Animal Responses Flashcards

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1
Q

Define the term “central nervous system”.

A

Consists of the brain and spinal cord.

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2
Q

Define the term “peripheral nervous system”.

A

Consists of all the neurones that connect the CNS to the rest of the body. These are the sensory neurones which carry nerve impulses from the receptors to the CNS, and the motor neurones which carry nerve impulses away from the CNS to the effector.

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3
Q

Define the term “somatic nervous system”.

A

Under conscious control, used when you voluntarily decide to do something i.e. moving a muscle in your arm.

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4
Q

Define the term “autonomic nervous system”.

A

Under subconscious control and happening all the time. It is involuntary - there is no decision making. I.e. heart beat, digesting food. Carries nerve impulses to glands and smooth muscle.

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5
Q

Define the term “sympathetic nervous system”.

A

A division of the autonomic nervous system. Initiates flight or fight response i.e. increased heart rate. Has noreadrenaline as a neurotransmitter.

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6
Q

Define the term “parasympathetic nervous system”.

A

A division of the autonomic nervous system. Initiates rest responses (Peace = Parasympathetic). Includes decreases in heart rating or breathing after exercise.

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7
Q

State 5 differences between the autonomic nervous system and the somatic nervous system.

A

1) Somatic is voluntary and autonomic is involuntary.
2) Autonomic controls things that are happening constantly, somatic is only sometimes.
3) Neurones in somatic nervous system are mostly myelinated, mostly unmyelinated in autonomic.
4) Somatic carries the impulse to skeletal muscles, autonomic carries the impulse to smooth, cardiac and glands.
5) In somatic, one neurone to connect CNS with effector. Autonomic, it is two neurones.

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8
Q

Define the term “antagonistic system” in relation to the sympathetic and parasympathetic nervous systems, and outline how they co-ordinate responses.

A

The parasympathetic and sympathetic nervous system have an antagonistic (opposing) effects on the organs they control.
The action of one system opposes the action of the other. Under normal conditions impulses are passing along the neurones of both systems at a relatively low rate. Changes to conditions lead to an altered balance between the two systems which leads to an appropriate response.

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9
Q

Draw a table to compare the structure and function of the sympathetic and parasympathetic nervous systems.

A
  • PNS is most active in sleep and relaxation.
  • SNS Is most active in times of stress.
  • SNS neurones of a pathway are linked at a ganglion just outside the spinal (long post-gangleonic neurones and short pre-gangleonic neurones).
  • PNS neurones of a pathway are linked at a ganglion within the target tissue (long pre-gangleonic neurones and short post-gangleonic neurones).
  • SNS uses noreadrenaline as a neurotransmitter and PNS uses acetylcholine.
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10
Q

Label a diagram of the human brain showing the location of the cerebrum, cerebellum, medulla oblongata, hypothalamus and pituitary gland.

A

See. 362

  • Main top bit is the cerebrum.
  • Skull surrounds the brain.
  • The corpus callosum is located just underneath the cerebrum.
  • Pituitary gland comes off the hypothalamus, and they are both under the corpus callosum.
  • Hypothalamus comes off the medulla oblongata.
  • The cerebullum is leafy structure which is connected to the spinal cord.
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11
Q

Describe the structure of the cerebrum.

A
  • Highly convoluted which increases its surface area considerably and therefore its capacity for complex activity.
  • Its split into left and right halves known as cerebral hemispheres. Each hemisphere controls one half of the body and has discrete areas which perform specific functions.
  • The outer layer of the cerebral hemispheres is known as the cerebral cortex.
  • It has six areas; the frontal lobe, parietal lobe, occipital lobe, the temporal lobe, medulla oblongata and cerebellum.
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12
Q

Describe the role of sensory areas, association areas and motor areas of the cerebral cortex.

A

1) Sensory areas - receives information from receptor cells located in the sense organs. The size of the sensory area allocated is in proportion to the number of receptors cells present in the body part.
2) Association areas - Info passed on from sensory areas to be analysed and acted upon
3) Motor areas - Impulses come into motor areas where motor neurones send out impulses e.g. to move skeletal muscles. Size of motor area in proportion to the number of the motor endings present.

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13
Q

Describe the role of the cerebellum in coordinated muscular movement.

A

Controls unconscious functions such as muscular movement, posture, balance and non-voluntary movement. It does not initiate movement but co-ordinates. Cerebellum receives information from the organs of balance in the ears and information about the tone of muscles and tendons. Then relays this information to motor areas.

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14
Q

Describe the structure, location and role of the pituitary gland.

A
  • Found at the base of the hypothalamus.
  • Controls most of the glands in the body.
  • Divided into the anterior pituitary and the posterior pituitary.
  • Anterior pituitary produces 6 hormones, including one which is involved in reproduction and growth.
  • Posterior pituitary stores and releases hormones produced by the hypothalamus, such as ADH.
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15
Q

Describe the roles of medulla oblongata.

A
  • Contains many important regulatory centres of the autonomic nervous system.
  • These control reflex activities such as ventilation, heart rate and peristalsis.
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16
Q

Describe the roles of the hypothalamus.

A
  • Main controlling region of the autonomic nervous system.
  • Has two centres, one for the sympathetic and the parasympathetic.
  • Controls patterns of behaviour such as feeding, sleeping and aggression.
  • Monitoring the composition of blood plasma, such as concentration of water and blood glucose therefore it has a very rich blood supply.
  • Producing hormones because it is an endocrine gland.
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17
Q

Define the term “reflex action”.

A

Involuntary response to a sensory stimulus.

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18
Q

Define the term “reflex arc”.

A

The pathway of neurones involved in the reflex action.

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19
Q

Define the term “stimulus”.

A

A detectable change in the internal or external environment.

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20
Q

Define the term “receptor”.

A

Extrinsic glycoproteins that binds to chemical, triggering a response by the cell.

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21
Q

Define the term “effector”.

A

Muscle or gland which carries out body’s response to a stimulus.

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22
Q

Define the term “response”.

A

The way a body reacts to a stimulus.

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23
Q

Draw, label and annotate a diagram to show the arrangement of neurones in the “withdrawal of the hand from a heat stimulus” reflex arc and the actions that occur in the stimulus-response pathway.

A

1) Stimulus heat from candle flame.
2) Thermoreceptor in skin detects heat.
3) Sensory neurone passes nerve impulse to spinal cord.
4) Relay neurone passes impulses across the spinal cord.
5) Motor neurone passes impulses to the muscle.
6) Effector contracts.
7) Response hand is moved quickly away from flame.

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24
Q

Describe the characteristics of reflex actions and the survival value of them.

A
  • Reflexes avoid the body being harmed or reduce the severity of any damage.
  • Involuntary responses, the decision-making regions of the brain are not involved, therefore the brain is able to deal with more complex responses. It prevents the brain from being overloaded.
  • Reflexes do not have to be learnt, they are present from birth to death and therefore provide immediate protection.
  • Extremely fast, the reflex arc is very short. It normally only involves one or two synapses, which are the slowest part of nervous transmission.
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25
Q

Draw, label and annotate a diagram to show the arrangement of neurones in the “knee jerk” reflex arc and the actions that occur in the stimulus-response pathway.

A

1) Stimulus is when the leg tapped just below the knee cap, it stretched the patellar tendon.
2) Stimulus initiates a reflex arc which causes the extensor muscle on top of the thigh to contract. At the same time, a relay neurone inhibits the motor neurone of the flexor muscle, causing it to relax.
3) This contraction co-ordinated with the relaxation of the antagonistic flexor hamstring muscle causes leg to kick.

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26
Q

Explain the “survival value” of the knee jerk reflex.

A
  • Helps maintain posture and balance.
  • Lack of the reflex will indicate nervous problems and the multiple oscillation of the leg may be a sign of a cerebellar disease.
27
Q

Draw, label and annotate a diagram to show the arrangement of neurones in the “corneal blinking” reflex arc and the actions that occur in the stimulus-response pathway.

A

1) Stimulus can be corneal irritation like a foreign body entering the eye, a loud sound more 40-60 dB or as a results of a very bright light. Reflex occurs in the brain, not spinal cord, so it is a cranial reflex.
2) Impulse triggered by stimulus and travels along the sensory neurone.
3) The impulse then passes through a relay neurone in the lower brain stem.
4) Impulses are then sent along branches of the motor neurone to initiate a motor response to close the eyelids.
5) The reflex initiated a consensual response - this means that both eyes are closed at the same time.

28
Q

Describe other stimuli that can trigger the blinking reflex and describe the response that occurs.

A

1) Bright light = optical reflex. Causes iris to contract, limiting amount of light that can enter the eye, protecting retina from damage.
2) Foreign body enters eye/ loud sound = corneal reflex.

29
Q

Explain the “survival value” of the blinking reflex.

A
  • Presence of reflex indicates that lower brain stem is functioning.
  • Presence or absence of reflex is used to determine wether a patient is brain dead.
  • Protects retina from damage.
30
Q

State the two systems which coordinate mammalian responses to stimuli.

A
  • Nervous and endocrine system.
31
Q

Define the term “fight or flight response”.

A
  • A series of physical responses intended to help mammals survive by preparing the body to either run or fight.
32
Q

Draw a diagram showing how the hypothalamus uses both the nervous system and the endocrine system to coordinate the physiological responses associated with the “fight or flight” response.

A

See pp.397 or notes.
Left Side:
1) Sympathetic nervous system is activated.
2) This activates the adrenal medulla which releases noradrenaline and adrenaline. These hormones go into the bloodstream.
3) Simultaneously the sympathetic nervous system sends impulses which activate glands and smooth muscles.
4) Hypothalamus also activates adrenal-cortical system by released CRF.
5) Pituitary gland then releases a hormone called ACTH.
6) ACTH arrives at the adrenal cortex and releases approximately 30 hormones which enter the bloodstream.
7) Combination of this neuronal and hormonal activity results in fight or flight response.

33
Q

State the role of corticosteroid releasing factor (CRF) in the “fight or flight” response.

A
  • Stimulates the pituitary gland to released ACTH.
34
Q

State the role of adrenocorticotropic hormone (ACTH) in the “fight or flight” response.

A
  • Stimulates the adrenal cortex to release around 30 hormones into the bloodstream.
35
Q

List 7 physiological changes that occur during the “fight or flight” response and describe the purpose of each.

A

1) Heart rate increases - to pump more oxygenated blood around the body.
2) Pupils dilate - to take in as much light as possible.
3) Arterioles in skin constrict - more blood to major muscle groups, brain, heart and muscles of ventilation.
4) Blood glucose levels increase - increase respiration to provide energy for muscle contraction.
5) Smooth muscle of airways relaxes - to allow more oxygen into lungs.
6) Non-essential systems (like digestion) shut-down - to focus resources on emergency functions.
7) Difficulty focusing on small tasks - brain solely focused on where threat is coming from.

36
Q

Define the term “first messenger”.

A

An extracellular substance (such as a hormone) that binds to a cell-surface receptor and initiates activity within the cell.

37
Q

Define the term “second messenger”.

A

Molecules that relay signals received at receptors on the cell surface to target molecules.

38
Q

State the two types of hormone and identify which type adrenaline is.

A
39
Q

Explain how the properties of the two types of hormone affect the mechanism by which they can influence cells.

A
40
Q

Draw a flow chart to show how adrenaline has its effect on cells.

A

1) Hormone adrenalin fuses to receptor site and activates the enzyme adenlyly cyclase.
2) The activated enzyme converts ATP to cyclic AMP which acts as a seconder messenger that activates other enzymes called protein kinases which trigger other enzymes.
3) Enzymes are convert glycogen to glucose.

41
Q

Explain why the second messenger system is said to have a “cascade effect”, and explain the usefulness of this effect.

A

One hormone molecule can cause many cAMP molecules to be formed. At each stage, the number of molecules increases so it is said to have a cascade effect.

42
Q

What is the main function of adrenaline in the fight or flight response?

A

Adrenaline is hydrophilic so it cannot pass through different tissue types. Adrenaline binds with receptors on the surface of a liver cell membrane and triggers a chain reaction inside the cell so that the liver cells undergo glycogenolysis. This means more glucose is released into the bloodstream, so more respiration can take place, providing more energy for muscle contraction.

43
Q

Suggest how adrenaline can have different effects on different tissue types.

A

cAMP activates different molecules in different cells and different types of interactions between the receptor protein and adenylyl cyclase

44
Q

Explain why there is a need to be able to alter heart rate in humans.

A

When you exercise, or in times of danger, it is essential that the heart rate increases to provide the extra oxygen required for increased respiration.

45
Q

Describe two ways in which the heart’s action changes in order to supply more oxygen and glucose to cells.

A
  • Impulses sent by the sympathetic nervous system to accelerator nerve.
46
Q

Define the term “heart rate”.

A

The number of heart beats per unit of time, usually per minute.

47
Q

Define the term “stroke volume”.

A

The amount of blood pumped by the left ventricle of the heart in one contraction.

48
Q

Define the term “cardiac output”.

A

The amount of blood the heart pumps through the circulatory system in a minute.

49
Q

Write an equation for cardiac output.

A

Cardiac output = stroke volume x heart rate

50
Q

State 4 factors that are detected by the body which affect heart rate – for each state where they are detected and by what.

A
  • PH (carbon dioxide concentration).

- Blood pressure.

51
Q

State which part of the brain controls heart rate, and describe how is role of controlling heart rate is divided into two centres.

A
  • The medulla oblongata controls heart rate.
  • It is divided into two centres, one that increases heart rate and one that decreases heart rate.
  • The centre that increases heart rate sends impulses through the sympathetic nervous system which are transmitted by the accelerator nerve.
  • The centre that decreases heart rate sends impulses through the parasympathetic nervous system which are transmitted by the vagus nerve.
52
Q

Which nervous system is heart rate controlled by?

A

Heart rate is involuntary so it is controlled by the autonomic nervous system.

53
Q

State the two receptors that detect changes in the blood and provide info to effect heart rate.

A
  • Chemoreceptor (chemical receptor).

- Baroreceptor (pressure receptor).

54
Q

What do chemoreceptors detect and how does this effect heart rate?

A
  • Chemoreceptors are located in the aorta, the carotid artery and the medulla.
  • They are sensitive to PH changes so they detect the level of carbon dioxide in the blood.
  • If the carbon dioxide level increases, the PH of the blood decreases because of the carbonic acid formed when CO2 interacts with water.
  • A response is triggered to increase heart rate, blood therefore flows more quickly to the lungs so carbon dioxide can be exhaled.
  • When CO2 level in the blood decreases the PH rises. This is detected by the chemoreceptors in the walls of the carotid artery and the aorta. This results in a reduction of the frequency of the nerve impulses being sent to the medulla oblongata. In turn, this reduces the frequency of impulses being sent to the SAN via the sympathetic nervous system and thus heart rate decreases back to its normal level.
55
Q

What do baroreceptors detect and how does this effect heart rate?

A
  • Present in the aorta, the carotid artery and vena cava.
  • Detect changes in the pressure.
  • If blood pressure is too high, impulses are sent to the medulla oblongata centre which decreases heart rate.
  • The medulla oblongata sends impulses along the parasympathetic neurones to the SAN which decreases the rate at which the heart beats.
  • This reduces blood pressure back to normal.
56
Q

What factor, other than pressure and PH, effects heart rate? How does this effect heart rate?

A
  • The presence of hormones.
  • In times of stress, adrenalin and noradrenalin are released. These hormones effect the pacemaker region of the heart - they speed up your heart rate by increasing the frequency of impulses produced by the SAN.
57
Q

Draw a flow chart to show the effect of exercise on cardiac output.

A

See pp.401

1) Increased muscular/ metabolic activity.
2) More carbon dioxide produced by tissues from increased respiration.
3) Blood PH is lowered.
4) Centre in the medulla oblongata that speeds up heart rate, increases frequency of impulses to the SAN via the sympathetic nervous system.
5) SAN increases heart rate.
6) Increased blood flow removes carbon dioxide faster.
7) Carbon dioxide level returns to normal.

58
Q

Describe when a “Student’s t-test” would be used to analyse data.

A

Student’s T-test is used to compare the mean values of two sets of data. To use this test the data collected must be normally distributed and enough data should be collected to calculate a reliable mean.

59
Q

Describe when a paired t-test would be used and when an unpaired t-test would be used to analyse data.

A

An un-paired T-test compares two different subjects/ two independent groups (e.g. height in female and heigh in males). A paired T-test compares the same subjects/ one group but before or after an event or manipulation.

60
Q

Describe the meaning of each of the symbols in the equation for calculating the t-value (the test statistic) from a paired Student’s t-test.

A

σ = Standard deviation
n1 / n2 = total number of values in sample 1 and sample 2
x̅1 / x̅2 = mean of population 1 and population 2

61
Q

Describe the meaning of each of the symbols in the equation for calculating the t-value (the test statistic) from an un-paired Student’s t-test.

A

σ = Standard deviation
n1 / n2 = total number of values in sample 1 and sample 2
x̅1 / x̅2 = mean of population 1 and population 2

62
Q

Describe how to carry out a un-paired student’s T-test.

A

1) State the null hypothesis: ‘There will be no significant difference between the length of leaves growing in the light and the length of leaves growing in the shade’.
2) Subtract the mean of sample two from the means of sample 1.
x̅1 - x̅2 =
3) For both populations, square the standard and divide by the number in the sample.
Population 1: σ2/ n1 =
Population 2: σ2/ n2 =
4) Add these values together.
(σ2/ n1 + σ2/ n2) =
5) Square root this value.
√(σ2/ n1 + σ2/ n2)
6) Put values into equation.
(x̅1 - x̅2) / √(σ2/ n1 + σ2/ n2) = T- value.
7) Calculate degrees of freedom using formula:
df (degrees of freedom) = (n1 + n2) - 2
8) Then find the critical value —

63
Q

Describe how to carry out a un-paired student’s T-test.

A

1) State the null hypothesis: ‘There will be no significant difference between the length of leaves growing in the light and the length of leaves growing in the shade’.
2) Subtract the mean of sample two from the means of sample 1.
x̅1 - x̅2 =
3) For both populations, square the standard and divide by the number in the sample.
Population 1: σ2/ n1 =
Population 2: σ2/ n2 =
4) Add these values together.
(σ2/ n1 + σ2/ n2) =
5) Square root this value.
√(σ2/ n1 + σ2/ n2)
6) Put values into equation.
(x̅1 - x̅2) / √(σ2/ n1 + σ2/ n2) = T- value.
7) Calculate degrees of freedom using formula:
df (degrees of freedom) = (n1 + n2) - 2
8) Then find the critical value —