BIOL 365 - Final Flashcards Preview

School > BIOL 365 - Final > Flashcards

Flashcards in BIOL 365 - Final Deck (468):
1

What characteristic of chemical messenger structure has the most significant impact on its signalling mechanism?

Hydrophobicity.

2

What effector(s) (and 2nd messenger(s)) are stimulated by Gαs?

Adenylyl cyclase (cAMP, PKA).

3

What does the Goldman-Hodgkin-Katz equation define?

The membrane potential of a cell based on distribution, relative permeability, and charge of ions across the membrane.

4

What 2 variables affect the time constant (τ)?

  • Resistance of the cell membrane (rm)
  • Capacitance of the cell membrane (cm)

5

What type of steroid hormone is aldosterone?

Mineralocorticoid.

6

Do GABAA receptors cause depolarization (excitatory) or hyperpolarization (inhibitory)?

Hyperpolarization (inhibitory).

7

What type of chemical messenger is norepinephrine?

Amine hormone.

8

Which type of pancreatic cell is destroyed in type 1 diabetes?

β cells only.

9

How is the medulla oblongata positioned in the brain?

At the top of the spinal cord.

10

Where is GLUT1 found?

In all tissues of the body.

11

What are the 2 major elements of the cytoskeleton?

  • Microtubules
  • Microfilaments

12

What type of channel are nicotinic acetylcholine receptors (nAChRs)?

Ligand-gated cation channels (for Na+, Ca2+, and K+ flux).

13

Which ions are transported through NMDA receptors?

  • Na+
  • K+
  • Ca2+

14

What is the main function of Na+/K+ ATPase?

To maintain the concentration gradients of Na+ and K+ across the cell membrane.

15

What is our blood glucose level after feeding?

9-11 mM. 

16

What pathway occurs when receptor guanylyl cyclase is activated by atrial natriuretic peptide (ANP)?

  • Receptor converts GTP to cGMP
  • cGMP activates PKG
  • PKG phosphorylates target proteins that relax smooth muscle
  • Smooth muscle relaxation causes vasodilation
  • Blood pressure is lowered

17

What type of chemical messenger are catecholamines?

Amine hormones.

18

What is described by the electrochemical driving force of a cell?

How far the membrane potential is from equilibrium.

19

What type of chemical messenger is aldosterone?

Steroid hormone.

20

What triggers oxytocin release for positive feedback regulation of uterine contraction?

Stretch receptors in the cervix, activated by contraction, send signals to the hypothalamus that are relayed to the posterior pituitary gland, which releases oxytocin to stimulate further contraction.

21

What is the equation for the time constant (τ)?

τ = rmcm

  • r = resistance of the cell membrane
  • c = capacitance of the cell membrane

22

Which 2 motor proteins are associated with microtubules?

  • Kinesin
  • Dynein

23

How many subunits are in a complete nicotinic acetylcholine receptor (nAChR)?

5.

24

What effector(s) (and 2nd messenger(s)) are inhibited by Gαi?

Adenylyl cyclase (cAMP, PKA).

25

What is the typical age of onset for type 1 diabetes?

Very young (childhood onset).

26

What are 2 major capping proteins associated with microfilaments?

  • Tropomodulin 
  • CapZ

27

Why is it important that a small number of steroid hormones in circulation are not bound to carrier proteins?

Any unbound molecules leaving circulation for the target cell cause a significant decrease in the concentration of free hormone, so more hormones are released from their carrier proteins to reach chemical equilibrium and are then free to diffuse into the target cell.

28

At what end do microfilaments tend to shrink?

(-).

29

What is the basic structure of cilia and flagella?

9 pairs of microtubules bundled in parallel around a central pair, arranged into an axoneme.

30

Which type of G-protein is involved in inositol-phospholipid signalling?

Gq.

31

What type of chemical messenger is AMP?

Purine.

32

What are the 2 main advantages of the greater number of neurons and synapses that comes with a more complex nervous system?

  • Integration of information happens at synapses: greater potential for complex behaviours
  • Memories are stored in synapses: greater potential for learning

33

What is MEK?

A protein kinase activated by Raf-1 that phosphorylates and activates MAP-kinase as part of the Ras-MAP-kinase signalling pathway.

34

What is GLUT4?

An intracellular glucose receptor that is translocated to the surface of a pancreatic β cell as a result of signal transduction in response to elevated blood glucose levels.

35

What region of the brain is the master controller of circadian rhythm?

Suprachiasmatic nucleus (SCN).

36

How is conductance related to resistance?

Conductance is the reciprocal of resistance. 

37

What property of action potentials prevents backward transmission and summation of action potentials along an axon?

The absolute refractory period. 

38

Which region of the brain is responsible for converting short-term memory to long-term memory?

Hippocampus (limbic system).

39

Which 2 scientists at the Montreal Neurological Institute determined the somatotropic organization of the cerebral cortex?

  • Wilder Penfield
  • Herbert Jasper

40

How are peptide hormones usually stored?

In intracellular vesicles, as prohormones.

41

Who won the 1923 Nobel for discovering insulin?

Frederick Banting.

42

How do ions flow through chemical synapses?

Across the synaptic cleft and into postsynaptic channels.

43

What is the main role of eicosanoids?

Inflammation and pain.

44

How are steroid hormones released?

They freely diffuse through the membrane and into the blood, where they are bound to carrier proteins for delivery to target cells.

45

In addition to GLUT1, which is expressed in all tissues, which glucose receptor is well expressed and working constantly in the brain?

GLUT3.

46

What is synaptotagmin?

A protein found in the synaptic vesicle membranes of chemical synapses; when activated by Ca2+, it binds SNARE proteins to bring vesicle and presynaptic membranes closer together in preparation for membrane fusion and neurotransmitter release.

47

What are tropic hormones?

Hormones that cause the release of another hormone.

48

What is the somatosensory function of muscle spindle receptors?

Proprioception.

49

Which region of the brain is responsible for maintaining homeostasis?

Hypothalamus (limbic system).

50

Where is acetyl CoA synthesized?

Mitochondria.

51

In a chemical synapse, what is the first thing that happens when an action potential reaches the presynaptic terminal?

Depolarization causes opening of voltage-gated Ca2+ channels.

52

What is a first-order endocrine pathway?

A signalling pathway in which the component receiving sensory input also acts as the integrating centre for the signal.

53

In what direction does kinesin move along microtubules?

Toward the positive end.

54

Which 2 types of receptors in the digestive tract relay information to the pancreas to regulate insulin secretion?

Glucose and stretch receptors.

55

What effector is activated by Gαo and Gαq?

PLC-β.

56

At which end do microtubules grow by dimer addition?

(+).

57

What types of G-proteins are involved in cAMP signalling?

Gs and Gi.

58

Does cortisol have an additive or a synergistic effect on glucagon and epinephrine?

Synergistic.

59

What conditions do NMDA receptors require before they can open?

  • Membrane depolarization (to relieve Mg2+ block)
  • Binding of glutamate and glycine

60

What is the general value of capacitance for cells (lipid bilayer)?

1 μF/cm2.

61

What is the reversal (equilibrium) potential for nicotinic acetylcholine receptors (nAChRs)?

Approx. 0 mV.

62

What is glutaminase?

An enzyme that catalyzes the conversion of glutamine to glutamate, which can be released as a neurotransmitter.

63

What are the 2 main functions of the cortex?

  • Integrate/interpret sensory information
  • Initiate voluntary movements

64

Which region of the brain is responsible for reward and addiction?

Nucleus accumbens (limbic system).

65

Do glutamate receptors cause depolarization (excitatory) or hyperpolarization (inhibitory)?

Depolarization (excitatory).

66

What is white matter?

The portion of brain/spinal cord tissue made up of tracts of axons and their myelin sheaths.

67

How does the absolute refractory period ensure unidirectional signalling along axons?

As depolarization travels down the axon, Na+ channels immediately behind a region of depolarization are in their absolute refractory period (inactive state) and cannot initiate another action potential, so further depolarization can only happen further away from the axon hillock.

68

What is the effect of lower resistance of the cell membrane on conductance?

Lower conductance (greater decrease in voltage along the axon).

69

In crustaceans, where is crustacean hyperglycemic hormone (CHH) synthesized and secreted?

Sinus gland cells in the eyestalks.

70

What does it mean for hormones to be additive?

The effect of the combined hormones on the target cell is equal to the sum of the individual effects of each hormone.

71

What enzyme synthesizes phosphatidyl inositol?

Phospholipase C.

72

What type of chemical messenger is thyroxine?

Amine hormone.

73

What is MAP-kinase?

An effector protein activated by MEK as part of the Ras-MAP-kinase signalling pathway that can phosphorylate many different cellular proteins, including transcription factors, to have many different effects in the cell.

74

Which somatosensory receptors have the lowest conduction velocity?

C-type free nerve endings (pain, temperature, itch): 0.5-2 m/s.

75

At what end do microfilaments tend to grow?

(+).

76

What is the role of Gαolf?

To stimulate adenylyl cyclase in olfactory sensory neurons.

77

What are the main 3 hormones involved in the HPA axis of the stress response?

  • Corticotropin-releasing hormone (CRH)
  • Adrenocorticotropic hormone (ACTH)
  • Cortisol

78

What are the 2 main disadvantages of large axons (as a means of increasing conduction speed)?

  • Take up more space, limiting number of neurons that can be packed into the nervous system
  • Require greater volume of cytoplasm, making them expensive to produce and maintain

79

What type of chemical messenger is ATP?

Purine.

80

In myelinated axons, what are internodes?

Myelinated regions between nodes of Ranvier.

81

What growth factor activates type II receptor serine/threonine kinases?

TGF-β.

82

What is the glucose affinity of GLUT1 and GLUT3?

1 mM.

83

What type of chemical messenger is vasopressin?

Peptide hormone.

84

What is crustacean hyperglycemic hormone (CHH)?

A neurohormone secreted from crustacean eyestalks to control glucose levels in crustaceans.

85

What 2 properties of an axon can increase its speed of conductance?

  • Myelination
  • Increased axon diameter

86

Why does a greater value of λ (length constant) increase the speed of conduction along an axon?

Higher λ means lesser decay of current over distance, so electrotonic current flow within the axon after an action potential is faster.

87

What motor protein is associated with microfilaments?

Myosin.

88

What is the monomeric form of actin?

G-actin.

89

Which 3 parts of the brain are permeable (i.e. are not shielded by the blood-brain barrier)?

  • Pineal gland
  • Pituitary gland
  • Parts of the hypothalamus

90

What is the equation for current (electrochemical driving force)?

Ix = gx(Vm - Ex)

  • Ix = current for ion x
  • gx = conductance of ion x
  • Vm = membrane potential (from Goldman-Hodgkin-Katz equation)
  • Ex = equilibrium potential of ion x (from Nernst equation)

91

What are ventricles (brain)?

Cavities in the brain that contain cerebrospinal fluid (CSF).

92

How does the number of K+ leak channels along an axon affect its ability to conduct electrical signals?

More K+ leak channels means more loss of positive charge for greater current loss and voltage decrease along the axon.

93

How are the different regions of the cerebral cortex organized?

Each region corresponds to a specific part of the body that it controls by motor output or from which it receives sensory input.

94

What type of chemical messenger is GTP?

Purine.

95

What type of steroid hormone is estrogen?

Reproductive hormone.

96

What is the value of the gas constant, R?

8.31 J/mole·K.

97

What are the 3 layers of the mammalian cranial and spinal meninges?

  • Dura mater (outer)
  • Arachnoid mater (middle)
  • Pia mater (inner)

98

What happens when a cell membrane depolarizes?

The membrane potential becomes more positive.

99

How are white and grey matter organized in the spinal cord?

  • White matter on the surface
  • Grey matter on the inside

100

What are the 3 subsystems of the somatosensory system?

  • Cutaneous mechanoreceptors (touch, vibration, pressure)
  • Proprioception (limb position, load on joints)
  • Pain/temperature

101

What is the frequency of type 1 diabetes in the general population?

Approx. 1-2 in 10,000.

102

What action is responsible for dynamic instability in microtubules?

Intrinsic GTPase activity of β-tubulin. 

103

Where are the adrenal glands in mammals?

On top of the kidneys.

104

What type of steroid hormone is progesterone?

Reproductive hormone.

105

Do 5-HT3 channels cause depolarization (excitatory) or hyperpolarization (inhibitory)?

Depolarization (excitatory).

106

Which region of the brain is responsible for aggression and fear responses?

Amygdala (limbic system).

107

What types of somatosensory receptors are involved in pain, temperature, and itch sensation?

Free nerve endings.

108

What is a connexin?

A protein complex forming part of each hemichannel in a gap junction.

109

What type of chemical messenger is epinephrine?

Amine hormone.

110

What is the axon hillock?

The region of a neuron cell body where incoming signals from dendrites converge just before the axon and may summate to produce an action potential.

111

Which motor protein moves toward the negative end of microtubules?

Dynein.

112

What type of receptor does crustacean hyperglycemic hormone (CHH) bind in glucose control pathways?

A receptor guanylyl cyclase.

113

What is a threshold potential?

A minimum level of depolarization that must be reached at an axon hillock in order for an action potential to fire.

114

Where is GLUT2 well expressed?

Pancreatic β cells and liver cells.

115

What type of chemical messenger is histamine?

Amine hormone.

116

What is the hippocampus?

The region of the limbic system responsible for converting short-term memory to long-term memory.

117

How do ions flow through electrical synapses?

Through gap junctions.

118

Which 2 groups of vertebrates have discrete adrenal glands?

Birds and mammals.

119

What is the effect of glucagon on blood glucose levels?

Glucagon raises blood glucose levels.

120

What type of chemical messenger is melatonin?

Amine hormone.

121

How does increased surface area of conducting surfaces affect capacitance?

Increases capacitance.

122

Which somatosensory receptors have the highest conduction velocity?

Muscle spindles (proprioception): 80-120 m/s.

123

What is the cerebral cortex?

The outer layer of the cerebrum.

124

What is CapZ?

A capping protein that associates with microfilaments at the (+) end to prevent actin polymerization, slowing growth.

125

In what type of signalling pathway are Gq proteins involved?

Inositol-phospholipid signalling.

126

Are amine hormones hydrophilic or hydrophobic?

Hydrophilic (except for thyroid hormones).

127

What happens when phospholipase C reacts with PIP2?

PIP2 is cleaved into IP3 and DAG, each of which can have several downstream effects.

128

Which tissue types have large intracellular pools of GLUT4 receptors?

Muscle and fat tissue.

129

What fuels the movement of kinesin and dynein along microtubules?

ATP hydrolysis.

130

What is the Nernst equation?

  • Ex = Nernst potential for ion x
  • R = gas constant (8.31 J/mole·K)
  • T = temperature (K; 295 K at room temp.)
  • F = Faraday's constant (96,500 coulombs/mole)
  • z = valence of ion x
  • [x]o/[x]i = concentration of ion x outside/inside the cell

131

What type of receptor are insulin receptors?

Receptor tyrosine kinase (RTK).

132

What is the main function of the mesencephalon (midbrain)?

Coordinating and initiating reflex responses to auditory and visual input. 

133

What is the olfactory bulb?

The region of the limbic system responsible for sense of smell.

134

Which region of the brain is reduced in size and function in mammals, compared to the same region in fish and amphibians?

Mesencephalon (midbrain).

135

What type of chemical messenger is triiodothyronine?

Amine hormone.

136

What is the equation for the length constant (λ)?

λ = [rm ÷ (ri + ro)]½

  • rm = resistance of the membrane
  • ri = resistance of intracellular fluids
  • ro = resistance of extracellular fluids

137

Which glutamate receptor subunits are found in NMDA receptors?

  • GluN1
  • GluN2A-D
  • GluN3A-B

138

What type of chemical messenger is atrial natriuretic peptide (ANP)?

Peptide hormone.

139

Which glucose receptor is well expressed and constantly working in all tissue types?

GLUT1.

140

What is the main function of the cerebellum?

Motor coordination.

141

What electrical property is an approximation of ion permeability in a cell membrane?

Conductance.

142

Which hormone lowers blood glucose levels?

Insulin.

143

Where are steroid hormones synthesized?

At the smooth ER or in the mitochondria.

144

Which ion is transported through GABAA receptors?

Cl-.

145

How does myelination affect the length constant (λ) of axons?

Myelin increases membrane resistance, which increases λ.

146

How are microtubules formed?

  • Tubulin dimers associate end-to-end to form a protofilament
  • Protofilaments line up laterally to form a sheet
  • Sheet rolls up into a tube
  • Microtubule grows at (+) end by addition of new dimers (and shrinks at (-) end)

147

In what form are peptide hormones usually synthesized?

Preprohormones.

148

What types of molecules can travel through gap junctions?

Ions and hydrophilic chemical messengers.

149

What is the main endocrine function of the pancreas?

Secrete insulin and glucagon to regulate blood glucose levels.

150

What are the 4 general components of a signal transduction pathway?

  • Receiver (ligand-binding region of receptor)
  • Transducer (conformational change of receptor)
  • Amplifier (increases number of molecules affected by signal)
  • Responder (molecular functions that change in response to signal)

151

What is cerebrospinal fluid (CSF)?

A fluid that fills spaces within the central nervous system and acts as a shock absorber. 

152

What 3 major steroid hormones are made directly from progesterone?

  • Cortisol
  • Corticosterone
  • Testosterone

153

Where are the receptors involved in proprioception located?

  • Muscles
  • Tendons
  • Joints

154

How does increased thickness of an insulating layer affect capacitance?

Decreases capacitance.

155

What is the effect of increased resistance of extracellular and intracellular fluids on conduction over distance?

Lower conductance (greater decrease in voltage along the axon).

156

True or false: The opening and closing of gap junctions can be regulated.

True.

157

What organ secretes epinephrine during the stress response?

Adrenal medulla.

158

What proportion of diabetics have type 1 diabetes?

Approx. 10%.

159

What is the limbic system?

A network of connected structures between the cortex and the rest of the brain that influences emotions, motivation, and memory (the "emotional brain").

160

What molecule is intermediate between progesterone and aldosterone?

Corticosterone.

161

How many neurons are in the brain?

Approx. 1011.

162

What type of chemical messenger is serotonin?

Amine hormone.

163

What are the 5 main regions of the prosencephalon (forebrain)?

  • Cerebrum
  • Hippocampus
  • Thalamus
  • Hypothalamus
  • Limbic system

164

Which region of the somatosensory system is responsible for relaying sensory information from the head and face?

Cranial root ganglia.

165

What feature of the central nervous system (CNS) is unique to vertebrates?

Hollow dorsal nerve cord (spinal cord).

166

What is Ras?

A protein kinase activated by SOS that activates Raf-1 as part of the Ras-MAP-kinase signalling pathway.

167

How are steroid hormones stored?

They can't be stored because they are hydrophobic--they have to be made on demand.

168

What happens to tyrosine kinase receptors (RTKs) when they are bound by a ligand?

One RTK dimerizes with another, and they phosphorylate each other to become active and recruit other kinases. 

169

What are the 2 main parameters regulated by atrial natriuretic peptide (ANP)?

  • Extracellular fluid volume
  • Blood pressure

170

What causes intracellular GLUT4 to be translocated to the cell surface?

Phosphorylation during insulin signal transduction.

171

What are the 3 main classes of steroid hormones?

  • Mineralocorticoids
  • Glucocorticoids
  • Reproductive hormones

172

What type of chemical messenger is acetylcholine?

Amine hormone.

173

Which nicotinic acetylcholine receptor (nAChR) subunits are found in muscle nAChRs?

  • α
  • β
  • γ/ε
  • δ

174

What nicotinic acetylcholine receptor (nAChR) subunits are found in neuronal nAChRs?

  • α2 - α10
  • β2 - β4

175

What causes the symptoms of type 1 diabetes?

Autoimmune destruction of pancreatic β cells (mediated by T cell lymphocytes), leading to a lack of insulin production.

176

What is the effect of insulin on blood glucose levels?

Insulin lowers blood glucose levels.

177

How many meninges do mammals have?

3. 

178

What effect does the opening of Na+ channels have on the cell membrane?

Depolarization.

179

What two signalling pathways are involved in the stress response?

  • Sympathetic nervous system
  • Hypothalamus-pituitary-adrenal cortex (HPA) axis

180

What type of chemical messenger is GMP?

Purine.

181

How many pairs of cranial nerves do vertebrates have?

13.

182

What are the cranial root ganglia?

Cell bodies of afferent fibres that relay sensory information from the face and head.

183

Do P2X receptors cause depolarization (excitatory) or hyperpolarization (inhibitory)?

Depolarization (excitatory).

184

What are 5 major factors affecting growth/shrinkage of microtubules?

  • Local tubulin concentration
  • Dynamic instability
  • Microtubule-associated proteins (MAPs)
  • Temperature
  • Chemicals (e.g. poisons)

185

Where do neurons of the hypothalamus terminate?

Posterior pituitary.

186

Once acetylcholine (ACh) has been broken down in the synaptic cleft by acetylcholinesterase (AChE) into choline and acetate, what happens to the choline and acetate?

  • Choline: taken up and recycled by the presynaptic neuron
  • Acetate: diffuses out of the synapse

187

Do glycine receptors cause depolarization (excitatory) or hyperpolarization (inhibitory)?

Hyperpolarization (inhibitory).

188

What are the 3 main regions of the vertebrate rhombencephalon (hindbrain)?

  • Medulla
  • Pons
  • Cerebellum

189

What protein makes up microtubules?

Tubulin.

190

What effect does the opening of K+ channels have on the cell membrane?

Hyperpolarization.

191

What is the main function of the hypothalamus?

Maintaining homeostasis.

192

What is the cingulate cortex?

The region of the limbic system responsible for executive function of the brain, including decision-making, motivation, and planning. 

193

What 2 subunits make up a tubulin dimer?

  • α-tubulin
  • β-tubulin

194

What proportion of type 2 diabetes patients are obese?

Approx. 85%.

195

What is the major downstream effect of increased cortisol secretion from the adrenal cortex during the stress response?

Increased blood glucose in many tissues throughout the body.

196

What is the polarity of each subunit in a tubulin dimer?

  • α-tubulin: (-)
  • β-tubulin: (+)

197

What type of chemical messenger is glutamate?

Amino acid.

198

How are microtubules oriented in axons w.r.t. polarity?

  • (-) end: toward cell body
  • (+) end: toward axonal terminals

199

Which organ secretes adrenocorticotropic hormone (ACTH) during the stress response?

Anterior pituitary.

200

Which region of the brain contains half of all of the neurons in the brain?

Cerebellum.

201

What is the polymeric form of actin?

F-actin.

202

What is the thalamus?

A large grouping of grey matter above the hypothalamus that receives input from the limbic system and all senses (except olfactory) and relays sensory information to the cortex and has a major role in sleep/wake regulation.

203

After an action potential triggers opening of Ca2+ channels in the presynaptic terminal of a chemical synapse, what is triggered by the influx of Ca2+?

Fusion of synaptic vesicles with the presynaptic membrane, followed by release of neurotransmitters into the synaptic cleft. 

204

In what 3 types of signalling does the pancreas participate?

  • Direct feedback loops
  • Neural signalling
  • Hormonal signalling

205

What are the 4 main types of receptor?

  • Intracellular receptors
  • Ligand-gated ion channels
  • Receptor-enzymes
  • G-protein-coupled receptors

206

What are the 4 lobes of the brain?

  • Frontal lobe
  • Temporal lobe
  • Parietal lobe
  • Occipital lobe

207

What are melanophores?

Cells containing aggregate pigment granules that can be compressed or spread out by microtubules to cause colour change in some animals.

208

What type of ligands bind to intracellular receptors?

Hydrophobic ligands.

209

How many layers are present in the cortex of the brain?

6.

210

What is the main type of effect caused by ligand-gated ion channels?

Change in cell membrane potential.

211

Which 2 animal phyla have well developed nervous systems but no cephalization?

  • Cnidaria
  • Echinodermata

212

What hormone is secreted by the hypothalamus during the stress response?

Corticotropin-releasing hormone (CRH).

213

What are the two parts of the adrenal gland?

  • Adrenal cortex
  • Adrenal medulla

214

What molecule activates tubulin monomers, causing them to dimerize?

GTP.

215

What type of somatosensory receptors are involved in proprioception?

Muscle spindle receptors. 

216

How do the 6 layers of the cortex differ from each other?

  • Shape and density of neurons
  • Number of connections between neurons

217

During the stress response, does secretion of epinephrine from the adrenal medulla increase or decrease blood glucose levels?

Increase.

218

What type of chemical messenger is glycine?

Amino acid.

219

Which 2 hormones secreted during the stress response result in elevated blood glucose levels?

  • Epinephrine
  • Glucagon

220

What happens after a type II receptor serine/threonine kinase has bound TGF--β?

It recruits and dimerizes with a type I receptor, then phosphorylates the type I receptor at the GS box.

221

Where is glucagon synthesized?

Pancreas (α cells).

222

How does temperature affect microtubule growth/shrinkage?

Low temperature causes disassembly of microtubules. 

223

What is the isocortex?

The outer layer of the cortex, necessary for cognition and higher brain functions.

224

What is the main role of cAMP?

To activate protein kinases (usually PKA), which phosphorylate proteins and open/close ion channels.

225

What does the Nernst equation describe?

The equilibrium potential across a cell membrane for a particular ion.

226

What type of steroid hormone is cortisol?

Glucocorticoid.

227

Which part of the adrenal gland secretes epinephrine (adrenaline)?

Adrenal medulla.

228

Do nicotinic acetylcholine receptors (nAChRs) cause depolarization (excitatory) or hyperpolarization (inhibitory)?

Depolarization (excitatory).

229

What is the value of Faraday's constant, F?

96,500 coulombs/mole.

230

What type of receptor are EGF receptors?

Receptor tyrosine kinase (RTK).

231

What is antagonistic pairing?

A type of signalling pathway involving separate hormones with opposite effects (e.g. stimulatory vs. inhibitory).

232

What happens when a cell membrane hyperpolarizes?

The membrane potential becomes even more negative than its (negative) resting value.

233

True or false: Graded potentials decay over distance.

True.

234

What are the 4 main parameters regulated by the medulla oblongata?

  • Breathing rate
  • Heart rate
  • Blood vessel diameter
  • Blood pressure

235

What is the nucleus accumbens?

The region of the limbic system responsible for reward and addiction.

236

How are responses at nicotinic acetylcholine receptors (nAChRs) kept brief?

Acetylcholinesterase (AChE) quickly hydrolyzes acetylcholine (ACh) in the synaptic cleft to limit the duration of the signal. 

237

What is the role of Gαt?

To activate cGMP phosphodiesterase in vertebrate rod photoreceptors.

238

What change occurs in the conversion of preprovasopressin to provasopressin?

The signal peptide is cleaved off.

239

How does myelination affect membrane resistance in axons?

Myelin insulation reduces current loss through leak channels, which increases membrane resistance.

240

How are microtubules anchored in the cell?

  • (-) end: microtubule organization centre (MTOC)
  • (+) end: integral proteins in the plasma membrane

241

What are the 2 types of summation that influence net change in membrane potential during integration of postsynaptic potentials?

  • Spatial summation
  • Temporal summation

242

What are the 3 main regions of the vertebrate brain?

  • Rhombencephalon (hindbrain)
  • Mesencephalon (midbrain)
  • Prosencephalon (forebrain)

243

What type of chemical messenger is testosterone?

Steroid hormone.

244

In what region of the brain is the cerebellum located?

Rhombencephalon (hindbrain).

245

What enzyme synthesizes cGMP?

Guanylyl cyclase.

246

How does myelination affect the membrane capacitance of axons?

Myelin increases the thickness of the insulating layer between intracellular and extracellular fluid, which decreases membrane capacitance.

247

What is the main role of reproductive hormones?

To regulate sex-specific characteristics.

248

What is saltatory conduction?

A very rapid form of conduction along myelinated axons in which the action potential "leaps" from node to node:

  • APs occur at nodes of Ranvier
  • Current spreads electrotonically through internodes

 

249

What happens when SMAD proteins interact with receptor serine/threonine kinases?

The SMAD proteins are phosphorylated by receptor serine/threonine kinases, then translocated to the nucleus to regulate gene expression.

250

What polymer is made up of actin?

Microfilaments.

251

What is resistance (R)?

The force opposing the flow of electrical current.

252

What does it mean for a transmembrane receptor (e.g. Na+/K+ ATPase) to be electrogenic?

Its activity produces an electrical current across the membrane.

253

What type of receptor is IGF1 receptor?

Receptor tyrosine kinase (RTK).

254

What second messenger is synthesized by guanylyl cyclase?

cGMP.

255

What type of chemical messenger is insulin?

A peptide hormone.

256

What is a GS box?

A region on type I receptor serine/threonine kinases that is phosphorylated by type II receptors during dimerization.

257

What is the Goldman-Hodgkin-Katz equation?

  • Vm = membrane potential
  • R = gas constant (8.31 J/mol·K)
  • T = temperature (K)
  • F = Faraday's constant (96,500 coulombs/mol)
  • Px = permeability of ion x

258

What type of chemical messenger are leukotrienes?

Eicosanoids.

259

Where is oxytocin synthesized?

Posterior pituitary.

260

What type of chemical messenger are prostaglandins?

Eicosanoids.

261

What are gyri?

Folds in the isocortex of the brain.

262

What is voltage (V)?

A change in electrical potential.

263

How does the hypothalamus interact with the pituitary gland to help maintain homeostasis?

By regulating secretion of pituitary hormones. 

264

What is the equation for electrical conductance?

g = 1/R

  • g = conductance
  • R = resistance

265

Which hormone raises blood glucose levels?

Glucagon.

266

What happens in temporal summation of postsynaptic potentials?

Postsynaptic potentials that occur at slightly different times influence net change in membrane potential. 

267

From what molecule are steroid hormones derived?

Cholesterol.

268

What are the dorsal root ganglia?

Cell bodies of afferent fibres relaying sensory information from every part of the body except the head and face.

269

What are the 2 main functions of the pons?

  • Control alertness
  • Initiate sleep/dreaming

270

Which ions are transported through AMPA and kainate receptors?

  • Na+
  • K+

271

Which region of the rhombencephalon (hindbrain) contains pathways between the spinal cord and the brain?

Medulla oblongata.

272

What type of chemical messenger is estrogen?

Steroid hormone.

273

In what direction does dynein move along microtubules?

Toward the negative end.

274

What type of steroid hormone is corticosterone?

Glucocorticoid.

275

What is an inhibitory postsynaptic potential (IPSP)?

A synaptic transmission involving inhibitory neurotransmitters that cause hyperpolarization of the postsynaptic membrane, making the postsynaptic cell less likely to generate an action potential. 

276

In what type of signalling are eicosanoids mainly involved?

Paracrine and nervous signalling.

277

What are the 2 main regions of the vertebrate prosencephalon (forebrain)?

  • Diencephalon
  • Telencephalon

278

How did Alan Hodgkin and Andrew Huxley win the 1963 Nobel prize?

By developing a theory of action potential initiation based on measured Na+ and K+ currents in squid giant axons.

279

What type of receptors do peptide hormones bind?

Transmembrane receptors.

280

What is an excitatory postsynaptic potential (EPSP)?

A synaptic transmission involving excitatory neurotransmitters that cause depolarization of the postsynaptic membrane, making the postsynaptic cell more likely to generate an action potential. 

281

Which subunit of a tubulin dimer is able to hydrolyze bound GTP?

β-tubulin.

282

What do pancreatic β cells produce?

Insulin.

283

What are the 3 major glutamate receptors?

  • NDMA
  • AMPA
  • Kainate

284

What is cofilin?

A regulatory protein that binds actin in microfilaments to promote disassembly.

285

What type of chemical messenger is cortisol?

Steroid hormone.

286

How are cnidarian nervous systems organized differently compared to other animals?

  • Neurons are not specifically divided into sensory or motor function
  • Neurons carry action potentials in both directions
  • Nervous system is an interconnected web (nerve net)--no central nerve cord

287

How many synapses are in the brain?

Approx. 1014 to 1015.

288

What type of proteins are able to dock to activated receptor tyrosine kinases?

Proteins containing SH2 domains. 

289

What is grey matter?

The portion of brain/spinal cord tissue made up of neuronal cell bodies.

290

What is the glucose affinity of GLUT2?

15-20 mM.

291

What is the somatosensory system?

The division of the nervous system that receives input from receptors in skin, muscle, and tendons to mediate a diverse range of sensations (touch, pressure, pain, vibration, limb position, temperature, etc.).

292

What type of chemical messenger are thyroid hormones?

Amine hormones.

293

What 2 parameters determine the membrane potential of a cell?

  • Relative permeability of the membrane to specific ions
  • Transmembrane concentration gradients of specific ions

294

What is Ohm's law?

V = I · R

  • V = voltage
  • I = current
  • R = resistance

295

What are the 4 main classes of cellular signalling?

  • Direct
  • Paracrine/autocrine
  • Nervous
  • Endocrine

296

What are the 2 main groups of components of the peripheral nervous system (PNS)?

  • Sensory components (afferent neurons)
  • Motor components (efferent neurons)

297

How are microtubules oriented in neuronal dendrites w.r.t. polarity?

Mixed: (+)/(-) ends can be oriented toward or away from the cell body.

298

Where are peptide hormones synthesized?

On the rough ER.

299

What molecule is intermediate between cholesterol and progesterone?

Prenenolone.

300

What does it mean for hormones to be synergistic?

The effect of the combined hormones on the target cell is greater than the sum of their individual effects; 1 hormone enhances the effect of the other. 

301

Is the combined effect of glucagon and epinephrine additive or synergistic?

Additive.

302

Which is more common: type 1 or type 2 diabetes?

Type 2 (80-90% of diabetics).

303

What are rapidly adapting afferents?

Somatosensory afferents whose action potentials become quiescent with continued stimulation. 

304

What are the 2 regions of the mesencephalon (midbrain) in mammals?

  • Inferior colliculi (auditory input)
  • Superior colliculi (visual input)

305

Which skin mechanoreceptor has the highest spatial resolution?

Merkel cell afferents (0.5 mm).

306

What is the major difference between more advanced and less advanced mammals with respect to the isocortex?

The isocortex is more heavily folded in more advanced mammals.

307

What type of chemical messenger is aspartate?

Amino acid.

308

What is a relative refractory period?

An interval of repolarization following hyperpolarization of a neuron, during which it is more difficult to generate a new action potential.

309

Which motor protein moves toward the positive ends of microtubules?

Kinesin.

310

What causes the movement of cilia and flagella?

Asymmetrical activation of dynein.

311

What is SOS?

A protein recruited by GRB2 that activates Ras as part of the Ras-MAP-kinase signalling pathway.

312

What structure allows direct cell signalling?

Gap junctions.

313

Where are Na+ channels concentrated in myelinated axons?

On the axonal membrane at nodes of Ranvier.

314

What type of chemical messenger is dopamine?

Amine hormone.

315

During the stress response, do blood glucose levels increase or decrease?

Increase.

316

Where is GLUT3 found?

In the brain.

317

What conditions do AMPA and kainate receptors require before they can open?

Binding of glutamate. 

318

In what region of the brain is the pons located?

Rhombencephalon (hindbrain).

319

What determines the rate of movement of kinesin and dynein along microtubules?

ATPase activity of the ATPase domains of the motor proteins and of regulatory proteins.

320

What is the most common carrier protein for steroid hormones?

Albumin.

321

What is the glucose affinity of GLUT4?

2.5-5 mM.

322

What is the reversal (equilibrium) potential of glutamate receptors?

Approx. 0 mV. 

323

How many meninges do amphibians, reptiles, and birds have?

2.

324

Are steroid hormones hydrophilic or hydrophobic?

Hydrophobic.

325

What ligand activates receptor guanylyl cyclase to regulate extracellular fluid volume and blood pressure?

Atrial natriuretic peptide (ANP).

326

Which 3 variables affect the value of the length constant (λ)?

  • rm (resistance of the membrane)
  • ri (resistance of intracellular fluids)
  • ro (resistance of extracellular fluids)

327

What is GRB2?

An SH2-containing protein that docks to activated receptor tyrosine kinases and recruits SOS as part of the Ras-MAP-kinase signalling pathway.

328

What are slowly adapting afferents?

Somatosensory afferents that continue to respond with action potentials for the duration of the stimulus.

329

In what form are peptide hormones usually stored?

Prohormones.

330

What second messenger is synthesized by phospholipase C?

Phosphatidyl inositol.

331

What is an islet of Langerhans?

A cluster of cells within the pancreas that contains the α and β cells responsible for synthesizing glucagon and insulin, respectively.

332

How does myelination affect the time constant (τ) of axons?

Myelin decreases membrane capacitance, which decreases τ.

333

What is the full name of type 2 diabetes?

Non-insulin-dependent diabetes mellitis.

334

What are nodes of Ranvier?

Areas of exposed axonal membrane between myelin on myelinated axons.

335

What protein makes up microfilaments?

Actin. 

336

Where is the microtubule organization centre (MTOC) positioned in the cell?

Near the nucleus.

337

Which two organs are stimulated by the sympathetic nervous system during the stress response?

  • Pancreas
  • Adrenal medulla

338

What is the corpus callosum?

A region of the cerebrum serving as a bridge between the left and right hemispheres where neurons cross over to innervate the opposite side of the body.

339

Which organ secretes corticotropin-releasing hormone (CRH) during the stress response?

Hypothalamus.

340

At which end do microtubules shrink by dimer removal?

(-).

341

What is the main role of mineralocorticoids?

Electrolyte balance.

342

Which organ secretes cortisol during the stress response?

Adrenal cortex.

343

How does a decrease in time constant (τ) affect electrical signalling across a cell membrane?

  • Capacitor becomes full more quickly
  • Faster depolarization
  • Faster conductance

344

In what region of the brain is the medulla oblongata located?

Rhombencephalon (hindbrain).

345

What proportion of diabetics have type 2 diabetes?

Approx. 80-90%.

346

Which region of the brain serves as a pathway between the medulla, the cerebellum, and the forebrain?

Pons.

347

What is the main type of effect caused by receptor-enzymes?

Changes in intracellular enzyme activity.

348

How are peptide hormones released?

They are stored in vesicles that are secreted by exocytosis.

349

What is the length constant (λ)?

The distance over which an electrical signal will decay to 37% of its maximum value. 

350

In what type of signalling are gases usually involved as chemical messengers?

Paracrine signalling.

351

What is glutamine synthetase?

An enzyme that catalyzes the conversion of glutamate (a neurotransmitter) to glutamine for recycling to the presynaptic neuron.

352

What is acetylcholinesterase (AChE)?

An enzyme that breaks down acetylcholine (ACh) into choline and acetate in the synaptic cleft to terminate an ACh-mediated signal in the postsynaptic cell.

353

Where is insulin synthesized?

Pancreas (β cells).

354

What type of chemical messenger is GABA?

Amino acid.

355

What 2 types of molecules are allowed through transporters at the blood-brain barrier?

  • Glucose
  • Amino acids

356

What type of receptor do steroid hormones bind to?

Transmembrane or intracellular receptors.

357

Which region of the somatosensory system is responsible for relaying sensory information from every part of the body except for the head and face?

Dorsal root ganglia.

358

Are eicosanoids hydrophilic or hydrophobic?

Hydrophobic.

359

What are the 4 functional zones of a neuron?

  • Signal reception (dendrites & cell body)
  • Signal integration (axon hillock)
  • Signal conduction (axon)
  • Signal transmission (synapse)

360

What is the blood-brain barrier?

A region of tight junctions in the brain capillary endothelium that limits the passage of solutes from blood into the cerebrospinal fluid, protecting the brain from harmful substances. 

361

What enzyme synthesizes cAMP?

Adenylyl cyclase.

362

Which type of sensory input is not received by the thalamus?

Olfactory.

363

What are meninges?

Layers of connective tissue that surround the brain and spinal cord. 

364

What is the infundibulum?

A structure in the brain connecting the hypothalamus to the pituitary gland.

365

What type of chemical messenger is glucagon?

Peptide hormone.

366

What is the main exocrine function of the pancreas?

Secrete digestive enzymes into the duodenum. 

367

Why is there no net movement of ions across a membrane at resting membrane potential?

The value of the resting potential corresponds to an electrical gradient that counteracts the chemical gradient of ions.

368

How does a higher value of λ (length constant) affect speed of conduction along an axon?

Higher λ allows more electrotonic current flow for faster conduction.

369

What are 3 major differences between electrical and chemical synapses?

  • Chemical: synaptic vesicles store neurotransmitters; electrical: no vesicles
  • Chemical: synaptic cleft; electrical: gap junctions
  • Chemical: neurotransmitters; electrical: ions

370

What are the 5 sets of spinal nerves in vertebrates?

  • Cervical
  • Thoracic
  • Lumbar
  • Sacral
  • Coccygeal

371

What is capacitance (C)?

The ability to store charge when a voltage difference occurs between two surfaces.

372

What is the main role of glucocorticoids?

Stress response.

373

What 3 factors determine the rate of removal of neurotransmitters from a synapse?

  • Passive diffusion of neurotransmitters out of the synapse
  • Degradation of neurotransmitters by synaptic enzymes
  • Uptake of neurotransmitters by surrounding cells

374

How are white and grey matter organized in the brain?

  • White matter on the inside
  • Grey matter on the surface

375

What are the 6 main components of the limbic system?

  • Hypothalamus
  • Amygdala
  • Hippocampus
  • Olfactory bulbs
  • Nucleus accumbens
  • Cingulate cortex

376

What 2 factors determine the strength of synaptic transmission and the response of the postsynaptic cell?

  • Amount of neurotransmitter in the synapse
  • Number/density of receptors on the postsynaptic cell

377

Which portion of receptor-enzymes have intrinsic kinase activity?

The cytosolic domain.

378

What type of mechanoreceptor is especially well expressed in fingertips?

Merkel cell afferents. 

379

What is GLUT2?

A transmembrane receptor that transports glucose into pancreatic β cells (if blood glucose is high) or out of pancreatic α cells (if blood glucose is low).

380

Where are the adrenal glands in birds?

Embedded within the kidneys.

381

What are the 3 functional divisions of the nervous system?

  • Afferent sensory
  • Integrating
  • Efferent motor

382

What are tropomodulins?

Capping proteins that associate with microfilaments at the (-) end to prevent actin dissociation, stabilizing the microfilament.

383

What is glycogen phosphorylase kinase (GPK)?

A kinase activated by PKA in response to glucagon (signalling low blood glucose) that leads to the breakdown of glycogen to glucose, which is then released into the blood to raise blood glucose levels.

384

What happens to the membrane potential of a cell as permeability to a specific ion increases?

The membrane potential will approach that ion's equilibrium potential (as defined by the Nernst equation).

385

How does the structure of a cell correspond to the structure of an electrical capacitator?

  • 2 conducting layers:
    • Intracellular fluid
    • Extracellular fluid
  • Insulating layer between conducting layers:
    • Phospholipids

386

Which region of the brain is responsible for executive function of the brain, including decision-making, motivation, and planning?

Cingulate cortex (limbic system).

387

What type of chemical messenger are eicosanoids?

Lipid-derived hormones.

388

How is the cerebellum positioned in the body?

2 hemispheres at the back of the brain.

389

What second messenger is synthesized by adenylyl cyclase?

cAMP.

390

Which is faster: kinesin or dynein?

Neither--they travel at approximately the same speed (1.5 μm/s for kinesin, 1.7 μm/s for dynein).

391

What is profilin?

A regulatory protein that binds to G-actin and promotes assembly of microfilaments.

392

What are the 4 components of preprovasopressin?

  • Signal peptide
  • Arginine vasopressin (AVP)
  • Neurophysin
  • Glycoprotein

393

Are peptide hormones hydrophobic or hydrophilic?

Hydrophilic.

394

What is the time constant (τ)?

The time over which a membrane potential will decay to 37% of its maximum value; a measure of how well the membrane holds its charge.

395

What are the 4 major effects of epinephrine secreted by the adrenal medulla during the stress response?

  • Increased heart rate
  • Increased breathing rate
  • Redistribution of blood flow from periphery
  • Increased blood glucose

396

What is the reversal (equilibrium) potential of GABAA receptors?

-99 mV (the Nernst potential for Cl-).

397

Which hormone regulates uterine contraction in a positive feedback loop during childbirth?

Oxytocin.

398

What does the "brainstem" refer to?

A grouping of the mesencephalon (midbrain), the pons, and the medulla oblongata.

399

Which glucose transporter has the highest affinity for glucose?

GLUT2.

400

How are incoming signals at the dendrites of a neuron conveyed to the axon hillock?

Input is converted to a change in membrane potential, which is propagated through the cell body toward the axon hillock.

401

What type of receptor does atrial natriuretic peptide (ANP) bind to regulate extracellular fluid volume and blood pressure?

Receptor guanylyl cyclase.

402

What is the main role of cGMP?

To activate protein kinases (usually PKG), which phosphorylate proteins and open/close ion channels.

403

What hormone is released by the adrenal cortex during the stress response?

Cortisol.

404

What are ependymal cells?

Ciliated cells that line ventricles in the vertebrate brain and circulate cerebrospinal fluid (CSF).

405

What hormone controls glucose levels in crustaceans?

Crustacean hyperglycemic hormone (CHH).

406

What happens when a cell membrane repolarizes?

The membrane potential returns to its resting (negative) value.

407

What is the amygdala?

The region of the limbic system responsible for aggression and fear responses.

408

Which glutamate receptor subunits are found in kainate receptors?

GluK1-5.

409

What are the 2 main roles of phosphatidyl inositol?

  • Activate protein kinase C (PKC)
  • Stimulate Ca2+ release from intracellular stores

410

Which region of the brain is responsible for initiating voluntary movements?

Cortex.

411

Why is cortisol able to have more rapid effects than other steroid hormones?

It binds to transmembrane receptors to cause non-genomic effects, which are faster than effects on transcription.

412

What happens in the pancreas during the stress response?

  • Decreased insulin secretion
  • Increased glucagon secretion

413

In crustaceans, is glucose control by crustacean hyperglycemic hormone (CHH) a positive or negative feedback loop?

Both!

  • Positive: CHH secreted in response to low glucose causes downstream glycogenolysis resulting in production of lactate, which stimulates further CHH release.
  • Negative: Glycogenolysis also results in production of glucose, which inhibits CHH release once the system reaches a certain level of glucose.

414

What is tubulin?

The protein that polymerizes to make microtubules.

415

What happens in spatial summation of postsynaptic potentials?

Postsynaptic potentials from multiple different sites influence the net change in membrane potential. 

416

What is the typical age of onset for type 2 diabetes?

Middle-age.

417

What is our resting blood glucose level?

4-6 mM. 

418

What is choline acetyl transferase?

An enzyme that catalyzes the conversion of acetyl CoA and choline to acetylcholine (ACh).

419

Which region of the brain is responsible for sense of smell?

Olfactory bulb (limbic system).

420

What are sulci?

Grooves in the isocortex of the brain.

421

What are the 2 SNARE proteins found in chemical synapses?

  • Syntaxin
  • SNAP-25

422

True or false: Action potentials decay over distance.

False.

423

What type of steroid hormone is cortisone?

Glucocorticoid.

424

What do pancreatic α cells produce?

Glucagon.

425

Is glucose hydrophobic or hydrophilic?

Hydrophilic.

426

What 3 factors cause decay of graded potentials?

  • Leakage of charged ions across the membrane
  • Electrical resistance of the cytoplasm
  • Electrical resistance of the membrane

427

What is a dermatome?

The territory innervated from a single dorsal root ganglion and its spinal nerve.

428

Which region of the brain has taken over many midbrain functions in lower vertebrates?

Cortex.

429

How is the firing frequency modulated in mechanosensory afferent nerve endings?

Firing frequency is proportional to strength of stimulus: stimulus alters ion permeability of cation channels, which alters magnitude of depolarization; greater stimulus means greater depolarization for generating action potentials.

430

What type of receptor are NGF receptors?

Receptor tyrosine kinase (RTK).

431

What is an absolute refractory period?

An interval between depolarization and repolarization of a neuron, during which the cell is incapable of generating a new action potential.

432

How is the pons positioned in the body?

Rostral to the medulla oblongata (which is at the top of the spinal cord).

433

What hormone is secreted by the anterior pituitary during the stress response?

Adrenocorticotropic hormone (ACTH).

434

How many meninges do fish have?

1.

435

What 2 processes are stimulated by glucagon release?

  • Glycogenolysis
  • Gluconeogenesis

436

What is the full name of type 1 diabetes?

Insulin-dependent diabetes mellitis.

437

Which part of the adrenal gland secretes cortisol and aldosterone?

Adrenal cortex.

438

What are the 2 main functions of the prosencephalon (forebrain)?

  • Processing/integrating sensory information
  • Coordinating behaviour

439

What causes the symptoms of type 2 diabetes?

Impaired signal transduction mechanisms in insulin receptors lead to insulin resistance, and pancreatic β cells are no longer responsive to elevated blood glucose levels.

440

Which glutamate receptor subunits are found in AMPA receptors?

GluA1-4.

441

Where is arginine vasopressin synthesized?

Posterior pituitary.

442

What is the exchange rate of Na+/K+ ATPase per molecule of ATP hydrolyzed?

  • 3 Na+ ions transported out of the cell
  • 2 K+ ions transported into the cell

443

How many subunits are in a complete ionotropic glutamate receptor?

4.

444

What type of receptor are VEGF receptors?

Receptor tyrosine kinase (RTK).

445

Which 4 major types of somatosensory receptors are involved in touch?

  • Merkel
  • Meissner
  • Pacinian
  • Ruffini

446

What type of steroid hormone is testosterone?

Reproductive hormone.

447

What form does adrenal tissue take in animals that don't have discrete adrenal glands?

They have chromaffin and interrenal cells dispersed throughout or near the kidney.

448

What type of nucleotides are G-proteins able to bind?

Guanosine nucleotides.

449

What is ecdysone?

The hormone that regulates molting in ecdysozoans.

450

How many people in the world are addicted to smoking?

Over 1 billion.

451

How many people in the world die each year from smoking-related illnesses?

Over 4 million.

452

How do rates of cardiovascular disease differ in smokers vs. non-smokers?

Cardiovascular disease rates are 70% higher in smokers.

453

What percentage of all cancer deaths are caused by smoking?

30%.

454

What percentage of all lung cancers is caused by smoking?

85%.

455

What 2 types of disease have the greatest increase in risk associated with smoking?

  • Cardiovascular disease
  • Cancer (especially lung cancers)

456

What are the 3 main characteristics of drug addiction?

  • Compulsion to obtain and take the drug
  • Inability to control or limit intake of the drug
  • Withdrawal symptoms when access to the drug is blocked

457

Which has greater expression of nicotinic receptors: dopaminergic or GABAergic neurons?

Dopaminergic (~twice as many nAChRs).

458

What are the 2 regions of the substantia nigra?

  • SNC (substantia nigra compacta)
  • SNR (substantia nigra reticulata)

459

Which type of neuron is more numerous in the substantia nigra compacta (SNC): dopaminergic or GABAergic?

Dopaminergic.

460

Which type of neuron is more numerous in the substantia nigra reticulata (SNR): dopaminergic or GABAergic?

GABAergic.

461

Which neurons degenerate in Parkinson's disease, causing loss of movement?

Dopaminergic neurons in the substantia nigra.

462

Which region of the brain is associated with feelings of pleasure and craving relief in addiction?

Mesolimbic dopaminergic pathway.

463

Which regions of the brain are associated with increased cognitive function, attention, and learning/memory that come with abused drug use?

  • Anterior cingulate cortex
  • Hippocampus

464

Which regions of the brain are associated with feelings of decreased stress and anxiety with abused drug use?

  • Lateral septum
  • Amygdala

465

Which regions of the brain are associated with decreased appetite that comes with drug addiction?

  • Lateral hypothalamic area
  • Paraventricular/arcuate nuclei

466

Which regions of the brain are associated with feelings of reduced depression in drug addiction?

  • HPA axis
  • Hippocampus
  • Frontal cortex

467

What does VTA stand for?

Ventral tagmental area.

468

What was the key finding of the U of T study (1992) on self-administration of nicotine in rat models?

The mesolimbic pathway plays a critical role in addiction.