Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A2 Biology > Plant And Animal Responses > Flashcards

Plant And Animal Responses Flashcards

(92 cards)

Start Studying
1
Q

What alters the frequency of the excision waves?

A

The cardiovascular centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where do you find the cardiovascular centre?

A

In the medulla oblongata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 2 nerves that alter heart rate?

A

Accelerans and Vagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which neurotransmitter increases heart rate?

A

Noradrenaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which neurotransmitter decreases heart rate?

A

Acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which neurotransmitter is released by the vagus nerve?

A

Acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which neurotransmitter is released by the accelerans nerve?

A

Noradrenaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of the cardiovascular centre?

A

To coordinate an appropriate output to effect the heart rate when inputs from environment are received

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the two input receptors to the cardiovascular centre?

A

Chemoreceptors

Stretch receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where can stretch receptors be found?

A

In the muscles and carotid sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the function of the stretch receptors in the muscle?

A

They detect movement of limbs. To inform that extra oxygen may be needed. Leads to an increase in heart rate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Function of chemoreceptors?

A

Monitor pH of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where are chemoreceptors found?

A

In the carotid artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where is the carotid sinus?

A

In the carotid artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Example of when chemoreceptors will send action potentials?

A

During exercise more carbon dioxide is produced from respiration. This combines with water to make a weak carbonic acid. Chemoreceptors will send action potential to increase heart rate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Fuction of stretch receptors in carotid sinus?

A

Monitors blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do stretch receptors respond?

A

If blood pressure becomes too high the stretch receptors will send action potential to lower heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 3 types of muscle?

A

Skeletal, cardiac and involuntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Other words for skeletal muscle?

A

Striated or voluntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe Involuntary smooth muscle diagram?

A

Individual cells- each containing a nucleus and bundles of actin and myosin
Spindle shaped
At rest- 500 micrometers long and 5 micrometers wide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe involuntary muscle contractions?

A

Contracts slowly and regularly. Does not tire quickly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What system controls smooth muscle?

A

The autonomic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where is involuntary muscle found?

A

In the walls of tubular structures

Eg- blood vessels and digestive system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How is involuntary muscle arranged?

A

In longitudinal and circular layers that oppose eachother

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Describe cardiac muscle?
Individual cells form fibres which branch to form cross bridges
26
Why is cardiac muscle arranged the way it is?
The cross bridges ensure that electrical stimulation spreads evenly over the walls and chambers. Also to ensure a squeezing action.
27
How are the cells in cardiac muscle joined?
By intercalated discs
28
What are intercalated discs?
Specialised cell surface membranes fused to produce gap junctions to allow diffusion between cells
29
Function of intercalated discs?
Allow for rapid pass of action potentials across the cardiac muscle fibres
30
Other facts about cardiac muscle?
Myogenic | Doesn't fatigue easily
31
How does skeletal muscle cause movement?
Contraction of the muscle causes bending or straightening of the joint
32
How is skeletal muscle arranged?
In antagonist pairs | When one contacts the other elongates
33
Describe the skeletal muscle cells?
Contains sarcoplasm Many mitochondria An extensive sarcoplasmic reticulum
34
Describe the skeletal muscle fibres?
100 micrometers in diameter Multinucleate Surrounded by a membrane called sarcolemmaa
35
How are the skeletal fibres arranged?
Into myofibrils- divided into a chin of subunits called sarcomeres
36
How are actin and myosin arranged?
In a banded pattern | Gives striated appearance
37
How does skeletal muscle contract?
Quickly and powerfully | Fatigues easily
38
What are the 2 types of protein filaments?
Thin filaments- light band | Thick filaments- dark band
39
What does the z line do?
Holds together the thin filaments
40
Do the filaments overlap?
Yes, except in the middle of the dark band (the H zone)
41
What is the distance between two z lines?
Sarcomere
42
What are the filaments surrounded by?
A sarcoplasmic reticulum
43
What are the thin filaments?
Actin
44
What other molecules does the thin filaments consist of?
Troponin | Tropomysin
45
Describe troponin?
Globular protein | Consists of 3 polypeptides
46
Function of troponin?
Has 3 binding sites to bind to actin, tropomysin, and calcium
47
What is tropomyosin?
Wound around actin
48
At rest what do troponin and tropomysin do?
Cover the binding sites
49
What does the thin filament consist of?
Bundle of myosin molecules
50
Describe the myosin molecules?
Has a mobile protruding head at each end
51
Why are the myosin heads mobile?
To bind to actin molecule binding sites when exposed
52
Sliding filament hypothesis?
Light bands and H zone shortens, z bands get closer, sarcomere gets shorter Thin and thick filaments slide past eachother
53
Stimulation of contraction step 1?
Action potential arrives at axon which causes calcium ion channels to open
54
Stimulation of contraction step 2?
Vesicles containing acetylcholine fuse with membrane
55
Stimulation of contraction step 3?
Acetylcholine molecules diffuse across gap and fuse with sarcolemma receptors
56
Stimulation of contraction step 4?
Sodium ion channels open. Sodium ions enter the muscle fibres causing depolarisation of the sarcolemma
57
Stimulation of contraction step 5?
The wave of depolarising travels down tubules
58
Which system stimulates the skeletal system?
Somatic
59
What is the neuromuscular junction?
The junction between the nervous system and muscle
60
What is a mortor unit?
When many motor neurones divide to connect to several muscle fibres which all contract together to provide a stronger contraction
61
Control of contraction step 1?
Arrival of action potential at sarcoplasmic reticulum causes the release of calcium ions into sarcoplasm
62
Control of contraction step 2?
The calcium ions bind to the triopin which alters the shape causing the tropomysin to expose binding sites
63
Control of contraction step 3?
Myosin head binds to actin to form cross bridges between fibres
64
Control of contraction step 4?
Myosin head tilts backwards to cause actin molecule to slide past
65
What is the role of ATP in the muscle contraction?
The ATP is hydrolysed to ADP and inorganic phosphate to release energy allowing the myosin heads to move
66
How does ATP get hydrolysed?
By part of the myosin head acting as ATPase
67
Which 3 ways is ATP generated?
Aerobic respiration- many mitochondria in muscle tissue Anaerobic respiration Creatine phosphate
68
Problem with anaerobic respiration?
Short term | Produces lactic acid- causes fatigue
69
Where does anaerobic respiration occur?
In the sarcoplasm
70
Where is creatine phosphate?
In the sarcoplasm
71
How does creatine phosphate generate ATP?
The phosphate can be transferred to ADP molecules to form ATP
72
What enzyme in involved in ATP production from Creatine phosphate?
Creatine photophotransferase
73
Where are calcium ions stored in the muscle?
In the sarcoplasmic reticulum
74
What must communication systems do?
Detect changes in the environment Carry out cell signalling Co-ordinate effectors Initiate responses
75
What are the divisions of the nervous system?
CNS | PNS
76
What are the divisions of the PNS?
The motor system | The sensory system
77
What does the motor system divide into?
Somatic nervous system | Autonomic nervous system
78
What does the CNS divide to?
Brain and spinal chord
79
What is the spinal chord made up of?
Many non-myelinated neurones.
80
What is the role and composition of PNS?
Ensures rapid communication between sensory receptors, the CNS and effectors Composed of motor and sensory neurones
81
Describe the somatic nervous system?
Under voluntary control Myelinated One single motor neurone connecting CNS to effector
82
Describe the autonomic nervous system?
Not voluntary Non- myelinated 2 neurones connecting CNS to effector
83
Role of sympathetic system?
Prepares body for activity
84
Role of parasympathetic system?
Conserves energy
85
Role of sympathetic system?
Increases HR and BR Dilates pupils Reduces digestive activity
86
Role of parasympathetic system?
Decreases HR and BR Constricts pupils Increases digestive activity
87
What is a reflex action?
A response to a stimuli which does not require brain processing to coordinate a response
88
Example of reflex actions?
Knee jerk | Blinking
89
What is a reflex arc?
When receptor and effector are in the same place
90
What may stimulate blinking?
Foreign object touching the eye- corneal reflex Sudden bright light- optical reflex Loud sounds Sudden movements close to the eye
91
Sympathetic system?
Ganglia outside the CNS Short pre-ganglionic neurones Long post ganglionic neurones Uses noradrenaline
92
Parasympathetic system?
Uses acetylcholine Short post-ganglionic neurones Long pre-ganglionic neurones Ganglia in effector tissue

A2 Biology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions