Exam 2 Muscle Flashcards
What are the 4 basic tissues of the body:
- Epithelium
- Connective Tissue
- Muscle Tissue
- Nervous Tissue
What are two other names for muscle cells
myocytes myofibers
Which layer do muscle fibers originate from?
Mesoderm
They cytoplasm of muscle cells
Sardcoplasm
What is contained in the Sarcoplasm?
Glycogen and Myoglobin
The plasma Memb. of the muscle cell
Sarcolemma
The highly specialized smooth ER of a muscle cell
Sarcoplasmic Reticulum
What is the importance of the SR
regulate calcium flow
What are the 2 types of Cross striated muscle
- Cardiac
2. Skeletal
What is another term for Myoepithelial cells?
Basket cells
T/F striations are seen in myocytes when cut in cross section?
F. Longitudinal Sections
Mesenchymal cells align and fuse together forming multinucleated tubes called:
Myotubes
Myotubes differentiate forming functional ______ and the nuclei are displaced against the plasma memb.
Myofilaments
Cells that do not differentiate and remain mesenchymal cells,
Satellite cells
What is the purpose of satellite cells?
muscle repair
Dense irregular connective tissue surrounding the muscle
Epimysium
A whole muscle can be made up of many smaller bundles known as:
Fascicles
Each Fascicle is surrounded by
Perimysium
What is a fascicle made up of?
Myocytes/Myofibers
Myofibers contain cylindrical bundles of ______ which in turn contain many smaller bundles of ______
Myofibrils, Myofilaments
Individual myocytes are surrounded by reticular fibers forming the _____
Endomysium
The contractile element of muscles
Sarcomere
What are Myofibrils made of?
Actin and Myosin
What are the regulatory proteins of Myofilaments?
Tropomyosin
T/F the light zone only contains Actin
T
T/F The dark zone only contains Myosin
F. Myosin +/- Actin
What is another name for the light zone
I Band
What is another name for the Dark zone
A Band
What is the H zone?
Only contains M
What is the M line
Center, where myosin is anchored
What is anchored to the Z-Line?
Actin
What are the 5 steps of muscle contraction?
- Calcium binds troponin
- Tropomyosin moves exposing byosin-binding site on actin
- Myosin head binds to Actin ATP to ADP
- Bound thin filament slides over thick
- shortening of entire muscle fiber
What is the main function of the SR?
Stores and releases calcium ions to initiate contractions
The expanded ends of the SR
Terminal Cisterna
What are the 2 types of skeletal muscles?
- Type 1 (red muscle)
2. Type 2 (White muscle)
Another name for red muscle
Slow twitch
What accounts for the dark color of red muscle?
Myoglobin
T/F Slow twitch muscle requires Aerobic metabolism to resist fatigue?
T
List 3 facts about slow twitch muscle
- High fat, low glycogen
- Many mitochondria
- Myoglobin to help transfer O2
What is another name for White Muscle?
Fast twitch
Give some examples of Slow twitch muscle
Postural muscles of mammals, pectoral muscles of birds
T/F White muscle undergoes anaerobic meabolism
T
T/F White Muscle is less prone to fatigue than red muscle?
F More prone to fatigue
List 3 facts about Fast twitch muscle
- low fat, high glycogen
- less myoglobin
- few mitochondria
Does cardiac muscle undergo aerobic or anaerobic metabolism?
Aerobic
What are the 2 types of intercalated discs in cardiac muscle
Gap junctions and desmosomes
Attach cardiac muscle cells to each other, providing strength and the ability to function as a syncytium
Intercalated Discs
Intercalated discs consist of 2 elements:
- Transverse element
2. Longitudinal element
What is the function of Transverse elements?
Anchor/ Strong attachment
What is the function of Longitudinal elements
Communication / Propagation of electrical impulses
A Desmosome is an example of a _______ element
Transverse
A Gap Junction is an example of a ______ element
Longitudinal
What are the 2 types of Cardiomyocytes?
- Contractile
2. Conductile
Modified cardiac muscle fibers in the subendothelial tissue, concerned with conducting impulses through the heart
Purkinje Fibers
Groups of purkinje fibers are known as
Purkinje Fibers also
What is the purpose of cytoplasmic dense bodies in smooth muscles
anchors for myofilaments
T/F smooth muscle is similar to skeletal muscle and contain Desmosomes, gap juncions, and t tubules
F. No T tubules
What are the 2 types of smooth muscle cells?
Single smooth muscle
Multi-unit smooth muscle
Where is single smooth muscle found
Visceral organs
how do cells of single smooth muscle communicate?
gap junctions
Where is Multi-unit smooth muscle found>
Iris of eye
what is the function of Multi unit smooth muscle
precise contraction
T/F Multi-Unit smooth muscle cells behave like syncytium contracting in a network
F Individual innervation of each myocyte
T/F Single smooth muscle behave like syncytium contracting in a network?
T
What are the 4 functions of smooth muscle cells?
- peristalsis- Wave like contractions
- Vascular Dynamics - blood pressure
- propulsion- bladder
- Secretion
Myoepithelial cells origin?
Ectoderm
What stimulates Myoepithelial cells?
Hormones
Where are myoepithelial cells located?
Salivary glands, mammary glands, lacrimal glands
What is another name for myoepithelial cells?
Basket cells