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Flashcards in Unit 2 Deck (97):
1

Mental and physical sluggishness and low body temperature may be signs of

Hypothyroidism

2

The zona fasciculata of the adrenal Cortez produces

Glucocorticoids

3

The zona glomerulosa of the adrenal cortex produces

Mineralocorticoids

4

Renin is responsible for the activation of

Angiotensin I

5

Alpha cells in the pancreas produce which hormone in response to low glucose concentrations?

Glucagon

6

Bata =

Insulin

7

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

Zona reticularis

8

A hormone that can lower blood levels of calcium ion is

Calcitonin

9

The hypothalamus controls secretion of hormones by the adrenal medulla through

Direct neural stimulation

10

The hypothalamus controls secretion by the anterior pituitary by

Secreting releasing and inhibiting factors into a portal system

11

The hormone that dominated during the alarm phase of the general adaptation syndrome is

Epinephrine

12

Which pattern of hormonal interaction occurs when the first hormone is needed for the second to produce its effect?

Permissive

13

Which pattern of hormonal interaction occurs when hormones produce different, but complementary results?

Integrative

14

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

Binding to a hormone receptor in the plasma membrane

15

The pituitary hormone that promotes sperm maturation in testes is

LH

16

The posterior pituitary gland releases

OXT

17

The pancreatic hormone that causes blood sugar levels to fall is

Insulin

18

Steroid hormones

Bind to receptors in the nucleus of their target cells

19

True or false
Renin is a hormone released by the kidney

False, renin is an enzyme, no target cell

20

True or false
Aldosterone causes the retention of sodium ions

True

21

True or false
Inhibin acts to surpress the release of FSH in both males and females

True

22

True or false
Neurons that extend from the hypothalamus release hormones from the posterior pituitary

True

23

Definition: hypophyseal portal system

Network of vessels that carries blood from capillaries in the hypothalamus to capillaries in the anterior lobe of the pituitary gland

24

Definition: hormone

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