Coordination & Response Flashcards
(140 cards)
1
Q
Cerebellum*
A
Coordinate body movements.
2
Q
Medulla Oblongata*
A
Controls involuntary actions.
3
Q
Dorsal root ganglion*
A
Contains cell bodies of Afferent neurones.
4
Q
Cerebrum
A
Carries out integrative functions.
5
Q
Spinal cords
A
- Relays nerve impulses into and out of the brain.
2. Responsible for most of the involuntary/reflex actions of the body.
6
Q
Afferent neurones/ Sensory neurones
A
Transmits nerve impulses from receptors to the Central nervous system (CNS).
7
Q
Interneurones
A
Transmits nerve impulses between Afferent neurones and the Efferent neurones.
8
Q
Efferent neurones/ Motor neurones
A
Transmits nerve impulses from the Central nervous system (CNS) to effectors.
9
Q
Axon
A
Transmits nerve impulses away from the cell bodies.
10
Q
Synapse
A
- Ensures that nerve impulses travel in one direction.
2. Control and integrate nerve impulses.
11
Q
Contents of grey matter*
butterfly or letter H
A
Cells bodies of Efferent neurones and Interneurones.
Cell bodies of Afferent neurones is located in the Dorsal root ganglion
12
Q
Contents of white matter
surrounds grey matter
A
Myelin-coated axons.
13
Q
Vertebral column
A
Protests the spinal cord.
14
Q
Cerebrospinal fluid
located in the central canal
A
1, Acts as a shock absorber.
2. Provides the spinal cord with nutrients.
15
Q
Mitochondria*
sing. Mitochondrion
A
Generate nerve impulses for the transmission of nerve impulses across the synaptic cleft.
16
Q
Cerebral cortex
A
Controls all voluntary muscle movements.
17
Q
Neurotransmitters
A
(Acetylcholine, Noradrenaline, Serotonin, Dopamine)
Facilitates the transmission of nerve impulses across the synaptic cleft.
(Stored in synaptic vesicles)
18
Q
Q: Explain the transmission of nerve impulses across the synaptic cleft
A
When an electrical impulse reaches the presynaptic membrane, the synaptic vesicles are triggered to release neurotransmitters into the synaptic cleft. The neurotransmitters diffuse across the synapse to bind to the receptor proteins. This leads to the generation of new nerve impulses in the postsynaptic membrane.
19
Q
Q: Effects of excessive alcohol consumption on the nervous coordination
A
The transmission of nerve impulses becomes slower, as alcohol affects the transmission of the neurotransmitters, thus affects the person’s coordination and the reaction.
20
Q
Synaptic vesicles
Located in Synaptic terminal/ Synaptic knob
A
Release neurotransmitters if triggered by electrical impulses in the presynaptic membrane.
21
Q
Q: Why are nerve impulses transmitted in one direction only?
A
It is because neurotransmitters can only be produced at the Synaptic knob of an axon terminal.
22
Q
Q: How are hormones secreted by the endocrine glands delivered to the target organs?
A
Hormones are secreted directly into the bloodstream and are carried by the blood to the target organs.
23
Q
Q: How the negative feedback mechanism acts to control the hormone content that is secreted by neck endocrine glands?
A
- When there are excess Thyroxine hormones, the Pituitary gland is not stimulated to secrete Thyroid-stimulating hormone (TSH). Hence, no thyroid-stimulating hormone is produced and the Thyroid gland stops secreting the Thyroxine hormone.
- When the level of thyroxine hormones are low, the Pituitary gland is stimulated to release Thyroid-stimulating hormone, which then stimulates the Thyroid gland to produce Thyroxine.
24
Q
Thyroxine*
A
Helps in the mental and physical development of the children. (Increase metabolic rate)
25
Myelin sheath*
1. Protects and insulates the axons
| 2. Speeds up the transmission of nerve impulses
26
Q: Difference between a reflex action and a reflex arc.
Reflex action: A quick, automatic response to a stimulus.
| Reflex arc: The pathway taken by the nerve impulses from a receptor to an effector during a reflex action.
27
Q: Explain why Dorsal root ganglion is found in the Dorsal root but not in the Ventral root.
There is no Ventral root ganglion because the cell bodies of efferent neurones are found In the grey matter of the spinal cord.
28
Q: Differences between Afferent neurone and Efferent neurone
Afferent neurone:
1. Transmits nerve impulses from receptors to the Central nervous system (CNS).
2. Has one long axon and one long dendron, cell bodies are not at one end of an axon
Efferent neurone:
1. Transmits nerve impulses from the Central nervous system (CNS) to effectors.
2. Has one long axon and many dendrite (plur. dendrites), cell bodies are at one end of an axon
29
Difference between
Response A: when a knee is knocked
Response B: kicking a ball
The knee is knocked: Involuntary
Involves Afferent neurones and Efferent neurones.
(2 types of neurones)
Kicking a ball: Involuntary
Involves Afferent neurones, Interneurones and Efferent neurones.
(3 types of neurones)
30
Q: Reflex actions that involve glands as the effector.
1. Increasing pulse rate.
| 2. Stimulating the digestive system.
31
Afferent pathway
Transmission of nerve impulses from the sensory receptors through the Afferent neurones to the integrating centre.
32
Efferent pathway
Transmission of nerve impulses from the Integrating centre through the Efferent neurones to the effectors.
33
Central nervous system (CNS)
Brain & Spinal cord
34
Peripheral nervous system (PNS)
12 pairs of Cranial nerves & 31 pairs of Spinal nerves
| all the nerve tissues outside CNS
35
Hypothalamus*
1. Carries out homeostatic regulation.
2. Controls the release of hormones from the Pituitary gland.
(Has Neurosecretory cells)
36
Thalamus
Integrates information.
37
Pituitary gland*
| Master gland
Secretes hormones and control the secretion of hormones from other endocrine glands.
38
Spinal nerve
Contains Afferent and Efferent neurones
39
Contents of Ventral root
Axons of Efferent neurones
| not cell bodies because of cell bodies of Efferent neurones in the grey matter of Spinal cord
40
Dendrite/ Dendron
Conducts nerve impulses towards the cell body.
41
Axon
Conducts nerve impulses away from the cell body.
42
Node of Ranvier
Nerve impulse jumps from one Node of Ranvier to the next as it travels along an axon
(Speeds up the transmission of nerve impulses)
43
Synaptic cleft
Separates the synaptic terminal from the dendrites of a receiving neurone.
(Space between the presynaptic membrane and postsynaptic membrane)
44
Synapse
The site where two neurones/ neurone and an effector cell communicate
45
Q: What happens after neurotransmitter bound with receptor proteins and has relayed its message?
1. Broken down by enzymes
| 2. Recycled by the synaptic terminal
46
Postsynaptic membrane
The plasma membrane of the cell body/ dendrite of a neighbouring neurone.
47
Peripheral nervous system (PNS)
1. Transmits signal to CNS for processing.
| 2. Transmits signal to the rest of the body after processing by CNS.
48
Reflex actions
Involuntary actions
49
Knee-jerk reflex/ Patellar reflex
Involuntary actions
| Involve 2 neurones
50
Reflex actions that involve brain
Opening and closing of pupil
51
Quadriceps muscle
When Efferent neurones transmit nerve impulses to the quadriceps muscle and the muscle contract, lower leg jerk forwards.
52
Sympathetic division
('Fight or Flight' responses)
Increases pulse rate, heartbeat rate, blood pressure and breathing rate.
Slows down the digestive system.
53
Parasympathetic division
Decreases pulse rate, heartbeat rate, blood pressure and breathing rate.
Stimulates the digestive system.
54
Difference between:
(all are in PNS)
Somatic nervous system
Autonomic nervous system
Somatic nervous system:
Voluntary: Reading.
Involuntary: Knee-jerk reflex, removing a hand from a hot stove.
Autonomic nervous system
All involuntary actions: Regulate heartbeat and body temperature.
55
Diseases of the nervous system
Parkinson's disease
| Alzheimer's disease
56
Q: How to treat Diabetes mellitus?
The patient can be injected with insulin. Insulin converts excess blood sugar to glycogen, which can be stored in the liver.
57
A decrease in Thyroxine hormone
Causes hypothyroidism, Cretinism occurs in a child
58
Q: Why is Pancreas both endocrine gland and exocrine gland
-Secrete hormones.
-Produce pancreatic juice containing enzymes such as Pancreatic amylase, Trypsin and Lipase.
(Transport by pancreatic duct to the Duodenum)
59
Differences between Endocrine and Nervous system
Endocrine system:
- Messages are conveyed slowly
- Controls involuntary actions
Nervous system:
- Messages are conveyed rapidly
- Controls voluntary and involuntary actions
60
Four hormones secreted by Anterior pituitary gland
| Anterior lobe
1. Thyroid-stimulating hormone (TSH)
2. Follicle-stimulating hormone (FSH)
3. Luteinising hormone (LH)
4. Growth hormone
61
Two hormones secreted by Posterior pituitary gland
| Posterior lobe
1. Antidiuretic hormone (ADH)
| 2. Oxytoxin
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Under secretion of ADH
Results in Diabetes Insipidus
| Person excrete a large amount of urine and is thirsty all the time
63
Over secretion of ADH
Results in high retention of water in the body.
64
Follicle-stimulating hormone (FSH)
Stimulates the development of follicles in the ovary.
65
Oestrogen
Stimulates the thickening of the endometrium of the uterus.
66
Lack of Growth hormone
Retardation in the growth of bones in the limbs
| Results in Dwarfism in adults
67
A circumstance which less ADH is stimulated
Drinking too much water
68
Q: Why can under secretion of ADH produce more urine?
The collecting duct and distal convoluted tubule become less permeable to water, less water is reabsorbed into the bloodstream, therefore a bigger volume and more dilute urine are produced.
69
Glucagon
(Secreted by Pancreas)
Stimulates the conversion of glycogen into glucose in the liver.
(Low blood glucose is returned to a normal level)
70
Q: Why is it possible to detect a diabetic by testing his urine?
The urine of a diabetic contains glucose. This is because the kidney cannot reabsorb all the glucose from the glomerular filtrate and thus glucose is excreted in the urine.
71
Q: Design a simple laboratory test to show that a person is diabetic.
Add 2 to 3 drops of Benedict's solution to 2ml of a urine sample in a test tube. Place the test tube inside a boiling water bath. A brick-red precipitate is observed if glucose is present in the urine.
72
Q: How to overcome a situation when a person injected too much insulin and feels weak.
Eat a glucose tablet or drink glucose solution immediately.
73
Low blood level
Inject Glucagon
74
High blood level
Inject Insulin
75
Over secretion of Insulin
Hypoglycaemia
| Low blood sugar
76
Under secretion of Insulin
Diabetes Mellitus
(Hyperglycaemia)
(HIgh blood sugar)
77
Thyroid-stimulating hormone (TSH)
Stimulates thyroid gland to release Thyroxine
78
Hormones secreted by Adrenal cortex
Aldosterone
| Increases reabsorption of mineral salts in the kidneys
79
Hormones secreted by Adrenal medulla
Adrenaline and Noradrenaline
| Increases heart activity and metabolic rate
80
Hormones secreted by Ovaries
Oestrogen and Progesterone
81
Hormones secreted by Testes
Androgen (eg. Testosterone)
82
'Fight or flight' situation
Hypothalamus sends nerve impulses directly to the Adrenal medulla
(No Pituitary glands involved)
(Adrenal medulla has neurones from the sympathetic division)
83
Oversecretion of Thyroxine
Cause Goitre
84
Goitre
Due to oversecretion of Thyroxine and deficiency of iodine.
85
Undersecretion of Thyroxine
| Lack of Iodine
Child: Cretinism
Adult: Myxedema
86
Oversecretion of Growth Hormones
Child: Gigantism (Abnormally tall)
Adult: Acromegaly
87
Undersecretion of Growth Hormones
Dwarfism
88
Function of Kidney
```
1. Carry out Osmoregulation
(Regulate the water and salt balance)
2. Regulate osmotic pressure
3. Excrete waste products
4. Regulate body pH
```
89
Q: Why a diet rich in protein can cause an increase in the urea content of urine?
Proteins are digested to amino acids and excess amino acids cannot be stored in the body, hence they will be deaminated in the liver. The amino group from the amino acids is converted to urea, urea is transported by the blood to the kidneys to be excreted in the urine.
90
Three processes involving formation of urine
Ultrafiltration, reabsorption and secretion
91
Q: How does Ultrafiltration occur?
The afferent arteriole diameter is wider than that in the efferent arteriole. High hydrostatic pressure is produced which forces the fluid from the glomerulus into the Bowman's capsule.
92
Two blood components found in glomerulus but not in the filtrate
Erythrocytes and Plasma Protein
| Size too large to enter small pores in the capillary wall and the inner wall of Bowman's capsule
93
The difference in chemical composition of the filtrate in the Bowman's capsule than that in the loop of Henle
The filtrate flows from the Bowman's capsule to the proximal convoluted tubule. In the proximal convoluted tubule, a large volume of water and all the glucose and amino acids are reabsorbed, while only a small amount of urea is reabsorbed. The filtrate in the loop of Henle is more concentrated as it contains no glucose and amino acids but a high concentration of urea.
94
How the reabsorption of sodium ions is controlled
When the blood osmotic pressure decreases, it stimulates the adrenal cortex to secrete aldosterone, which causes the distal convoluted tubule and collecting duct to become more permeable to sodium ions, hence more sodium ions are reabsorbed.
95
Q: Why proteins and glucose are not present in the urine of a healthy person
1. A protein molecule is too large to pass through the filtration membrane
2. Although the glucose molecule is small enough to pass through the filtration, it will fully reabsorb by the renal tubule back into the bloodstream
96
Q: How does an athlete regulate his blood osmotic pressure on a hot day?
1. Secrete a lot of sweat to lose heat
(Increase blood osmotic pressure)
2. Then, Hypothalamus stimulate the pituitary glands to release more ADH into the blood. High level of ADH increases the permeability of the distal convoluted tubule and collecting duct, more water is reabsorbed.
The blood osmotic pressure reduces to normal
97
One important factor to consider before a kidney transplant
Matching of the donor with the patient to avoid the problem of organ rejection.
98
Meaning of high osmotic pressure
Osmotic pressure is a pressure of the solutes in the water. High osmotic pressure means a high concentration of solutes in the water.
99
Q: How an alcoholic can suffer from dehydration
Alcohol inhibits the release of ADH and decreases water reabsorption in renal tubules. A large volume of urine produced can lead to dehydration.
100
Q: Explain how osmoregulation occurs in kidney
Osmoregulation is the regulating of the volume of urine production from the kidneys. The process is achieved by a negative feedback mechanism.
101
Erector muscle on a cold day
Contract, raising the skin hairs and trapping insulation of warm, still air next to the skin.
(Prevents heat from escaping the body)
102
Smooth muscle in the arterioles on a cold day
```
Vasoconstriction occurs
(The smooth muscles around the afferent arterioles constrict)
```
103
Sweat gland on a cold day
Sweating does not occur and body heat is conserved,
104
Skeletal muscles on a cold day
The skeletal muscles are stimulated, shivering occurs and heat is generated.
105
Renal artery
Supplies oxygenated blood and nutrients to the kidney.
106
Renal vein
Carries filtered blood away from the kidney.
107
Capsular space
Space between the two layers of cells of Bowman's capsule
108
Podocytes
Make up the inner wall of the Bowman's capsule
109
Glomerular filtrate
The fluid that enters into the capsular space.
110
Secretion at distal convoluted tubule
| also but less, taking place in renal tubules and collecting ducts
Passive diffusion and active transport
Secreted substances:
H+, K+, urea, creatinine, toxic substances, drugs
111
Example of stimulants
Cocaine, Caffeine
112
Example of Depressants
Alcohol
113
Example of Hallucinogens
LSD (D-Lysergic acid diethylamide)
114
Example of Narcotics
Heroin, Morphine
115
Q: What kind of change occurs on the seedling used as the control?
The seedling will grow and bend towards the light.
116
Q: Which part of the seedling is sensitive to light?
Shoot tip of the seedling
117
Q: What would happen if the shoot of seedling is cut off
The seedling will show stunted growth because there is no auxin produced.
118
Q: What would happen if the shoot of seedling is replaced with aluminium piece?
The seedling will grow vertically up because there is no stimulus of light.
119
Q: What would happen if the shoot of seedling is replaced with agar block?
The seedling will grow upwards and bend towards the light because the hormone auxin can diffuse through the agar block.
120
Q: What would happen if the shoot of seedling is replaced with mica?
The seedling will show stunted growth because auxin cannot diffuse through mica plate.
121
Q: What material is responsible for the growth of seedlings?
Auxin
122
Function of Auxin
Stimulates the elongation of cells at the shoot tip of shoot at high concentration.
123
Q: Explain the action that causes the response in seedling which shoot is replaced by agar block?
1. When exposed to unilateral light, the shoot of seedling will secrete auxin.
2. The auxin can diffuse through the agar block into the zone of cell elongation.
3. In the zone of cell elongation, auxins will accumulate at the shaded part.
4. The high concentraion of auxin at the shaded part of root stimulates growth. Hence, the shaded part elongates faster than the bright part of the shoot, causing the shoot tip to grow and bend towards the light.
124
Q: What do you call the sheath that enclose the shoot of a grass seedling ?
Coleoptile
( Tough protective sheath that encloses shoot tips of monocotyledonous plants)
eg. maize
125
Q: What is meant by phototropism?
Phototropism is a growth response of part of a plant to unilateral light.
It is caused by uneven distribution of auxin.
The direction of growth response is determined by the direction of unilateral light.
126
Q: What is a coleoptile?
A coleoptile is a sheath that covers and protects the plumule.
127
Q: State three commercial uses of auxin.
1. Synthetic auxins
eg. 2,4-D are used as weed killers as they inhibit the growth of weeds
2. Auxins are used in rooting powders to stimulate the development of adventitious roots in stem cuttings.
3. Spraying auxins onto fruit trees prevent premature fruits from failing. When auxin is sprayed onto stigmas of flowers, it can cause formation of fruits without fertilisation
(Parthenocarpy)
128
Q: The coleoptile response in contol seedling
The coleoptile tip produce auxin, less auxin diffuse to the growth zone exposed to light and more to the growth zone in the dark.
The zone in the dark grows faster than the zone in light, and the tip grows toward the light.
129
Q: Explain the different responses in the root and shoot.
In shoot, the tips produce auxin. Because of gravity, the auxin diffuses to the lower part of the horizontally-placed root and shoot.
In the root, the auxin inhibits growth in the lower region. The upper portion grows faster and the root bends downwards.
In the shoot, the auxin stimulate growth in the lower region, the lower portion grows faster and the shoot bends upwards.
130
Q: Two parts of a plant in which the auxins is produced
Shoot meristem and shoot tips
131
Q: Explain how auxin plays its role in resulting an upward growth of a plant.
Auxins promotes cell elongation. From the meristems, auxins diffuse to the zone of cell elongation and stimulates the cells to elongate. If the distribution of auxins in the shoot meristem is uniform, the plant will grow upwards.
132
Q: Explain the role of auxin in the production of mature tomato fruits.
Auxin stimulates the ovaries of tomato flowers to develop into fleshy fruits wiithout pollination. These fruits are produced without fertilisation.
133
Q: Name process in which plants produced fruits artificially and naturally.
Artificially: Parthenocarpy
Naturally: Double fertilisation
134
Q: Suggest why the tomatoes are harvested and transported when they are still unripe.
It is easier to harvest when the fruits are unripe, this is to prevent damage during storage and transpiration and to delay decay.
135
Q: How can tomatoes be ripened quickly before they are sold in supermarkets?
By exposing the fruits to ethylene/ethene.
136
Q: What are plant hormones and how do they function
Plant hormones are original chemicals, which occur in very low concentrations in plant tissues.
They act to regulate plant responses and to stimulate, inhibit or modify growth and development of the plant
137
Q: How bananas help promote the ripeness of tomatoes?
Ethane is released from ripe banana tissues.
The gas diffuses and spread through the air inside the box.
The ethane gas diffuses into the tissues of the unripe tomatoes.
It stimulates the production of the enzyme cellulase. Cellulase hyrdolysis cell wall and soften the fruits. Organic acids are converted to sugars and chlorophyll pigments break down.
This causes the green unripe tomatoes to become red and ripened.
138
Q: What is meant by Parthenocarpy?
Parthenocarpy is the development of a fruit from an ovary without fertilisation.
139
Q: Explain the process of Parthenocarpy.
Stigma and style will shrivel, ovary develops into fruit without fertilisation.
Ovules do not develop into seeds and seedless grapes are produced.
140
Q: Why do ethylene diffuse freely through the air?
Ethylene is a gas.
