Muscle-Mace (exam 2) Flashcards
Striations=
Alternating light and dark bands
What muscle tissue is associated with striations?
skeletal muscle tissue (and cardiac muscle tissue)
Skeletal muscle tissue is mostly ______ muscle tissue, consciously controlled
voluntary
Describe skeletal muscle tissue:
- fibers? how are they arranged?
- Nuclei?
Long, unbranched, cylindrical cells (skeletal muscle fibers), arranged in parallel bundles that run length of the entire muscle
- Multinucleated (many nuclei adjacent to cell membrane)
Where is skeletal muscle located?
locations:
attach to bone, skin, surrounds distal end of digestive and urinary tracts as sphincters
Skeletal muscle contraction moves:
bones, causes facial expression, controls defecation or urination
Describe cardiac muscle tissue:
- ___ _____ cardiac muscle cells
- # of nuclei?
- mitochondria?
- striations?
- branched or unbranched?
- Short, branched cardiac muscle cells
- 1 or 2 centrally located nuclei, mitochondria-rich
- Striated, branched
- Cells closely packed in one direction
Describe the function of intercalculated discs and which muscle type they are located in
- located in cardiac muscle tissue
- Intercalated Discs= junction between cells (strengthens attachments between cells and promotes rapid conduction of electrical activity through cardiac cells)
Locations of cardiac muscle tissue
heart
T/F: cardiac muscle tissue is involuntarily controlled
True.
**Syncytium!
Describe Smooth Muscle tissue:
- ____-shaped cells
- branched or unbranched?
- nuclei? location?
Spindle-shaped cells - short, closely packed in one direction, unbranched, single nuclei, centrally located
Does smooth muscle tissue have striations?
NO! *Lacks striations, appears smooth
Locations of Smooth muscle tissue
Walls of digestive, respiratory, & urinary tracts; ***skin (erector pili), surrounds the blood vessels, digestive tract, urinary tract, reproductive tract, respiratory tract as sphincters
Is smooth muscle voluntarily or involuntarily controlled?
Involuntarily controlled
List the functions of smooth muscle tissue (list 5)
- Moves substances along internal passages (peristalsis)
- Erects hairs
- Controls blood flow and blood pressure
- Regulates airflow in lungs
- Controls urination and defecation
Functions of Skeletal Muscle (5)
- Body movement: Muscular contraction moving bone
- Maintenance of posture: Stabilizes joints and helps maintain the body’s posture
- Protection and support: Muscles along the walls of abdominal and pelvic cavity protect the internal organs and support normal position
- Storage and movement of materials:
- -Contract and relax sphincters to regulate passage of material.
- Allow voluntary expulsion of feces and urine
- Heat production: Heat is released as a byproduct of muscle contraction
- –**Main source of the heat produced in the body
Describe the gross anatomy of skeletal muscles:
- each muscle is composed of?
- muscle cells are organized into____
- each muscle contains?
- Each muscle is composed of thousands of muscle cells
- Muscle cells are organized into bundles, termed fascicles
- Each muscle contains connective tissue, blood vessels, nerves
Gross anatomy of skeletal muscle:
- name the 3 ______ layers of CT
- what is their function? (list 3 functions: hint “PSM”)
-3 concentric layers of connective tissue: epimysium(superficial), perimysium, endomysium(inner)
- Function:
- -Protection
- -Sites for blood vessel and nerve distribution
- -means of attachment to skeleton or other structures
Describe the epimysium
layer of dense irregular CT, surrounds whole skeletal muscle
Describe the Perimysium
dense irregular CT surrounding the fascicles, contains extensive blood vessels and nerves supplying fibers
Describe the endomysium
areolar CT, surrounds and electrically insulates each muscle fiber
“think E in endomysium for Electrical”
Describe a Tendon:
- structure?
- formed by?
- attaches ____ to bone
- cordlike structure composed of dense regular CT
- formed by the three CT layers
- attaches **muscle to bone, skin or another muscle
Describe aponeurosis:
- describe it
- it’s formed from the ___ CT layers
- Holds muscles together for ____?
- thin, flattened sheet of tendon with wide area of attachment
- formed from the three connective tissue layers
- Holds muscles together for functional enhancement
Describe Deep Fascia
- additional sheet of dense irregular CT
- external to the epimysium
- separates individual muscles
- binds together muscles with similar functions
- contains nerves, blood vessels, and lymph vessels
- fills spaces between muscles
Muscle hypertrophy= a greater # of _______
contractile elements**
There are less _____ _____ in muscle atrophy
contractile elements
T/F: muscle hypertrophy= muscle hyperplasia
FALSE. Muscle hypertrophy IS NOT muscle hyperplasia
Describe Fascia of Skeletal muscles:
- what kind of CT?
- Separates neighboring _____
- separates muscles from the ______
- Intermuscular septum=
=dense irregular CT
3 main things:
- Separates neighboring muscles (organs) or muscle groups from each other
- Separates muscles from hypodermis
- Intermuscular septum - fascia separating muscles
Endomysium, peri-, and epimysium continue into _____
tendons
When muscle cells contract, they pull on these CT wrappings (endo-,peri-, and epimysium), which in turn pull on the tendon, and therefore move the _____
bones they attach to
If the muscle gets a pump– vasodilation is occurring within the muscle itself– and then it stops contracting– you lose ____
the pump
When muscles contract– it pulls on endomysyium which pulls on perimysium which pulls on epimysium and that pulls on ______
tendons
Describe multinucleated muscle cells:
-in which muscle type?
and contains _____ proteins
(in skeletal muscles)
-dominant cells in the muscle, contain contractile proteins
Describe Satellite cells
(in skeletal muscles)
**No contractile proteins, may be stimulated to differentiate for repairing the injured muscle multinucleated muscle cells
Describe the sarcolemma
=muscle cell membrane
Describe T-tubules
aka transverse tubules
=Deep invaginations of sarcolemma, for transmitting nerve impulses from sarcolemma inward
Describe the Sarcoplasmic reticulum:
- a ______ network around ______ proteins
- modified _____ endoplasmic reticulum
- stores ______ ?
- what structure is at the end of the SR?
-a tubular network around contractile proteins
-modified smooth endoplasmic reticulum
-stores calcium which is released into sarcoplasm during muscle contraction
-**Terminal cisternae
(SR= network around contractile proteins that releases Ca 2+ into the Terminal cisternae)
What is a terminal cisternae?
- serve as reservoirs for ______ ions
- they can combine with _____ to form triads
- dilated ends of sarcoplasmic reticulum, serve as reservoirs for calcium ions, combine with T-tubule to form triads (middle of triad= t tubule, and on each side you have a terminal cisternae)= triad!!! KNOW
Go over slide 13
slide 13
Describe the microscopic anatomy of skeletal muscles
- multinucleated cells
- satellite cells
- sarcolemma
- T-tubules
- Sarcoplasmic Reticulum (contains Terminal cisternae)
- myoglobin
- Myofibrils
- thick filaments
- thin filaments
- sarcomere (Z discs, I bands, A bands)
- H zone
- M line
Myoglobin=
- _____ protein located in the?
- allows the muscle cells to store ____
=Reddish golobular protein in sarcoplasm (the cytoplasm of muscle cells)
-allows the muscle cells to store oxygen
-gives the muscle the red color, the redder the muscle , the more myoglobin it contains
(skel muscle has lots of myoglobin)
Myofibrils=
- located in the _______
- the _____ proteins
- account for ___% of cell volume
- each myofibril is composed of a ______
- Located in sarcoplasm (the cytoplasm of muscle cells)
- The contractile proteins (the special organelles that allow the muscle to contract)
- account for 80% of cell volume
- Each myofibril is composed of a bundle of thin and thick myofilaments, interactions b/w the thin & thick filaments of are responsible for muscle contraction
Thick filaments=
- are assembled from?
- describe each myosin protein
- each strand with a globular head and ________ tail
- Assembled from bundles of protein molecules, myosin
- each myosin protein with two intertwined strands
- each strand with a globular head and elongated tail
Thick filaments:
- tails point toward?
- heads point toward?
- Myosin head contains ___
- tails pointing toward center of thick filaments
- heads pointing toward edges of thick filaments
***head with a binding site for actin (thin filaments)
actin= _____ filament
- myosin head contains the actin ____ _____
- thick filament= entirely ______
- thin filament=
Actin= thin filament
-Myosin head with actin binding site
Thick filament= entirely myosin
Thin filament= different types of actin and tropomyosin and troponin
Thin filaments are composed of (3 things?)
actin, tropomyosin, troponin