How many chromosomes does each cell have?
46. 23 from mother 23 from father. Sex cells have 23 all others have 46.
Who studies the effects of disease and injury on individuals?
Physicians and other clinical practitioners.
Who studies the effects of disease on a group or population?
i.e Rheumatic diseases (auto-immune, body over-reacting or attacking itself). Rheumatic Fever, Allergies, Asthma
- Alpha cells: create glucagon, glucose
- Beta cells: create insulin
- Somatomatic cells: regulate Alpha and Beta cells
Type I: Usually before age 40, sometimes in childhood. Pancreas produces no or very little insulin due to Beta cell disfunction. Take Insulin daily. Family history related. 20% of diabetics
Type II: Usually after age 40. More family related. Decrease in insulin production or ineffective insulin receptors. Diet/obesity related. Can be controlled with excercise and oral medication. 80% of diabetics
Hemophilia: Bleeding disorder causes by genetic clotting factors. Serious bruising, bleeding can occur.
Hemochromatosis: Excessive accumulation of iron in the blood causing weight loss, joint pain and abdominal pain.
Anemia: Reduction in the number of red blood cells. Hemolytic anemia (red blood cell destroying)
Neurological disorder which results in uncontrollable jerking or spasming of muscles.
A chronic inflammation of the wall of the digestive tract that usually affects the small intestine, large intestine or both. Unknown cause.
Affects 1% of the world's population. Loses contact with reality and suffers from hallucinations, delusions, abnormal thinking and disrupted social function.
Inflammation of the gallbladder that usually results from a gallstone.
The supplying of oxygen and nutrients to the body tissues as a result of the constant passage of blood through the capillaries.
Inadequate perfusion of the body tissues resulting in an inadequate supply of oxygen and nutrients to the body tissues. Also called Shock
Components of the circulatory system
- The pump (Heart)
- The fluid (Blood)
- The container (Blood Vessels)
Receives blood from the veins, pumps it to the lungs for oxygenation and then pumps it to the peripheral tissues.
- The amount of blood ejected by the heart in one contration.
- Factors affecting it include:
- -Cardiac Contractile Force
Typically around 70 ml in an adult male.
The amount of blood delivered to the heart when the heart fills with blood between contractions (diastole)
Cardiac Contractile Force
The strength of the contraction of the heart. Uses Frank-Starling Mechanism. Also effected by catacholamines (epinephrine and norepinephrine)
Determines Contractile Force. The more preload the more the heart stretches thus increasing the amount of force when release. Similiar to a rubber band. The more force the harder the heart pumps.
Epinephrine and Norepinephrine. Hormones which strongly affect the nervous and cardiovascular systems, metabolic rate, temperature and smooth muscle actions. They enhance cardiac contractile strength by action on the beta-adrenergenic receptors on the cell surfaces.
The resistance a contraction must overcome in order to eject blood. Tension of the cardiac muscle during contraction (Systole)
The amount of blood pumped by the heart in one minute. Stroke Volume X Heart Rate.
Peripheral Vascular Resistance
The resistance of the vessels to the flow of blood. Increases when vessels constrict, decreased with vessels relax.
Receptors located in the Aortic Arch and Carotid Sinuses which closely monitor blood pressure signalling the brain if it leaves normal limits.
Composed of 54% plasma (92%water), 45% Hematocrit (Red Blood cells), 1% white blood cells and platelets. Transports oxygen, CO2 and other nutrients.
Precapillary and Postcapillary Sphyncters
Valves before and after the capillary beds which regulate the rate at which blood enters and leaves the capillaries.
Natriuretic Peptides (NPs)
Peptide hormones synthesized by the heart, brain and other organs with effects that include excretion of large amounts of sodium in the urine and dilation of the blood vessels. Atrial Natriuretic Peptide (ANP) Brain Natriuretic Peptide (BNP).
- Movement and use of Oxygen is dependent on:
- -Adequate concentration of inspired oxygen
- -Appropriate movement of oxygen across the capillary/alveolar bed into the arterial blood
- -Adquate number of red blood cells to carry oxygen
- -Proper tissue perfusion
- -Efficient off-loading of oxygen at the tissue level
CO2 is carried by the blood away from the cells and exhaled. About 70% is transported as HCO3- (Carbonic Acid).
Causes of Hypoperfusion
- Inadequate Pump (Cardiogenic Shock)
- -Inadequate preload
- -Inadequate cardiac contractile strength
- -Inadequate heart rate
- -Excessive afterload
- Inadequate Fluid (Hypovolemic Shock)
- -Hypovolemia (Low volume of circulating blood)
- Inadequate Container (Distributive/Neurogenic Shock)
- -Dilated container without raise in fluid volume
- -Leak in container
Anaerobic and Aerobic Metabolism
- Stages of the cells metabolism
- Anaerobic: The first stage of metabolism where the cell does not use oxygen. Uses gycolysis to break down glucose which produces pyruvic acid and yields very little energy.
Aerobic: Second stage of metabolism which the cell uses oxygen to break down glucose. Uses pyruvic acid (turned into citric), oxygen and glucose in the Krebs (citric acid) cycle. Yields high amounts of energy.
Causes of shock at the cellular level
Impaired use of Oxygen: Not receiving it or unable to use it effectively. Usually do Anaerobic then Aerobic Metabolism. Without oxygen can only do Anaerobic which yields very little energy.
Impaired use of Glucose: Caused by similiar means as oxygen deprivation. Without glucose cells start to convert glycogen to glucose in a process called glycogenolysis. After glycogen is depleted they start to produce glucose from proteins and lipids in a process called gluconeogenesis. These processes use alot of energy and contribute to cell death.
Stages of Shock
- Body activates several systems when it senses dropping blood pressure. Sympathetic nervous system stimulates adrenal gland and releases catecholamines (epi and norepi).
- Also the renin-angiotensin system goes into action. Renin is released from the kidneys into circulation. Renin acts on specialized plasma proteins called angiotensis to produce angiotensin I which is then converted into angiotensin II by angiotensin converting enzyme (ACE). Angiotensin II is a potent vasoconstrictor which attempts to raise blood pressure.
- Also, the pituitary glands release anti-diuretic hormone (ADH) which causes the Kidneys to retain more water keeping it in the circulation in an effort to raise BP.
Advanced stages of shock when the body's compensatory mechanisms are no longer able to maintain adequate perfusion. This is where there is a drop in blood pressure and the pulse climbs and then will drop as the heart begins to lose strength and effectiveness. This leads to irreversible shock if not treated quickly.
Shock that has progressed so far that no medical intervention can reverse the condition and death is inevitable.
Types of Shock
Shock caused by insufficient cardiac output. The inability of the heart to pump enough blood to perfuse all the parts of the body. Caused by Myocardial infarction or any other issue with the heart itself.
- Shock due to loss of intravascular fluid volume.
- Caused by:
- -Internal or external hemorrhage (aka Hemorrhagic shock)
- -Traumatic injury
- -Long-bone/open fractures-
- -Severe dehydration
- -Plasma loss from burns
- -Excessive sweating
- -Diabetic ketoacidosis with resultant osmotic diuresis
- (increased urination and dehydration due to high levels of glucose that cannot be reabsorbed into the blood from the kidney tubules causing a loss of water into the urine)
Shock resulting from brain or spinal injury that causes an interruption of nerve impulses to the arteries with loss of arterial tone, dilation and relative hypovlemia.
Caused by anaphylaxis. A life threatening allergic reaction. Caused by a foreign substance entering the body causing the body to over react to it and attempt to rid itself of it. Causes bronchoconstriction, vasodilation and other life threatening issues.
Begins with septicemia (sepsis), an infection which enters the bloodstream and is carried throughout the body. Shock sets in when the toxins brought by the infection overwhelm the body's compensatory mechanisms. Can cause MODs
Multiple Organ Dysfunction
- Progressive impairment of two or more organ systems resulting from uncontrolled inflammatory response to a severe illness or injury. Infection->Sepsis->Septic Shock->MODS->Death (if not corrected)
- After 24 hours: Low grade fever, tachycardia, dyspnea, altered mental status, pulmonary failure