the Heart Flashcards
Cardiovascular system circuit
pulmonary circuit
systemic circuit
Pulmonary circuit
carries blood to the lungs for gas exchange and returns it to the heart.
- Right side of the heart
- delivers oxygen and nutrients
- Picks up CO2 and waste
systemic circuit
Supplies blood the every organ of the body including other parts of the lungs and the wall of the heart itself
- Left side of heart
- Leaves by aorta route
Mediastinum
Undelineated group of structures in the thorax, surrounded by loose connective tissue. It is the central compartment of the thoracic cavity.
Mediastinum
Contains the heart, the great vessels of the heart, the esophagus, the trachea, the phrenic nerve, the cardiac nerve, the thoracic duct, the thymus, and the lymph nodes of the central chest
Artery
High Pressure vessel
carries oxygenated blood from the heart to the body (red)
Vein
Blood reservoir Carries oxygen-depleted blood back to the Heart. (blue) -Capacitance vessels -thin wall and flacid -expand easily- increase blood flow -Valves present to prevent regutgitation
Capillary
-Exchange vessel (e.g. nutrients, wastes, hormones)
-Most abundant of all B.V.
2 types
-Fenestrated
-Continuous
Regurgitation
The Backward flow of blood
Continuous Capillary
Capillary type
- Made up of endothelium (no muscle)
- Cells held together by tight junctions
- More wide spread
- Most tissues, skeletal muscle
Fenestrated Capillary
Capillary type
- Made up endothelium (no muscle)
- Filtration slits/openings that allow rapid passage of small molecules
- Retain most prtns & large particles in B,steam
- kidneys, endocrine glands, small intesine
3 layers of a B.V.
Tunica interna (intima) Tunica media Tunica externa (adventitia)
Tunica Interna
Layer of BV
(Intima)
-Made up of simple squamous (endothelial) tissue
-Smooth surface promotes laminar flow
-Clotting factors increase resistance to flow
-Selective permeable barrier- chem. that dilate or constrict of the vessel
Tunica Media
Layer of BV
- smooth muscle
- beta rec- promote relaxation-> vasodialation
- inc. B.flow, dec. B. Press
- Alpha rec.- contraction-> vasoconstriction
- Dec.B. flow, inc. B. Press
Tunica Externa
Layer of BV
Adventitia
-loose aereolar C.T
-anchors vessel and provides passage for small nerves, lymphatic vessels ->supply passage for small nerves
Arteries
3 types
Large (conducting/ elastic)
Medium (Distributing/ muscular)
Small (Resistance)
Large artery
(conducting/ elastic)
- the biggest
- Aorta, pulmonary trunk/artery, carotid, subclavian artery
- Have smooth muscle
- internal elastic lamina- promote stretching and recoil
Large artery
- expand during ventricular systole and recoil during diastole
- recoil between H.beats prevent BP drop
Medium artery
Distributing/ muscular
- Small branches take oxygenated Blood to specific organs
- skeletal muscle, kidneys
- very abundant
Medium artery
- No elastic tissue
- smooth muscle so amnt of blood reaching organ can be controlled
Small artery
Resistance artery
- Arteriole
- High resistance Vessels (small Diameter)
- little elastic tissue
- thick tunica media
Arterial receptors
Send info to medulla oblongata (in braun stem)
- Baro receptors
- Chemo receptors
Baro receptors
Arterial receptors
Carotid sinuses
-Pressure sensors that respond to change in BP
-Cranial nerve IV (9) that sends info to M.O.
-Glossypharyngeal
Chemo receptors
Arterial receptors
responds to chemicals
-CN IV(9), X(10) vagus
types of Veins
Post capillary veules
Medium veins
Large veins
Post capillary veins
Type of veins
- Smallest vein
- receive blood from capillaries
- leukocytes can emigrate (Diapetesis) in to & out of B vessels
Medium vein
Type of vein
- Little more muscular than venules
- Effective in skeletal pump
Large vein
Type of vein
- Empty in to heart ->vena cavea
- some smooth muscle on tunics
- vena cavea, pulmonary veins, internal jugular vein, renal vein
Anastomoses
A point where two B.V. merge and combine their blood stream or where two nerves or ducts converge
Venus Anastomoses
one vein empties directly into another
-provide alternative routes of drainage from an organ to prevent blockage
Arterial Anastomoses
Two arteries merge, provide collateral (alternative) route of blood supply to a tissue.
Autorhythmicity
heart muscle cells or neurons, that show rhythmic activity without being driven by rhythmic external stimulation.
Pacemaker cells
pecialized cells that cause involuntary muscles and tissues to contract or dilate.
-Found in all involuntary muscle groups, including both striated and smooth tissues.
systole
The contraction of any heart chamber
-ventricular contraction
Diastole
Period in which a heart chamber relaxes and fills with blood
-ventricular relaxation
Cardiac arrhythmia
Any abnormal cardiac rhythm
-heart block
Heart block
Cardiac arrhythmia
- failure of any part of the cardiac conduction system to transmit signals
- result of disease and degeneration of cond. sys fibers
Bradycardia
Slows HR- Adult HR below 60
Distance between waves are greater
-common during sleep and in endurance athletes
Tachycardia
Faster HR-Adult HR above 100
Distance between sets of waves are closer
-Caused by stress, anxiety, drugs, H disease
Stroke Volume
The volume of blood ejected by one ventricle of the heart in one contraction
Cardiac output
The amount of blood pumped by each ventricle of the heart in one minute
End diastolic volume
The volume of blood in each ventricle at the end of diastole,
-About 120–130 mL but sometimes reaching 200–250 mL in the normal heart.
End Systolic Volume
The volume of blood remaining in each ventricle at the end of systole,
-about 50–60 mL but sometimes as little as10–30 mL in the normal heart.
Atrial Reflex
increase in heart rate due to an increase in central venous pressure
Frank starling principle
States that SV is proportional to EDV
- Ventricles then to eject as much blood as they receive
- with in limits–> the more they are stretched the harder they contract on the next beat
