Ib Biology HL - Transport B2.3

what gets transported by respiratory system

• water

• glucose

• haemoglobin ( oxygen and CO2 )

• Urea

• hormones

• immune cells

• heat<

components of blood

• water ( plasma )

• platelets/ thrombocytes - blood clotting

• erythrocytes - CO2 and O2 transport

• leukocytes ( white blood cells )

arteries

• oxygenated blood

• high pressure

• small lumen thick wall

arteries parts

• inner layer: tunica intima; endothelium ( thin layer of flat cells )

• middle layer: tunica media => withstand high blood pressure. contain thick smooth circular muscles ( vasoconstriction ) and elastic fibers

• tunica externa: tough outer layer made of connective tissue and collagen fiber. can withstand the pressure

veins parts

• inner layer: tunica intima; endothelium ( thin layer of flat cells ). reduces friction

• middle layer: tunica media => withstand high blood pressure

• tunica externa: tough outer layer made of connective tissue and collagen fiber.

• valves: prevent blood from flowing backwards

veins

• deoxygenated blood

• lower blood pressure

• large lumen

• smaller tunica media

• when muscles contract, they exert pressure on them and it allows it to move

capillaries

• low pressure

• large sa

• diameter of only ten micrometers => only one erythrocyte=> blood slows down and allows that more time is present for exchange

• fenestrations in areas where diffusion has to occur really quickly

• thin walls for short diffusion pathway

• endothial cells

occlusion of coronary arteries

• can be narrowed or blocked by atheroma, made of lipids such as cholesterol

• restriction of blood flow => increases risk of thrombosis

• if calcium deposits occurs, can harden

• heat attacks

name for cardiac muscle cell

cardiomyocytes

mammalian heart adaptations

• impulses of myogenic origin=> they are autogenerated, not from brain

• 3D, interconnected branching fibers; shared plasma membrane called sarcomena; electrical impulses are progagated and shared

• many mitochondria and capillaries

• sinoatrial node; mass of specialised cardiac muscle cells which generate electric impulses at given intervals ( act like pacemaker ) => their sarcomeres are the first to depolarise in the heart

myogenic

impulses which can trigger contractions independently of motor neurons

Process of atrial systol

• Sinoatrial node (upper right atrium) generates impulse → spreads across atria → atria contract, pushing blood through atrioventricular valves into ventricles.

• Impulse reaches Atrioventricular node (lower right atrium) → short delay allows ventricles to fill.

• Impulse travels down the bundle of His in the interventricular septum.

• Impulse spreads via Purkinje fibers through ventricular walls → ventricles contract, forcing blood through semilunar valves into arteries.

• Diastole → heart relaxes → atrioventricular valves reopen → blood flows into ventricles.

what is tissue/interstitial fluid

formed from blood plasma pushed through capillary walls into surrounding tissues. facilitates the exchange of substances between the blood and the cells. Pushed out by hydrostatic pressure on capillary wall

chemical signals (inflammation ) occurs when there is infection, which are detected by white blood cells which go through capillary walls

how does the xylem transport water

• unidirectional transport of water

• possible due to the process of transpiration (loss of water from stomata), which creates negative pressure gradient outside the leaf, pulling water through the xylem

• capillary action (cohesion and adhesion )

exchange of substances blood vessels/tissue fluid/tissues

• nutrients/hormones/oxygen gets passively or actively transported from tissue fluid to tissue

• so low nutrient concentration in tissue fluid at arterial end, causes diffusion from blood plasma, which again go into tissue

• waste products move from cells to fluid, so concentration of waste higher in fluid than in plasma, which causes it to diffuse out

what is IN tissue/interstitial fluid

contains ions, hormones and nutrients. plasma proteins, platelets and red blood cells are too small to pass through capillary walls. immune cells can also be present in cases of inflamation

lymph

a small amount of tissue fluid will not go back to blood, and will go to the lymphatic capillaries and become lymph. it transports immune cells, proteins, and contains dendritic cells

adaptations for gas exchange flowering plants

• large surface area: leaf and spongy parenchyma

• guard cells at stomata; prevents water loss when high temperature

plan diagram

type of drawing; doesn’t show individual cell, each line shows difference between 2 tissues. have to be at scale, no gaps between lines. labelling lines have to be done by ruler, and horizontal

root pressure plants

• positive pressure potential

• created by active transport of mineral ions

• which decreases water potential in root cells

• drawing water in through osmosis

• creates hydrostatic pressure which pushes contents of xylem upwards

Stomata

pore which allows water vapour and other gases to enter the plan. has guard cells which swell up to close, happens at night and when dehydration

adaptations of xylem

• formed from dead specialised cells which lost their content, becoming hollow

• cells are joined together by pits, areas with thinner cell walls + no lignin. allows movement

• made of lignin, complex waterproof polymer ( impermeable ), in ring or spiral structure, which give strength and rigidity

• contain no cytoplasm

sources plants

any part of a plant which produces/ releases carbon compounds ( ie root tubers release carbon compounds in winter )

sinks plants

any part of a plant which stores or consumes carbon compounds

translocation

• process of transporting carbon compounds from source to sink through phloem

• active transport into phloem

• decreases water potential, which causes osmosis from xylem, increasing pressure

• this pressure causes pushing effect, moving sap along the phloem towards the sink

• when at sink, carbon compounds get active transported out, increasing water potential, making it osmose to phloem, decreasing pressure

• bidirectional

phloem structure

• formed of sieve tube elements ( individual cells )

• attached through perforated walls called sieve plates ( sap can flow)

• contain only some cytoplasm and mitochondria, but no nucleus, vacuole, cytoskeleton or ribosomes so more space=> atypical cell structure

• require companion cells

• have plasmodesmata with companion cells; holed plant junction for nutrient transport and communication

plants compagnion cells

• many mitochondria, produce most ATP necessary for active transport metabolism of sieve tube elements

• and help unloading of carbon based at sink with passive or active transport

mass flow plants

movement of both water and solutes together in phloem

dicotyledonous plants

have two embryonic leaves (cotyledons) in the seeds

epidermis of plants

• outermost layer of tissue

• one cell thick ( usually )

• in stem, have a cuticle ( waxy layer which prevents water loss )

• in roots, absorbs water and mineral from soil from root hairs ( increase sa )

• veins ( for transport of water

vascular bundles plants

made up of xylem and phloem

xylem more central while phloem closer to epidermis

stele plants

location of vascular bundle in root

the cambium plants

thin layer of cells which are actively dividing between xylem and phloem which can differentiate between the two types of vascular cells

cortex plants

between vascular bundles and epidermis

provides structural support, storage, and potential photosynthesis

advantages of double circulary system

high oxygen concentration all throughout

factors which affect transpiration

Light, temperature, humidity, and wind.

difference in gas exchange between flowering plant and mammal