Shared Flashcard Set

Details

Lecture 9
Muscular System
39
Anatomy
Undergraduate 1
03/03/2012

Additional Anatomy Flashcards

 


 

Cards

Term
Critical functions of the muscular system
Definition
-movement
-thermoregulation
-posture, body and organ support
-cardiovascular pump
Term
Types of muscle tissue
Definition
Skeletal
Cardiac
Smooth
Term
Skeletal muscle tissue
Definition
this tissue is striated and under voluntary nervous control
Term
Cardiac muscle tissue
Definition
this tissue is striated and under involuntary nervous control
Term
Smooth muscle tissue
Definition
this tissue is non-striated and under involuntary nervous control
Term
Basic characteristics of muscle tissue
Definition
-Irritability
-Contractility
-Extensibility
-Elasticity
Term
Irritability
Definition
the ability to respond to a nervous stimulus
Term
Contractility
Definition
the ability to respond by shortening
Term
Extensibility
Definition
the ability to stretch
Term
Elasticity
Definition
the ability to return to the original shape
Term
Groups of muscles classified by shape
Definition
-Parallel
-Convergent
-Pennate
-Circular
Term
Structures of muscle
Definition
-Origin tendon
-Insertion tendon
-body
Term
origin tendon
Definition
always attaches to a bone; it is also the most proximal and/or least mobile portion of the muscle.
Term
insertion tendon
Definition
usually attaches to a bone or may attach to the skin or an organ; it is usually the most distal and/or most mobile protion of a muscle
Term
belly
Definition
the region of contraction as it consists of muscle tissue; it is the only portion of the muscle that does contract.
Term
-epimysium
-perimysium
-endomysium
Definition
increasingly smaller portions of loose connective tissue that ensheath the components of skeletal muscles
Term
epimysium
Definition
Outer sheath of connective tissue.
Consists of two distinct portions:
-fascia
-epimysium proper
Term
fascia
Definition
Outer portion of epimysium. Consists of dense irregular connective tissue and helps to separate individual muscles within a group and from other structures.
Term
epimysium proper
Definition
Inner portion of epimysium.
This layer consists of loose connective tissue and helps to provide a means of holding the entire muscle together.
Term
perimysium
Definition
Middle sheath of skeletal muscle. Ensheathes the muscle bundles known as muscle fasciculi and is composed of loose connective tissue
Term
endomysium
Definition
Inner sheath of skeletal muscle tissue.
Ensheathes specific muscle cells also known as muscle fibers and is composed of loose connective tissue.
Term
Skeletal muscle cells (fibers)
Definition
Somewhat spindle-shaped and striated.
Each fiber is surrounded by a sheath of endomysium. These groups of fibers are arranged as bundles and the bundles comprise an entire muscle.
Term
myofibrils
Definition
hundreds to thousands of long protein fibers that traverse the long axis of the cell
Term
sarcomeres
Definition
Form the basic structural and functional unit of contraction in a skeletal muscle cell. Each myofibril consists of thousands of these repeating protein units
Term
myofilaments
Definition
Sarcomeres are composed of these structural protein filaments that are arranged in a specific alignment
Term
Actin
Definition
Long, thin filaments that are directly attached to the Z line myofilament. Composed of a series of globular proteins that are twisted around each other to form a double helical structure.
Term
Myosin
Definition
Thick filaments that occur between successive actin filaments. Consists of a series of rod-like proteins that form a tail-like structure and a globular head-like structure that forms a hinge onto the tail.
Term
Z-line
Definition
Composed of a fibrous protein called actinin that directly attach the actin filaments. Every two successive lines form a single sarcomere.
Term
neuromuscular junction
Definition
the interface of two plasma membranes of a nerve terminus and a skeletal muscle cells
Term
pre-synaptic membrane
Definition
depressed into the cell membrane near the middle of the muscle cell and anchored by the endomysium.
Term
sarcolemma
Definition
The muscle cell membrane.
Serves as the post-synaptic membrane.
Term
action potential
Definition
a nerve impulse
Term
acetylcholine (ACh)
Definition
neurotransmitter molecules that are held in the synaptic vesicles
Term
ACh receptor molecules
Definition
Located on the sarcolemma. When neurotransmitter molecules diffuse across synaptic cleft and attach, this action opens channels for sodium ions that result in an action potential (i.e. an electrical impulse) in the muscle cell that eventually results in its contraction.
Term
acetylcholinesterase (AChase)
Definition
Enzyme that breaks down the ACh for re-uptake into the bouton so that ACh is recycled.
Found in the motor end plate.
Term
Synaptic Cleft
Definition
The space between the motor end plate and the nerve terminus
Term
Motor End Plate (MEP)
Definition
The post-synaptic memebrane is known as this at the place where the terminal bouton occurs. It is invaginated and the membrane folded to increase the surface area.
Term
Synapse
Definition
Consists of a pre-synaptic membrane, synaptic cleft, and post-synaptic membrane.
Term
Sliding Filament Model of Contraction
Definition
Thick and think filaments slide over one another. Length of each sarcomere shortens, muscle contracts.
Supporting users have an ad free experience!