c3.1 (integration of body systems) Flashcards
10 characteristics of life
movement
responsiveness
growth
reproduction
respiration
digestion
absorption
circulation
assimilation
excretion
systems of communication that plants use x1
hormonal signalling
systems of communication that animals use x2
hormonal signalling
electrical signals
hierarchy of systems in multicellular organisms x5 tiers
cell
tissue
organ
organ system
organism
define tissue
groups of cells that work together to perform a function
4 basic types of tissue in humans & function
connective tissue: supports other tissues and binds them together (bone, blood, and lymph tissues)
epithelial tissue: provides a covering (skin, the linings of the various passages inside the body) (alveolar epithelium is an example of a tissue where more than one cell type is present, because different adaptations are required for the overall function of the tissue)
muscle tissue: includes striated muscles that move the skeleton, and smooth muscle, such as the muscles that surround the stomach
nerve tissue: is made up of neurons and is used to carry electric impulses to and from various parts of the body
3 basic types of organs in seeded plants & function
roots- multiple tissues working together to anchor the plant, absorb water and store nutrients
stems - multiple tissues working together to support the plant and transport nutrients
leaves - multiple tissues working together to perform photosynthesis
human organ systems x11
nervous
respiratory
circulatory
digestive
excretory
muscular
skeletal
integumentary (nails skin hair)
immune
reproductive
endocrine (horomone related organs)
what does “emergent properties” mean?
when a property (attribute, quality, or characteristic) emerges (becomes apparent, important, or prominent) when the parts interact as a wider whole
example steps of property emergence at each level x5
life @ cellular level
contractions @ tissue level
pump blood @ organ level
transport blood @ organ system level
survive & reproduce @ organism level
watch video(s) on all human organ systems
-
what are the two body systems responsible for integration?
nervous & endocrine
main consequences of multicellularity & how it has been adapted to
nutrient delivery and waste processing must be done on a larger scale (cannot be cell specific)
transport vessels and aqueous fluids have evolved to serve this purpose.
define system integration
the process by which different physiological systems in the body coordinate and work together to maintain homeostasis and/or perform a function
4 things blood transports
nutrients
oxygen
water
waste (i.e. CO2)
2 main types of cells in the brain & their functions
neurons, which transmit electrical impulses
glial cells, which act to support both the structure and function of neurons
cerebellum location & 3 functions
back of the head (between brainstem and cerebrum
maintenance of balance & posture
coordination/timing of muscle movements
facilitates motor memory
what movements does the spinal cord control?
unconscious processes, especially reflexes
what is the spinal cord composed of (2 tissue types & structure)
white matter—axons of neurons
grey matter—synapses
conscious vs unconscious
x3 components each
unconscious:
awake or asleep
involuntary
coordinated by brain & spinal cord
conscious:
awake
voluntary
coordinated by brain
function of a neuron
a nerve cell that processes and transmits physical stimulus into an electrical signal called an action potential
define signal transduction
process of transmitting information from outside a cell to inside a cell involving a chain of reactions
6 components of a sensory neuron
dendrites
cell body
schwann cell
axon
axon terminal
myelin sheath
dendrites function
primary site for receiving sensory information from the environment
what are schwann cells?
glial cells that wrap around the axon and form the myelin sheath
myelin sheath function
layers of lipid that acts as an insulator, allowing for faster signal transmission along the axon
define saltatory conduction
process of signal transmission along the axon
axon function
carries the electrical signal
characteristic of an axon in sensory neurons
most sensory neurons have a single axon that branches into two parts, one extending to the periphery and the other to the spinal cord
axon terminal function
releases neurotransmitters into the synapse to transmit signals to other neurons or cells
sensory neurons are located in the skin and sense organs. sensory neurons have receptors activated by: x4
(stimuli & receptor & what it responds to)
light - photoreceptors respond to wavelengths of light
chemicals - chemoreceptors respond to chemicals signals, such as taste, smell, blood pH and blood glucose concentration
physical forces - mechanoreceptors respond to mechanical stimulation, such as touch, pressure, vibration, and sound
temperature - thermoreceptors respond to changes in temperature
the spinal cord receives sensory information about what? x4
pain
temperature
touch
body position
cerebrum location & main function (1 main & list a few others)
top area of the brain
muscle function, speech, thought, emotions, reading, writing, learning, etc.
primary motor cortex location & main function
strip in the cerebrum
controls voluntary movement via motor neurons to skeletal muscles in the body
motor neurons can form a two-neuron circuit. what is this & how does it work?
one motor neuron will originate in the cerebral cortex and travel down to the brainstem or spinal cord.
there it forms a synapse with a second motor neuron which will extend to innervate muscles and glands throughout the body
5 components of a motor neuron
cell body
dendrites
axon
myelin sheath
neuromuscular junction
neuromuscular junction function
point of contact between a motor neuron and a muscle fiber, where the nerve transmits an electrical impulse to the muscle to cause it to contract
motor neuron function
carry information away from the central nervous system towards a muscle or gland
2 divisions of the nervous system & their components
central nervous system (CNS): the brain and spinal cord
peripheral nervous system (PNS): the nerves outside the brain and spinal cord
nerve structure
a nerve is a bundle of neurons and supportive tissues surrounded by a protective sheath
3 examples of demyelinating diseases & definitions
charcot-marie-tooth disease (CMT):a disease that causes schwann cells to grow more slowly and reduces their number
diabetic neuropathy:high blood glucose levels associated with diabetes damage schwann cells
guillain-barre syndrome:an autoimmune disease that can be life-threatening if it affects the muscles used for breathing
define epineurium
connective tissue sheath which encases the whole nerve
define fascicles
bundles that neuron axons are further sub-grouped into
define perineurium
connective tissue sheath that encases fascicles
look at slide 71 of c3.1 for nerve micrographs
-
5 components involved in a reflex arc & what purpose they serve in the process
- receptor: initial signal activates a sensory receptor
- sensory neuron: carries the signal from the sensory receptor to the spinal cord
- interneuron: receives and processes the information from the sensory neuron before activating a motor neuron
- motor neuron: exits the spinal cord and stimulates an effector muscle or gland
- effector muscle: causes the response of the reflex
define circadian rhythms
the physiological and and behavioral changes of an organism over a roughly 24-hour cycle
what do circadian rhythms dictate? what are they synchronized by?
multiple processes in the body, including alertness, sleepiness, appetite, and body temperature
by light and darkness, however they will continue even if an organism is placed experimentally in continuous light or continuous darkness.
what is the suprachiasmatic nucleus (SCN)? (in mammals)
a small region of the brain that acts as the pacemaker of the circadian rhythm of neuron firing frequency
how does light/dark sensory input affect melatonin levels?
light/dark information reaches the suprachiasmatic nuclei from cells of the retina in the eyes
with the onset of darkness, the SCN stimulates release of melatonin from the pineal gland, a small endocrine gland located in the center of the brain
melatonin effects in humans x6
lower blood pressure
lower urine production
lower body temperature
cause drowsiness/promote sleep
regulation of gonadotropin-releasing hormone (GnRH)
enhance helper-T immune responses
define signalling pathway
the process in which binding of an extracellular chemical to a receptor is translated into changes in the cell
3 main steps of signalling pathway
- reception: the process by which a cell detects a signal in the environment
- transduction: the process of activating a change within the cell
- response: the change that occurs in the cell as a result of the signal
why are melatonin receptors on the surface of the target cells?
melatonin is hydrophilic and cannot pass through the hydrophobic center of the plasma membranes of cells
what is the primary melatonin receptor in humans?
G-protein coupled receptor
melatonin receptor activation occurs when: x5 steps
melatonin binds to the G-protein-coupled receptor, causing the receptor to change shape
the shape changes causes GDP (guanosine diphosphate) to detaches from the alpha subunit of the G-protein
GTP (guanosine triphosphate) binds in its place
binding of GTP causes the G protein subunits dissociate into two parts: the GTP-bound alpha subunit and a beta-gamma dimer
both parts remain anchored to the plasma membrane, but they are no longer bound to the GPCR, so they can now diffuse laterally to interact with other membrane proteins
melatonin signal transduction begins when what occurs?
the activated alpha subunit of the G-protein inhibits an enzyme in the cell membrane called adenylate cyclase
melatonin signal transduction occurs when: x2 steps
the inhibited adenylate cyclase can not catalyze the conversion of ATP in the cytoplasm to cyclic AMP (cAMP). intracellular levels of the second messenger cAMP decrease
cyclic AMP (cAMP) increases cell activity. activation of the melatonin receptor will inhibit formation of cAMP, thereby reducing cell activity
what does epinephrine/adrenaline bind to?
the adrenergic receptor (a type of G-protein-coupled receptor )
what is the “fight or flight” response produced by?
the reaction produced by epinephrine
epinephrine effects x4
causes liver and muscle cells to break down glycogen into glucose
dilate bronchi and bronchioles due to relaxation of smooth muscles, widening the airway for increased air flow during ventilation
speeds up firing of the sinoatrial node & strength of cardiac contraction, increasing the heart rate & volume of pumped blood, which moves more blood to the tissues faster
dilates arterioles that carry blood to the skeletal muscles, widening so more blood flows to them. Vasodilation redirects blood flow to the areas of the body that are most crucial for dealing with the immediate threat, while inversely, Vasoconstriction redirects blood flow away from areas of the body that are not vital for dealing with the immediate threat
how does epinephrine maximize the muscle’s ability to produce ATP & perform contractions?
skeletal muscles used during vigorous activity receive a greater volume of blood, with an increased supply of oxygen and glucose
two distinct parts of the pituitary
anterior lobe and posterior lobe
within the hypothalamus are cells that control different homeostasis variables in the body. these cells receive signal from sense organs and other parts of the brain about what? x3
blood glucose
body temperature
blood osmolarity
how do the hypothalamus and pituitary work to trigger responses in target cells? x3 steps
- hypothalamus receives signal
- hypothalamus then communicates with the pituitary
- pituitary sends hormones (signaling molecules) in the blood to target cells in other organs
watch a video on osmoreceptors moitoring blood solute concentration
-
how does the hypothalamus initiate puberty?
secreting GnRH (gonadotropin-releasing hormone), which in turn stimulates secretion of LH and FSH from the pituitary
These hormones cause secretion of reproductive hormones from testes and ovaries, leading to changes associated with puberty
what is the sinoatrial valve?
the heart’s built-in pacemaker
define stroke volume
the amount of blood ejected from the ventricle with each cardiac cycle
what increases stroke volume in the body?
active cells in the body produce more CO2 as a result of increased respiration. heart then needs to pump faster to clear it and pump more blood with each ventricular contraction
when are baroreceptors activated?
when heart rate and stroke volume increase
what are baroreceptors? where are they located?
mechanoreceptors that regulate heart rate bysensing blood pressure changes and sending signals to the brain
one location for baroreceptors is the aorta
when blood pressure increases, baroreceptors do what?
increase the frequency of signalling to the medulla
how is heart rate/contraction/stroke volume decreased?
the medulla signals to the sinoatrial (SA) node to decrease heart rate, force of contraction, and stroke volume
what role do chemoreceptors play in affecting heart rate?
detects changes in O2, CO2, and pH
where are chemoreceptors (used for influencing heart rate) found in
found in tissue near where baroreceptors are located, but are not in the blood vessels themselves
at rest, respiratory centers in the medulla maintain respiration rate by doing what?
sending consistent signals to the diaphragm and intercostal muscles to maintain steady breathing
purpose of chemoreceptors located in the medulla
monitor blood passing through the medulla (allow feedback control of ventilation rate during and after exercise)
typical blood pH (range of .1)
7.35 to 7.45
what causes change in pH in blood?
exercise leads to drop in pH by increasing hydrogen ions
how does the body respond to a change in blood pH?
chemoreceptors sense increase in H+ and send action potentials at a higher rate to increase clearing of CO2
decreasing pressure in lungs (expiration) results in what?
the diaphragm and intercostals relax, causing the thorax and lungs to recoil
how does the kidney facilitate pH balance?
maintaining H+ and bicarbonate concentrations
when blood is acidic, kidneys secrete more H+ in urine and reabsorbs bicarbonate in urine (binds to protons) to produce H2CO3 (increasing pH)
define peristalsis
a series of wave-like muscle contractions that move food and waste through the digestive tract
what is peristalsis controlled by? x2 systems
central nervous system (CNS) & enteric nervous system (ENS)
what is the enteric nervous system (ENS)?
a network of nerves comprised of sensory, motor, and relay neurons (a type of interneuron with a long axon) in the digestive tract that controls digestion
what initiates the peristaltic reflex? what are the 5 steps that happen after initiation?
food masses
- food stretches tube, which stimulates stretch receptors in ENS
- stretch receptors stimulate relay neurons
- relay neurons stimulate motor neurons
- motor neurons release excitatory neurotransmitter, causing smooth muscle above bolus contracts
- motor neurons release inhibitory neurotransmitter, causing smooth muscle below bolus relaxes
tropic responses in plants (& definitions) x6
(watch videos on each one after)
(if cannot find, look at diagrams)
Phototropism:Plants grow towards light sources.
Gravitropism:Plants grow in response to gravity.Stems grow away from the center of gravity, while roots grow towards it.
Hydrotropism:Plants grow towards or away from water.Roots grow towards water sources, which helps protect plants from drought and over-saturation.
Thigmotropism:Plants grow in response to mechanical stimulation, such as touch.
Chemotropism:Plants grow in response to specific substances.
Traumatotropism:Plants grow in response to wound lesions
watch this https://www.youtube.com/watch?feature=oembed&v=pCFstSMvAMI
-
what are phytohormones? what do they control?
chemicals that regulate plant growth and development
control processes like cell division, elongation, and response to environmental stimuli
examples of key phytohormones x5
auxins
cytokinins
gibberellins
ethylene
abscisic acid
look at slide 138 for phytohormone control c3.1
-
what does auxin do? where specifically is it found?
moves through plant tissues to regulate growth.
found in tips of roots and shoots (root meristem, apical meristem)
what do auxin efflux carriers do?
concentrate auxin on one side of cells, creating a directional flow of the hormone
how does auxin promote cell growth? x4 steps
auxin binds to proton pumps
this acidifies the cell wall through the secretion of H+ into the apoplast
increase in [H+] activates a protein called expansin which loosens cellulose allowing the wall to expand and cells to elongate
turgor pressure from inside the cell provides force that pushes cellulose fibers, then H-bonds reform
how does cytokinin promote cell development for division? x2
controls the development of shoots, roots, flowers, and vascular bundles
increases the number of seeds produced per pod or unit area
where is auxin produced? how is it transported?
in the shoot tips
transported shoot to root via phloem
where is cytokinin produced? how is it transported?
in the root tips
transported root to shoot via xylem
explain the positive feedback of fruit ripening via ethylene
how is this beneficial to the fruit plant?
ethylene triggers the ripening of fruit, and as fruit ripens, it produces more ethylene, speeding up the process
ensures fruit ripening is rapid and synchronized, increasing the likelihood of successful seed dispersal
