Topic 7 Flashcards
1
Q
what type of muscle is used for movement?
A
skeletal, e.g. biceps and triceps
2
Q
what do ligaments attach?
A
bones to bones
3
Q
what do tendons attach?
A
muscles to bones
4
Q
what is a flexor?
A
a muscle that contracts to bend a joint
5
Q
what is an extensor?
A
a muscle that contracts to cause the extension of a joint
6
Q
which muscle in on the top of the arm? is it an extensor or flexor?
A
biceps- flexor
7
Q
which muscle is on the bottom of the arm? is it an extensor or flexor?
A
triceps- extensor
8
Q
what is a pair of muscles that work together to move a bone called?
A
an antagonistic pair
9
Q
why do muscles need to work in pairs?
A
they can only pull (when they contract) and not push, so two muscles of opposite directions are needed to create opposite forces
10
Q
what are skeletal muscles made of?
A
large bundles of long cells called muscle fibres
11
Q
what is the cell membrane of a muscle fibre cell called?
A
sarcolemma
12
Q
what is the sarcolemma?
A
the cell membrane of a muscle fibre cell
13
Q
what is the cytoplasm of muscle fibre cells called?
A
sarcoplasm
14
Q
what are transverse T tubules?
A
inward folds of the sarcolemma which stick into the sarcoplasm
15
Q
what is the function of the transverse T tubules?
A
help to spread electrical impulses throughout the sarcoplasm so they reach all parts of the muscle fibre
16
Q
what is the sarcoplasmic reticulum?
A
a network of internal membranes that run through the sarcoplasm in a muscle fibre cell
17
Q
what is the function of the sarcoplasm reticulum?
A
stores and releases calcium ions that are needed for muscle contraction
18
Q
why do muscle fibre cells have lots of mitochondria?
A
to provide the ATP that’s needed for muscle contraction
19
Q
which type of cell are multinucleate? what does this mean?
A
muscle fibre cells- have many nuclei
20
Q
what are muscle fibres made of?
A
long, cylindrical organelles called myofibrils
21
Q
how is a muscle fibre cell related to its specialised function?
A
many mitochondria for respiration
presence of myofibrils/ actin and myosin
myofibrils allow for contraction
22
Q
what are myofibrils made of?
A
proteins
23
Q
what are myofibrils highly specialised for?
A
contraction
24
Q
what are myofibrils made of?
A
bundles of thick or thin myofilaments that move past each other to make muscles contract
25
what are thick myofilaments made of?
the protein myosin
26
what are thin myofilaments made of?
the protein actin
27
what does myofibril look like under a microscope?
has alternating dark and light bands
28
what is a sarcomere?
a section of myofibril
29
what are the dark bands in myofibril?
the thick myosin filaments and some overlapping thin actin filaments (A bands)
30
what are in A bands?
mostly thick myosin filaments which the ends overlapping with thin actin filaments
31
what are the light bands in myofibril?
thin actin filaments (I bands)
32
what are in I bands?
thin actin filaments
33
what is a sarcomere?
the short units which make up myofibril
34
what are Z lines?
they mark the end of each sarcomere, sarcomeres are joined lengthways at their Z lines
35
what is the M line?
marks the Middle of the sarcomere, is always in the Middle of the Myosin filament
36
what is the H zone?
the zones in the middle of the sarcomere- only contains myosin filaments
37
what is the theory which explains muscle contraction?
sliding filament theory
38
what fundamentally happens during contraction?
actin and myosin filaments slide over each other to shorten the sarcomere
39
during muscle contraction which zones/bands shorten and which stay the same length?
H-zone and I-band shorten
A bands stay the same length
40
what 3 things shorten during contraction?
sarcomeres, myofibrils and muscle fibres
41
what are the 9 features of the knee?
tendon, muscle, ligament, synovial membrane, synovial fluid, fibrous capsule, bone, pad of cartilage, cartilage
42
what is the function of the synovial membrane?
secretes synovial fluid
43
what is the function of the synovial fluid?
acts as a lubricant
44
what is the function of the pad of cartilage?
gives additional protection
45
what is the function of cartilage?
absorbs synovial fluid, acts as shock of absorber
46
what is the function of the fibrous capsule?
encloses joints
47
define tropomyosin
an actin-binding protein which regulates muscle contraction
48
define troponin
a complex of three proteins, attached to tropomyosin
49
what is the resting state of a muscle?
tropomyosin blocks binding site on actin
50
what is the first step of muscle contraction?
action potential reaches neuromuscular junction and depolarises sarcolemma and sarcoplasmic reticulum
51
what happens after the sarcoplasmic reticulum is depolarised?
sarcoplasmic reticulum releases calcium ions which bind to troponin
52
what happens when the calcium ions bind to troponin?
troponin changes shape which causes tropomyosin to move so the myosin binding sites (on the actin) are exposed
53
what happens once the myosin binding sites are exposed?
the myosin heads can bind to binding site on actin
actin-myosin cross bridge forms
54
what happens after the actin-myosin cross bridge forms?
the myosin head nods forward causing the actin filaments to slide over the myosin filaments and the sarcomere shortens
55
what happens after the sarcomere shortens?
ATPase in myosin head hydrolyses ATP and head moves back to original position- breaking cross bridge
56
what is the final stage of muscle contraction?
myosin head reattaches to a different binding site further along the actin filament
57
what is the equation for respiration?
glucose+oxygen -> carbon dioxide + water
58
what is the overall explanation for aerobic respiration?
the splitting of glucose to release carbon dioxide as a waste product, and reuniting hydrogen with oxygen with the release of a large amount of energy
59
what are the 2 types of respiration?
aerobic and anaerobic
60
what are the stages in aerobic respiration?
glycolysis, link reaction, Krebs cycle, oxidative phosphorylation
61
where does the link reaction occur?
the matrix of the mitochondria
62
where does glycolysis occur?
the cytoplasm
63
where does the Krebs cycle occur?
the matrix of the mitochondria
64
where does oxidative phosphorylation occur?
between the matrix and the inter-membrane space
65
how many ATP are made in aerobic respiration?
38 total ATP
66
what is involved in glycolysis?
the splitting of glucose
67
what are the 2 stages of glycolysis?
phosphorylation and oxidation
68
what is produced in glycolysis?
2x pyruvate, 2x ATP (net gain), 2x NADH
69
what 2 things are needed for the link reaction?
pyruvate and co enzyme A
70
what is produced in the link reaction? (per pyruvate not per glucose)
carbon dioxide, acetyl coA, and NADH
71
what is needed for the Krebs cycle?
acetyl coA
72
what is produced by the Krebs cycle? (per cycle not per glucose)
2x carbon dioxide, 3x NADH, FADH, ATP
73
where do the H atoms come from in oxidative phosphorylation?
they are released as the coenzymes are oxidised
74
where do the electrons go in oxidative phosphorylation?
move down ETC
75
where do the H+ ions get pumped in oxidative phosphorylation?
from the matrix into the inter-membrane space of the mitochondrion
76
what process occurs during oxidative phosphorylation?
chemiosmosis
77
what is the final electron acceptor in oxidative phosphorylation (aerobic respiration)?
oxygen
78
what is the final product of oxidative phosphorylation?
water
79
what are the stages of anaerobic respiration?
glycolysis and lactate fermentation
80
does aerobic respiration need oxygen?
yes
81
does anaerobic respiration need oxygen?
no
82
what is needed for lactate fermentation?
pyruvate and NADH
83
what is made in lactate fermentation?
lactate/ lactic acid
84
what is the issue with lactate?
accumulates in cytoplasm of cells, decreases pH, neutralises negatively charged groups on the active sites of enzymes, affects binding and activity of enzymes
85
what can lactate be converted into in lactate fermentation?
cells can convert into pyruvate and liver cells can convert into glucose
86
why can anaerobic respiration continue?
because the NAD needed for glycolysis is produced in lactate fermentation from the NADH produced in glycolysis
87
what happens after anaerobic respiration?
most lactate converted back to pyruvate, this takes lots of oxygen, some lactate converted to glucose and forms glycogen in liver or muscles
88
why can aerobic respiration not happen with no oxygen?
no oxygen to accept electrons from ETC, coenzymes not oxidised, NAD not regenerated, no NAD for Krebs cycle or link reaction
89
why do fast twitch fibres contain more glycogen than slow twitch?
fewer capillaries in fast twitch so less glucose supplied, more glucose needs to be supplied by a store
90
which type of muscle fibre uses aerobic respiration?
slow twitch
91
which type of muscle fibre uses anaerobic respiration?
fast twitch
92
which type of muscle fibre has lots of miochondria?
slow twitch
93
which type of muscle fibre has few mitochondria?
fast twitch
94
which type of muscle fibre contract quickly?
fast twitch
95
which type of muscle fibre contract slowly?
slow twitch
96
which type of muscle fibre is tired more quickly?
fast twitch
97
where are slow twitch muscle fibres found?
in back and posture muscles
98
where are fast twitch muscle fibres found?
in eye and leg muscles
99
what activities are fast twitch fibres adapted for?
short bursts of speed and power- sprint
100
what activities are slow twitch fibres adapted for?
endurance activities- marathon
101
which type of muscle fibre has high blood supply?
slow twitch fibres
102
what colour are fast twitch muscle fibres?why?
white as low levels of myoglobin (protein which stores oxygen)
103
what colour are slow twitch muscle fibres? why?
red as rich in myoglobin (protein which stores oxygen)
104
why does rate of aerobic respiration increase during exercise?
your muscles contract more frequently which means they require more energy
105
how does the body respond to exercise?- And why?
breathing rate and depth increase to obtain more oxygen and remove more carbon dioxide
heart rate increases to increase rate of blood flow to deliver oxygen and remove carbon dioxide from respiring muscle cells
106
what controls breathing rate?
the medulla oblongata contains two ventilation centres
107
what are the 2 ventilation centres in the medulla oblongata?
the inspiratory centre and the expiratory centre
108
how does inhalation occur?
the inspiratory centre sends impulses to the external intercostal and diaphragm muscles to make them contract and to inhibit the expiratory centre
this increases volume and decreases pressure in the lungs
air enters the lungs due to pressure in the lungs being lower than in the air
this stimulates stretch receptors
109
how does expiration occur?
the stimulated stretch receptors send nerve impulses to the medulla oblongata which inhibits the inspiratory centre
the expiratory centre (no longer inhibited) sends impulses to relax the diagram and intercostal muscles
lungs deflate and expel air
stretch receptors become inactive and inspiratory centre in no longer inhibited (cycle starts again)
110
what type of receptor detects changes in blood pH?
chemoreceptors
111
why does the pH of the blood decrease during exercise?
carbon dioxide dissolves in the blood plasma and forms carbonic acid which dissociates into hydrogen and hydrogen carbonate ions
112
what happens after the chemoreceptors detect a decrease in pH?
impulse sent to medulla oblongata which sends more frequent impulses to the intercostal muscles and diagram. increasing depth and rate of breathing
113
where are chemoreceptors found?
in the medulla oblongata, aorta, and carotid arteries
114
what are baroreceptors?
detect change in blood pressure and found in aorta and carotid arteries
115
how is heart rate increased due to low blood pressure or low pH?
baroreceptors detect low bp or chemoreceptors detect low pH, send impulses to the cardiovascular control centre, control centre sends impulses along sympathetic neurones which secrete the neurotransmitter noradrenaline, noradrenaline binds to receptors on the SAN causing it to fire more frequently, heart rate increases
116
what neurone pathway is used to increase heart rate and which neurotransmitter is used?
sympathetic pathway uses noradrenaline
117
how is heart rate decreased due to high blood pressure or high pH?
baroreceptors detect high bp or chemoreceptors detect high pH, send impulses to cardiovascular control centre, control center sends impulses along parasympathetic neurones which secrete the neurotransmitter acetylcholine, acetylcholine binds to receptors on the SAN causing it to fire less frequently, heart rate slows
118
what neurone pathway is used to slow heart rate and which neurotransmitter is used?
parasympathetic pathway uses acetylcholine
119
define minute ventilation
the amount of air that enters the lungs per minute
120
define inspiration
the process of taking in oxygen rich air
121
define expiration
the process of expelling air from the lungs
122
define spirometer
an apparatus for measuring the volume of air inspired and expired by the lungs
123
define residual volume
the small volume of air always retained in the lungs
124
define breathing rate
the number of breaths in one minute
125
define tidal volume
the amount of air that moves in or out during inspiration or expiration
126
define oxygen consumption
the amount of oxygen taken in, in one minute
127
define vital capacity
the maximum air which can be exhaled from the lungs
128
define total lung capacity
the maximum amount of air the lungs can hold (including residual air)
129
how do you find respiratory minute ventilation from a spirometer trace?
find tidal volume (difference between a peak and a trough)
find ventilation rate (number of breaths in one minute)
multiply together
130
how do you find oxygen consumption per minute from a spirometer trace?
find gradient of bottom of peaks
divide by time and multiply by 60
131
what has to be considered when selecting candidates for spirometry?
whether the candidate is healthy or meets criteria (age, health, gender)
132
what 3 points have to be included in a spirometry method?
soda lime to absorb carbon dioxide for health reasons
nose clip to ensure all air exhaled and inhaled goes through the spirometer
equipment sterilised between candidates to prevent spread of bacteria/viruses
133
what are the symptoms of altitude sickness?
breathing rate increases, headaches, blue lips, dizziness, feeling faint, hyperventilation, hypoventilation
134
why does altitude sickness occur?
as altitude increases, oxygen levels decrease
135
what are the 5 warming mechanisms?
vasoconstriction, boosting metabolic rate, shivering, hairs, less sweating
136
how does vasoconstriction increase body temp?
in the arterioles near the skin, the walls constrict minimising the heat radiated to the surroundings, blood passes further under the skin
137
how does boosting metabolic rate increase body temp?
most metabolic reactions are exothermic and so give out energy. thyroxine and adrenaline increase metabolic reactions
138
how does shivering increase body temp?
the muscles are effectors which rapidly contract providing heat
139
how do hairs increase body temp?
the erector pili muscles contract- causing hairs to stand, this forms an insulating layer of air around the skin
140
how does less sweating increase body temp?
sweat glands produce less sweat, less heat lost through evaporation
141
what are the 3 cooling mechanisms?
vasodilation, sweating, flattening of hairs
142
how does vasodilation decrease body temp?
arterioles near the skin dilate, increasing the amount of heat radiated to the surroundings
143
how does sweating decrease body temp?
this cools the skin via evaporation, as energy is lost with the water as it turns from liquid to a gas
144
how does the flattening of hairs decrease body temp?
the erector muscles in the skin relax, muscles act as effectors, stops hairs forming a layer of insulation
145
what is hyperthermic?
37 + (too hot)
146
what is hypothermic?
less than 37 (too cold)
147
why is hyperthermia worse than hypothermia?
hypothermia- the enzymes slow down due to lack of energy (could be recoverable)
hyperthermia- enzymes denature- not recoverable
148
which tissue is myogenic?
cardiac muscle
149
define myogenic
can beat without external stimulus
150
what is the normal heart rate?
60bpm
151
what is the SAN?
sinoatrial node- a group of cells in the wall of the right atrium which generates electrical impulses
152
where is the non-conducting tissue in the heart?
between the bottom of the atria, and the top of the ventricles
153
why is there a slight delay in the conduction of the heart?
the impulse cannot directly pass from the atria to the ventricles due to non-conducting tissue
154
what does the delay in the conduction of the heart allow?
time for the atria to complete contraction and the ventricles to fill with blood
155
what is the AVN?
atrioventricular node- a region of conducting tissue between the right atrium and right ventricle
156
where is the bundle of His and what is it made of?
in the septum of the heart, purkyne fibres
157
where do the ventricles contract from?
the apex/ bottom of the heart upwards
158
what are the 4 features of an electrocardiogram?
P wave, QRS complex, T wave, U wave
159
what causes the P wave on an ECG?
depolarisation of the atria
160
what causes the QRS complex on an ECG?
the depolarisation of the ventricles
161
why is the QRS complex the largest on an ECG?
ventricles have the largest muscle mass and so greater amount of electricity needed to depolarise
162
what causes the T wave on an ECG?
the repolarisation of the ventricles
163
what causes the U wave on an ECG?
scientists are unsure but may be the repolarisation of the Purkyne fibres
164
why is the repolarisation of the atria not shown on an ECG?
it occurs at the same time as the depolarisation of the ventricles and is smaller than the QRS complex
165
what is tachycardia?
when the heart beats too fast- resting heart rate 100+ bmp
166
what is bradycardia?
when the heart beats too slow- resting heart rate less then 60bpm
167
what is arrhythmia?
when the heart beats irregularly
168
define cardiac output
the volume of blood that is pumped by the heart (left and right ventricles) in one min (cm cubed per min)
169
define stroke volume
the volume of blood pumped out of the left ventricle during one cardiac cycle (cm cubed)
170
what is the equation for cardiac output?
cardiac output= heart rate x stroke volume
171
what are the 5 impacts of lots of exercise?
suppression of immune system
healthy weight maintenance
reduced blood pressure
improves wellbeing
wear and tear on joints
172
what are the 2 disadvantages of too much exercise?
suppression of immune system
wear and tear on joints
173
what are the 4 reasons why athletes have a higher risk of upper respiratory track infections?
lots of people in close proximity
travel- more likely to come into contact with pathogens
more cortisol and adrenaline which reduces inflammatory response and antibody production
lowers activity and production of T killer cells
174
how does too much exercise suppress the immune system?
higher levels of cortisol and adrenaline which reduces inflammatory response and antibody production
lowers activity and production of 'natural' killer cells
175
what are the effects of doing too little exercise?
increased risk of obesity, cardiovascular disease and diabetes (type 2)
176
where are thermoreceptors found?
in the hypothalamus
177
what are the 8 features of the endocrine system?
testes, ovaries, pancreas, adrenal gland, parathyroid, thyroid gland, pituitary gland, hypothalamus
178
what is the role of the pancreas?
regulates blood sugar by secreting insulin and glucagon
179
what is the role of the adrenal gland?
help to trigger the fight or flight response by secreting adrenaline and cortisol
180
what is the role of the testes?
secretes male sex hormones (testosterone)
181
what is the role of the ovaries?
secretes female sex hormones (oestrogen and progesterone)
182
what is the role of the parathyroid?
to help regulate the level of calcium in the blood
183
what is the role of the thyroid gland?
regulates metabolism by secreting thyroxine
184
what is the role of the pituitary gland?
secretes many hormones including LH and FSH
185
what is the role of the hypothalamus?
contains thermoregulatory centre
186
what are the 2 types of hormone?
peptide and steroid
187
which type of hormone cannot cross the cell membrane?- why?
peptide- due to charge
188
how do hormones which can cross the cell membrane cause an effect?
hormones enter cell, enter nucleus, bind to transcription factors
189
how do hormones which cannot cross the cell membrane cause an effect?
bind to receptors on the membrane, activates second messengers in the cytoplasm, these molecules activate enzymes called protein kinases, causes a cascade of reactions, cascade results in change in activity of transcription factors affecting gene expression
190
give an example of a hormone which can cross the cell membrane
thyroxine- regulates body temperature by changing metabolic rate
191
what is a transcription factor?
a protein that controls the transcription of genes by binding to a specific region of DNA
192
what are the 2 types of transcription factors? and what do they do?
activators (increases rate at which gene is expressed) and repressors (decrease gene expression)
193
what 2 things do transcription factors allow?
allow organisms to respond to their environment, ensure the correct genes are being expressed in the correct cells at the correct time
194
what is doping?
using drugs to enhance performance
195
what is the WADA?
world anti-doping agency
196
what is the advantage of blood doping?
more blood, more haemoglobin, more oxygen transportation
197
what is the advantage of human growth hormone?
increase of muscle mass and bone density
198
what is the advantage of insulin?
increases blood glucose levels for more respiration
199
what is an exocrine gland?
secretes hormones into a duct not directly into the blood
200
what is an endocrine gland?
secrets hormones directly into the blood
201
why don't all hormones effect every cell?
hormones only affect the target organs with the target cells which have the target receptors (so localised effect caused)
202
what are the stages of treatment for a joint injury?
1. RICE (rest, ice, compress, elevate) and take anti-inflammatory painkillers (ibuprofen)
2. surgical repair
203
what are the benefits of key-hole surgery?
lower risk of infection, shorter recovery time, shorter stay in hospital, less invasive, less blood loss,
204
what is a prosthesis?
an artificial version of a missing body part
205
what are some of the ways prostheses can be adapted to their uses?
may have rough surface on the bottom of a prosthetic foot to provide friction/grip for rock climbers, a plastic spacer can be placed between the metal pieces of a knee joint to provide cushioning and reduce the impact on the knee for people in sports
206
what are the 2 types of prosthesis?
articulated (with joints) or non-articulated (no joints/only knee)
207
what is the mechanism used to maintain homeostasis?
negative control
208
what is the effect of a negative feedback system?
reverses a change and brings the body back to normal limits
209
what 3 things are included in a negative feedback loop?
a receptor which detects a change/ stimulus
a coordination system to transfer information to different parts of the body (hormonal or nervous)
an effector which carries out a response (muscles or glands)
210
what is the effect of a positive feedback system?
enhances the effect of the original stimulus
211
give an example of a positive feedback loop
dilation of the cervix during labour-
cervix stretches, stretch receptors stimulated and send impulses to the brain, pituitary gland produces oxytocin which increases intensity of uterine contraction, pushes baby further down birth canal and stretches cervix further.
212
Give 3 performance enhancing drugs
Erythropoietin (EPO), testosterone, anabolic steroids
213
describe Erythropoietin
peptide hormone
made by kidneys
stimulates bone marrow to make new red blood cells
difficult to test if high levels are natural or not
risk of blood clotting exasperated by dehydration
binds to receptors in bone marrow, altering gene expression involved in haemoglobin formation
214
describe testosterone
steroid hormone
made from cholesterol
risks of high blood pressure, liver damage, kidney failure and heart disease
215
what are the 2 ways of detecting illegal performance enhancing drugs?
mass spectrometry
testosterone: epitestosterone ratio above 4:1
216
what is the absolutists view on performance enhancing drugs?
no drugs for improving performance should be allowed in sport and so maximum red cell count testing/ guidelines is not adequate as it allows for the use of drugs
217
what is the relativists view on performance enhancing drugs?
setting a maximum level for total red blood cell count is the only fair way to make sure that nobody is tempted to add to their natural count to a point where they may damage their bodies using either high-altitude training (legal) or EPO (illegal)
