Muscle-microanatomy

Question 1

This is the cytoplasm of muscle cells , contains myoglobin and glycogen

Answer 1

sarcoplasm

Question 2

This is the plasma membrane of muscle cell

Answer 2

sarcolemma

Question 3

A highly specialized smooth endoplasmic reticulum of a muscle cell regulating calcium flow

Answer 3

sarcoplasmic reticulum

Question 4

cylindrical multi nucleated cells

Answer 4

myofibers

Question 5

contractile elements composed of repeating sections of myofilaments .

Answer 5

myofibrils

Question 6

known as Thick myosin and thin actin

Answer 6

myofilaments

Question 7

dense irregular connective tissue surrounding muscle

Answer 7

epimysium

Question 8

surrounds smaller bundles of muscle (fascicles)

Answer 8

perimysium

Question 9

individual myocytes are surrounded nu reticular fibers forming the..

Answer 9

endomysium

Question 10

contractile or functional unit of myocyte

Answer 10

sarcomere

Question 11

At a full contraction, these lines will be drawn close to each other.

Answer 11

z line

Question 12

This line is located in the H band(H band within A band)

Answer 12

m line

Question 13

corresponds to the area where thick and thin filaments overlap(dark band)

Answer 13

A-band

Question 14

Composed of only thin actin filaments(pale band)

Answer 14

I-band

Question 15

This band is located in the center of A band and M line is located within it.

Answer 15

H band

Question 16

Protein that lies within the groove between actin filaments in muscle tissue. In a relaxed muscle this protein blocks the attachment site for the myosin cross bridge , preventing contraction

Answer 16

tropomyosin

Question 17

complex protein that works with tropomyosin

Answer 17

troponin

Question 18

a deep invagination of the sarcolemma that allows depolarization of the membrane to quickly penetrate to the interior of the cell allowing calcium release from the sarcoplasmic reticulum

Answer 18

T- tubule or transverse tubule

Question 19

The actin filaments of contractile units are attached to ___ ____ The intermediate filaments are connected to other intermediate filaments via ___ ___, which eventually are attached to adherens junctions in the cell membrane of the smooth muscle cell, called the sarcolemma.

Answer 19

dense bodies

Question 20

These attach cardiac muscle cells to each other , providing strength and the ability to function as a syncytium

Answer 20

intercalated discs

Question 21

These cells are positioned between basal lamina and sarcolemma of muscle cell , retain mitotic potential and accomplish in some form of repair.

Answer 21

myosatellite cells

Question 22

These are modified cardiac muscle cells with 1 or 2 nuclei , sparse and restricted to periphery of the cell

Answer 22

purkinje fibers

Question 23

What is the germ layer origin of muscle? and what shape are muscle cells?

Answer 23

muscle cells are spindle shaped and originate from the mesoderm (myoblast)

Question 24

what are the 3 types of muscle?

Answer 24

skeletal,smooth , cardiac

Question 25

This type of muscle: - makes up 50% body weight - tongue , masseter (cheek) and heart are strongest muscles of the body - myocytes contain MULTIPLE PERIPHERALLY LOCATED NUCLEI - STRIATIONS are seen in myocytes when cut in longitudinal section - VOLUNTARY muscles - limited regeneration capacity- satellite cells are b/w basal lamina and sarcolemma of muscle , these cells have mitotic potential, therefore they can accomplsh some repair

Answer 25

Skeletal muscle

Question 26

What development is the following? - mesenchymal cells align and fuse together forming multinucleated tubes(myotubes) - myotubes differentiate forming functional myofilaments and the nuclei are displaced against plasma membrane. - some cells do not differentiate and remain mesenchymal cells (satelitte cells function in muscle repair)

Answer 26

skeletal muscle development

Question 27

This muscle is surrounded by dense irregular CT layer(epimysium) - whole muscle is made up of smaller bundles called fascicles surrounded by perimysium - each fascicle is made up of many muscle cells - myofibers contain cylindrical bundles of myofibrils which in turn contain many smaller bundles of myofilaments (endomysium surrounds individual myocytes)

Answer 27

skeletal muscle organization

Question 28

this type of muscle contains a single cell with one central nucleus

Answer 28

cardiac muscle | Cardiomyocyte=myocardiocyte=cardiac myocyte

Question 29

this type of muscle is cross striated and lacks the ability to regenerate. Contains intercalated discs- which attach ___muscle cells to each other , providing strength and ability to function as a syncytium.

Answer 29

cardiac muscle

Question 30

cardiac muscle contains ___-___: longitudinal element for communication , allowing electrical impulse and _____: transverse element acting as a strong anchor

Answer 30

gap junctions and desmosomes.

Question 31

cardiac muscle contains sarcoplasmic reticulum and many _____ present (requires abundant oxygen). -cardiomyocytes are ___ and conductile

Answer 31

mitochondria | contractile

Question 32

- These are modified cardiac muscle cells with 1-2 nuclei - myofibrils are sparse and restricted to periphery of cell - arranged in groups

Answer 32

purkinje fibers

Question 33

- single centrally located nucleus - nostriations or myofibrils,actin/myosin present but no order to them - desmosomes and gap junc. are seen - no T-tubules - spindle shaped FUSIFORM cells surrounded by basal lamina and reticular fibers - single central nucleus-cigar shaped - parasympathetic and sympathetic innervation - CONTRACTION INVOLUNTARY

Answer 33

smooth muscle

Question 34

type of smooth muscle found in visceral organs, cells behave like syncytium contracting in a network, sparse nerve innervation but cell communicate via multiple gap junctions

Answer 34

single smooth muscle

Question 35

type of smooth muscle found in iris of eye , precise contraction, individual innervation of each myocyte, lack gap junctions which makes them function individually

Answer 35

multi-unit smooth muscle

Question 36

Functions of smooth muscle: - _____ wave like contractions ex. gastrointestinal tract - ____ ___ - contraction alters blood flow and important in blood pressure - ____ - urinary bladder, uterus - ___ (minor role)

Answer 36

peristalsis vascular dynamics propulsion secretion

Question 37

in smooth muscle regeneration is ___ , new smooth muscle cells may be derived from mesenchymal cells. Repair in smooth muscle is completed by ___ tissue formation formed by fibroblasts

Answer 37

limited, scar tissue

Question 38

smooth muscle is seen in the wall of ___ organs - tunica___ - tunica_____

Answer 38

luminal organs tunica mucosa and tunica submucosa

Question 39

what are the two types of non muscle contractile cells

Answer 39

myoepithelial cells and myofibroblasts

Question 40

these non-muscle contractile cells have ectodermal origin , contain actin/myosin, smiliar to smooth muscle, can be stimulated by horomones(mammary gland) , basketlike shape(encloses clusters of glandular cells), and are found in salivary, mammary and lacrimal glands

Answer 40

myoepithelial cells

Question 41

These non muscle contractile cells play a role in wound contraction:

Answer 41

myofibroblast