lecture 5 animal Flashcards
whenn is diffusion rapid
only over short distances
what is diffusion
molecules move randomly due to their kinetic energy
what does the random movement cause
net flow from an area of high conecntrarion gto an area of low concentration
rate of diffusion is inversely proportional to what and proportional to what
-proportional to surface area (greater SA faster diffusion)
-inversely proportional tp distance (longer distance, slower diffusion)
each cell in a multicellular organism must exchange
molecules with the environment (nitrients, gasses,)
some animals have a body size and shape that
keeps most cells in contact with the environment
– small animals – flat shape –> flatworm – exchanges gasses through both gastrovascular cavity and directly through skin therefore does not need respiratory or circulatory system
larger animals require
a circulatory system – to transport materials between all the body cells and organs that exchange those materials with the enviironment `
materials only need to diffuse over..
short distsnces as they enter or exit circulatory system
what are the three basic components of the circulatory system
circulatory fluid, interconnected vessels, muscular pump
circulatory fluid
– blood in a CLOSE circulatory system – mammals, birds, earthworms, fish, octopus
– hemolymph in OPEN circulatory system – insects, spiders, crabs
closed circulatroy system
fluid is enclosed within vessels and not floating around body
– nutrients have to reach across the interstitial fluid to get to the cells they need
open syatem
mix of blood and lymphatic fluid – open cavities, organs are bathed in fluid
double circulation
two circuits of flow to and from the heart (pulmonary circuit, systemic circuit)
pulmonary circuit
leads to lungs
systemic circuit
leads to rest of body, limbs,head..
oxygenated blood and deoxyginated blood do not
mix within the heart
blood flow process step 1
deoxygenated blood is returning from the systemic circuit (your limbs that have used up the oxygen) via the superior and inferior vena cava (superior head region – inferior bottom region)
– from the vena cavas, the blood enters the right atrium
blood flow process step 2
right atrium will contract and push the blood into the right ventricle
blood flow process step 3
right ventricle will contract and push the blood into the pulmonary artery sending it to the lungs for oxyfgen to get pumped into vblood
blood flow step 4
oxygenated blood returns from the pulmonary circuit(lungs) and enters via the pulmonary veins – will enter into the left atrium
blood flow step 5
from the left atrium – it will contract and send blood down into left ventricle
blood flow step 6
left ventricle will contract and pushes blood through the aorta – sending the blood to the systemic circuit back to the limbs
valves ensure what type of flow by doing what
ensure unidirectional flow by closing to prevent backflow
what two types of valves do we have
atrioventricular, semilunar valves
atrioventricular valve
separates the atria and ventricles – prevent backflow into atria when atria relax
semilunar valve
separates the ventircles from the arteries and prevent backflow into the ventricles when ventricles relax
the cardiac cycle – diastole vs systole
both left and right side happening around the same time
diastole – relaxation
systole – contraction
step 1 cardiac cycle
blood enters atrium and ventricleright now both relaxed diastole
step 2 cardiac cycle
atrium contractd (stystole) to send blood to relaxed (diastole) ventricle
step 3 cardiac cycle
artium relaxes – blood comes in – ventricle contracts – pushes blood artery
simplified blood flow overview
superior vena cava, inferior vena cava – right atrium – right ventricle – pulmonary artery – capillaries of left and right lungs – pulmonary veins – left atrium – left ventricle – aorta – capillaries of head region and capillaries of limb region
blood vessel structure felects..
function
structure of artery
3 tissue layer – endothelium – smooth – connective (very thick tissues) – subdivided into medium vessel (arterioleO and even more subdivided into capillaries)
– blood out of heart
structure of vein
3 tissues but thinner than artery (endothelium, smooth, connective) – also has valve (prevent backflow)
– blood into heart
subdivided into medium (venule) and into capillaries
capillaries structure q
only 1 tissue layer thick – endothelium – surrounded by basal lamina for support (membrane) – think bc optimizes diffusion
area (capillaries vs veins vs artery
capillaries have most area – increased branching increases the area
velocity veins vs artery vs capillary
the same amount of fluid moves more slowly through a grreateer area (slowest in capillary) fastest in artery – just coming out of the heart – faster
medium branching of artery salows down flow to enter capillarioes, medium branching of vein speeds up flow from capillaries to vein
presure veins vs artery vs capillary
increase in area of capillaries causes pressure to drop off – blood not repressurized until returns to heart (arteries have highest pressure – why theyre thixck - to withstand pressure)
blood flow is regulated by what three things
nerve impulses, hormones, and local cehcmicals
what sdo nerve impuldses, cormones, and local chemicals affect
arteriole diamter and pre capillary sphincters
what are sphincters doing most of the time and why
they are contractng because it redirects blood flow so it is more direct from the artery to vein
– if needed, sphincters will relax to allow blood flow to different capillaries
thin capillary walls and slow blood velocity allow for whgat
exchange of materials between blood and interstitial fluid – capillaries branch – increase SA
what is blood
a tissuev – consisting of cells in liquid called plasma
plasma
55% blood – water, ions, proteins, nutrients, metabolites, and wastes
cellular elements of blood
45% – erythrocytes (red), leukocytes (white BC) , platelets
respiratory surfaces are specialized for
gas exchange
3 main respiratory surfaces
gills, trachea, lungs
what do all three respiratory systems have
-large surface area, – greater than rest of body
- veery thin exchange surfaces – single epithelial layer
respiratory media vary in
their O2 concentration
what is respiratory media
source of O2. – air has high O2 concentration , water has much lower O2 concentration LESS THAN 1%
animals that obtain O2 from water need to be..
much more efficient than animals thatobtain O2 from air (need to be 80% more efficient)
gills are efficienct for
extracting O2 – but are unsuitable in terrestrial environments – must be wet – ansd bc they are on outside of bodty, will dry out in air
respiratory surfaces musrt be
moist
respiratory surfaces of terrestrial animals are
enclosed within the bodsy to preven excess water loss (trachea and lungs)
mammilian respiratory system (basic run down)
air enters through nasal cavity – down pharynx – larynx – trachea – into both right and left lung through – bronchus – smaller branchings of bronchus (bronchiole) – end of bronchiole have sacs called alveoli -
alveoli
covered in capillaries where blood vessels reachvto get oxygen
– branch of pulmonary artery – deox blood comes in to reoxygenate itself – gets rid of CO2
– branch of vein – obtains oxygen goes back to heart
red blood cells are packed wit
protein called hemoglobin – red blood cells is how we carry O2 and CO2 throughout body
O2 binds to hemoglobin for
the transport in red blood cells
basic rundown of red blood cells, hemoglobin and oxygen
red blood cells contain hemoglobin – hemoglobin is capable of binding to oxxyfen – oxygen bonds w hemoglobin – and then gets released to tissue cells
hemoglobin has hiow many binding sites
4 – these binding sites are called heme – each has iron which is involved in the binding of oxygen and blood flow
what are the three ways CO2gets transported
CO2 travels through amino acids in hemoglobin(bound to amino acids) (23%)
travels in the blood plasma AS CO2 (7%)
travels in blood plasma as bicarbonate (70%)
loading and unloading of respiratory gases step 1
inhaled air contains O2 – enters the alveolar spaces – exchanges through alveolar cells
loading and unloading respiratory st 2
from cells enters alveolar capillaries – oxygenates blood
respiratroy loading unlosing st 3
oxygenated blood flows through pulmonary veins and into heart – from heart leaves throuhg systemic arteries
respiratory unloading loading st 4
blood from systemic arteries flows to systemic capilarries – exchanges O2 with body tissue cells
respiratory unloading loadsing st 5
body tissue cells exchange CO2 as well – enters systemic capillaries and enters systemic veins
respiratory unloading loading st 6
systemic veins (deoxygenated blood) flows to hear – and out through pulmonary arteries
respiartory unloading loading st 7
pulmonary arteries – blood flows through alveolar capillaries – exchanges CO2 with alveolar cells and breathes out CO2
