Please help me with my Physiology class. I will upvote for correct answers. I kn
ID: 3472202 • Letter: P
Question
Please help me with my Physiology class. I will upvote for correct answers. I know this seems long but its only one question. Thanks,
1a. (8 pts) Excitable cell function. Use the terms below to fill in this chart.
Neurons
Skeletal myocyte
Cardiac myocyte
Cardiac pacemaker Cells
List the channel types in the plasma membrane that open in response to depolarization.
Voltage-gated Na+ channges
List the channel types that are opening and closing to promote repolarization.
What is a primary role for calcium in this cell type?
How is Ca2+ released from intracellular stores?
N/A
N/A
Place the following terms in the boxes above.
exocytosis of neurotransmitter, removing tropomyosin block of actin (2x), depolarization (2x), prolonged absolute refractory period, mechanical activation by membrane depolarization, activation of Ca2+ release channels by Ca2+, Na+ (3x), Ca2+ (3x), K+ (4x), K+ opening (4x), Na+ closing (2x), Ca2+ closing (3x)
1b. (7pts) Muscle Cell Comparison Match the letter of the term(s) with the phrases below.
Some blanks use more than one term.
A. skeletal muscle (4x) (use this term when features are common to both type I and type II muscle fibers)
B. cardiac contractile myocytes (6x)
C. cardiac pacemaker cells (2x)
D. type I (slow twitch muscle fibers) (2x)
E. type II (fast twitch muscle fibers) (1x)
_______ prefer to make ATP through aerobic respiration
_______ use plasma membrane Ca2+ channels for cellular depolarization
_______ make use of cross bridge cycle
_______ generates tension without shortening of sarcomeres
_______ contraction involves shortening of sarcomeres
_______ contraction is controlled by motor units
_______ connected via gap junctions
_______ make significant use of anaerobic respiration
_______ contain a great number of mitochondria and myoglobin
Neurons
Skeletal myocyte
Cardiac myocyte
Cardiac pacemaker Cells
List the channel types in the plasma membrane that open in response to depolarization.
Voltage-gated Na+ channges
List the channel types that are opening and closing to promote repolarization.
What is a primary role for calcium in this cell type?
How is Ca2+ released from intracellular stores?
N/A
N/A
Explanation / Answer
1. List the channel types in the plasma membrane that open in response to depolarization-
Neurons- ligand-gated Na+ ion channels
Skeletal myocyte- Voltage-gated Na+ changes
Cardiac myocyte- Voltage-gated Na+ changes, Ltype Ca++ channel
Cardiac pacemaker Cells- Ltype and T-type Ca++ channel
List the channel types that are opening and closing to promote repolarization.-
Neurons- A-type sodium channels, Na+ ion delayed rectifiers, and Ca2+-activated K+ channels
Skeletal myocyte - Rapid rectifier K+ channels
Cardiac myocyte – slow and rapid rectifier K+ channels and inward rectifier
Cardiac pacemaker Cells- cyclic nucleotide gated K+ channel
What is a primary role for calcium in this cell type?=
Neurons- exocytosis of neurotransmitter [ secondary messenger for neurotransmitter release]
Skeletal myocyte- removing tropomyosin block of actin [excitation-contraction coupling]
Cardiac myocyte- repolarization and cardiac myocyte contraction
Cardiac pacemaker Cells- repolarization
How is Ca2+ released from intracellular stores?-
Neurons- depolarization[from axonal endoplasmic reticulum (ER)]
Skeletal myocyte- mechanical activation by membrane depolarization [endoplasmic reticulum]
Cardiac myocyte and Cardiac pacemaker Cells- activation of Ca2+ release channels by Ca2+ [extracellular ions (like from skeletal muscle)]
2.
type I (slow twitch muscle fibers) prefer to make ATP through aerobic respiration
cardiac contractile myocytes use plasma membrane Ca2+ channels for cellular depolarization
Skeletal muscle make use of cross bridge cycle
cardiac contractile myocytes generates tension without shortening of sarcomeres
skeletal muscle contraction involves shortening of sarcomeres
skeletal muscle contraction is controlled by motor units
cardiac contractile myocytes connected via gap junctions
type II (fast twitch muscle fibers) make significant use of anaerobic respiration
skeletal muscle contain a great number of mitochondria and myoglobin