Cardiac Tissue Flashcards
How is cardiac muscle nucleated
single mono nucleated cells
How is the nuclei of cardiac cells positioned
Centrally
Does cardiac tissue have a sarcomeric arrangement
Yes
Cardiac muscle tissue cells communicate via
Gap Junctions
What are the gap junctions in cardiac muscle cells
intercalated discs
Are cardiac muscle tissues directly innervated
No
Are the T-Tubules as extensive as those in skeletal muscle
No
Each T-tubule in cardiac muscles interacts with
one cisterna (rather than two as in skeletal muscle)
Cardiac muscle tissues T-Tubules form a
Diad
Where are the diads of cardiac muscles located
at the level of the Z-lines
What is the composition of Intercalated disks
Macula adherentes (desmosomes)
Fascia adherentes
Gap junction
What link intermediate filaments (desmin) of adjoining cardiac muscle cells
Macula adherentes (desmosomes)
The macula adherentes (desmosomes) are part of _______ component of intercalated disk
Transverse
Fascia adherentes anchor _____ filaments of sarcomeres in intercalated disks
actin
Fascia adherentes are part of _____ component of intercalated disks
Transverse
The gap junctions are part of the ______ component in intercalated disks
Longitudinal
Atrial Natriuretic Peptides (ANP) is secreted by
cardiac cells in the atria
Atrial natriuretic peptides (ANP) regulate what
fluid electrolyte balance
Atrial natriuretic peptides (ANP) relax what
vascular smooth muscle
The main function of Atrial Natriuretic Peptides (ANP)
reduces blood volume and BP
Where is Atrial Natriuretic Peptide (ANP) stored and as what
In secretory vesicles stored as prohormone
When is atrial natriuretic peptide released
release is stimulated by atrial stretch
- results in cleavage of prohormone
What are synonyms of smooth muscle tissue
Involuntary
Visceral
Smooth muscle tissue is what nucleation
mononucleated
Where is the nucleus of smooth muscle tissue located
Central nuclei
Does smooth muscle tissue have a sarcomeric arrangement
No
Smooth muscle tissue is innervated via what
ANS or Enteric system
Does smooth muscle tissue respond “all or nothing”
No
How are smooth muscle tissues connected
via gap junctions
In smooth muscle cells ___ and ____ bundles are incorporated into a meshwork arrangement
actin and myosin
Where are the actin and myosin bundles incorporated in smooth muscle cells
Found throughout cytoplasm except in nuclear area
Do smooth muscle cells have dense bodies
yes
What anchor actin filaments to each other and to cell membrane of smooth muscle cells
Dense bodies
Dense bodies of smooth muscle cells contain what
Alpha-actinin
Dense bodies are interconnected by what
a specific type of desmin
What communicate force of contraction to cytoskeleton and cell membrane of smooth muscle cells
Dense Bodies
Where are dense bodies of smooth muscle cells found
in cytoplasm and in the cell membrane
Do smooth muscle cells have a T-Tubule system or extensive SR
No
Where do smooth muscle cells get calcium
They are dependent on extracellular calcium concentration
What may transport calcium ions from extracellular fluids to sarcoplasmic reticulum of smooth muscle cells
Pinocytotic Vesicles
Lipid rafts are composed of what
cholesterol and sphingolipids
Caveolin binds to what ______ in lipid rafts and initiates the formation of what
Cholesterol, Caveolae
What are Caveolae
permanet depressions of the cell membrane that are involved in fluid and electrolyte transport
Vesicles that are formed detach and participate in what
vesicular trafficking
Innervation fo smooth muscles may either ____ or _____ contraction of the muscle cells
facilitate, inhibit
Adrenergic and muscarinic receptors are linked to what
G-proteins
Nicotininc cholinergic receptors
cation channel
Smooth muscle sheets of most major organs are what
poorly innervated
Excitation in smooth muscles is spread through numerous what
gap junctions
