Negative feedback ensures that conditions remain favourable. A stimuli is detected and a change occurs, integrator will produce signal and send to effector. Effector responds to stimuli. Stimuli is no longer detected and effector stops.
New cards
4
What is positive feedback?
Body senses a change and activates mechanism that accelerates or increases that change. Can be life threatening.
New cards
5
What does a sensory cell do?
Detect stimuli in the environment.
New cards
6
What does an integrator do?
Direct an impulse to produce the appropriate response.
New cards
7
What does an effector do?
It is a muscle or gland that produces the response?
New cards
8
What are the effectors of thermoregulation?
Vasodilatation/sweat and Vasoconstriction/shivering
New cards
9
What is the function of the neurons?
Receives stimuli from the environment and coordinates an appropriate response.
New cards
10
What are glial cells?
Support neurons.
New cards
11
What are the three types of neurons?
Sensory, Interneuron, motor
New cards
12
What is a Sensory neurons?
Detect change
New cards
13
What is a interneuron?
Connects sensory to motor
New cards
14
What is a motor neuron?
Creates the response.
New cards
15
What is a dendrite?
An extension of the beginning of the neuron that connects to other neurons. Receives info.
New cards
16
What is the cell body (soma)?
Contains cell organelle to support function, it processes info from dendrites.
New cards
17
What is an axon?
It sends messages through nerve impulse transmission.
New cards
18
What is the axon terminal?
The end of the neuron.
New cards
19
What is synapse?
The axon terminal linked to dendrite of another neuron.
New cards
20
What are the conditions for action potential?
Ion channels present, no myelin.
New cards
21
Explain the resting membrane.
Lots of K on inside, lots of Na on the outside keeps a charge difference. Pumps will move 3Na ions out and 2K ions in, creates positive charge on outside and negative charge on inside. Some diffusion of K will occur, this makes the outside even more positive.
New cards
22
What is the propagation of impulse?
The movement of impulse down the membrane.
New cards
23
Explain depolarization.
Na channels open and it rushes in, charges have flipped and inside becomes positive. K channels remain closed. A wave of depolarization occurs.
New cards
24
Explain repolarization.
K channels open and K moves out so the pumps can reestablish resting membrane. Na channels remain closed.
New cards
25
Explain the steps of synapse transmissions.
Impulse reaches end of neuron, Ca2 channels open and Ca2 comes into cell. This causes vesicles with NT to move to presynaptic membrane. NT diffuses across synapse and bind to receptor. Na channels open and depolarization begins. Channels close when NT is released.
New cards
26
What is a motor nerve?
Send impulse from brain to all muscles.
New cards
27
What is a sensory nerve?
Send message from muscles to brain.
New cards
28
What is mixed nerve?
Both sensory and motor nerve arranged together.
New cards
29
What is the central nervous system?
Spinal cord and brain, mainly inter neurons, process information.
New cards
30
What is the peripheral nervous system?
Parts of N.S except for brain and spinal. Relay information.
New cards
31
What is the autonomic nervous system?
Controls internal environment. Regulates processes not under conscious control.
5/6 of the brain, the folds increase S.A. Grey matter on outside w lots of connections, White matter on inside that moves info. Has 10 billion neurons & connections but only small % are used.
New cards
44
What are the cortex controls?
Sensory info (sight, hearing, limb positions, taste, touch, odor), Motor info (motion, speech, position of limbs), Thought behaviour (consciousness, attention, memory, reasoning, judgement, emotion, imagination, will power)
New cards
45
What is excretion?
The removal of metabolic waste from blood or ECF.
New cards
46
What is secretion?
The movement of substances from the blood to another location.
New cards
47
What is reabsorption?
Movement of materials back into the blood of ECF.
New cards
48
What is elimination?
The emptying of an organ in which waste is store.
New cards
49
What is egestion?
The elimination of solid waste that never enter cells/blood.
New cards
50
What is diffusion?
Movement of molecules from \[high\] to \[low\]
New cards
51
What is osmosis?
Diffusion of water
New cards
52
What is facilitated diffusion?
Membrane that channels specific molecules through. Selective permeability.
New cards
53
What is active diffusion?
uses energy but can move against or with the gradient.
New cards
54
What is the function of the kidney?
Excretion of urine due to protein→ammonia→urea→urine.
New cards
55
Describe how the glomerulus and bowman’s capsule work.
Blood goes into glomerulus, decrease size of blood vessels increases pressure. Dissolved solutes and water are pushed through walls of glomerulus (non-selective filtration) and are picked up by Bowman’s capsule.
New cards
56
Describe the proximal tubule.
It does passive and selective reabsorption of minerals (Na, Cl, HCO3), glucose, aminos and vitamins. This increases water/solvent levels.
New cards
57
Describe the descending tubule.
Reabsorption water. Walls are only permeable to water, not to salt. This decreases water/solvent levels.
New cards
58
Describe the ascending tubule.
Thin section is permeable to salt and not water, this brings water/solvent levels up. The thick section will actively reabsorb salt and fine tunes the levels.
New cards
59
Describe the distal tubule.
Reabsorbs water, Specific and active reabsorption and secretion.
New cards
60
Describe the collecting duct.
Moves waste into kidney and bladder. More water absorption, some urea can be reabsorbed.
New cards
61
What is a molecular messenger?
Chem molecule released when regulator cell detects change in environment. Acts on a target cell.
New cards
62
What are the characteristics of hormones?
Produced by a gland
Secreted into blood or ECF
Works on different cell than what produced it
Required in small amounts to trigger target cell
Acts only on specific target cells
New cards
63
What is antagonistic effect?
A hormone may be produced to work antagonistically against the other (insulin vs glucagon)
New cards
64
What is a chain reaction effect?
Release of one hormone stimulates the release of a second hormone. Second hormone then inhibits the release of the first one.
New cards
65
What is steroid hormone action?
Steroid enters cell and binds with receptors. Receptor/hormone binds at specific DNA site. Transcription occurs, proteins made via translation, proteins change activity of that cell or secreted into blood to affect other cells.
New cards
66
What is Second messenger?
Bind to cell surface receptors, can’t pass through membrane. Receptor change shape so it binds to cytoplasm protein, causes formation of a reaction activator. Needs an enzyme.
Studied by 1 person
