Circulatory & Immune Sys

science is killing me

Blood flow through heart

Deoxygenated blood—vena cava—RA—tricuspid—RV—pulm. SL valves—pulm. Trunk—pulm. Arteries—lungs—pulm. veins—LA—bicuspid—LV—aortic SL valves—aorta

Arteries (& aterioles)

Carry blood away from heart

Capillaries

Allow exchange of materials with tissues

Veins (& Venules)

Return blood to heart

Arteries

-Leaves ventricles with high BP towards tissue of body
-Thick walls w/ 3 layers (inner, middle, outer)
-have muscle cells & elastic givers that maintain BP b/t pumps
-Expand to accommodate sudden increase in blood volume after heartbeat

Arterioloes

-small arteries
-constrict or dial are, adjusting blood pressure (more dismayed= lower BP)

Capillaries

-microscopic, one cell layer thick (permeable walls: allow exchange of O2/CO2 and nutrients/wastes)
-in all regions of body
-can divert blood from a triple to venue (bypass capillary)

Venules

-drain blood from capillaries
-joint to form vein

Vein

-brings blood back to atria at low BP
-also 3 layers but middle layer much thinner
-contain valuables that ensure circulation & prevent backward flow of blood

Hypertension

-Heart disorder
-abnormally high BP (140/90)
-causes: sedentary life style, salty + fatty diet, alcohol, tobacco, medications, secondary diseases
-no actual symptoms
-"silent killer" not detected until stroke or heart attack
-diastolic pressure is emphasized

Atherosclerosis

-accumulation of fatty materials (particularly cholesterol)
-deposits (plaque) protrude into vessel interfering with blood flow
-begins early adulthood develops through middle age
-diet low in saturated fat and cholesterol
-plaque causes clot on wall = THROMBUS
-clot dislodges = EMBOLUS
-must treat thromboembolism

Stroke

-associated with hypertension and atherosclerosis
-portion of brain died due to lack of oxygen
-small arteriole bursts or blocked by embolus paralysis or death
-warning: numbness in hands or face, difficulty speaking, temp blindness in one eye

Heart attack

-associated with hypertension and atherosclerosis
-portion of heart muscle dies due to lack of O2
-coronary artery blocked due to atherosclerosis: suffer ANGINA PECTORIS (symptoms are left pain in arm)
-when coronary artery is completely blocked due to thromboembolism = heart attack

Anigoplasty

(Treatment for blocked coronary artery)
Clear clogged arteries by threading plastic tube into artery of arm or leg through towards heart

-when it meets plaque region in coronary artery ballon inflates forcing vessel open
-vessel may not remain open or may cause clots to form

Coronary bypass surgery

(Treatment for blocked coronary artery)
Take segment of another blood vessel and stitch one end to aorta and other coronary artery past point of obstruction

Varicose veins

abnormal and irregular dilations in superficial veins
most common in legs

-when valves beckons weak and ineffective due to backward pressure of blood
-aggravated by crossing legs or sitting in chair with edges pressed on back of knees
-in rectum = HEMORRHOIDS

Adrenal glands

Adrenaline, estrogen + testosterone

Pancreas

glucagon and insulin

Ovary

Estrogen + progesterone

Cerebrum

Upper part of brain, higher level of thinking

Cerebellum

Little brain, balance + coordination

Central nervous system

brain and spinal cord

Peripheral nervous system

nerves outside the brain and spinal cord

Somatic nervous system

Communicated with sense organs and voluntary muscles

Autonomic nervous system

Communicates with internal organs and glands

Sensory (afferent) nervous system (sensory input)

Part of somatic nervous system. Includes sensory organs
-eyes, nose, ears, mouth, skin

Motor (efferent) nervous system (motor output)

Part of somatic nervous system
-muscles

Parasympathetic division (calming)

Part of automatic nervous system
-"housekeeper"
-ex low HR, pupils constrict

Sympathetic division (arousing)

Part of automatic nervous system
-fight/flight/freeze
-Ex. Increase HR, sweat, adrenaline, increase BS and BR, pupils dialate

Cardiac Cycle

-series of events that occur over duration of 1 heartbeat
-periods of contraction & relaxation
-2 atria contract simultaneously
-2 ventricles contract simultaneously
-all chambers relax

Systole (contracting)

-bld returning to heart flows into A & V's, b/c pressure in them is lower (low blood volume)
-when V's ~70% full, atria contract (atrial systole), incr. press in atria, force blood into V
-V's contract, ventricular pressure > atrial, AV valves close to prevent back flow (LUB)
-both sets of valves closed, pressure builds in contracting ventricles (isovolumetric contraction)
-when V press > aortic press, aortic SL valve opens releasing blood into aorta

Diastole (relax)

-blood exits V and down aorta, ventricular press falls bc no bld inside (just emptied)
-V press < aortic press, aortic SL valve closes to prevent back flow (DUB)
-V press drops below A press, AV valve opens and blood flows from A to V (repeat)

Atrial systole

Chambers: A contract, V relax
Blood flow: A—> V
Valves: AV open, Aortic SL closed

Ventricular systole

Chambers: A relaxed, V contract
Blood flow: V—> aorta
Valves: AV closed, Aortic SL open

Diastole

Chambers: A & V relaxed
Blood flow: into A & V
Valves: AV open, aortic SL closed

Cardiac output

-amount of blood pumps through circ sys in 1 min
-good indicator of heart efficiency

Cardiac Output = Heart Rate X stroke volume

Heart rate

-number of contractions /min
-typical pulse rate is 60-100 bpm
-determined by feeling of expansion & recoil of artery (side off reaches)
-can be affected by:
-exercise, age, disease, temp, emotional state
-changes in stroke volume will be
compensated by heart rate

-aortic arch (first part of aorta) has aortic bodies which contains nerve receptors sensitive to O2 and CO2 content in blood
-maintains homeostasis, change HR and BP

Increased heart rate

sympathetic nervous system
-releases neurotransmitter no adrenaline (aka norepinephrine)

Decreased heart rate

Parasympathetic nervous system NS (vague nerve)
-release nt acetylcholine

Stroke volume (70mL)

-amount of blood pumped to body with each beat of heart
-can be affected by:
-volume of blood in body
-contractility of heart
-level resistance from blood vessels

Cardiac conduction system

-contraction of myocardium is myogenic (signal initiated by heart muscle not brain signal)
-nodal tissue (cluster of cells) found in 2 regions

SA (sinoatrial) node

Upper dorsal wall of right atrium

AV (atrioventricular) node

Base of right atrium near septum

Atrial contraction

Primary pacemaker (70bpm)
-SA node initiated heartbeat, sends out excitation impulse every 0.85 seconds (70.6 bpm)
-causes atrial systole (contraction)

Ventricular contraction

Secondary pacemaker (40-60 bpm)
-AV node sends signals down septum via bundle of HIS to innervate nerve fibres called Purkinje fibres (3 pacemaker)
-ventricular systole (from apex first to squeeze up to arteries)

Diastole

-A & V relax
-period of insensitivity to stimuli aka. Refractory period
-relatively long to allow heart to refill, prevents fatigue

Atrial relaxation/d is hidden by large QRS wave

Electrocardiogram

-measured with electrocardiograph which generates ECG
-pattern has atrial & ventricular phase
-P wave: excitation & contraction of atria
-QRS wave: excitation & contraction of atria
-T wave: recovery of ventricles

P-wave

-depolarization of atria
(Atrial contraction systole)

QRS wave

-depolarization of ventricles (ventricular contraction/ventricular systole)

T wave

-repolarization of ventricles (ventricular relaxation/diastole)

P-R interval

Blood flows A—>V

S-T interval

Blood flows V—> aorta/pulm. Arteries

Normal sinus rhythm

Complexes normal, evenly spaced. Rate 60-100 bpm

Arrhythmia

All complexes normal, rhythm irregular

Bradycardia

Complexes normal, evenly spaced. Rate < 60 bpm, slower than normal.
(Artificial pacemaker)

Tachycardia

Complexes normal. Evenly spaced. Rate > 100 bpm, faster than normal m

Atrial fibrillation

Baseline irregular. Ventricular response irregular

Ventricle fibrillation

Rapid. Wide irregular ventricular complexes

Artificial pacemaker

-externally programmable (cardiologist can adjust w/o going back in)
-treats: arrhythmias, bradycardia, tachycardia

Defibrillation

-treat life threatening cardiac conditions (atrial + ventricular fibrillation)
-fibrillation is when the heart muscles convulse spasmodically
-applies controlled electrical current through heart
-depolarize heart tissue in an attempt to stop unsynchronized contractions
-tried to re-establish normal rhythm

Coronary occlusion

-partial or complete obstruction (usually plaque) of bld flow in coronary artery
-may cause heart attack (cardiac attack)

Thrombosis

-formation of clot within a bld vessel
-in arteries when damaged, cholesterol deposits forming

Atherosclerosis

-fat deposits reduce diameter of lumen of bld vessel leads to hypertension
-restrict bld flow, increases BP, damage walls of artery
-damage repaired by fibirous tissue, reduce elasticity + stick out into lumen

Thrombus

-clot on wall
-dislodges from wall

Embolus

-(moves through circ. System)
-block bld flow to various organs
-brain —> stroke
-heart —> cardiac arrest
-lungs —> pulmonary embolism
-legs —> DVT (deep vein thrombosis)

Coronary heart disease (CHD)

-when arteries of heart can't bring enough O2
-consequences of atherosclerosis
-risk factors: same if hypertension
-leads to heart attacks
-signs: chest pain, cold sweats, dizzy/nausea, weakness, shortness of breath

Blood

-transports molecules (nutrients, amino acids, monosaccharides, nucleotide, O2, CO2, hormones, antibodies, waste, urea) to and from capillaries
-involved in fluid, ion and pH balance
-guard (WBC's) body against microbes (bacteria)
-clots

Blood composition

-all blood cells originate from stem cells (able to differentiate into any type of cell) in bone marrow
-if left (or centrifuged (spin machine) blood will separate into 3 things

Formed elements

(Blood composition)
-low layer
-45% total volume of blood
-consist of 3 things
A) erythrocytes: red blood cells
B) leukocytes: white blood cells
C) thrombocytes: platelets

Plasma

(Blood composition)
-55% total volume of blood
-various inorganic & organic substances dissolved or suspended in water

Erythrocytes

-made in bone marrow of skull, ribs, vertebrae & ends of long bones
-4-6 million per mm3 of blood
-20-39 trillion RBC's in body at one time
-each contains ~200-270 million hemoglobin molecules (red pigment)

-1 Hb has 4 polypeptide chains
-each chain associated with heme
-iron portion of hemoglobin binds oxygen in lungs and gives it up in tissues
-incr. oxygen-carrying capacity of bld by more than 60 times
-assist in transporting CO2

-no nucleus, Nixon cave in shape
-lives 100-120 days (90 in newborns)

Erythropoiesis

Process of making RBC (7 days)

Anemia

Insufficient number of RBC or not enough hemoglobin
-tired, run down
-iron deficiency anemia: change diet
-pernicious anemia: SI can't absorb vit B12
-essential to proper formation of RBC
-sickle cell anemia: genetic disorder

Leukocytes

-larger, have nucleus, no hemoglobin
-white in colour
-fight infection
-made in bone marrow
-lives days, months or years
-divides into 2 groups

Neutrophil

Granular leukocytes
multi lobed nucleus (polymorphonuclear)
-most abundant WBC
-phagocytize & digest bacteria/fungi

Basophil

Granular leukocyte
-release histamines (cause inflammation)

Eosinophil

Granular leukocytes
Digest larger particles

Thrombocytes (platelets)

-not complete cells
-fragments of megakaryocytes present only in bone marrow
-200 billion produced a day
-involved in blood clottong

Plasma proteins

-albumin (transport), globulins, fibrinogen (clotting), immunoglobulins (able to help fight infection)

Fibrinogen

-protein manufactured by liver

Prothrombin

-protein manufactured by liver
-required vit K for production

Partial seal

Platelets clump at site in blood clotting

First line of defence

-non-specific defence method

A. Skin
-protect external structures

B. Mucous membranes
-protects internal structure (externally available)
-secretions contains lysozymes (cause lysis)
-may be cilia to remove pathogens

Second line of defence

-non-specific (innate immunity) defence mechanisms
-always have same response

Phagocytotic leukocytes (aka macrophages)

Second line of defence
-circulate blood by move to body tissue in response to infection
-damaged body cells release chems (histamine), draws WBC's to site infection (via chemotaxis) macrophages then concentrate at site of infection
-pseudopodia (cellular extensions) surround/engulf pathogens, form internal vesicle—> phagocytosis

Inflammatory reaction

-4 signs due to histamine (cause capillaries to incr)
-redness, heat, swelling, pain

Natural killer cells (cytotoxic T-cells)

-kills virus infected cells & tumour cells
-identifies cells by markers

Third line of defence (adaptive immune system)

-coordinated by lymphocytes
-recognize/respond to diff types of microorganisms & have memory

B lymphocytes (B cells)

Antibody- producing cells, develop in bone marrow, produce highly specific antibody

Self cells (body cells)

-all uncleared cells of body have unique, distinctive molecules
-markers= MHC class 1
-immune system doesn't normally react to them

Non-self cells (foreign)

-trigger immune response
-recognize by antigens by lymphocytes
-lymphocytes bind to shape of epitope (exposed) porion

Antigens

-substance that body recognize as foreign, can evoke immune response
-activated B lymphocytes

Antibody

-antibodies are produced by B lymphocytes or plasma cells in response to antigen

-structure:
-4 polypeptide chains (2 light 2 heavy)
-forms Y shaped molecule
-ends or arms/variable regions: where antigens bind
-each type of antibody recognized unique antigenic fragment

Blood pressure

-the force of the blood against blood vessel walks
-greatest when ventricles contracting
-change in SV affects BP
- normally measured on brachial artery of arm

Active immunity

Due to production of antibodies by organism itself after defence mechanisms stimulated by antigens

Passive immunity

Due to acquisition of antibodies from another organism in which active immunity has been stimulatef

Vaccinations

-induce artificial active immunity
-stimulating production of memory cells
-contains weakens forms of pathogens
-trigger secondary immune response
-produce long term immunity

HIV (human immunodeficiency virus)

-retrovirus (genetic info is RNA instead of DNA) infects helper T cells
-reverse transcriptase allows viral DNA to be produced from RNA code, integrated into host cells genome

Lysogenic life cycle

Years of inactivity (infected T cells have been reproducing, virus become active and spreads destroying T cells in process)

Antibiotic

-kill/slow microbe growth
-kill bacteria by targeting prokaryotic metabolism w/o harming host