Transport in Animals Flashcards
the way us animals harness the breeezy goodness...
Features + purpose of ARTERIES
- Carries blood away from heart!
- Small lumen = mantains high blood pressure, Thick walls = withstands high blood pressure
- Inner Wall (tunica intima)»_space; innner elsatic tissue layer: allows recoil + strecth for pressure, Middle layer (tunica media)»_space; mid layer of smooth muscle, Outer layer(tunica adventitia)»_space; thicker collagen and elsatic tissue!
Features + purpose of ARTERIOLES
- Carries blood FROM ARTERIES TO CAPPILERIES!
- CAN CONTRACT = able to regulate blood flow, directing O2 to areas of greater demand…
Features + purpose of Cappileries
- Carries blood to tissue fluid from arterioles!
- VERY Small lumen = 1 RBC thick, hence RBC squshed to very surface, reducing diffusion distance of O2 + nutrients into tisse fluid
- Porous, leaky walls = allows blood plasma to leave blood into surrounding tissue!
Features + purpose of Veins and Venules
- Carries blood towards the heart!
- Large lumen = ease of blood flow in low pressure, Valves = prevents blood backflow due to low pressure
- venules(not many more special features…..
Define Oncotic and Hydrostatic Pressure?
- O = pressure inflicted by osmotic movements with solutes
- H = Where a fluid will exert a force against container/vessel sides
Define Tissue fluid and Lymph
- simply the fluid that surrounds tissues and cells near the cappileries
- made up of EXCESS TISSUE FLUID, drained from cappileries site into lymphatic system
Differences/Similarities with Tissue Fluid and Blood Plasma…
- Blood plasma = Travels in bloodstream, contains all plasma protiens, bloodd cells, nutrients and dissolved gasses
- Tissue Fluid = leaks from CAPPILERIES to SURROUNDING tissues, containing the dissolved gasses not protiens, but returns to CARRIES WASTE PRODUCT back into bloodstream!
Process of forming Tissue Fluid!
- Oxygenated blood moves to arteriole opening, with LARGE HYDROSTATIC PRESSURE via Left Ventricle!
- Hydrostatic > Oncotic pressure, hence plasma will move from** capilleries to surrounding** tissue via small openings
- Net Flow of fluid will move OUT, carries o2 and nutients along with it
Process of returning Tissue Fluid to Plasma!
- Tissue fluid moves back to cappileries, with SAME ONCOTIC PRESSURE via LOWER HYDROSTATIC PRESSUE!
- ONCOTIC > HYDROSTATIC pressure, hence plasma will move from tissue fluid to cappileries via small openings
- Net Flow of fluid will move IN, carries co2 and urea and waste product along with it
Common misconception with Hydrostatic and Oncotic pressure changes in cappileries?
- ONCOTIC PRESSURE will remain the SAME on bBOTH ENDS of cappileries, while HYDROSTATIC PRESSURE will be the one that CHANGES
- Therefore, this will determine the direction of fluid movement in and out of cappilieries
- Hence, PLASMA PROTIENS help to determine WATER POTENTIAL GRADIENT (oncotic pressure…), as too large to pass through cappiliers walls
Name all valves in Ventricles, and Blood Vessels in the Heart!
- Left Side = Mitral Bicuspid Valve into Aortic Semi-Lunar Valvle
- Right Side = Tricuspid Valve into Pulmonary Semi-Lunar Valve
Purposes of Atria and Ventricles of the Heart!
- Atria = To push blood into the ventricles, after recieving from veins!
- Right V = will pump deoxygenated blood into lungs
- Left V = pumps oxygenated blood AROUND BODY (hence, THICKER!!)
Define Cardiac Cycle, and stages in ORDER
- sequence of contactions and relaxions per full heatbeat, of heart chambers
- Atrial and Ventricular DIASTOLE, Atrial Systole then Ventricular Systole
What occurs during Atrial and Ventricular Diastole??
- Muscular walls RELAX via Elastic Recoil, pressure LESS than surrounding veins, blood flows into ATRIA
- Atrio-Ventricular valves open (mitral bicuspid/Tricuspid)
“CHILL AND FILL” stage!
What occurs during Atrial Systole??
- Atria contracts, pressure increases as blood flows into ventricles!
- Mitral Bicuspid/ Tricuspid valves close as ventricles fill!
What occurs during Ventricular Systole??
- Contracts from ventricle base, pressure increases in ventricles, GREATER PRESSURE THAN the ATRIA
- Semi-Lunar valves will OPEN, blood moves upwards into arteries from ventricles
- Semi-Lunar Valves CLOSE AGAIN as ventricles begin to relax and decrease in pressure, and cycle occurs over again…….
What causes the pulse in head/neck we feel?
when AORTIC SEMI-LUNAR VALVE closes, and a large pressure changes takes place!
heart graphing, Ms P HUGE catchup, book notes and texbook details
CHECK ABOUT SEPERATING CARDS INTO CERTAIN DECKS!!
How can we describe the Pressure Graph of Heart Chambers
Bottom Line = Atrial Pressure detected, mini-dip: atrioventricular valves close, mini-rise as they OPEN
Hill Line = Ventricular Pressure detected, steep rise during ventricular systole, steep fall as diastole occurs
Top Line = Arterial Pressure detected, as rise occurs, semi-lunar valves open, closes at falling end.
ONE CYCLE PER GRAPH READING!!
How can we describe Heart Muscle?
- This is myogenic!, self-able to contract, independant of nervous system, initiating own muscle contraction!
Why does the cardiac cycle require coordination?
- to ensure that a regular intrinsic rhythm is mantained within the heart, allowing for healthy blood circulation!
What is the order of electrical coordination of Cardiac Cycle
- The sinoatrial node (SAN) is a group of cells in the wall of the right atrium. The SAN initiates a wave of depolarisation that causes the atria to contract
- The Annulus fibrosus is a region of non-conducting tissue which prevents the depolarisation spreading straight to the ventricles
- Instead, the depolarisation is carried to the atrioventricular node (AVN), a region of conducting tissue between atria and ventricles
- After a slight delay , the AVN is stimulated and passes the stimulation along the bundle of His
slight delay due to allowing ventricle to fill completly with blood, contracting AFTER atria
- The bundle of His is a collection of conducting tissue in the septum. The bundle of His divides into two conducting Purkyne fibres, and carries the wave of excitation along.
- The Purkyne fibres spread around the ventricles and initiate the depolarization of the ventricles from the apex of the heart allowing for ventricle contraction!
Hoe does an ECG work?
- Sensors in the skin will record electrical exitations initiated by the heart, and gives a reading..
How can we describe PQRSTU waves on ab ECG?
- P = atrial systole due to depolarisation in the atria, via The sinoatrial node [SAN] (small initial lump)
- QRS Complex = ventricle systole due to depolariation in ventricles via atrioventricular node [AVN] (much larger spike and fall)
- T = Ventricular diastole due to rpolarisation of ventricles!
- U = unknown [repolarisation of Purkyne Fibers….?]
Define the following: Brachycardia, Tachycardia, Fibrillation-Artia, Ectopic Heartbeat
B = Much slower heartbeat rhythm
T = Much faster heartbeat rhythm
FA = Atria beating more frequently than ventricles, uncoordinated heartbeat rhythm
EH = additonal/lack of ventricle beating [skipped heartbeats]
How can we explain the Lub-Dub sounds of heartbeat..?
- Lub = This occurs during ventricular systole, when the AV valves close, meaning pressure created by ventricular contraction forces the blood against the closed AV valves, generating the characteristic “lub” sound, during pressure changes.
- Dub = This occurs during ventricular diastole, when the semilunar valves close, as the ventricles relax, pressure in the aorta and pulmonary artery is higher than in the ventricles, leading to the closure.
This prevents the backflow of blood into the ventricles and produces the sounds.
