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Practical #2 Part. 2 Intro to Muscle System

Review for Practical 2 (Ch 6-11) Skeletal and Muscular Systems
STUDY
PLAY
Smooth Muscle of the Uterus (Longitudinal section) A=nuclueus.
Identify the specific tissue, name one location in the body where it can be found, and identify structure A.
Cardiac Muscle of Heart
A=Intercalated disk
B=Nucleus
Identify the specific tissue, name one location in the body where it can be found, and identify structure A and B.
Skeletal Muscle of the Tongue (Longitudinal section)
A=Nucleus
B=Striations
C=Sarcolemma
Identify the specific tissue, name one location in the body where it can be found, and identify structure A, B, C.
Two Skeletal Muscle Cells (Longitudinal section). Dark objects are peripheral nuclei, striations are clearly seen.
Identify the specific cells, and the structures shown
Skeletal Muscle cells, Cross section of a fascicle.
A=Perimysium
B=Endomysium
Identify the specific tissue, name one location in the body where it can be found, and identify structure A and B.
Dense Regular Connective Tissue (Tendon)
A=Fibroblast nuclei
B=Collagen fiber
Identify the specific tissue, name one location in the body where it can be found, and identify structure A and B.
X= tendons (epimysium) for posterior torso muscles.
What are the structures marked as X?
Longitudinal view of Connective tissues of Skeletal muscle
A=Epimysium (attaches muscle to tendon)
B=Perimysium (attaches group of cells "fascicle" to epimysium)
C=Endomysium (attaches muscle membrane to perimysium)
Name specific tissue (and muscle cell). Identify structures A, B, C and describe its functions
Motor unit/Cross section of Skeletal muscle
A=Endomysium
B=Perimysium
C=Epimysium
D=Muscle cell
E=Nucleus of cell
F=neuromuscular junction. (yellow is motor neuron axon membrane)
Identify model shown, including structures A-F
Motor end organ (neuromuscular junction) of Skeletal muscle
A=Motor neuron
B=Sarcolemma
C=Striations (within cell, under sarcolemma)
Name the model shown, identify structures A, B, C
Neuromuscular junction
A=Endomysium
B=Sarcolemma
C=Motor neuron.
Identify the model, and the areas A, B, C
Neuromuscular junction
A=Motor neuron
B=Sarcolemma
C=Sarcomeres (within cell)
Identify the model, and the areas A, B, C
Skeletal muscle with Neuromuscular junction
A=Actin filament
B=Myosin filament
C=transverse tubules(blue)
D=sarcoplasmic reticulum (beige)
E=nucleus
F=sarcolemma
G=axon of motor neuron
H=myelin sheath of Schwann cell.
Identify the model, and areas A-H
Skeletal muscle with Neuromuscular junction
A= Endomysium
B= Sarcolemma
C= Axon of motor neuron
D= Transverse tubules (blue)
E= Sarcoplasmic reticulum (beige)
F=Actin filament
G=Myosin filament.
Identify the model, and areas A-G
A=Sarcomeres
B=Motor neuron
C=Sarcolemma of skletal muscle cell.
Identify areas A, B, C
A=Sarcolemma of skletal muscle cell
B=Sarcomeres
C=Motor neuron.
Identify areas A, B, C
Skeletal muscle cell model
A=Sarcolemma (green)
B=Sarcoplasmic reticulum (blue)
C=Transverse tubules (T-tubules, green)
D=Glycogen granules
E=Myosin filaments
F=Actin filaments
Identify the muscle cell type, and areas A-F
Skeletal muscle cell model
A=Transverse tubules(T-tubules)
B=Sarcoplasmic reticulum (SR)
what muscle is shown in this model? Identify structures A and B.
Sarcomere of a Myofibril
A=Transverse tubules
B=Sarcoplasmic reticulum
C=Z lines (Z to Z = sarcomere)
D=A band (myosin)
E=I band (actin)
Identify model, and areas A-E
Single Muscle Twitch Myogram
A=Latent period
B=Contraction period
C=Relaxation period
What is this model? what are the areas A, B, C
Multiple muscle contractions myogram
A=Treppe
B=Wave summation
C=Tetanus
D=Fatigue
Identify the model and name the areas listed as A, B, C
Tendon of Collagen fibers (dense regular connective tissue)
Identify tissue type shown here
increasing availability of calcium from previous contractions and increased enzyme efficiency due to increased heat, produces stronger contractions.
Identify the psychological changes occurring inside the muscle fiber during the portion of the myogram labeled A. (not the phase!)
action potential stimulates calcium release from SR which unblocks cross bridge attachment sites.
Identify the psychological changes occurring inside the muscle fiber during the portion of the myogram labeled A. (not the phase!)
calcium reenters SR, cross bridge attachment site blocked and muscle tension returns to baseline (muscle lengthens)
Identify the psychological changes occurring inside the muscle fiber during the portion of the myogram labeled C. (not the phase!)
a) Near skeletal system
b) Long muscle cells, multinucleated, many mitochondria, with striations
c) Strong rapid contractions with small groups of cells, generally being under voluntary nervous control
Describe a function and location of the skeletal muscle tissues.
Skeletal Muscle
This type of muscle is attached primarily to bones. It appears to have striations (bands of light and dark) when examined under the microscope. Its function is under voluntary control because it can be made to contract and move a bone by conscious control
Cardiac Muscle
This type of muscle forms most of the heart. This tissue appears striated under the microscope but is involuntary (not under conscious control). It exhibits autorhythmicity (self-contracting) and is influenced by hormones and neurotransmiters.
Muscle Twitch
A brief contraction of all the muscle fibers in a motor unit of a muscle inresponse to a single threshold stimulus is called:
Muscle fiber
This cell is elongated and multinucleated. It also has a striated appearance in skeletal and cardiac muscles
Actin
This contractile protein makes up the thin filaments. These filaments stretch inward from each end of sarcomere (both Z discs) towards center of sarcomere thereby overlapping (but not connected to) myosin filaments
Tendon
This cord of dense regular connective tissue attaches muscles to the periosteum of a bone. Its function is to transmit the force produced by the contraction of the muscles to the bone to be moved.
Wave summation
If two identical stimuli are delivered to a muscle in rapid succession, the second contraction will be stronger than the first. Name this phenomenon which occurs because the muscle is already partially contracted and additional calcium is released during the second contraction increasing tension and further shortening the muscle.
Sarcoplasm
This term refers to the cytoplasm of a muscle fiber which contains unusually large amounts of stored glycogen and myoglobin, a unique oxygen-binding protein found only in muscle fibers. It also contains modified organelles found only in muscle.
Transverse Tubules (T-Tubules)
This term refers to continuations of the muscle cell plasma membrane that encircles each sarcomere. They conduct nerve impulses to every sarcomere within the muscle fiber which ensures that every myofibril in the muscle fiber contracts at the same time.
Sarcomere
This segment of a muscle cell is the actual contractile unit of the cell and is composed of myofilaments made of contractile proteins. It limits defined by pair of Z discs (place where actin filaments are anchored to each other)
Epimysium
This sheath of dense irregular connective tissue surrounds the entire muscle. Its function is to provide additional protection and support for the muscle
Myofibril
This organelle is the contractile element of skeletal muscle fibers. They are rodlike and run parallel the entire length of the cell and account for 80% of the cell volume. and are surrounded by transverse tubules and SR
Treppe
Name the phenomenon that occurs when a relaxed muscle is stimulated to contract by several identical stimuli causing each successive contraction to be stronger than the last and appearing like a staircase on a myogram.
Smooth Muscle
This type of muscle is located in the walls of blood vessels, most abdominal organs and the skin attached to hair follicles. This tissue appears nonstriated under the microscope and is usually under involuntary control influenced by neurotransmitters and hormones.
Endomysium
This sheath of areolar connective tissue surrounds each individual muscle fiber. Its function is to protect and support the delicate and fragile muscle cell
Myosin
This contractile protein makes up the thick filaments. Each protein molecule has a rod-like tail and two heads. The heads link the thick and thin filaments together during contraction. These filaments reside in center of sarcomere and anchored to each other at M line
Fascia
This sheath of fibrous connective tissue binds muscles into functional groups. Its function is to allow free movement of muscles and support nerves, blood vessels and lymphatic vessels.
Sarcolemma
This is another name for the plasma membrane of a muscle fiber (cell). Its function is to regulate the passage of materials in and out of the muscle fiber.
a. Found in heart
b. Medium-long, 1 nucleus, branched, gap junctions (intercalated disks), with striations
c. Medium strength, rhythmic contractions of large groups of cells under involuntary nervous control
Describe a function and location of the cardiac muscle tissues.
a. Found in hollow visceral organs (digestive system, urinary and gall bladders, uterus) as well as blood vessels and bronchioles in lungs.
b. Short, spindle-shaped, 1 nucleus with gap junctions, no striations
c. Weak, sometimes rhythmic, contractions of large layers of cells under autonomic nervous control
Describe a function and location of the smooth muscle tissues.
1. Motion (move body and fluids)
2. Maintain posture, joint support (no movement) 3. Heat production
what are the major functions of the muscular system?
1. muscles typically pass over joint, e.g., brachialis 2. origin: least moveable attachment site e.g., humerus
3. insertion: most moveable attachment site e.g., ulna
4. action:movement of body part e.g., flex forearm
what are the muscle's relationship to the skeletal system?
a. Each muscle cell is surrounded by endomysium b. Group of cells (fascicle) are connected together by perimysium
c. Entire muscle is covered by epimysium which continues as tendons
FUNCTION is to transmit force of muscular contractions to attachment sites
Relationship between muscle and connective tissue? Function?
(muscle cell membrane) spreads throughout cell interior (as transverse tubules) allowing electrical signals to trigger the sarcoplasmic reticulum (which releases Calcium)
Skeletal Muscle cell histology:
Define sarcolemma
(or muscle cell's endoplasmic reticulum); contains calcium ions that are released upon receiving electrical signal.
Skeletal Muscle cell histology:
Define Sarcoplasmic reticulum
a motor unit is bunch of muscle cells stimulated by single motor neuron
what is the physiology of single motor unit contractions?
Tetany
The sustained contraction force after wave summation is called _____. Fused _____ is normal manner of contraction resulting in plateau shape.