attack or atrial fibrillation • kidney damage • damaged sight
Symptoms & Complications2
Symptoms & Complications2
Low blood pressure.May be a sign of severe disease and requires
urgent medical attention.When blood pressure and blood flow
decrease beyond a certain point, the perfusion of the brain becomes critically decreased (i.e., the blood supply is not sufficient), causing lightheadedness, dizziness, weakness and fainting.
Sometimes the blood pressure drops significantly when a patient stands up from sitting. This is known as postural hypotension; gravity reduces the rate of blood return from the body veins below the heart back to the heart, thus reducing stroke volume and cardiac output.
Hypotension
1. Lifestyle Modification to lower high blood pressure.
2. Medicinal Treatment.
3Treatment of Hypertension
I. Lifestyle Modifications to lower high blood pressure.
1. Lose weight2. Regular physical activity3. Have a low salt intake4. Eat a healthy diet5. Drink alcohol in moderation
If lifestyle changes do not lower the blood pressure enough, Medicinal therapy will begin.
3Treatment of Hypertension
II. Medicinal Treatment.
1. Alpha 2 agonists = central acting.2. Diuretics.3. Beta blockers.4. Ca++ antagonists.5. ACE inhibitors.6. Angiotensin II antagonists (AT1 receptor
blockers).7. Vasodilators.8. Combination therapy.
3Treatment of Hypertension
II. Medicinal Treatment.
1. Alpha 2 agonists = central acting:
(Clonidine and Guanabenz) block the transmission of nerve impulses with the autonomic nervous system, which controls the involuntary action of the heart and blood vessels among other organs.
3Treatment of Hypertension
II. Medicinal Treatment.
2. Diuretics or "water pills”:Increase the elimination of salt and water through urination, thereby lessening blood volume and pressure.
3. Beta-blockers (such as propranolol, atenolol, nadolol, pindolol and
labetolol) lower blood pressure by reducing the amount of blood pumped by the heart.
3Treatment of Hypertension
II. Medicinal Treatment.
4. Calcium-channel blockers (nifedipine, nicardipine, verapamil and diltiazem) relax blood-vessel walls, thereby lowering pressure.
5. Angiotensin Converting Enzyme (ACE) inhibitors (captopril, enalapril and lisinopril) lower blood pressure by blocking the production of a hormone known as Angiotensin, which increases blood pressure.
3Treatment of Hypertension
II. Medicinal Treatment.
6. Angiotensin II receptors blockers. lower blood pressure by blocking the production of a
hormone known as Angiotensin, which increases
blood pressure. 7. Vasodilators
(hydralazine and minoxidil) relax the smooth muscle of the peripheral arteries, which causes them to dilate and so reduce the resistance to blood flow.
3Treatment of Hypertension
Prepared ByGeorge Shafik
Product Manager
Medical Background