BIOS 251 ANATOMY AND PHYSIOLOGY 2 FINAL EXAM STUDY GUIDE / BIOS251 ANATOMY AND PHYSIOLOGY 2 FINAL EXAM STUDY GUIDE (LATEST 2021) | CHAMBERLAIN COLLEGE OF NURSING

BIOS 251 ANATOMY AND PHYSIOLOGY 2 FINAL EXAM
STUDY GUIDE



Chapter 10:
 3 types of Muscular Tissue-
o Skeletal-
 Location- Skeletal System
 Function- Moves Bone
 Appearance- Multi Nucleated and Striated
 Control- Voluntary
o Cardiac-
 Location- Heart
 Pumps Blood
 Appearance- One Nucleus, Striated, and intercalated Discs
 Control- Involuntary
o Smooth-
 Location- Various Organs. Ex: GI tract
 Function- Various Functions. Ex peristalsis (Digestion)
 Functions of Muscular Tissue
o To Produce Body Movements
o Stabilizing body position
o Storing and Mobilizing substances within the body
o Generating Heat
 Properties of Muscular Tissue
o Electrical Excitability- If a muscle tissue is shocked, it will contract.
o Contractility- muscle can contract
o Extensibility- The ability for muscle to extend, within limits, without
being damaged
o Elasticity- The ability for muscle to move back to its original form
after being extended.
 Making a Skeletal Muscle
o Step 1: Myofilaments bundle together to make a myofibril

, o Step 2: Myofibrils bundle together with endomysium, making one
muscle fiber.
o Step 3: Muscle fibers are wrapped with perimysium making one
muscle fascicle
o Step 4; Muscle Fascicles are wrapped by epimysium, making one
muscle fiber.
 Components of a Sarcomere
o Z Discs- Narrow, Plate shaped regions of dense material that sperate
one sarcomere to the next
o A Band- Dark, middle part of the sarcomere that extends the entire
length of thick filaments and includes those parts of thin filaments that
overlap thick filaments.
o I Band- Lighter, Less dense area of a sarcomere that contains thin
filiments, but no thick filiments. A Z Discs passes through each I band
o H Zone- Narrow region in the center of each a band that contains
thick filiments but no thin filiments
o M Line- Region in the center of the H Zone that contains proteins that
hold thick filaments together at the center of the sarcomere
 Muscle Proteins-
o Contractile: Generate force during muscle contractions
 Myosin- Thick Filiment, Binds to Actin
 Actin- Main component of thin filament, contains myosin
binding sites
o Regulatory: Help switch the muscle contraction prorocess on and off
 Troponin- Componet of thin filament, When CA ions bind, it
changes shape, this change moves tropomyosin away from
actin, muscle contraction begins as myosin binds to actin.
 Tropomyosin- Componet of thin filament, when muscle fibers
relax, this covers actin molicules, preventing myosin from
binding to actin.
o Structural
 Titin- Connects Z Discs to the M line of a sarcomere
 Nebulin- Wraps around the entire length of each thin filament,
helping them anchor to Z- Discs
 Alpha Actin- Protein of Z Discs that attaches to actin and titin
molecules

,  Myomesin- Forms the M line of the sarcomere
 Dystrophin- Helps transmit tension generated by sarcomeres to
tendons
 Sliding Filament Mechanism-A mechanism of muscle contraction in which
the actin and myosin filaments of striated muscle slide over each other to
shorten the length of the muscle fibers. Myosin-binding sites on the actin
filaments are exposed when calcium ions bind to troponin molecules in these
filaments. This allows bridges to form between actin and myosin, which
requires ATP as an energy source. Hydrolysis of ATP in the heads of the
myosin molecules causes the heads to change shape and bind to the actin
filaments. The release of ADP from the myosin heads causes a further
change in shape and generates mechanical energy that causes the actin and
myosin filaments to slide over one another.
 The Contraction Cycle-
o Step1: ATP hydrolysis- Myosin head hydrolyzes ATP and becomes
energized and oriented
o Step 2: Myosin head binds to actin, forming a cross bridge
o Step 3: Power Stroke- Myosin head pivots, pulling the thin filament
past the thick filament towards the center of the sarcomere
o Step 4: As Myosin head binds ATP, the ross bridge detaches from
actin
 Excitation–Contraction Coupling- the physiological process of converting
an electrical stimulus to a mechanical response. It is the link between the
action potential generated in the sarcolemma and the start of a muscle
contraction.
o A motor neuron connects to a muscle at the neuromuscular junction,
where a synaptic terminal forms a synaptic cleft with a motor-end
plate.
o The neurotransmitter acetylcholine diffuses across the synaptic cleft,
causing the depolarization of the sarcolemma.
o The depolarization of the sarcolemma stimulates the sarcoplasmic
reticulum to release Ca2+, which causes the muscle to contract.
o Motor-end plate: post junctional folds which increase the surface
area of the membrane (and acetylcholine receptors) exposed to the
synaptic cleft