Unit 2 Flashcards
1
Q
Mental and physical sluggishness and low body temperature may be signs of
A
Hypothyroidism
2
Q
The zona fasciculata of the adrenal Cortez produces
A
Glucocorticoids
3
Q
The zona glomerulosa of the adrenal cortex produces
A
Mineralocorticoids
4
Q
Renin is responsible for the activation of
A
Angiotensin I
5
Q
Alpha cells in the pancreas produce which hormone in response to low glucose concentrations?
A
Glucagon
6
Q
Bata =
A
Insulin
7
Q
Shelly has a hormone secreting tumor of the adrenal gland. The tumor is causing her to have a deep voice, grow extensive body hair, and stop menstruating. This tumor probably involves cells of the
A
Zona reticularis
8
Q
A hormone that can lower blood levels of calcium ion is
A
Calcitonin
9
Q
The hypothalamus controls secretion of hormones by the adrenal medulla through
A
Direct neural stimulation
10
Q
The hypothalamus controls secretion by the anterior pituitary by
A
Secreting releasing and inhibiting factors into a portal system
11
Q
The hormone that dominated during the alarm phase of the general adaptation syndrome is
A
Epinephrine
12
Q
Which pattern of hormonal interaction occurs when the first hormone is needed for the second to produce its effect?
A
Permissive
13
Q
Which pattern of hormonal interaction occurs when hormones produce different, but complementary results?
A
Integrative
14
Q
The action of thyroid hormone on a target cell involves all of these steps except one. Identify the incorrect step.
- binding to a cytoplasmic receptor protein
- transport into the target cell
- activation of mitochondria
- activation of a specific gene
- binding to a hormone receptor in the plasma membrane
A
Binding to a hormone receptor in the plasma membrane
15
Q
The pituitary hormone that promotes sperm maturation in testes is
A
LH
16
Q
The posterior pituitary gland releases
A
OXT
17
Q
The pancreatic hormone that causes blood sugar levels to fall is
A
Insulin
18
Q
Steroid hormones
A
Bind to receptors in the nucleus of their target cells
19
Q
True or false
Renin is a hormone released by the kidney
A
False, renin is an enzyme, no target cell
20
Q
True or false
Aldosterone causes the retention of sodium ions
A
True
21
Q
True or false
Inhibin acts to surpress the release of FSH in both males and females
A
True
22
Q
True or false
Neurons that extend from the hypothalamus release hormones from the posterior pituitary
A
True
23
Q
Definition: hypophyseal portal system
A
Network of vessels that carries blood from capillaries in the hypothalamus to capillaries in the anterior lobe of the pituitary gland
24
Q
Definition: hormone
A
Chemical that is secreted by one cell and travels through the bloodstream to affect the activities of target cells in another part of the body
25
Describe the three main phases of general adaptation syndrome, and the dominant hormones involved in each of the first two phases
Alarm phase “fight or flight”
Resistance phase
Exhaustion phase
26
In response to actions potentials arriving along the transverse tubules, the sarcoplasmic reticulum releases
Calcium ions
27
When a muscle fiber is stimulated repeatedly at a high rate, the amount of tension gradually increases to a steady maximum tension. This is called
Complete tetanus
28
In skeletal muscle fibers, active sites on action become available for binding after
Calcium binds to troponin
29
According to the length tension relationship
Greatest tension is achieved in sarcomeres where all myosin heads can engage with actin upon stimulation
30
Edges of a sarcomere are defined as
Z lines
31
The tension produced by a muscle fiber can vary Due to
The resting length of the sarcomeres and the frequency of actions potentials reaching the fiber
32
A weight lifter strains to life a heavy weight and there is no movement of the persons arms holding onto the weight. This type of contraction is called a (blank)
Isometric
33
When a skeletal muscle fiber contracts, the only band to remain constant in width is the
A band
34
In a sarcomere, cross bridge attachment occurs specifically in the
Zone of overlap
35
Decreased blood flow to a muscle could result in all of the following except
- muscle fatigue
- an oxygen debt
- an increase in intracellular glycogen
- a shift to anaerobic glycolysis
- an increase in intracellular lactic acid
An increase in intracellular glycogen
36
During the recovery period the body’s need for oxygen is increased because
Additional oxygen is required to restore energy reserves consumed during exercise
37
In a sarcomere, the central portion of thick filaments are linked laterally by proteins of the
M line
38
The area in the center of the A band that contains no thin filaments is the
H band
39
At rest, the tropomyosin molecule is held in place by
Troponin molecules
40
At rest, active sites on the action are blocked by
Tropomyosin molecules
41
Active sites on the actin become available for binding after
Calcium binds to troponin
42
The most important factor in decreasing the intracellular concentration of calcium ions after contraction is
Active transport of calcium into the sarcoplasmic reticulum
43
Triggering of the muscle action potential occurs after
Acetylcholine binds to chemically gated channels in the motor end plate
44
List the events that occur during a muscle contraction
- Calcium ion is released from the sarcoplasmic reticulum
- calcium ion binds to troponin
- myosin cross bridges bind to the actin
- the myosin head pivots toward the center of the sarcomere
- the myosin head binds an ATP molecule and detaches from the actin
- the free myosin head splits ATP
45
How would the loss of acetylcholinesterase from the motor end plate affect skeletal muscle?
It would cause muscles to stay contracted
46
The rapid rise and fall in force produced by a muscle fiber after a single action potential is a
Twitch
47
Which of the following statements about excitation-contraction coupling is incorrect?
— calcium ions travel through the transverse tubule
48
A patient takes a medication that blocks ACh receptors of skeletal muscle fibers. What is this drugs effect on skeletal muscle contraction?
Reduces the muscles ability for contraction
49
The increase in muscle tension that is produced by increasing the number of active motor units is called
Recruitment
50
During the recovery period following exercise, all of the following are true except
- Lactic acid is removed from muscle cells
- the muscle actively produces ATP
- muscle fibers are unable to contract
- oxygen is consumed at above the resting rate
- heat is generated
-muscle fibers are unable to contract
51
True or false
| Rigor mortis occurs due to lack of calcium in the sarcoplasm
False
| ATP
52
True or false
| The lower pH in exercising muscles reduces binding of calcium to troponin
True
53
True or false
| The increase in tension produced by increasing the frequency of stimulation is called recruitment
False, motor unit
54
True or false
| Contracting muscle fibers generate maximum tension when sarcomeres begin at their maximum length
False
| Optimal
55
True or false
| The A band shortens during muscle fiber contraction
False
| Width of filaments
56
Definition: motor unit
All the muscle cells that are controlled by a single motor neuron
57
Definition: Creatine phosphate
High energy compound found in muscle cells and involved in muscle activity
-phosphate donated to ADP to become ATP
—-ATP + creatine —> ADP + creatine phosphate
58
Definition: sarcolemma
Plasma membrane of a muscle cell
59
Definition: oxygen debt
During recovery period, oxygen demand is much higher than the normal levels. With this, the more ATP required for recovery, the more oxygen is needed. Oxygen debt means there this is the amount of oxygen needed to return the muscle to normal levels after exercise.
60
Definition: optimal resting length
Normal range of sarcomere length in the body is 75 to 130 percent of the optimal length. Maximum tension is produced when the zone of overlap is large but the thin filaments do not extend across the sarcomere center.
61
Definition: wave summation
Occurs when successive stimuli arrive before the relaxation phase has been completed, Ca++ becomes more and more each time and builds
62
Steps in initiating muscle contraction, from the motor neuron to the contraction cycle
- ACh is released at the neuromuscular junction and binds to ACh receptors on the sarcolemma
- action proteins reaches T tubule
- sarcoplasmic reticulum releases stored calcium ions
- calcium ions bind to tropinin, exposing the active sites on the thin filaments. Cross bridges from when myosin heads bind to those active sites
- contraction cycle begins
63
Events that occur during the contraction cycle
Myosin head has split ATP, is cocked
- ca++ binds with troponin, exposes actin on head
- myosin head binds active site
- power stroke: myosin head pivots and pulls actin forward and releases ADP
- ATP binds to myosin head, breaks link with active site
- myosin head splits ATP, recodos
64
Steps in muscle relaxation.
-ACh is broken down by acetylcholinesterase (AChE), ending action potential generation
-sarcoplasmic reticulum reabsorbs Ca2+
-active sites covered, and cross bridge formation ends
—-without calcium ions, the tropomyosin returns to its normal position and the active sites are covered again
-contraction ends
-muscle relaxation occurs and returns to resting length
65
The primary taste sensations include all of the following except
Spicy
66
Which of the special sense has a “direct line” to the cerebral cortex, which makes the association with memories and emotions stronger?
Olfaction
67
Movement of the endoymph in the semicircular canals
Signals rotational movement
68
Under which condition would the release of neurotransmitter by photoreceptors be greatest?
In a pitch black room after 30 min
69
The following steps occur in rods when they are excited by photons of light
1. Membrane sodium channels close.
2, cGMP is broken down
3. Retinal changes form.
4. The membrane hyperpolarizes and the rate of neurotransmitter release declines.
5. Opsin activates enzymes.
6. Opsin activation occurs.
3,6,5,2,1,4
70
The optic disc is a blind spot because
There are no photoreceptors in that area
71
(Blank) celos connect photoreceptors to ganglion cells
Bipolar
72
Amacrine and (blank) cells facilitate or inhibit communication between photoreceptors and ganglion cells
Horizontal
73
In the light adapted state,
Photoreceptors are much less sensitive to stimulation
74
The cell of the retina that produces an action potential that goes to the brain is a(n)
Ganglion cell
75
The first step in the process of photo reception is
Absorption of a photon by a visual pigment
76
Where are the visual pigments located in the rods and cones?
Inside membrane discs stacked in the outer segment
77
Photoreceptor celos that are most useful in dim light are
Rods
78
Which of the following descriptions best matches basilar membrane?
- moves up and down due to currents in perilymph
- transmits movement of the tympanic membrane to the inner ear
- supports the olfactory organ
- tiny duct necessary for the static sense of equilibrium
- covers over the oval window
Moves up and down due to currents in the perilymph
79
Which of the following descriptions best matches the term otoliths?
- move up and down when the stapes moves back and forth
- transmit movement of the tympanic membrane to the inner ear
- bending these produces receptor potential in hair cells
- tiny weights necessary for the static sense of equilibrium
- seal the oval window
Tiny weights necessary for the static sense of equilibrium
80
Standing still in an elevator that suddenly lowers will stimulate receptors in the
Utricle and saccule
81
Low frequency sounds stimulate hair cells on which part of the basilar membrane?
Distal end
82
Steps that occur in the production of an auditory sensation.
- movement of the tympanic membrane causes displacement of the malleus
- movement of the malleus causes movement of the incus and stapes
- movement of the oval window establishes pressure waves in the perilymph of the scala vestibuli
- the pressure wave distorts the basilar membrane on its way to the round window
- distortion of the basilar membrane forces the hair cells of the spiral organ to vibrate against the tectorial membrane
- displacement of the stereocilia stimulates sensory neurons of the cochlear nerve
83
Perception of gravity and linear acceleration depends on
The force exerted by otoliths on hair cells of the maculae
84
When you spin quickly, you may feel dizzy. Which component of the inner ear generates the sensations that can lead to this feeling?
Semicircular canals
85
Why does the smell of formaldehyde seem to dissipate during the time you spend in the dissection lab, yet you are able to detect the cologne of someone who just entered the lab?
Central adaptation has occurred, through olfactory receptors retain sensitivity to other smells
86
Why are rods best suited for night vision?
Rods have a low threshold for activation
87
Where are the sensory receptors that respond to rotational movements of the head?
In the anterior, posterior, and lateral semicircular ducts
88
Which of the following statements correctly describes the location of rods and cones on the retina?
Cones are located at the center of the retina, rods at the peripherary.
89
Which of the following statements is true?
- gustatory receptors are mechanoreceptors
- rods are mechanoreceptors
- olfactory receptors are chemoreceptors
- hair cells are chemoreceptors
Olfactory receptors are chemoreceptors
90
Our taste buds are most receptive to
Bitter
91
Which of the following is not true about the resting state of rods?
- it is during darkness
- retinal is in 11-cis form
- gated sodium channels are open
- bleaching occurs
- membrane potential is around-40mV
Bleaching occurs
92
The frequency of a perceived sound depends on
Which part of the cochlear duct is stimulated
93
True or false
| Olfactory receptors are modified neurons
True
94
True or false
| At least two different types of cones are necessary for color vision to occur
True
95
True or false
| Your eyes are light adapted when all visual pigments have recovered from bleaching
False
96
During the time when the action potential moves through the sarcolemma a muscle twitch is in
Latent period
97
The type of contraction where the tension is less than the load is called
Isotonic eccentric contraction
