test #2 Flashcards
(239 cards)
1
Q
Eyespot
A
photoreceptor cells over a lining of screen pigment cells.
no lens, provides info about surrounding black/white, but no detail.
2
Q
Simple eye
A
similar to the eyespot + refracting lens and some kind of an image.
for pattern recognition and locomotion.
3
Q
Vertebrate eye
A
elaboration of the simple eye. adds a small variable aperture + a lens.
4
Q
Ommatidia
A
The compound eyes of arthropods are image-forming eyes composed of many units.
takes in about 2-3 degrees.
5
Q
cornea
A
outer cover
6
Q
Retina
A
inner wall of the eye
7
Q
Aqueous humor
A
A watery solution that fills the anterior chamber help focus the image on the retina
8
Q
Vitreous humor
A
A jelly like solution that fills the posterior cavity
help focus the image on the retina
9
Q
Pigment epithelium
A
Stores vitamin A1 and produces light-absorbing molecules
10
Q
fovea
A
Part of the macula
An area of the retina that receives the center of the image axis and is rich in cones to allow distinction of small detail and colors.
11
Q
Binocular convergence
A
The ability of both eyes to focus on the same object, enhancing 3-d vision.
12
Q
Visible light
A
Violet light (400nm) to red light (700nm)
13
Q
Photoreceptor cells
A
__________ initiate the response light and transmit the signal to afferent neurons as neurotransmitters.
14
Q
Outer segment
A
contains stacks of membranes with receptor molecules
positioned AWAY from incoming light
connected to the inner seg. by cillium
15
Q
Inner segment
A
contains the nucleus and organelles and releases neurotransmitters.
connected to the outer seg. by cillium
16
Q
Rods
A
light sensitive
processes achromatic vision with lower resolution
17
Q
Cones
A
less light sensitive
process color vision with higher resolution
18
Q
Light is on
A
dark Na+ current channels close.
hyper polarization of the photoreceptor cell membrane.
19
Q
Light is off
A
Steady inward iNa (dark current)
resting photoreceptor cell membrane potential.
20
Q
Light
A
_____ acts as a negative stimulus
21
Q
Electroretinogram
A
The sum of the responses from different cell types to light
22
Q
What is happening in b wave?
A
electrical activity
23
Q
What is happening in a wave?
A
hyper polarization of photoreceptor cells
24
Q
What is happening in c wave?
A
Appears to be from pigment epithelial cells.
25
Rhodopsins
a family of transmembrane proteins in the outer segment of photoreceptor cells.
26
Opsin
```
a polypeptide
(part of rhodopsin)
```
27
Retinal
a light absorbing molecule
| part of rhodopsin
28
Opsin
Sensitivities of the cone receptors to different light depend on
29
Visible light, all trans
_______ changes the conformation of retinal from 11-cis to ____.
30
Metarhodopsin
all-trans separate retinal from rhodopsin, which then becomes______________.
31
Transduction
________ (g protein) activates a phosphodiesterase, which breaks cGMP --->gNa
32
Action Spectrum
magnitude of a photoreceptors response to different wavelengths.
33
Rods
____ are 10 times more sensitive to light then cones.
34
Primordial arc system
a single cell that serves as afferent
| sensory neuron and effector neuron (“sensing effector”).
35
if the osmolarity of blood plasma or extracellular fluids
| decrease
```
the cell swells and stretch-inactivated Na+
channels close, causing a decrease in the release of
antidiuretic hormone (ADH)
```
36
if osmolarity increases
the cell loses water and shrinks, the
membrane becomes depolarized, and ADH release is
stimulated
channels open
37
Monosynaptic
separate neurons for sensory and motor
| functions, but no interneurons
38
Polysynaptic
interneuron(s) moderate central processing.
39
Hydra nervous system
nerve nets, but no CNS
40
Sea star nervous system
nerve ring and radial nerves, no cephalization
41
Flatworms and round worms
segmented pattern, CNS and cephalization
42
cephalization
is the coalescence of neurons in the anterior
| end of the nervous system (the brain)
43
nerve cord
bundles of
neurons (homologous
to the spinal cord in
vertebrates)
44
ganglion
cluster of somata
(somata in most animals
tend to be clustered)
45
connectives
axons between ganglia
46
nuclei (in vertebre)
clusters of
somata with similar
functions within
the CNS
47
ganglia (in vertebre)
clusters
of somata outside
the brain and
spinal cord
48
dorsal root
the somata of sensory neurons are clustered in the ___
49
dorsal horn of the gray matter
the somata of interneurons are clustered in the _____
50
ventral horn of the gray matter
the somata of motor neurons are clustered in the ___
51
ventral root
axons from motor neurons exit the spinal cord through
| _____
52
forebrain (prosencephalon) midbrain (mesencephalon) and hindbrain (rhombencephalon)
___, ___, ___, are primary vesicles of the CNS.
53
___, ___, are secondary vesicles of the forebrain
telencephalon and diencephalon
54
___, is a secondary vesicles of the midbrain
mesencephalon
55
___, ___, are secondary vesicles of the hindbrain
metencephalon and myelencephalon
56
___, is the adult structures of the telencephalon
cerebrum
57
___ and __ are adult structures of the diencephalon
Thalamus and hypothalamus
58
___, is the adult structures of the mesencephalon
tectum
| lower invertebrates
59
___ and __ are adult structures of the metencephalon
pons and cerebellum
60
___ and __ are adult structures of the myelencephalon
medula and oblongata
61
Medulla
Action
mediates respiration and autonomic functions
receives and relays sensory and motor information
62
Cerebellum
| Action
receives and integrates sensory information from the
semicircular canals, and joins the visual and auditory
systems
coordinates motor outputs related to position, posture, and
orientation in space
63
pons (in higher vertebrates)
| Action
contains tracts that connect
| the medulla and the cerebellum with higher centers
64
Tectum (optic lobe)
| Action
receives and integrates visual, auditory, and tactile inputs
these functions have been taken over by the cerebral cortex
in higher vertebrates
65
Cerebral cortex
the folds in higher vertebrates increase the surface area and
the number of neurons
processes sensory and motor information and association
(intelligence)
it is most elaborated in humans and primates
66
the hippocampus
___ assists in the
storage of long term memory related to spatial navigation
(limbic system)
67
Amygdala & Hypothalamus
| action
process information and organize outputs related to emotions
are the centers of visceral functions and emotional responses
the hypothalamus also control water and electrolyte balance,
and the secretory activities of the pituitary gland
68
Thalamus
| action
a major coordinating center for sensory and motor signaling
receives sensory information and relays it to the cortex
receives motor information from the cortex and relays it to
the motor centers
69
visceral and involuntary
The two branches of the autonomic nervous system control
| ____ and ___ functions.
70
What does Sympathetic system do?
```
increases heartbeat rate
pupillary dilation
inhibits exocrine secretion
increase in blood flow to
skeletal muscles
```
71
What does Parasympathetic system do?
```
decreases heartbeat rate
pupillary constriction
stimulates exocrine secretion
increase housekeeping
functions (like digestion)
```
72
autonomic reflex arc
The parasympathetic autonomous nervous system is also
| based on the _____
73
the motor outputs do not pass through ____
the sympathetic chain
| ganglia
74
the synapses between the pre- and post- ganglionic neurons
| occur at ______ ganglia, or ____ organs
peripheral
| target
75
all preganglionic neurons originate from___
and extend into the _____, parallel to the
vertebral column
spinal cord and sympathetic chain
76
parasympathetic, preganglionic neurons originate only from the__
head area
| (through cranial nerves) and from the sacral spinal cord
77
parasympathetic, preganglionic neurons synapse onto ___
postganglionic neurons (usually short) near the target organs, or at peripheral ganglia
78
preganglionic neurons are cholinergic, which means
they all use acetylcholine as neurotransmitter
79
postganglionic neurons in the parasympathetic division are
| are ___
use acetylcholine as neurotransmitter
80
postganglionic neurons in the sympathetic division are
| are ___
are adrenergic
| they use norepinephrine as NT
81
Autocrine
the cell responds to its own secreted signals.
82
Paracrine
the secreted signals reach only the neighboring
| cells.
83
Synaptic
(a special type of paracrine signaling): the signal (a
neurotransmitter) is secreted by a neuron into a synapse.
The target is a specific cell.
84
Endocrine
```
the signals (hormones) can enter the bloodstream
and reach distant target cells.
```
85
Neuroendocrine
```
the signal (a neurohormone) is secreted by a
neuron into the bloodstream.
```
86
Exocrine
the signals are released from the skin or from the
| lining of the gut.
87
synthesis of secreted proteins occurs in the ___ ____
endoplasmic reticulum
88
at the trans-Golgi network, protein are ___ and ___
sorted and distributed
89
exocytosis
protein secretion
90
ions are released by secretory cells into the ___
acinus (the blind
| cavity that is lined by the secretory epithelium)
91
```
the negatively charged sialic
acids at the ends of some
oligosaccharides give the
structure an overall _____
charge, which are ____
by high concentrations of Ca2+
```
negative and neutralized
92
Describe Secretion by endocrine glands
ductless glands
the water-soluble secretions are releases directly into the
bloodstream by exocytosis of secretory vesicles
lipid-soluble secretions can diffuse through the plasma
membrane
93
Constitutive secretion
proteins are secreted
| right after they are sorted from the trans-Golgi network
94
Regulated secretion
only in specialized cells
proteins are stored in special secretory
vesicles and are released from the cell by exocytosis only
in response to external signals
95
the depolarization of the membrane and the increase in Ca2+ permeability causes ____
inflow of Ca2+
96
in simple endocrine cells, external signals cause the opening of ____
intracellular Ca2+ stores
97
Glands secrete:
exocrine
paracrine
endocrine
98
Neuroendocrine systems secrete
regulate hormone secretion from some endocrine glands
99
Describe hormone features
secreted by specialized tissues
```
secreted into the bloodstream to
target tissue(s)
```
modulate the activity of the target tissues/organs
100
Hormone functions:
maintenance of blood osmolarity (antidiuretic hormone)
maintenance of blood sugar levels (insulin, glucagon)
regulation of metabolic rates (growth hormones, thyroxine)
control of behavior (epinephrine)
control of reproductive cycles and sexual activity (sex
hormones)
101
what does short loop negative feedback do?
the accumulation of the
hormone, or the product of the hormone’s direct target,
stops hormone secretion
102
what does long loop negative feedback do?
the product of an effector
| series stops hormone secretion
103
what does positive feedback do?
the hormone’s direct target tissue
| stimulates additional hormone production
104
no feedback regulation:
open loop
105
Fast responses of hormones
depend exclusively on existing cellular components
their effects are usually transient
106
slow responses of hormones
depend on the modulation gene expression:
a component of the cascade needs to be synthesized, or:
the modulation of gene expression itself is the response
their effects are usually long lasting
107
the Lipid-insoluble hormone signal is ___inside the cell
transduced
108
Lipid-soluble hormones are (diffused) transported in the bloodstream
as _____ and bind to
___
water-soluble protein complexes and
| intracellular receptors
109
Second messengers synthesized in response to hormones
| Cyclic nucleotides:
cAMP and cGMP
110
Second messengers synthesized in response to hormones
| Inositol phospholipids:
DAG and IP3
111
What is the result when receptor (s) which bind stimulatory and inhibitory hormones respectively.
the activation (or inactivation) of adenylate cyclase, and the increase (or decrease) in cytoplasmic cAMP levels.
112
cAMP activates Protein Kinase A
| (PKA) by binding to its ____subunits and causing the release of the ___ subunits.
regulatory
| catalytic
113
The kinase activity of the released catalytic subunits ____ multiple effector proteins.
phosphorylate
114
Transient effects of PKA activation in anticipation
of muscular activity
In response to epinephrine:
converts glycogen into glucose 1-phosphate
and
inactivating glycogen synthase
115
PLC is activated by a _____
G protein
116
A single hormone can activate two signaling pathways that
| result in
independent effects.
and/or
in the same effect
117
Amines
amino acid-derived
118
Eicosenoids:
derived from arachidonic acid
119
Steroids:
synthesized from cholesterol
120
Peptide hormones
amino acid chains (the largest and most
| complex group)
121
Autacoid hormones:
active substances not included in
| the above categories (serotonin, histamine)
122
The neurosecretory cells release
| ____into ____
neurohormones into capillaries:
123
the bloodstream carries the signal (neurohormones) to a target endocrine tissue,
which_________________
secretes a hormone that
| targets another organ, or (its rarer) directly targets an organ.
124
Endocrine and neuroendocrine systems in the pituitary gland
Adenohypophysis (anterior lobe)
| Neurohypophysis (posterior lobe)
125
Endocrine and neuroendocrine systems in the hypothalamus gland
contains soma of neurosecretory cells
part of the diencephalon (the posterior region of the
forebrain)
contributes to the control of the autonomic nervous system
126
Adenohypophysis (anterior lobe):
non-neuronal tissue
| endocrine
127
Neurohypophysis (posterior lobe):
```
extension of the brain;
neuronal tissue (neuroendocrine)
```
128
para intermedia
in lower vertebrates only
129
In vertebrates, the master gland of the endocrine system is the _________
pituitary gland
130
neurosecretory cells terminate ___
median eminence
131
portal vessels carry their signals to the ____ and respond by secreting ____
adenohypophysis, hormones.
132
What do Releasing hormones (RHs) or
| release inhibiting hormones (RIHs) do?
stimulate or inhibit the release
of adenohypophyseal
hormones
133
Tropic hormones
act on other endocrine tissues to stimulate hormone production
134
examples of Tropic hormones
gonadotrophins: LH and TSH
135
Non-tropic:
act on nonendocrine tissues to modulate metabolism and other cellular functions
136
examples of non-trophic
MSH and growth hormone
137
Antidiuretic hormone (ADH):
promotes water retention
| by the kidney.
138
Oxytocin:
promotes uterine
contractions during
childbirth and the release of
milk from mammary glands.
139
Metabolic and developmental hormones:
```
Catecholamines
Glucocorticoids
Thyroid hormones
Pancreatic hormones
Growth hormone
```
140
Hormones that regulate water and electrolyte balance:
Parathyroid hormone
Calcitonin
Mineralocorticoids
141
What is the source of Catecholamines
adrenal medulla
142
What is the source of Glucocorticoids
adrenal cortex
143
What is the source of Thyroid hormones
thyroid gland
144
What is the source of Pancreatic hormones
pancreas
145
What is the source of Growth hormone
adenohypophysis
146
What is the source of Parathyroid hormone
parathyroid gland
147
What is the source of Calcitonin
thyroid gland
148
What is the source of Mineralocorticoids
various tissues
149
What is the function of Catecholamines
fight-or flight reaction
150
What is the function of Glucocorticoids
circadian adaptation to long-term stress
151
What is the function of Thyroid hormones
increase metabolic rate
152
What is the function of Pancreatic hormones
regulate blood sugar levels
153
What is the function of Calcitonin
decrease blood Ca2+
154
What is the function of Mineralocorticoids
stimulate retention of Na+
155
What is the function of Growth hormone
stimulates tissue growth, fatty acid consumption
156
What is the function of Parathyroid hormone
increase blood Ca2+
157
adrenal medulla produces
catecholamines
158
adrenal cortex produces
glucocorticoids
159
catecholamines regulate
smooth muscle contractions and cardiac activity
| regulates stress responses
160
catecholamines function as ____ when released by ____.
neurotransmitters when released by adrenergic neurons
161
The sympathetic nervous system
| regulates the _______ response
fight-or-flight
162
a1 adrenoreceptors stimulate
smooth muscle contraction
| sarcomere contraction
163
b1 and b2 adrenoreceptors activate
```
both activate adenylate cyclase
(AC)
effect: increase in cAMP, the
activation of PKA, and the
stimulation of glycogen
breakdown
```
164
sympathetic regulation of digestion express what kind of receptor?
inhibitory a2 adrenoreceptors.
165
a2 adrenoreceptors cause
inhibition of AC
activity and inhibit the release
of norepinephrine from
adrenergic neurons
166
Other effects of b1 adrenoreceptors
are stimulated mostly by neuronal norepinephrine
cause the release of Ca2+ from the ER and an increase in cardiac activity
stimulates the release of fats from adipose tissue
167
Other effects of b2 adrenoreceptors
stimulated mostly by circulating catecholamines
mediate bronchiodilatation and vasodilatation
activate Ca2+ pumps, resulting in a decrease cytoplasmic Ca2+ levels
effect: smooth muscle relaxation
168
```
neurohormones from hypothalamic neurosecretory cells induce _____ production in the ____ lobe of the
pituitary gland (adenohypophysis)
```
hormone
| anterior
169
ACTH
adrenocorticotropic hormone
| stimulates glucocorticoid production at the adrenal cortex
170
ACTH effects:
adaptation to long term stress (raise blood glucose levels, mobilize fat)
171
ACTH subject to
negative feedback regulation: glucocorticoids stop the secretion of ACTH and CRH
172
Thyroid hormones
derived from the amino acid tyrosine.
secreted by the thyroid gland for heat generation
lipid soluble
activate intracellular receptors that induce the
expression of genes that code for metabolic enzymes
results: increase metabolic rate at the liver, heart, kidneys, skeletal muscles, and nervous system--> heat generation
173
TRH _____ the production of ____ hormone
induces
| thyroid-stimulating
174
A dietary iodine deficiency may result in the __________________
excessive stimulation of the thyroid gland and abnormal growth.
175
What are some effects of Parathyroid hormone ?
```
mobilizes the release of calcium and
phosphate (PO43-) from bones
increases calcium reabsorption from
urine in the kidneys
stimulates the kidneys to activate
vitamin D, which promotes the
intestinal uptake of Ca2+ from food
increase in the levels of blood Ca2+
```
176
Calcitonin has the ability to _____ blood calcium levels by effecting two target organs; _____ and ___
decrease
| kidneys and bones
177
Osteoclast
a cell that nibbles at and breaks down bone and is responsible for bone resorption. Osteoclasts are large multinucleate cells that differentiate from macrophages.
178
effect of insulin:
decrease in blood glucose
179
Type I diabetes:
decreased insulin production in the pancreas
180
Type II diabetes:
reduced insulin sensitivity at the target tissues
| insulin resistance
181
Glucagon
secreted by pancreatic a cells in response to low blood glucose (hypoglycemia)
182
Glucagon inhibits
glucose uptake and glycogenesis in the liver
183
Glucagon stimulates
stimulates glycogenolysis in the liver; and as glucose is
released and blood glucose levels increase:
stimulates pancreatic b cells to produce insulin
184
GRH stimulates the release of _____
growth hormone
185
GH inhibits
uptake of glucose by most tissues
186
GH stimulates
fat cells to release fatty acids and the release of glucose from the liver
187
hypothalamic gonadotropin-releasing hormone (GnRH, a peptide hormone) stimulates the secretion of
luteinizing hormone (LH, a peptide hormone) and follicle-stimulating hormone
188
LH stimulates the production of______
testosterone in Lydig cells (in the testes)
189
FSH stimulates the production of ____
inhibin (a peptide hormone) in Sertoli cells (also in the testes)
190
Muscle fibers develop from
the fusion of myoblasts during myogenesis
191
satellite cells
stem cells that are arrested in G0
192
M line
contains enzymes for muscle energy metabolism
193
H zone:
myosin only
194
A band:
zone where actin and myosin are visible
195
I bands:
portions between A bands (actin and actinin)
196
cross bridges:
regions where myosin heads interact with actin filaments
197
Titin
very large protein (3000 kd)
extends from M line to the Z disc
thought to act like springs that keep the myosin filaments
centered in the sarcomere and maintain the resting tension
that allows a muscle to snap back if overextended
198
Nebulin
filaments associated with actin
| thought to act as regulators of F-actin assembly and length
199
Heavy chains
two supercoiled a helices that terminate in the
| amino heads.
200
Light chains
essential myosin light chain (dark blue) and
| regulatory myosin light chain (light blue).
201
Tension
a reaction force applied by a stretched object on the objects which stretch it.
202
Isometric
energy is spent and force is generated but the
| muscle is not allowed to contract
203
Isotonic
as force is generated the muscle contracts
| the muscle does work
204
Momentum
the quantity of motion of a moving body,
| measured as the product of its mass and velocity.
205
Force
an influence that may cause an object to accelerate
(increase its momentum), measured as the product of the
mass of the object and acceleration.
206
Work:
the exertion of force to overcome resistance. Can only
| happen with isotonic contraction.
207
Power:
the rate at which work is performed.
208
Tropomyosin
long filamentous protein that binds F-actin lengthwise
209
If no Ca2+ is present on tnC
tropomyosin blocks the binding sites of myosin on actin
210
tnT binds:
binds tropomyosin
211
tnI binds:
binds actin and tnC
212
when ATP is added in the experiments :
the tension exerted by the myofibril does not increase
213
when Ca2+ added the experiments :
the tension exerted by the myofibril increases
214
Cytosolic calcium is necessary for ___ contraction
muscle
215
the tension exerted by the fiber in the presence of Ca2+
| increases only when ___ is added
ATP
216
if ATP is removed while Ca2+ is still present:
no drop in the tension exerted by the fiber
217
if ATP is added when Ca2+ is not available:
the tension exerted by the fiber drops
218
what happens After a short latency period following the AP:
| muscle tension increases briefly (a twitch).
muscle tension increases briefly (a twitch).
219
a tension transducer measures ___
force
220
a stimulating electrode transmits a _______
stimulus current
221
the resulting voltage changes are detected by the _______
recording electrode
222
During the latent period there is an increase in ________
cytoplasmic calcium
223
T-tubules:
extensions of the cell membrane that extend into
the cell and run around the perimeter of the myofibrils and
over the Z-discs.
224
Sarcoplasmic reticulum:
the endoplasmic reticulum of the
| muscle fibers, which sequesters and stores Ca2+.
225
Ca2+ pumps use ATP to sequester Ca2+ into the _____ of the SR
lumen
226
inside the SR, Ca2+ binds _____, reducing the gradient of free Ca2+ across the SR membrane
calsequestrin
227
Dihydropyridine (DHP) receptors:
voltage-activated membrane proteins of the T-tubule.
228
Ryanodine (Ry) receptors:
Ca2+ channels* on the SR.
229
The depolarization of the T-tubule membrane induces a
_____________ in the DHP receptor that induces
the Ry receptor to ___.
conformation change
| open
230
Ca2+ is released from the SR to the cytosol and binds TnC,
| causing ______
sarcomere contraction
231
when the depolarizing stimulus stops,
Ca2+ is re-sequestered into the SR and the muscle relaxes
232
Slow generation:
aerobic respiration and oxidative phosphorylation
| requires O2
233
Fast generation (during periods of intense demand):
anaerobic glycolysis (generates lactic acid)
direct phosphorylation: the transfer of a P from creatine
phosphate to ADP both are O2-independent
234
Antagonistic pairs in vertebrate skeletal muscles:
flexor and extensor
235
flexor:
a muscle that pulls a joint and causes it to close
236
extensor:
a muscle that opposes the flexor to open the joint
237
Motor pool:
a group of neurons that innervates a muscle.
238
Motor unit:
a motor neuron and the muscle fibers it
| innervates
239
the length and the strength of a sustained contraction
| depends on the _______
frequency of APs
