Mods9 Flashcards
Which of the following descriptions characterizes skeletal muscle tissue?
It contains striations
What is the functional unit of muscle contraction?
sarcomere
Which of the following is not a general function of muscle tissue?
Movement
Protection
Heat Production
Posture
Protection
The skeletal muscle fiber characteristic of excitability directly results in these cells being capable of….
responding to nerve signals
shortening
returning to resting length after contracting
producing heat
responding to nerve signals
I. Muscles
A. Special Characteristics
B. Main functions
II. Types of Muscles
1. Skeletal Muscles
2. Cardiac muscles
3. Smooth muscles
III. Gross Anatomy of a Skeletal Muscle
- Nerve and Blood Supply
- Connective Tissue Sheaths
- Microscopic Structure and Function
ok ok ok overview
These are elongated, and are called muscle fibers.
Skeletal and smooth muscle(but not cardiac muscle cells)
prefixes myo or mys are word roots meaning?
muscle
it is referenced as muscle
Sarco(flesh)
Plasma membrane of muscle cells
sarcolemma
muscle=
sarco
husk=
lemma
muscle cell cytoplasm is called
sarcoplasm
What are the special characteristics of muscle tissue? (4) E C E E
Excitability
Contractility
Extensibility
Elasticity
- responsiveness
- the ability of a cell to receive and respond to a stimulus by changing its membrane potential
- in the case of muscle, the stimulus is usually a chemical like (neurotransmitter) released a nerve cell.
Excitability
- shorten forcibly
- this ability sets muscle apart from all other tissue types
Contractility
- extend or stretch
- muscle cells shorten when contracting, but can be stretched beyond their resting length, when relaxed.
Extensibility
- recoil
- and resume its resting length after stretching
Elasticity
B. Main Functions (of Muscle Tissue) P M S G
Produce movement
Maintain posture and body position
Stabilize joints
Generate heat
- responsible for all locomotion and manipulation
- enable you to quickly jump, direct your eyes, and smile or frown
- Blood courses through your body
- Smooth muscle in organs of the digestive, urinary, and reproductive tracts substances through the organs and along the tract
Produce movements
-…. Maintain body posture
-… Making one tiny adjustment after another to counteract the never-ending downward pull of gravity
Maintain posture and body position
Pull on bones to cause movement
Stabilize joints
- Muscle generate heat as they contract
- plays role in maintaining normal body temperature
Generate heat
II. Types of Skeletal Muscles? (3) S C S
Skeletal muscle
Cardiac Muscle
Smooth muscle
____________
- organs that attach and cover skeleton
- ____ ___ ____ are the longest muscle cells and have obvious stripes called ______.
- Called _____ muscle because it is the only type subject to conscious control
- responsible for overall body _____
- it can contract rapidly, but tires easily and must rest after short periods of activity
- words to keep in mind: ____ _____ ______ (3)
Skeletal Muscle
- skeletal muscles
- skeletal muscle fibers, striations
- voluntary
- mobility
-
- skeletal, striated, voluntary
______
- occurs only in the heart
- it’s not voluntary (it can and does contract without being stimulated by the nervous system). We have no subconscious control over it.
- contracts fairly _____ rate by the heart’s peacemaker
- keywords to remember: ___ ____ ____(3)
Cardiac muscle
- cardiac muscle
- ^
- steady
- cardiac, striated, voluntary
______
- found in the walls of hollow visceral organs (stomach, urinary bladder, respiratory passages)
- its role is to force fluids
- also forms valves tor regulate the passage of substances…
- has elongated cells, BUT no striations
- key words: __ ___ __(3)
visceral, nonstriated, involuntary
Nerve and Blood supply
- has __ nerve, __ artery, and ___ or ___ veins serve each muscle.
1, 1, 1 or more
- Has several connective tissue sheaths
- these sheaths support each cell and reinforce and hold together the muscle
Connective tissue sheaths
“outside the muscle”
Epimysium
- is an overcoat of dense irregular connective tissue that surrounds the whole muscle
- sometimes it blends with the deep fascia
epimysium
the muscle fibers are grouped into fascicles
Perimysium and fascicles
Surrounding each fascicle is a layer of dense irregular connective tissue called _____.
Perimysium
“Around the muscle”
perimysium
“within the muscle”
endomysium
is a wispy sheath of connective tissue that surrounds each individual muscle fiber. It consists of fine areolar connective tissue
Endomysium
cordlike extension of the preceding three linings. It extends beyond the muscle tissue to connect the muscle to a bone or to other muscles.
tendon
- contractile cells
Microscopic structure and function
- contractile cells are called ____; connective tissue holds muscle fibers..
muscle fibers
- fibers of cytoskeleton form cylinders that contain ___ _____ (containing _____) and ____ ____ (containing mainly ___)
thick myofilaments, myosin
thin myofilaments, actin
Basic functional (contractile) unit called
sarcomere
- sarcmeres separated from each other by dark bands called=
z lines
