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[OBSELETE] Edexcel - A Level Bio > Topic 7 > Flashcards

Topic 7 Flashcards

1
Q

How do movements work?

A
  • Produced by the coordinated action of several muscles
  • Where the muscles shorten
  • Pull on the bone and move the joint
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2
Q

What are agnostic muscles?

A
  • Since muscles can only pull not push
  • Two muscles are needed to move bone (extensor and flexor)
  • These muscles are agnostic and work against each other

****Bicep + Tricep, Quadceps + Hamstrings****

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3
Q

What do extensor muscles do?

A

A muscle that contracts the extension of a joint

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4
Q

What do flexor muscles do?

A

A muscle that reverses the movement of a joint

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5
Q

What are synovial joints?

A
  • Bones that articulate
  • Separated by cavity-filed synovial fluid enabling free movement
  • All have the same basic structure

Examples = Hip, Knee and Ankle

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6
Q

What is the synovial joint structure?

A
  • Bones held in position and controlled by ligaments
    • Restricting the amount of movement
  • Tendons attach muscles to bones
    • Enabling muscles to power joint movement
  • Cartilage protects bones within joints and provides support
    • Reducing wear and tear of joints
  • The synovial membrane secretes synovialal fluid
    • Which acts as a lubricant to reduce friction between bonds
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7
Q

What is the ball-and-socket joint?

A
  • A round head fits into a cup-shaped socket
  • Allowing for Omni-directional movement

**Like the hip**

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8
Q

What is the Gliding joint?

A
  • Two flat surfaces slide over one another

**Vertebrae where there are articulating surfaces****

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9
Q

What is the hinge joint?

A
  • Convex surface fits into a concave surface
  • Allowing for movement in two directions

**The elbow****

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10
Q

What is the pivot joint?

A
  • Part of the bone fits into a ring-shaped structure
  • Allowing rotation

**The joint at the top of the spine**

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11
Q

What are muscles made up of?

A
  • Made up of bundles of muscle fibres
  • Each fibre is a muscle cell (several cm in length)
    • Each cell is multinucleate (multiple nuclei)
    • Needed for shear size of muscle cell
    • From several cells fusing together
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12
Q

What is each muscle fibre made up of?

A
  • Numerous myofibrils
  • Made up of contractile(elastic) units called sarcomeres
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13
Q

What are the different parts of the muscle from largest to smallest?

A
  1. Tendons
  2. Which contain connective tissue which contains
  3. Bundle of muscle fibres which are surrounded by cell surface membrane
  4. Which contains muscle fibres which have
  5. Lots of myofibrils
  6. Which are sections of sarcomeres put together
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14
Q

What are sarcomeres made up of?

A
  • Made up of thin filaments made up of protein
  • Actin (I band) + Myosin ( A band, thicker)
  • Contracts happen when the two slide over each other in a coordinated way
  • This gives the sarcomeres the stripped appearance
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15
Q

What other molecules are associated with actin?

A
  • Troponin part of the thin filament
  • Tropomyosin unblocks to allow the myosin heads to bind
  • Involved in the sliding filament theory
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16
Q

What are the steps that come before sliding filament theory?

A
  1. Nerve impulse arrives at a neuromuscular junction
  2. Sarcoplasmic reticulum releases Ca2+
    1. Has membrane-bound sacs around myofibrils
  3. Ca2+ diffuse through the sarcoplasm
  4. Initiates sliding filament theory
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17
Q

What are the steps in sliding filament theory?

A
  1. Ca2+ attaches to tropin molecules causing movement
  2. Tropomyosin on actin filament shifts into position
    1. Exposing myosin-binding sites
  3. Myosin heads bind with binding sites forming cross bridges
  4. ADP and P are released from the myosin head
  5. Myosin changes shape causing movement of filaments with attached actin moving over the myosin
  6. ATP binds to the myosin head
    1. Myosin head detaches from actin
  7. ATPase on the myosin head hydrolyses ATP into ADP and P1
    1. Changing shape of myosin and returning to the upright position
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18
Q

What happens when muscles relax?

A
  • No more never impulse stimulation
  • Ca2+ pumped out of muscle sarcoplasm with ATP
  • Troponin and tropomyosin move back blocking myosin binding sites
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19
Q

What happens when there is a lack of ATP?

A
  • Cross bridges remain attached
  • Ca2+ cant be pumped out of sarcoplasm
  • Meaning myosin binding sites are unblocked
  • Causing Rigor Mortis
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20
Q

What is aerobic respiration?

A
  • A large amount of energy is released which is used for phosphorylation for ATP production
  • Splitting of glucose into CO2 and H2
    • H2 combines with O2 in atmosphere to create H20
  • Metabolic Pathway (series of chemical reactions)
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21
Q

What is the overall equation for aerobic respiration?

A
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22
Q

What are the four stages of aerobic respiration?

A
  • 1-3 are a series of reactions where the products are used in 4 to make ATP
  • Each reaction uses its own specific intracellular enzyme
    • The enzyme with the slowest rate is limiting
    • Determining the overall rate of respiration
      1. Glycolysis (Cytoplasm)
      2. Link reaction (Mitochondria)
      3. Krebs cycle (Mitochondria)
      4. Oxidative phosphorylation (Mitochondria)
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23
Q

What other can biological molecules be broken down?

A

**Other Complex Organic Molecules****

  • Fatty Acids
  • Amino Acids
  • Lipids
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24
Q

What is glycolysis?

A
  • Splitting of one molecule of glucose into two smaller molecules of pyruvate (3 Carbon Molecules)
  • Happens in the cell cytoplasm
  • Anaerobic process (doesn’t require oxygen)
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25
Q

What is the first stage of glycolysis?

A
  • Glucose is phosphorylated
    • 2 molecules of phosphates + ATP
  • Creating 2 molecules of triose phosphate + 2 molecules of ADP
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26
Q

What is the second stage of glycolysis?

A
  • Triose phosphate is oxidised (hydrogen)
    • Forming 2 molecules of pyruvate
  • NAD collects leftover hydrogen forming 2 reduced NAD
  • Produces 4 ATP
    • 2 used in first stage
    • Net gain of 2 ATP
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27
Q

What happens to the products of glycolysis?

A
  • Overall products are 2 reduced NAD + 2 Pyruvate molecules
  • Reduced NAD is used in oxidative phosphorylation
  • Pyruvate molecules are used for link reactions in a matrix of mitochondria
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28
Q

Where are the enzymes needed for the link reaction?

A
  • Located in the mitochondria matrix
  • Reduced NAD is produced in the link reaction is used by oxidative phosphorylation
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29
Q

What are the steps in the link reaction?

A
  1. Pyruvate is decarboxylated
    1. One carbon atom is removed
    2. Forming CO2
  2. NAD is reduced
    1. Collects hydrogen from pyruvate
    2. Turning pyruvate into acetate
  3. Acetate is combined with Co enzyme A
    1. Forming acetyl co enzymes A
  4. No ATP is produced in this reaction
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30
Q

What is produced for each glucose molecule in the link reaction and Krebs cycle

A
  • Two molecules of acetyl coenzyme A
  • Two CO2 molecules are released as a waste product
  • Two molecules of reduced NAD are formed in the last stage
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31
Q

What is the Krebs cycle simplified?

A
  • Series of oxidation-reduction reactions
  • Controlled by the specific intracellular enzyme
    • Found in the matrix of the mitochondria
  • The cycle happens once for every pyruvate molecule and twice for every glucose molecule
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32
Q

What is the first stage of the Krebs cycle?

A
  • Acetyl CoA (link reaction) combines with oxaloacetate to form citrate
  • Co-Enzyme A goes back to the link reaction to be reused
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33
Q

What is the second stage of the Krebs cycle

A
  • 6C citrate is converted to the 5C molecule
  • Decarboxylation , CO2 is removed
  • Dehydrogenation, Hydrogen is removed
    • Hydrogen is used to produce reduced NAD from NAD
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34
Q

What is the third stage of the Krebs cycle?

A
  • 5C molecule converted to 4C
  • Decarboxylation + Dehydrogenation
    • Produces **********reduced FAD + 2 reduced NAD**********
  • ATP is produced
    • The direct transfer of phosphate group and intermediate compound from ADP
  • Create has now been converted into oxaloacetate
    • Substrate-level phosphorylation
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35
Q

Where do all of the products of the Krebs cycle go?

A
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36
Q

What is oxidative phosphorylation?

A
  • Energy is carried by electrons
    • From reduced coenzymes
    • NAD and FAD
  • To produce ATP
  • Which involves the **********electron transport chain********** and **chemiosmosis**
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37
Q

What are the steps in oxidative phosphorylation?

A
  1. H atoms are released from reduced NAD and FAD
    • Oxidised to NAD and FAD which releases e-
  2. Electrons move down the transport chain
    1. Losing energy at each carrier
  3. Energy is used for pumping protons from the mitochondrial matrix to intermembrane space
  4. The concentration of proteins is higher in intermembrane space than mitochondrial membrane
    1. Forms electrochemical gradient
  5. Protons move down the gradient into the mitochondrial matrix
    1. Via ATP synthase
    2. Driving the synthesis of ATP from ADP and P
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38
Q

Where do the other products go in phosphorylation?

A
  • Movement of H+ for ATP production is chemiosmosis
  • The protons, electrons and oxygen from the electron transport chain form water
    • Where oxygen is an electron acceptor
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39
Q

How much ATP can be made from one glucose molecule?

A
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40
Q

What is the diagram for anaerobic respiration?

A
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41
Q

What are the steps in anaerobic respiration?

A
  1. Glucose is converted to pyruvate
    1. with 2 ATP being produced from 2ADP and 2P1
    2. 2 hydrogens then go onto regenerate reduced NAD
  2. Pyruvate is then converted to lactate
    1. Where 2 hydrogens from the regenerated reduced NAD allows for lactate to form
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42
Q

What doesn’t form during anaerobic respiration?

A
  • No NAD and FAD coenzymes are being replaced
  • Stops at the link reaction
  • pyruvate cannot form actyle A
  • meaning Krebs cant place
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43
Q

What are the effects of lactate?

A

Lactate is produced instead due to high CO2

  • Increased blood acidity
  • Where the enzymes’ amino acids have + and - charges meaning substrates can bind
  • Where the hydrogen ions build up and neutralise the negative charges meaning the substrate can’t bind to the active site
  • where there is vomiting and faint
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44
Q

What is post-exercise oxygen consumption?

A
  • AKA Oxygen debt
  • Oxygen is taken into oxidising lactate into water and CO2 in Krebs
  • Releasing energy to synthesise ATP
  • Lactate can also be converted into glycogen and stored in the liver or muscles
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45
Q

How does regenerating of ATP occur in anaerobic respiration?

A
  • Known as the ATP/CP
  • Immediate regeneration of ATP is achieved by ******creatine phosphate******
    • Stored in muscles
    • Can Be hydrolysed for energy
  • Where the phosphate from creatine phosphate is used with ADP to form ARP
  • Which starts as soon as the exercise starts
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46
Q

What are the three energy systems?

A
  • Aerobic respiration cannot meet demands for energy
    • Due to insufficient oxygen to the muscles from the lungs
  • This then means that ATP will be generated through the ATP/CP system
  • Then anaerobic preparation will allow for ATP regeneration
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47
Q

What is tidal capacity?

A
  • The volume of air we breath in and out is our **tidal capacity**
  • 0.5dm3
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48
Q

What is vital capacity?

A
  • Increase in breathing rate and depth of breathing (exercise)
  • The maximum volume of ait we can inhale and exhale is out ******vital capacity******
  • 3-4dm3
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49
Q

What is a spirometer?

A
  • Measures depth and frequency of breathing
  • Determine rate of oxygen consumption
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50
Q

How do you calculate the oxygen consumption?

A
  • Work out the decrease in volume between two points on the trace
    • Giving the volume of oxygen in a given time
  • Which you divide by the time for the fall in seconds giving the value in cm3 s-1
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51
Q

What is minute ventilation?

A
  • Volume of air taken into the lungs at one minute
  • Calculated by multiplying the tidal volume by the breathing rate
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52
Q

What happens during inhalation?

A
  • Ventilation center sends nerve impulses every 2-3 seconds
  • To intercostal and diaphragm muscles
    • Both contract during inhalation
  • Neck and upper chest muscles are also brought into play
53
Q

What happens during exhalation?

A
  • Lungs inflate stimulating stretch receptors (In bronchioles)
  • Sending impulses to ventilation center
  • Which stop impulses to the muscles causing them to relax
54
Q

What is exhalation caused by?

A
  • Caused by recoil of the lungs + gravity helping to lower the ribs
  • With not all air in the lungs being exhaled with each breath
    • Residual air mixes with air inhaled with each breath
55
Q

What stimulates control of breathing and heart rate?

A
  • Concentration of dissolved CO2 in the blood
    1. CO2 dissolves in the blood plasma making carbonic acid
    2. Which then dissociates into H+ and HCO3- ions lowering pH of blood
    3. Chemoreceptors (H+ sensitive in medulla oblongata) detect rise of H+ conc
    4. Impulses are sent to parts of the ventilation center
    5. Impulses are sent from ventilation center to stimulate the muscles involved in breathing
56
Q

What affect does CO2 conc have on breathing and heart rate?

A
  • Increase in CO2 / Increase in fall in pH = Increase in rate and depth of breathing
  • Where stronger impulses are sent which cause stronger and more frequent contraction of muscles
  • Maintaining a steeper conc gradient of CO2 between alveolar air and the blood
  • Ensuring efficient removal of CO2 from the blood and uptake of oxygen into the blood
57
Q

How is breathing controlled during exercise?

A
  • Motor cortex of brain controls movement
  • Which sends impulses which has a direct effect on the ventilation center in the medulla oblongata which sharply increases ventilation
    • Also increased in response to impulses reaching the ventilation center from stretch receptors in tendons and muscles that are moving
  • Chemoreceptors sensitive to H+ ions will also increase depth and rate of breathing via ventilation center
58
Q

What does cardiac output mean?

A
  • The volume of blood pumped by the heart in one minute
  • Increases during exercise
59
Q

How do you calculate cardiac output?

A
  • Depends on volume of blood ejected from the left ventricle
  • Cardiac output (CO) = stroke volume x heart rate
60
Q

What does stroke volume mean?

A
  • The volume of blood pumped out of the left ventricle each times the ventricle contracts
  • Increase by heart muscle being stretched to a greater extent causing stronger contractions
    • Forcing more blood to be expelled during diastole
61
Q

What is venous return?

A
  • Greater muscle action
  • More blood returns to the heart
  • During exercise
62
Q

What does myogenic mean?

A
  • Muscles that do not require any outside stimuli to contract and relax
  • Heart muscles are myogenic and can depolarise by themselves causing contraction
63
Q

What is the SAN

A
  • Sinoatrial Node / Pacemaker
  • Where depolarisation starts
  • Small area of muscle fibres in right atrium wall
64
Q

How does the SAN cause contraction?

A
  • Generates electrical impulse
  • Spreads across the right and left atria
  • Causing contraction a the same time
  • Sending impulses to the AVN (atrioventricular node)
    • Which is conducted to ventricles after delay
65
Q

Why is there a delay during heart contraction?

A
  • Delay ensures that atria have finished contracting
  • Before the ventricles have filled with blood before they contract
66
Q

What happens after the delay in heart contraction?

A
  • Signals react Purkyne fibres
  • Bundle of His = Right and Left bundles of Fibres
  • Conduct impulses rapidly to the apex of ventricles
    • Carry impulses to inner cells of the ventricles
    • Spreading through the entire ventricle wall
  • Causing depolarisation, beginning contraction
67
Q

What is the overall steps for starting contraction in the heart?

A
  1. Electrical impulses from SAN spread across atria walls causing contraction
  2. Impulses pass to ventricles via the AVN
  3. Impulse pass down the Purkyne fibres to the apex of the heart
  4. Impulses spread up through the ventricle walls causing contraction from the apex upwards. Blood is squeezed into arteries
68
Q

What is an ECG?

A
  • Detects and displays electrical activity on an electrocardiogram
  • Uses electrodes to record electrical currents produced in cardiac cycle
  • When depolarisation occurs the ECG detects it
69
Q

What is the waves in the QRS complex?

A
70
Q

What is the waves in the QRS complex?

A
  • Wave of depolarisation resulting in the contraction of the ventricles
  • Ventricular Systole
71
Q

What is the P wave?

A
  • Depolarisation of the atria
  • Leading to atrial contraction
  • Atrial Systole
72
Q

What is the PR Interval?

A
  • Time taken for impulses to be conducted from the SAN to the atria to the ventricles through the AVN
73
Q

What is the T wave?

A
  • Repolarisation of the ventricles during the heart’s relaxation phase
  • Diastole
74
Q

How do you measure heartrate using ECG?

A
  • 5 Large squares = 1s
  • 300 Large Squares = 1 minute
    1. Multiply large squares between QRS complexes by 0.2
    1. Gives time for one beat in seconds
      1. Then divide by 60 to get BPM
75
Q

What can ECG traces detect?

A
  • Abnormal heartbeats
  • Areas of damage
  • Inadequate blood flow
76
Q

What is tidal capacity?

A
  • The volume of air we breath in and out is our **tidal capacity**
  • 0.5dm3
77
Q

What is vital capacity?

A
  • Increase in breathing rate and depth of breathing (exercise)
  • The maximum volume of ait we can inhale and exhale is out ******vital capacity******
  • 3-4dm3
78
Q

What is a spirometer?

A
  • Measures depth and frequency of breathing
  • Determine rate of oxygen consumption
79
Q

How do you calculate the oxygen consumption?

A
  • Work out the decrease in volume between two points on the trace
    • Giving the volume of oxygen in a given time
  • Which you divide by the time for the fall in seconds giving the value in cm3 s-1
80
Q

What is minute ventilation?

A
  • Volume of air taken into the lungs at one minute
  • Calculated by multiplying the tidal volume by the breathing rate
81
Q

What happens during inhalation?

A
  • Ventilation center sends nerve impulses every 2-3 seconds
  • To intercostal and diaphragm muscles
    • Both contract during inhalation
  • Neck and upper chest muscles are also brought into play
82
Q

What happens during exhalation?

A
  • Lungs inflate stimulating stretch receptors (In bronchioles)
  • Sending impulses to ventilation center
  • Which stop impulses to the muscles causing them to relax
83
Q

What is exhalation caused by?

A
  • Caused by recoil of the lungs + gravity helping to lower the ribs
  • With not all air in the lungs being exhaled with each breath
    • Residual air mixes with air inhaled with each breath
84
Q

What stimulates control of breathing and heart rate?

A
  • Concentration of dissolved CO2 in the blood
    1. CO2 dissolves in the blood plasma making carbonic acid
    2. Which then dissociates into H+ and HCO3- ions lowering pH of blood
    3. Chemoreceptors (H+ sensitive in medulla oblongata) detect rise of H+ conc
    4. Impulses are sent to parts of the ventilation center
    5. Impulses are sent from ventilation center to stimulate the muscles involved in breathing
85
Q

What affect does CO2 conc have on breathing and heart rate?

A
  • Increase in CO2 / Increase in fall in pH = Increase in rate and depth of breathing
  • Where stronger impulses are sent which cause stronger and more frequent contraction of muscles
  • Maintaining a steeper conc gradient of CO2 between alveolar air and the blood
  • Ensuring efficient removal of CO2 from the blood and uptake of oxygen into the blood
86
Q

How is breathing controlled during exercise?

A
  • Motor cortex of brain controls movement
  • Which sends impulses which has a direct effect on the ventilation center in the medulla oblongata which sharply increases ventilation
    • Also increased in response to impulses reaching the ventilation center from stretch receptors in tendons and muscles that are moving
  • Chemoreceptors sensitive to H+ ions will also increase depth and rate of breathing via ventilation center
87
Q

What are slow twitch fibres?

A
  • Darker Muscle in the legs and body
  • Specialised for slower sustained contraction
  • Allowing for long periods of exercise
    • Through carrying out large amount of aerobic respiration
88
Q

What are the key features of slow twitch muscle fibres?

A
  • Many mitochondria
  • High amounts of respiratory enzymes
  • Large amounts of dark red pigment myoglobin
    • Protein that has a high affinity for oxygen
    • Releasing only when the oxygen concentration falls
  • Has numerous capillaries for oxygen supply
89
Q

What are fast twitch fibres?

A
  • Paler muscles that are lighter
  • Specialised to produce rapid intense contractions
  • ATP used is mostly from anaerobic
90
Q

What are the key features of fast twitch fibres?

A
  • Few mitochondria
  • Little myoglobin so few reserves for oxygen
  • Few associated capillaries
  • fatigue easily due to buildup of lactate from dependence on anerobic respiration
  • High glycogen content
91
Q

What is the need for homeostasis?

A
  • Body’s internal conditions must be maintained
  • Within a narrow range of the cells optimum condition
  • Which includes conc of solutes with water and pH levels
92
Q

How does negative feedback work?

A
  1. Controlled condition has a norm value/set point (optimum value)
  2. Receptors connected to control center detect deviations from norm
  3. Which turns on or off effectors (muscles or glands) to bring condition back to norm value

**Controlled by control center by hormones or impulses**

93
Q

How does positive feedback work?

A
  • Opposite of negative feedback
  • Output from control center deviates further from set point
  • Rare but important in certain situations like child birth
94
Q

What is thermoregulation?

A
  • Control of body temperature
  • 37.5 degrees allows for enzyme controlled reactions to occur at reasonable rate
95
Q

What happens when the body is too hot?

A
96
Q

What happens when the body is too cold?

A
97
Q

How does sweating help reduce heat?

A
  • Sweat released from sweat gland via sweat ducts
    • Stimulated by heat loss center in hypothalamus
  • Which evaporates taking heart energy away from the skin
98
Q

How does hair help increase heat?

A
  • Erector muscles raise hair in cold weather
  • Producing goose bumps which trap layer of air insulating bodies
  • Not very effective due to low amounts of hair on the skin
99
Q

How does vasocontraction work?

A
100
Q

How does the heart get enough oxygen during exercise?

A
  • Increase cardiac output
  • Faster rate of breathing
  • Deeper breathing
101
Q

What is aerobic capacity?

A

The ability to:

  • Take in oxygen
  • Transport oxygen
  • Use oxygen
102
Q

How does diastole change stroke volume and cardiac output?

A
  • During exercise the heart fills with a larger volume of blood
  • Heart muscle is stretched more
  • Causing stronger contractions expelling more blood
  • ******************Increasing stroke volume and cardiac volume******************
103
Q

How do you carry out an ECG?

A
  1. Electrodes are attached to a persons chest and limbs
  2. Recording electrical currents during the cardiac cycle
    1. Changes in polarisation of the cardiac muscles
    2. Sends an electrical current which can be detected at the skins surface
104
Q

What controls the heart rate?

A
  • Controls the cardiovascular control center
  • In the medulla oblongata in the brain
105
Q

How does the brain slow down heartrate?

A
  • Impulses are sent from the vague nerve
    • Decelerator nerves
    • Parasympathetic nerve
106
Q

How does the brain increase heartrate?

A
  • SAN node sends impulses to the heart
    • Accelerator nerve
    • Sympathetic nerve
107
Q

What does the brain do to the heart at the sight of a dangerous stimulus?

A
  1. Skeletal muscles contract
    1. Stretch receptors in muscles and tendons are stimulated
  2. Sending impulses to the cardiovascular center
    1. Which raises heartrate via the sympathetic nerve
  3. Causing an increase in venous return
    1. Increasing cardiac output and stroke volume
  4. Transporting oxygen to fuel muscles more quickly
108
Q

What is the links and symptoms of overexercising?

A
  • Sore throats and flu-like symptoms
  • From upper respiratory tract infections, URTI’s
  • U Shaped relationship between infection risk and exercise amount
109
Q

What are the two main factors that contribute to higher infection rates?

A
  • Increased exposure to pathogens
    • Suppressed immunity with hard exercise
  • Location of competition and amount of travel
    • Exposes the athlete to greater range of microorganisms
110
Q

What are natural killer cells?

A
  • Exercise increases amount of natural killer cells (lymphocyte)
    • NO antigen recognition
    • Non specific immunity against URTI’s
  • Activated by cytokines and interferons
  • Targets cells that don’t display self markers
    • Kills through protein perforin
    • Makes pores in the cell surface membrane
    • Causing apoptosis
111
Q

What effect does overexercising have on the immune system?

A

Decrease in

  • Natural killer cells
  • Phagocytes
  • B Cells
  • T Helper cells - reducing activation of lymphocytes with cytokines
112
Q

What effects does overexercising have on the knees

A
  1. Articular Cartilage covering surfaces on the bone wear away
    1. Bones grind against each other
    2. Inflammation + Arthritis
  2. Patellar tendonitis - kneecap doesn’t glide smoothly across femur
    1. Due to articular cartilage damage
  3. Bursae (fluid sacs) - cushions bones, tendons and ligaments swell up with extra fluid
    1. Sacs may push against other tissues in the joint
    2. Inflammation and tenderness
  4. Damage to ligaments
    1. Sudden twisting or abrupt movements of knee joints
113
Q

What is keyhole surgery?

A
  • Uses fibre optics or minute video cameras
  • Repair damaged joints to remove diseased organs through small holes
  • Which require small incisions which can recover quickly
  • Surgery on joints = arthroscopy
114
Q

What is prothesis?

A
  • Artificial body parts used y someone with disability
  • Enabling them to regain a degree of normal function or appearance
  • Can be used to replace damaged or diseased joints that hasn’t reponed to other solutions
115
Q

What are the advantages of exercising?

A
  1. Increases arterial vasodilation lowering blood pressure reducing CVD
  2. Increases HDLs transporting cholesterol, reduces LDLs
  3. Energy budget ensures healthy weight
  4. Increased insulin sensitivity for muscles improving blood glucose regulation reducing risk of type 2 diabetes
  5. Increases bone density delaying onset of bone wasting disease osteoporosis)
  6. Reduces risk of cancers and improves metal health
116
Q

What does the pituitary gland do?

A
  1. Growth hormone - Controls growth
  2. Follicle-stimulating hormone - controls testes and ovaries
  3. Antidiuretic hormone - causes reabsorption of water in kidneys
117
Q

What does the thyroid gland do?

A
  • Releases Thyroxine
  • Raises basal metabolic rate
118
Q

What does the adrenal gland do?

A
  • Releases adrenaline
    • Raises basal metabolic rate
    • Dilates blood vessels
    • Prepares body for action
119
Q

What does the pancreas do?

A
  • Releases insulin
  • Lowers blood glucose concentration
120
Q

What does the ovary do?

A
  • Releases oestrogen
  • Promotes development of ovaries and female secondary sexual characteristics
121
Q

What does the testis do?

A
  • Releases testosterone
  • Promotes development of male secondary sexual characteristics
122
Q

What is the general way that hormones work?

A
  • Targets cells modifying their activity
  • Enter target cells or bind to complementary receptor molecules on the outside of the cell membrane
  • Characteristic responses caused by hormones effect on enzymes
    • Some bind to receptors on cell surface
    • Some produce a second messenger activating enzymes
    • Some control transcription directly or indirectly
123
Q

How does peptide hormones effect cells?

A
  • Peptide hormones (EPO, insulin) cant pass through cell membranes so they bind to target cell receptors
    • Due to having charge
  • Binding causes another molecule in the cytoplasm (secondary Messager) to be released
    • Bringing chemical changes within cell affecting gene transcription
124
Q

How does steroid hormones effect cells?

A
  • Formed from lipids with complex ring structures
  • Passes through cell membrane binding to receptors within cytoplasm
  • Once activated hormone receptor complex acts as a transcription factor controlling enzyme synthesis
125
Q

What is erythropoietin?

A
  • EPO = peptide hormones used to treat anemia
  • Produced in kidneys
  • Stimulating new red blood cells in bone marrow
  • Can be synthesised using DNA technology
126
Q

How does erythropoietin work?

A
127
Q

What is testosterone?

A
  • Steroid hormone made from cholesterol
  • Produced in testes in small amounts by the adrenal glands
  • Development of sex organs and sexual characteristics like aggression
  • Binds to androgen receptors on target tissues modifying gene expression
    • Altering development of the cell
    • Increasing anabolic reactions like protein synthesis in muscle cells increasing size and strength
128
Q

What is creatine?

A
  • Considered nutrition supplement
  • Amino-acid derived
    • Found in meat and fish
    • Carries to skeletal muscle tissue
  • Increases creatine phosphate allowing for improvement in short burst exercises
  • Increasing muscle mass and strength with decreases in recovery time

[OBSELETE] Edexcel - A Level Bio (9 decks)

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