c3.1 integration of body systems Flashcards
emergent properties
whole function is greater than the sum of all individual parts
tissue
contains different cell types that all contributes to the function
order of body systems (small to large)
organelles → tissue → organ → organ system → organism
tissue eg
trachea
diff cell types eg [2]
- ciliated cells
- goblet cells
property of AT1 cell + adaptation
very thin → allows efficient gas exchange
property of AT2 cell + adaptation
secretes surfactant so alveoli wont collapse
organ
a group of tissues in an animal or plant that work together to carry out a specific function of life
organ systems
when groups of organs interact with each other to perform an overall function of life
organisms
a living individual made up of interconnected parts but the parts are independent
brain as a central information integration organ function [3]
receives, processes, stores information
hippocampus function
convert short term memory to long term memory
white matter in spinal cord
sensory neurones, sends signal up
grey matter in spinal cord
motor and inter-motor neurones, sends signals down
conditions for brain to override spinal cord processes
have to be conscious
sensory neurones function
convey messages from receptor cells to central nervous system
receptor cells eg
rod and cone cells in retina detect changes in light
how do axons of sensory neurones enter spinal cord or the brain
using spinal nerves or cranial nerves
nerve
bundle of nerve fibres consists of sensory or motor neurones, enclosed in a protective sheath
neurone
the entire cell
nerve fibres
just the axons part of the neurones
reflex arc
- receptor to CNS: sensory neurones
- within CNS: relay neurones (interneurones)
- CNS to effectors: motor neurones
endocrine system mechanism
- stimulus is received
- use of hormones secreted into the blood
- transported to target tissues
- hormone changes conditions of the tissue
how is change in the endocrine system monitored
through feedback
how to ensure hormone is transported in endocrine system
as long as the cell has the receptor
hypothalamus
controls endocrine system using the pituitary gland
posterior pituitary gland function
stores and releases hormones made by the hypothalamus
anterior pituitary gland function
makes and secretes own hormones that regulate many body functions
diurnal pattern of melatonin
secreted by the phenol gland to control rhythms in behaviour in a 24 hr cycle
sleep mechanism [3]
- melatonin secretion increases in the evening (high levels causes drowsiness and promote sleep)
- detects amount of blue light → melatonin secretion drops
- melatonin in blood is broken down by the liver rapidly → wake up
where is epinephrine/adrenaline secreted from
adrenal glands
what does epinephrine/adrenaline do
binds to adrenergic receptors of target cells
factors that facilitate intense muscle contraction [5]
- muscle cells break down glycogen into glucose for respiration
- liver cells break down glycogen and release glucose into the bloodstream
- smooth muscle cells in bronchi and chanchiole relax to dilate the airways for better ventilation
- pacemaker in the heart speeds up the heart rate
- artirole going to muscle vasodilate while the ones foing to the intestines, skin and extremities vasoconstrict so more blood goes to the muscle
feedback control of heart rate
the cardiovascular centre of the medulla oblongata receives signals to determine if the heart should pump faster or slower suing negative feedback
what do signals from the sympathetic nerve do
pacemaker- increase heart rate
what do signals from the vagus nerve do
pacemaker- reduce heart rate
where do the signals to the pacemaker come from [2]
- baroreceptors (detects blood pressure)
- chemoreceptors (detects blood oxygen and pH)
where are the receptors for heart rate located
aorta and carotid arteries
what happens when blood pressure is low
pump faster
what happens when blood has low pH
means high co2
pump faster to get rid of co2
negative feedback eg
- high blood pressure, high blood oxygen level and high pH (low co2 concentration) will cause heart rate to slow down
- low blood pressure, low blood pressure level and low pH (high co2 concentration) will cause the heart rate to speed up
what receptors detect blood pH + location
central chemoreceptors in the brainstem (medula oblongata) and the peripheral chemoreceptors in the aorta and carotid arteries
what happens when pH drops
- chemoreceptors send signals to the respiratory centres in the brainstem increase the ventilation rate by contracting the diaphragm and external intercostal muscles
- increase in ventilation rate will reduce the co2 concentration inside the alveoli allowing the co2 in the blood to diffuse out faster due to the steep concentration gradient
- blood pH will go up and when it is back to normal level, the chemoreceptors stop sending a signal and the ventilation rate goes back to normal
swallowing andegestion of faeces controlled by
central nervous system
peristalsis controlled by
enteric nervous system
hormone
chemical message produced and released in one part of an organism to have an effect in another part of the organism
name of plant hormones
phytohormones
phytohormones function [3]
- signal cell growth
- development
- response to stimuli
where is auxin produced
shoot tip
IAA
most abundant type of auxin
where is IAA synthesised
apical meristem of the shoot (stem cells at the shoot tip)
function of IAA [2]
- controls growth at the shoot tip
- promotes elongation of cells in the stems
how auxin enter cells
diffusion
how does auxin reacts once it enters a plant’s cell cytoplasm
loses a proton and become negatively charged → form water cage
how to pump auxin out and into the cell wall
auxin efflux carriers
what happens when auxin reaches the cell wall
becomes uncharged again and can diffuse into the next cell
phototropism
- proteins (phototropins) absorb light of the correct wavelength and change shapes
- increase gene expression of a group of auxin efflux carrier (PIN3 transporter proteins)
- more PIN3 transporter proteins are produced and moved to the cell membrane
PIN3 protein function
carry and transport IAA from cells to cells
more PIN3 transporter proteins means
more IAA
to elongate the shaded side of the shoot
- shaded side will phototropin increase the expression of PIN3 gene
- so IAA elongate cells in the shaded sides of the shoot
cell wall function
allows cell to stay turgid without bursting
- cant stretch or extend
cell wall structure
made of inelastic cellulose that are bundled up into structure called microfibrils and then reinforced cross linking with pectin
how does auxin elongate the shaded side
- promotes the synthesis of proton pumps (H+ ions) proton pumps are added to the plasma membrane and pumps protons from inside the cell to the outside making it acidic and the crosslink of the cell wall weaker
- allows the cell wall to expand and the cell can elongate due to the turgor pressure inside the cell
cytokinin function
promotes cell division/cytokinesis
where is cytokinin produced
root tips
cytokinin transport
transported up the shoots via the xylem
apical dominance
totipotent
the closer the nodes are to the shoot tip, the higher the IAA concentration and higher the growth inhibition
why need apical dominance
- when the shoot grows upwards, the apical meristem leaves some meristem at the node (ie the auxiliary body) to allow for branches to grow
- however, the apical meristem wants to make sure the shoot tip is always at the top
what will happen when auxin is produced by the shoot tip + how
inhibit development of auxiliary buds and promote root growth
by increasing gene expression of cytokinin
eg antagonistic interaction
auxin and cytokinin
how does cytokinin help growth of auxiliary buds
moving nutrients towards them so they can become the new main shoot
what determines whether an auxiliary bud will develop
ratio of cytokinins and auxins
gibberellin function
contributes to stem elongation
main purpose of fruits
attract other organisms to consume them and help seed dispersal
how to know when seeds arent fully developed by the fruit
fruit will be hard, acidic and lacks scent
- so wont attract other organisms
what causes the changes when food ripens
ethylene
ethylene released by what
seeds when they are mature
eg of positive feedback in fruits + why
ethylene stimulates fruit ripening and ripening fruit will release more ethylene
- will diffuse to other fruits too
why ethylene will diffuse to other fruits too
encourages organisms to visit the area if there are a lot of ripe fruits
