Transport in Animals

Question 1

Features + purpose of ARTERIES

Answer 1

1. Carries blood away from heart!
2. Small lumen = mantains high blood pressure, Thick walls = withstands high blood pressure
3. Inner Wall (tunica intima)&raquo_space; innner elsatic tissue layer: allows recoil + strecth for pressure, Middle layer (tunica media)&raquo_space; mid layer of smooth muscle, Outer layer(tunica adventitia)&raquo_space; thicker collagen and elsatic tissue!

Question 2

Features + purpose of ARTERIOLES

Answer 2

1. Carries blood FROM ARTERIES TO CAPPILERIES!
2. CAN CONTRACT = able to regulate blood flow, directing O2 to areas of greater demand…

Question 3

Features + purpose of Cappileries

Answer 3

1. Carries blood to tissue fluid from arterioles!
2. VERY Small lumen = 1 RBC thick, hence RBC squshed to very surface, reducing diffusion distance of O2 + nutrients into tisse fluid
3. Porous, leaky walls = allows blood plasma to leave blood into surrounding tissue!

Question 4

Features + purpose of Veins and Venules

Answer 4

1. Carries blood towards the heart!
2. Large lumen = ease of blood flow in low pressure, Valves = prevents blood backflow due to low pressure
3. venules(not many more special features…..

Question 5

Define Oncotic and Hydrostatic Pressure?

Answer 5

1. O = pressure inflicted by osmotic movements with solutes
2. H = Where a fluid will exert a force against container/vessel sides

Question 6

Define Tissue fluid and Lymph

Answer 6

1. simply the fluid that surrounds tissues and cells near the cappileries
2. made up of EXCESS TISSUE FLUID, drained from cappileries site into lymphatic system

Question 7

Differences/Similarities with Tissue Fluid and Blood Plasma…

Answer 7

1. Blood plasma = Travels in bloodstream, contains all plasma protiens, bloodd cells, nutrients and dissolved gasses
2. Tissue Fluid = leaks from CAPPILERIES to SURROUNDING tissues, containing the dissolved gasses not protiens, but returns to CARRIES WASTE PRODUCT back into bloodstream!

Question 8

Process of forming Tissue Fluid!

Answer 8

1. Oxygenated blood moves to arteriole opening, with LARGE HYDROSTATIC PRESSURE via Left Ventricle!
2. Hydrostatic > Oncotic pressure, hence plasma will move from** capilleries to surrounding** tissue via small openings
3. Net Flow of fluid will move OUT, carries o2 and nutients along with it

Question 9

Process of returning Tissue Fluid to Plasma!

Answer 9

1. Tissue fluid moves back to cappileries, with SAME ONCOTIC PRESSURE via LOWER HYDROSTATIC PRESSUE!
2. ONCOTIC > HYDROSTATIC pressure, hence plasma will move from tissue fluid to cappileries via small openings
3. Net Flow of fluid will move IN, carries co2 and urea and waste product along with it

Question 10

Common misconception with Hydrostatic and Oncotic pressure changes in cappileries?

Answer 10

1. ONCOTIC PRESSURE will remain the SAME on bBOTH ENDS of cappileries, while HYDROSTATIC PRESSURE will be the one that CHANGES
2. Therefore, this will determine the direction of fluid movement in and out of cappilieries
3. Hence, PLASMA PROTIENS help to determine WATER POTENTIAL GRADIENT (oncotic pressure…), as too large to pass through cappiliers walls

Question 11

Name all valves in Ventricles, and Blood Vessels in the Heart!

Answer 11

1. Left Side = Mitral Bicuspid Valve into Aortic Semi-Lunar Valvle
2. Right Side = Tricuspid Valve into Pulmonary Semi-Lunar Valve

Question 12

Purposes of Atria and Ventricles of the Heart!

Answer 12

1. Atria = To push blood into the ventricles, after recieving from veins!
2. Right V = will pump deoxygenated blood into lungs
3. Left V = pumps oxygenated blood AROUND BODY (hence, THICKER!!)

Question 13

Define Cardiac Cycle, and stages in ORDER

Answer 13

1. sequence of contactions and relaxions per full heatbeat, of heart chambers
2. Atrial and Ventricular DIASTOLE, Atrial Systole then Ventricular Systole

Question 14

What occurs during Atrial and Ventricular Diastole??

Answer 14

1. Muscular walls RELAX via Elastic Recoil, pressure LESS than surrounding veins, blood flows into ATRIA
2. Atrio-Ventricular valves open (mitral bicuspid/Tricuspid)

“CHILL AND FILL” stage!

Question 15

What occurs during Atrial Systole??

Answer 15

1. Atria contracts, pressure increases as blood flows into ventricles!
2. Mitral Bicuspid/ Tricuspid valves close as ventricles fill!

Question 16

What occurs during Ventricular Systole??

Answer 16

1. Contracts from ventricle base, pressure increases in ventricles, GREATER PRESSURE THAN the ATRIA
2. Semi-Lunar valves will OPEN, blood moves upwards into arteries from ventricles
3. Semi-Lunar Valves CLOSE AGAIN as ventricles begin to relax and decrease in pressure, and cycle occurs over again…….

Question 17

What causes the pulse in head/neck we feel?

Answer 17

when AORTIC SEMI-LUNAR VALVE closes, and a large pressure changes takes place!

Question 18

heart graphing, Ms P HUGE catchup, book notes and texbook details

CHECK ABOUT SEPERATING CARDS INTO CERTAIN DECKS!!

Question 19

How can we describe the Pressure Graph of Heart Chambers

Answer 19

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!!

Question 20

How can we describe Heart Muscle?

Answer 20

1. This is myogenic!, self-able to contract, independant of nervous system, initiating own muscle contraction!

Question 21

Why does the cardiac cycle require coordination?

Answer 21

1. to ensure that a regular intrinsic rhythm is mantained within the heart, allowing for healthy blood circulation!

Question 22

What is the order of electrical coordination of Cardiac Cycle

Answer 22

1. 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
2. The Annulus fibrosus is a region of non-conducting tissue which prevents the depolarisation spreading straight to the ventricles
3. Instead, the depolarisation is carried to the atrioventricular node (AVN), a region of conducting tissue between atria and ventricles
4. 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

5. 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.
6. The Purkyne fibres spread around the ventricles and initiate the depolarization of the ventricles from the apex of the heart allowing for ventricle contraction!

Question 23

Hoe does an ECG work?

Answer 23

1. Sensors in the skin will record electrical exitations initiated by the heart, and gives a reading..

Question 24

How can we describe PQRSTU waves on ab ECG?

Answer 24

1. P = atrial systole due to depolarisation in the atria, via The sinoatrial node [SAN] (small initial lump)
2. QRS Complex = ventricle systole due to depolariation in ventricles via atrioventricular node [AVN] (much larger spike and fall)
3. T = Ventricular diastole due to rpolarisation of ventricles!
4. U = unknown [repolarisation of Purkyne Fibers….?]

Question 25

Define the following: ***Brachycardia, Tachycardia, Fibrillation-Artia, Ectopic Heartbeat***

Answer 25

**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*]

Question 26

How can we explain the **Lub-Dub** sounds of heartbeat..?

Answer 26

1. ***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. 2. ***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.

Question 27

What is Haemoglobin, and what is it **made** of?

Answer 27

1. **Quaternary-structure conjugated protien**, made of 4 polypeptide chains *2 alpha and 2 beta*, EACH bound to a heam group, main role to CARY O2 MOLECULES! 2. Haem group consists of **Fe2+ ion as PROSTHETIC GROUP!** 3. **Each haem groups can bind to 1** oxygen molecule = **1 haem molecule carries 4** o2 molecules!!

Question 28

**Define method of unit** measuring and attraction for O2 and CO2

Answer 28

1. **partial pressure** = p(o2) 2. amount of gas pressure exerted relative to all other gasses present in mixture 3. AFFINITY = a stronger atraction to something!

Question 29

How does **haemolgloin bind to o2?**

Answer 29

1. **Association** of o2 at alveoli, and **dissociation** at respiring cells 2. This is a reversible process, allows for the dis/asociation...

Question 30

Describe the **Oxygen Dissociation** curve..

Answer 30

1. ***Beginning*** = at **low** p(o2), Hb lowest affinity to O2, more difficult for O2 to bind 2. ***Mid*** = **increasing** p(o2), Hb increases in affinty for O2, more O2 binding increases tendancy for EVEN MORE O2 to bind! 3. ***End*** = **highest** p(o2), Hb highest affinty for 02, max saturatioon = no more incersesing affinty as result (limiting factor)

Question 31

Describe and Explain **Adult and FETAL** haemoglobin

Answer 31

1. **Fetal** = relies on MOTHERS blood supply for O2 2. p(o2) in placenta will be low, as most is used by mothers respiring cells... 3. **FETAL HAEM** = MUCH HIGH AFFINITY for O2 at lower p(o2), to allow o2 binding for O2 at such low p(o2) (survival)

Question 32

Define **myoglobin!**

Answer 32

1. molecule **similar in structure to haemoglobin**, with only a ***SINGLE haem group!*** 2. very high O2 affinty, found mostly in cardiac muscle.... 3. oxymyoglobin able to dissociate at a lower p(o2)....

Question 33

How does CO2 diffuse into RBCs from tissue fluid...

Answer 33

1. CO2 diffuses into RBC, reacting with water to form *CARBONIC ACID*, via enzyme ***carbonic anhydrase***! 2. *Carbonic acid* will then dissociate into H+ ions and HCO3- bicarbonate ions, where H+ ions bind to Hb to from ***Haemoglobinic Acid*** 3. ***Conformational change in tertiary structure of haemoglobin*,** with haem groups with **LOWER AFFINTY** as a result (for o2)

Question 34

Explain what and why **Chloride Shift occurs!**

Answer 34

1. Due to *hydrogencarbonate ions leaving RBCs* into blood plasma, chloride ions will *move INTO rbcs*, to mantain charge and pH levels!

Question 35

What really is the **Bohr Effect? [explained]**

Answer 35

1. Where **haemoglobin is in a region of high p(CO2), O2 dissociation curve will be shifted to** ***RIGHT!*** [compounding effect] 2. *Higher* p(CO2) = *lower* O2 affinity! 4. CO₂ dissolves in the blood – It reacts with **water to form carbonic acid (H₂CO₃), which then dissociates into hydrogen ions** (H⁺), lowering the blood pH. 5. Haemoglobin responds – The low pH causes haemoglobin to change tertairy structure shape, **reducing its affinity** for oxygen. 6. Oxygen is released – Because haemoglobin **has less affinity for O2**, it is more readily released to the respiring tissues. 7. Oxygen ***dissociation curve shifts right*** – meaning Hb needs a higher (pO₂) to remain saturated!

Question 36

Linking benefits of the **Bohr Effect? [explained]??**

Answer 36

* Whereever tissues contract **MOST**, CO2 will be released, **IN TURN, more H+ ions dissociating from carbonic acid** (upon reacting with water..) * ***Further reduces affinty fro O2 in Hb***, meaning dissociation of O2 is increased at such region, beneficial!