Animal Responses Flashcards
(158 cards)
1
Q
what does the CNS consist of
A
brain / spinal cord
2
Q
what does the PNS consist of
A
all neurones in body
3
Q
split the nervous system by functional organisation
A
somatic and autonomic
4
Q
what is the somatic nervous system
A
voluntary / conscious control
5
Q
what is the autonomic nervous system
A
involuntary / subconscious control
6
Q
what can you split autonomic nervous system into
A
parasympathetic and sympathetic
7
Q
what is the sympathetic nervous system known as
A
fight or flight
8
Q
what is the parasympathetic nervous system known as
A
rest and digest
9
Q
sympathetic responses
A
increases heart rate
dilates airways
redirects blood flow to the muscles
10
Q
where do the sympathetic branches originate from
A
middle of spinal column
thoracolumbar region
11
Q
where are the ganglia located in the sympathetic branches
A
close to spinal cord
12
Q
are the post ganglionic fibres long or short in the sympathetic branches
A
long
13
Q
does the sympathetic nervous system have few or many postganglionic branches and whats the purpose of this
A
many postganglionic branches
multiple organs activated at once
14
Q
what is the neurotransmitter for sympathetic
A
norepinephrine
15
Q
parasympathetic responses
A
slows down the heart rate
constricts airways
promotes digestion
16
Q
where do the parasympathetic branches originate from
A
from higher up spinal column
craniosacral region
17
Q
where are the ganglia located in the parasympathetic branches
A
close to target organs
18
Q
are the post ganglionic fibres long or short in the parasympathetic branches
A
short
19
Q
does the parasympathetic nervous system have few or many postganglionic branches and whats the purpose of this
A
few - targeted organs activated at a time
20
Q
what is the neurotransmitter for parasympathetic
A
acetylcholine
21
Q
summarise all the information on sympathetic + parasympathetic on two diagrams
A
22
Q
salivary glands - sympathetic and parasympathetic stimulation
A
sympathetic - saliva production reduced
parasympathetic - saliva production increased
23
Q
lung - sympathetic and parasympathetic stimulation
A
sympathetic - bronchiole muscle relaxed (more airflow)
parasympathetic - bronchiole muscle contracted
24
Q
kidney - sympathetic and parasympathetic stimulation
A
sympathetic - decreased urine secretion
parasympathetic - increased urine secretion
25
stomach - sympathetic and parasympathetic stimulation
sympathetic - peristalsis reduced
parasympathetic - gastric juice secreted
26
small intestine - sympathetic and parasympathetic stimulation
sympathetic - peristalsis reduced
parasympathetic - digestion increased
27
what are ganglia + its function
collection of nerve cell bodies found outside CNS
a site of integration + relay for signals in PNS
28
are the pre and postganglionic neurones in the autonomic system myelinated
(from CNS to effector)
the preganglionic neurones are lightly myelinated
the postganglionic neurones are unmyelinated
29
what is the brain protected by
skull
protective membrane - meninges
30
what does the cerebrum control
voluntary actions
learning / memory / personality + conscious thought
31
what is the structure of the cerebrum
- highly convoluted
- split into left + right hemispheres which are joined by the corpus callosum (band of fibres)
- the outer layer is the cerebral cortex
- has sensory + motor areas
- has white + grey matter
32
why is the cerebrum being highly convoluted significant
increases its SA
+ therefore capacity for complex activity
33
thickness of the cerebral cortex
2-4mm thick
34
function of the cerebral cortex
carries out most sophisticated processes
- reasoning + decision making
35
structure of the sensory area in the cerebrum
size of sensory area – proportional to relative number of receptor cells present in that body part
36
function of the sensory area in the cerebrum
receives info from receptor cells in sense organs
37
where does the impulse go after the sensory area in cerebrum
passed to association areas – analysed + acted upon
38
where does the impulse go after the association area in cerebrum
motor areas
39
structure of the motor area in the cerebrum
size of motor area
– proportional to relative number of motor endings in it
40
function of the motor area in the cerebrum
main area that controls movement
– primary motor complex in back of frontal lobe
41
what is special about the base of the cerebrum
impulses from left + right side of body cross
e.g – inputs from eye pass to visual area in occipital lobe
impulses from right side of field of vision in each eye – sent to visual cortex in left hemisphere
easy to judge distance + perspective
42
where is grey matter found
in the cerebral cortex
43
what does grey matter contain + why is it grey
contains neurone cell bodies / dendrites / synapses
grey – abundance of cell bodies + lack of myelin sheath
44
function of grey matter
involved in processing + integrating sensory info
45
structure of grey matter and its significance
highly convoluted
increase SA – more neurones – more complex cognitive behaviours
46
where is white matter found
beneath grey matter
47
what does white matter contain
myelinated axons
48
function of white matter
forms nerve tracts – connect different regions of brain + allow communication
49
example of white matter
corpus callosum
50
what does the cerebellum control
controls unconscious functions
e.g. posture / balance / non-voluntary muscular movement
also involved in adjusting movements based on feedback to improve accuracy + efficiency over time – (motor learning)
- essentially compares intended movement with actual movement
51
where does the cerebellum receive + relay impulses to and from
receives info from organs of balance in ears + tone of muscles / tendons
relays this info to motor area of cerebral cortex
52
structure of medulla oblongata
has many regulatory centres used in automatic control
- cardiac centre
- vasomotor centre
- respiratory centre
53
function of cardiac centre in medulla oblongata
controls heart rate
54
function of vasomotor centre in medulla oblongata
controls blood pressure by controlling the contraction of smooth muscles in arteriole walls
55
function of respiratory centre in medulla oblongata
controls breathing rate
contains an inspiratory centre and an expiratory centre
56
overall functions of medulla oblongata
control reflex activities
–breathing rate + heart rate / swallowing / peristalsis / coughing
serves as a relay station for info passing from spinal cord to higher brain centres
57
what is the hypothalamus
main controlling region for autonomic nervous system
58
sections of hypothalamus
has parasympathetic + sympathetic centre
59
what does the hypothalamus control
controls complex patterns of behaviour = feeding / sleeping / aggression
monitors composition of blood plasma – conc of water + glucose
produces hormones as an endocrine gland
controls temp + water balance – negative feedback
60
where is the pituitary gland located
base of hypothalamus
61
structure of pituitary gland
anterior pituitary - front
posterior pituitary - back
connected by thin stalk
62
function of anterior pituitary gland
produces 6 hormones that regulate growth + reproduction + metabolism
e.g. FSH
63
function of posterior pituitary gland
stores + releases hormones produced by hypothalamus
e.g. ADH / oxytocin
64
what is the pituitary gland controlled by
controlled by hypothalamus through hormones
65
describe the reflex arc
receptor – detects stimulus + creates action potential in sensory neurone
sensory neurone – carries impulse to spinal cord
relay neurone – connects sensory + motor neurone in spinal cord / brain
motor neurone – carries impulse to effector
66
what is the spinal cord
column of nervous tissue running up back
67
what is the spinal cord protected by
spine
68
draw a diagram of the spinal cord and draw the direction of impulse from the receptor to the effector
69
what type of reflex is the knee-jerk reflex
spinal reflex
neural circuit only goes into spinal cord not brain
70
describe the knee jerk reflex
legs tapped at patella (below kneecap) + stretches patellar tendon
stretch receptor generates action potential
passed via sensory neurones to spinal cord
relay neurone passes action potential to motor neurones
travels to the extensor muscle
quadriceps on top of thigh to contract
at same time – relay neurone inhibits motor neurone of the flexor muscle – it relaxes
contraction AND relaxation – antagonistic – cause leg to kick
71
receptor for knee jerk reflex
stretch receptor in quadriceps muscle
72
coordinator of knee jerk reflex
spinal cord
73
effector of knee jerk reflex
extensor muscle
quadriceps contract
74
purpose of knee jerk reflex
used to maintain posture + balance
75
advantage of knee jerk reflex not passing through brain
synapses delay impulse
quicker overall
76
what type of reflex is the blinking reflex
cranial reflex
passes through cranial nerve in brain stem // medulla
77
stimulus examples for blinking reflex
cornea drying
being touched
hear sounds greater than 40-60dB
bright light
= protect lens + retina
= optical reflex
78
describe the blinking reflex
stimulus causes action potential to be generated in the trigeminal nerve (receptor)
passed on via sensory neurone to the medulla
passed via motor neurones to the effector
= muscle lowers upper eyelid
= + other muscle helps pull eyelid inwards
response – eyelids close
79
blinking reflex receptor
trigeminal nerve
80
blinking reflex coordinator
medulla
81
blinking reflex effector
multiple
- superior levator palpebrae muscle lowers upper eyelid
- orbicularis oculi helps pull eyelid inwards
82
what does the blinking reflex indicate
lower brain stem functioning
83
why are reflexes important for survival
avoid damage or reduce severity of damage
84
how do reflexes increase chance of survival
* being involuntary response
= decision making regions not involved
= prevents brain from being overloaded with situations where response is same
* not having to be learnt
= present at birth + immediate protection
* Being very fast
= Arc very short – only 1 or 2 synapses
= Synapses delay response
85
how is the flight or fight response coordinated
Threat detected by autonomic nervous system
Hypothalamus communicates with sympathetic nervous system + adrenal-cortical system
Sympathetic – uses neuronal connections
Adrenal – cortical system – uses hormones
86
draw out a diagram for the coordination of responses for the fight or flight response
CRF – peptide hormone
87
physical responses + their purposes for fight or flight
88
main function of adrenaline in fight or flight
trigger liver cells to undergo glycogenolysis
= increase respiration
89
what type of hormone is adrenaline
non steroid hormone
cant pass through membranes
90
effects of adrenaline
(5)
stimulates muscle in iris to contract = pupils dilate
increases diameter of bronchioles by relaxing smooth muscle – increase airflow to alveoli
vasoconstriction – decrease amount of blood to gut
vasodilation – increase blood to muscles / brain
breakdown of glycogen to glucose in liver cells
91
mechanism of how adrenaline increases blood glucose concentration
binds to receptors on liver cell
forms adrenaline-receptor complex
causes adenylyl cyclase to change shape = activated enzyme
catalyses ATP to cyclic AMP – secondary messenger
cAMP activates protein kinase enzymes – by binding to them
protein kinase phosphorylates other enzymes
catalyse break down of glycogen to glucose = glycogenolysis
92
what nervous system is the heart rate controlled by
controlled by autonomic nervous system
93
how is heart rate controlled by autonomic nervous system
cardio regulatory centre in medulla
= acceleratory centre - speed up
= inhibitory centre - slow down
94
does the acceleratory centre use the sympathetic or parasympathetic nervous system to speed up
sympathetic
95
does the inhibitory centre use the sympathetic or parasympathetic nervous system to slow down
parasympathetic
96
what are the acceleratory + inhibitory centres activated by
baroreceptors
chemoreceptors
97
how do baroreceptors activate the acceleratory + inhibitory centres
if blood pressure high
impulses sent to inhibitory centre in medulla
impulses along parasympathetic to SAN
98
where are baroreceptors found
aorta
vena cava
carotid arteries
99
how do chemoreceptors activate the acceleratory + inhibitory centres
detect changes in chemicals
e.g. carbon dioxide = by changes in pH
100
describe what happens when carbon dioxide conc gets too high + low and what that activates
if carbon dioxide increases, pH decreases
=more carbon dioxide in blood
=more carbonic acid
increase frequency of impulses to medulla + trigger acceleratory centre
blood flow quicker to lungs to increase exhalation
if carbon dioxide decreases = pH rises
detected by chemoreceptors in walls of carotid arteries + aorta
results in reduction of frequency of nerve impulses sent to medulla
reduces frequency of impulses to SAN
heart rate back to normal
101
describe how the acceleratory centre in medulla increases heart rate
when centre activated – impulses sent along sympathetic neurones ( accelerator nerve) to SAN
neurotransmitter - noradrenaline secreted at synapse with SAN
increases permeability of SAN cell membrane to sodium ions / calcium ions
influx of ions – enhances depolarisation
causes SAN to increase frequency of electrical waves
increased heart rate
102
describe how the inhibitory centre decreases heart rate
when activated – impulses sent along parasympathetic neurones ( along vagus nerve ) to SAN
acetylcholine secreted with SAN
binds to receptors on SAN cell
increases permeability to potassium ions
efflux of potassium ions / hyperpolarise = slower heart rate
causes SAN to reduce frequency
reduces elevated heart rate back to resting state
103
put all together in diagram - from stimulus (increase + decrease in carbon dioxide) to response (change in heart rate)
104
what are the three types of muscle tissue
skeletal muscle
cardiac muscle
smooth muscle
105
what is the bulk of muscle tissue
skeletal muscle tissue
106
what is skeletal muscle responsible for
movement
107
where is smooth muscle found
walls of hollow organs = stomach + bladder
walls of blood vessels + digestive tract
108
state the
- fibre appearance
- control
- arrangement
- contraction speed
- length of contraction
for skeletal muscle
- striated
- conscious control
- regularly arranged so muscle contracts in one direction
- rapid speed
- short length of contraction
109
state the
- fibre appearance
- control
- arrangement
- contraction speed
- length of contraction
for cardiac muscle
- specialised striated
- involuntary control
- cells branch + interconnect resulting in simultaneous contraction
- intermediate speed
- intermediate length
110
state the
- fibre appearance
- control
- arrangement
- contraction speed
- length of contraction
for smooth muscle
- non striated
- involuntary control
- no regular arrangement - cells can contract in different directions
- slow speed
- can remain contracted for a relatively long time
111
structure of cardiac muscle
- shows striations but fainter than skeletal muscle
- fibres are branched + uninucleated
112
structure of smooth muscle
- shows no cross striations (non-striated)
- fibres are spindle shaped + uninucleated
113
which is cardiac skeletal + smooth
114
plasma membrane of muscle
sarcolemma
115
cytoplasm of muscle
sarcoplasm
116
endoplasmic reticulum of muscle
sarcoplasmic reticulum
117
what is a sarcomere
functioning unit of myofibril
118
describe the structure of skeletal muscle
muscle fibres are long + multinucleated (strength)
T tubules - parts of sarcolemma fold inwards
lots of mitochondria + sarcoplasmic reticulum
119
why are skeletal muscle fibres long + multinucleated
formed from many embryonic muscle cells fusing together
120
how are skeletal muscles strong
long fibres from many muscle cells
junctions between adjacent cells are point of weakness
121
purpose of t tubules
helps spread electrical impulse throughout sarcoplasm
ensures whole fibre contracts at same time
122
structure of myofibrils
each muscle fibre has many myofibrils
long + cylindrical + made of protein
lined up in parallel for max force when contracting
made up of two protein filaments - actin + myosin
123
what is actin
thinner filament
two strands twisted around eachother
124
what is myosin
thicker filament
long / rod-shaped fibres with bulbous heads that project to one side
125
structure of a muscle fibre
126
zoom into a muscle
bone
tendon
many muscle fibres
many myofibrils
actin + myosin
127
describe the structure of a myofibril
I band – isotopic bands
(only actin - light)
A band – anisotropic bands
(myosin + actin overlap - dark)
H zone
(only myosin)
Z line
(centre of I band)
M line
(centre of H zone)
128
how to measure a sarcomere
difference between two z bands
129
draw out a myofibril structure
130
how to identify skeletal muscle
Individual muscle fibres
= Long + thin
= Multinucleated
= Crossed with regular pattern of fine lines
Highly structured arrangement of sarcomeres
Streaks of connective + adipose tissue
Capillaries running in-between fibres
131
describe the features of fast fibres - skeletal
- speed
- amount of Ca 2+
- type of respiration
- level of activity
- fatigue
- colour
- storage
- exampe
Contract rapidly
myosin heads bind + unbind from the actin-binding sites 5 times faster
need large amounts of calcium ions = forming more cross bridges
Rely on anaerobic respiration
Short bursts of high-intensity activity
fatigue quickly from lactate produced
Pale – low levels of myoglobin + blood vessels
Store creatinine phosphate – rapidly make ATP from ADP
E.g. - eyelids
132
describe the features of slow fibres - skeletal
- speed
- power
- activity
- respiration
- fatigue
- colour
- example
Contract slower
Less powerful but over longer period
Endurance
Aerobic respiration
Do not fatigue easily
Red - Denser network of capillaries + High amounts of myoglobin + mitochondria
e.g. Human back + calf muscles – contract for long periods of time to keep skeleton erect when standing
133
compare slow and fast fibres - skeletal
- contraction time
- capillaries
- respiration
- mitochondria
- calcium ions
- storage
- fatigue
134
describe the sliding filament model
myosin heads pull actin inwards towards centre of sarcomere
sliding causes Z lines to come together
I bands shorten
A band stays same
( Myosin filaments have NOT shortened just overlap more )
H band narrows
Sarcomeres shorten
135
describe the structure of myosin
Globular heads
On head – binding site for ATP/ADP and actin
Tails of several hundred myosin molecules – aligned to form myosin filament
136
describe what happens at the neuromuscular junction - up until sarcoplasmic reticulum
Action potential arrives at neuromuscular junction
Stimulates calcium ion channels to open on presynaptic membrane
Calcium ions diffuse into synaptic knob
Causes snare proteins to contract
Causes vesicles containing acetylcholine to be released via exocytosis
Acetylcholine bind to receptors on postsynaptic membrane – sarcolemma
Causes opening of sodium ion channels – influx of sodium ions
Depolarises sarcolemma
Travels down t tubules into the sarcolemma + sarcoplasmic reticulum
Stimulates calcium ion channels to open
Calcium ion travel down conc gradient into the sarcoplasm
137
what is a neuromuscular junction
Point where a motor neurone and a skeletal fibre meet
138
what is a motor unit
All of the muscle fibres supplied by single motor neurone
139
what happens to the acetylcholine once it has caused a conformational change + opened sodium channels
Broken down by acetylcholinesterase into choline + ethanoic acid
diffuse back into neurone to make acetylcholine
140
describe the mechanism of muscle contraction
what happens after the calcium ions have been released into the sarcoplasm?
Calcium ions binds to troponin – causes a change in shape
Pulls on tropomyosin – moves away from actin-myosin binding site
Charge difference between myosin head + binding site causes head to be attracted to site
Forms actin-myosin cross bridge
Force of binding causes release of ADP and Pi molecule from myosin head
As myosin head in high energy state + now no molecules holding back – flexes forward
Pulls actin filament along = POWER STROKE
ATP molecule attaches to myosin head – conformational change
Causes head to pull away from binding site + break cross link
Calcium ions attach to head + activates ATPase activity of myosin
Hydrolyses ATP to ADP + phosphate ion – releases energy
Myosin head now in high energy state + can attach at another binding site when calcium ions bind to THAT NEW troponin
141
which protein is blocking the actin-myosin binding site
tropomyosin
142
when the muscle fibre is depolarised which ions are secreted from sarcoplasmic reticulum and where do they bind to
calcium ions
troponin
143
what causes the tropomyosin to pull away from the binding site
the change in shape of the troponin
when the calcium ions bind to it
144
the attachment of myosin causes what change in the myosin head
causes ADP + Pi to be released
145
what does the release of ADP + Pi cause
the myosin head to flex forward
146
after the power stroke - what causes the detachment of the myosin head from the binding site
ATP binding to myosin head
147
what causes myosin head to return to original high energy state
hydrolysis of ATP into ADP + Pi
releases energy
148
what happens to move the tropomyosin back into its original position of blocking the binding site
the lack of a calcium ion
action potential stopped being generated
149
summarise muscle contraction
150
what does the hydrolysis of ATP provide energy for
for movement of myosin head
and active transport of calcium ions back into tubules
151
energy supply during contraction
aerobic respiration
anaerobic respiration
creatinine phosphate
152
what is creatine phosphate
chemical stored in muscle fibres
153
how does creatinine phosphate provide energy for muscle contraction
Provide phosphate ion to rapidly convert ADP to ATP
154
write the equation for the use of creatinine phosphate to provide energy
155
what enzyme catalysis this reaction
creatine phosphokinase
156
what is the emergency store for aerobic respiration in muscles
myoglobin
Single chain polypeptide
157
why is myoglobin a good emergency store
Very high affinity for oxygen – only release oxygen at very low partial pressures
158
limitation of phosphocreatine
limited amount
only provides extra ATP for shirt bursts
