homeostasis Flashcards
define homeostasis
maintainance, constant internal environment -> optimum for physiological processes in body
Besides arterioles
what else may vasodilate?
Arteries.
Muscular fibers allow vasodilation // constriction
capillaries cannot vasoconstrict/dilate, coz’ one-cell thick wall
What is negative feedback?
process
receptor detect, restoration, internal env. to norm, stimulate effector, reduce intensity -> homeostatic corrective mechanism
e.g. after ADH has done its work the negative feedback loop causes levels of ADH secreted to return back to normal
what is uric acid
urine excretory product
can write for urine excretory product.
define homeostasis [4]
- maintainance of constant internal env.
- self-regulatory process, receptor detects change in internal env. -> send signal effector organs -> corrective mechanism -> restore internal env. to norm
- when normal point acheived -> negative feedback
hormones are for homeostasis only. True or false?
False
- homeostasis
- reproduction
- metabolism
Define hormone. [4]
- chemical substance
- produce by endocrine gland
- secrete in minute quantities directly -> bloodstream, transported by bloodstream to one/more effector organs
- hormone exerts it’s effect -> destroyed in liver to prevent excessive stimulation of effector organs
composition: protein, fats
substance
production
transport
excretion/how get rid of
all hormones are protein. True or false?
False
- some protein
- some fatty in nature
characteristics of endocrine gland
ductless gland;
secrete hormones directly into bloodstream
enzyme v. hormones
enzymes
- increase rate of biochemical reaction
hormones
- chemical substance
(produce endocrine gland)
- targets effector organ
2 conditions that anything needs to maintain homeostasis
- body must be able to detect changes
- set in place series of actions -> regulate, return internal env. of body to ideal state
not so fun fact about keywords
- ideal state: no need define anything
- normal conc.: must define what “normal” is -> e.g. concentration in a healthy person?
2 systems that play cruicial roles in homeostasis for humans
- hormonal
- nervous
two parts of nervous system + their parts
- Central Nervous System (brain+spinal cord)
- Periphial Nervous System (cranial, spinal nerves, sense organs)
what is the function of nervous system
co-ordinate, regulate bodily funct.
what is stimulus
any change in internal/external env. -> elicits response from organism
where are cranial and spinal nerves located?
cranial: near brain
spinal: near spine
what is voluntary action?
deliberate action, elicit by nerve impulses, generated by brain under conscious control
which organ detects blood glucose levels above/below norm?
pancreas
4 examples of endocrine gland
- pitutary
- ovaries
- testes
- islets of Langerharn
what is reflex action?
immediate response -> specific stimulus, w/o conscious control
voluntary action and reflex action similarities
- involve effector carry out action
- transmission of nerve impulses within nervous system
voluntary action and reflex action differences
Voluntary:
- neurons in brain generate nerve impulses
- Under conscious control
Involuntary:
- receptors in sense organ generate nerve impulses
- need stimulus
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit page 17
fill in the blanks
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit page 18
no need label
visualise 1 sensory neuron, 1 relay neuron and 1 motor neuron as well as direction of nervous impulses
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit page 19
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit page 20 fill the blanks
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit page 21
where are sensory neurons found at?
At sense organs, where receptors will trigger nerve impulses
(i.e. skin’s pain receptors detect a bee sting, send nerve impulses)
where are relay neurons found at?
Spinal cord, brain
where are motor neurons found at?
motor end plate (i.e. muscles)
- motor end plate is essentially the target tissue that has to act in order to achieve something. (e.g. biceps muscles to act in order to cause hand to move backwards)
- Only use of neurons where the action is reflex/not purely endocrinal
e.g. for ADH secretion there is no nervous system involved
how does pain lead to an action? explain with the nervous system
- (receptor) in (sensory organ) detect (stimulus/change in ext. environment), generate nerve impulses
- nerve impulses transmit along sensory neurone -> (CNS) -> pass across synapse -> relay neurone
- another synapse -> motor neurone, that transmits nerve impulses from (CNS) to (effector)
- at same time, nerve impulses transmitted via relay neurone -> brain, allow perception of pain
- (muscles/glands) (contract/secrete (hormone)) causing (action)
keyword stuff
nerve impulses are transmitted along neurones, nerve impulses travel across synapses
TAKE NOTE
- BULLET PT 4 ONLY IF HAVE PAIN!!
- Pain is together w/ motor neurone nerve impulse
- All brackets have to be filled based on context
- Endocrinal glands do not use any nervous signals (i.e. pitutary gland secrete ADH directly into bloodstream, no nervous signals involved in ADH secretion)
types of receptors
common: osmo, thermo, pain
others: photo,baro,chemo
e.g. qn: Describe and explain what happens when a pin pricks the hand
- pain receptors in skin detect pin prick, generate nerve impulses
- nerve impulses, transmit along sensory neurone -> spinal cord -> pass across synapse -> relay neurone
- another synapse -> motor neurone, that transmits nerve impulses from spinal cord -> effector muscles in arm
- at same time, nerve impulses transmit via relay neurone -> brain, allow perception of pain
- biceps contract -> hand move away from pin
nerve impulses are transmitted along neurones, nerve impulses travel across synapses
how to decide if relay neurone transmit signal to which CNS?
above neck: brain
below neck: spinal cord
osmo/thermo: ALWAYS HYPOTHALAMUS
eye: brain
when is brain and spinal cord involved?
- draw it out - if the effector is below head it requires a relay neurone
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit what tissue/organ is this? (page 22)
spinal cord
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit (page 23) label all
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit (page 24)
does thermoregulation involve nervous system?
What is the:
- receptors
- sense organ
- stimulus
- CNS
- effector
- glands
- horomes
- action
in thermoregulation of skin when temperature is hot?
yes
- thermoreceptors
- skin
- increase in skin temperature
- hypothalamus
- effector tissues in skin
- sweat glands
- NONE
- vasodilation, sweat glands more active
how does nerve impulses travel from skin to effector when surface temp. increase?
- thermoreceptors, skin detect increase temperature generate nerve impulse
-
transmit along sensory neuron ->spinal cord,
pass across synapse -> relay neuron - Nerve impulses transmit along relay neurone -> hypothalamus
- hypothalamus elicits THERMOREGULATIVE corrective mechanism, generate nerve impulse
- nerve impulse transmit along RELAY NEURON down spinal cord
- where it passes across synpase, motor neurone, trasmit nerve impulses, down spinal cord -> effector tissues, skin
effector glands = secrete hormones directly into bloodstream
torturous = pain receptor
page 36 https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit?tab=t.0
corrective mechanism + negative feedback loop when its too hot
Arterioles under skin ->
a. undergo vasodilation -> increase blood flow in capillaries near surface of skin -> increase heat loss via c, c, r
b. Sweat glands become more active , secrete more sweat -> more
water evaporates from surface of skin, remove latent heat of vaporisation.
decrease skin temp. -> normal, stimulate hypothalamus, reduce intensity, thermoregulation corrective
mechanism thru negative feedback loop
c, c, r -> conduction, convection, radiation
Negative Feedback:
process
receptor detect, restoration, internal env. to norm, stimulate effector, reduce intensity -> homeostatic corrective mechanism
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit page 25
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit page 26
what is the receptor that detects a rise/fall in core temperature?
thermoreceptors (hypothalamus)
what is receptor that detects a rise/fall in shell temperature?
thermoreceptors (skin)
what is CNS of thermoreception
hypothalamus
Nerve impulses medium of transport
neurones
british spelling neurones
example of neurones: sensory neurone, relay neurone, motor neurone
specific effectors that nerve impulses reach when its too cold
specific effectors are the named ones, not the vague ones like “effector tissue”
- skeletal muscles (shivering)
- skin
think of the effectors when its too cold first
corrective mechanism + negative feedback loop when its too cold
Arterioles under skin ->
a. vasoconstrict -> decrease blood flow in capillaries near surface skin -> decrease heat loss via c, c, r
b. Hair erector muscles, contract, body hair stand on ends, trap layer (air, poor conductor heat), reduce heat loss, c,c
Skeletal muscles ->
shivering (uncontrolled muscle contractions)
increased rate, respiration
more heat released (by-product)
example of hormone-coordinated homeostasis
ADH coordinate osmoregulation
example of endocrinal gland and it’s function
ovaries
- ductless;
- secrete oestrogen, progesterone directly -> bloodstream
- effector, uterine lining, coordinate changes, menstrual cycle
add o behind, its british spelling.
what is diabetes mellitus? [2]
- disease, body unable regulate blood glucose conc within normal limits
- unstored excess glucose, excreted -> urine
essentially its diabetes
Type 1 Diabetes risk factors, what happens to body when someone has it
risk
- genetic factors
what happens
- islets of Langerharns, unable produce enough insulin
treatment/ways to cope with type 1 diabetes
- keep ready supply, sugary food
- insulin injections
Type 2 Diabetes risk factors, what happens to body when someone has it
risk
- genetic predisposition
- high caloric diet, lacking exercise worsens
what happens to body
- effector cells, insensitive (insulin), continuously higher than norm blood glucose conc.
define predisposition
higher tendency to act a certain way
type 1 vs type 2 diabetes differences
type1
- early-onset diabetes
- genetic condition
type2
- late-onset diabetes
- genetic predeposition
- high caloric diet, lack exercise worsen
Type 2 diabetes treatment
control blood sugar levels, dieting, exercising
what stimulus can cause rise in blood glucose levels?
carbohydrate-rich meal
what stimulus can cause fall in blood glucose levels?
vigorous exercise
starvation
what receptor detects rise/fall in blood glucose levels?
pancreas
what is the endocrinal gland that acts when blood glucose level is low/high? what does it secrete?
pancreas
high: insulin
low: glucagon
in: glucose in
gon: glycogen gone
what are the effector organs of insulin?
-
- liver
- muscles
what are corrective mechanisms for?
restore () to norm
what is the corrective mechanism when high blood glucose levels?
- target cells increase uptake, glucose
- glucose -> glycogen
- increase rate, cellular respiration
what is the corrective mechanism when low blood glucose levels?
- convert glycogen -> glucose
- gluconeogenesis
- release glucose -> bloodstream
hormones vs nervous (signal involved)
- nerve impulses
- hormones
nervous bold
hormone non bold
hormones vs nervous (nature of signal)
- electrical
- chemical
nervous bold
hormone non bold
hormones vs nervous (means of transmission)
- via neurones
- via bloodstream
nervous bold
hormone non bold
hormones vs nervous (rate of response)
- fast
- slower
nervous bold
hormone non bold
hormones vs nervous (range of effect)
- located, specific organ/tissues
- widespread (multiple organs/systems)
nervous bold
hormone non bold
hormones vs nervous (voluntary/involuntary)
- voluntary/involuntary
- involuntary
nervous bold
hormone non bold
hormones vs nervous (length of effect)
- short lived
- short lived(e.g. insulin)/long-term (growth hormones)
nervous bold
hormone non bold
hormones vs nervous all differences
- signal involved
- nature of signal
- means of transmission of signal
- rate of response
- range of effect
- control
- length of effect
use this card to recall all
can spinal cord elicit voluntary action
nope lol.
where are relay neurones found?
- CNS
- from bottom of spinal cord to brain
what kind of action is it called if your receptors is involved but not life-threatening?
response action
what does brain do to make meaning out of stuff
- process nerve impulse
brain diagram
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit?tab=t.0 page 1
scroll down for ans
https://docs.google.com/document/d/1LQacTU0A416kWYxp3Du0-mVf9HBosNswJ_jQ2zTk5X0/edit?tab=t.0
page 1, scroll down