[2] Lecture 17: Smooth And Cardiac Muscle

Question 1

Not as extensive in skeletal muscle

Answer 1

T tubules in cardiac muscle

Question 2

Single mononucleated cells
Centrally positioned nuclei 
Sarcomeric arrangement
Communicate via gap junctions
Cells not directly innervatd

Answer 2

Cardiac muscle tissue

Question 3

Cardiac muscle tissue-cells communicate via gap junction. What’re they called?

Answer 3

Intercalated discs

Question 4

Cardiac t tubule:

Answer 4

Loacated along z line and diad-interacts w/ one cisterna [as opposed to skeletal triad]

Question 5

Cardiac muscle composed of 3 types of junctions:

Answer 5

Macula adherentes (desmosomes)

Fascia adherentes

Gap junctions

Question 6

Part of longitudinal component

Answer 6

Gap junctions

Question 7

Link intermediate filaments [desmin] of adjoining cardiac muscle cells - part of transverse component

Answer 7

Macula adherentes

Question 8

Anchor actin filaments of sarcomeres—-transverse component

Answer 8

Fascia adherentes

Question 9

Secreted by cardiac muscle cells in atria
Regulate electrolyte imbalance
Relaxes vascular smooth muscle
Stored as prohormone in secretory vesicles
Release stimulated by atrial stretch

Answer 9

ANP- atrial natriuretic peptide

Question 10

ANP relaxing vessels causes:

Answer 10

Reduces blood volume and pressure

Question 11

How atrial stretch causes ANP release

Answer 11

Causes cleavage of pro hormone

Question 12

Involuntary and visceral muscle tissue:

Answer 12

Smooth muscle tissue

Question 13

Single mononucleated cells w/ central nuclei
No sarcomeric arrangement
Don’t respond “all or none”
Cells innervated via ANS or enteric system
Communicate via gap junctions

Answer 13

Smooth muscle cells

Question 14

Where are the actin and myosin bundles which are in mesh work arrangement in smooth cells where are they found?

Answer 14

Cytoplasm except in nuclear area

Question 15

Anchor actin filaments to each other and to cell membrane
Contains alpha actinin
Inteconnected by a specific type of desmin
Communicate force of contraction to cytoskeleton and cell membrane
Found in cytoplasm and in cell membrane

Answer 15

Dense bodies

Question 16

Permanent depressions of the cell membrane thatre involved in fluid and electrolyte transport
Preceded by membrane lipid rafts composed of cholesterol and sphingolipids
Caveolin binds to the cholesterol in the lipid rafts and initiates the formation of caveolae
Vesicles are formed detach and participate in vesicular trafficking

Answer 16

Cavolae and lipid rafts

Question 17

Recptors in smooth muscle cells

Answer 17

Adrenergic and muscuranic —- g-proteins

Nicotinic cholinergic receptor—cation channel

Question 18

Smooth muscle sheets of most major organs are poorly innervated by what type junctions:

Answer 18

Gap junctions

Question 19

Don’t have t tubule system or extensive SR;
Dependent on ECM Ca+ for contraction
Pinocytotic vesicles: may transport Ca++ ions from ECF to SR

Answer 19

Smooth muscle cells