Chapter 7- Muscular System Flashcards
Name the four main characteristics of skeletal muscle?
- Makes up 40% of body weight.
- Named skeletal because it is attached to the bones (skeleton)
- Many nuclei per cell (near periphery)
- Striated
List the main functions of the muscular system?
Movement, Maintain posture, Respiration, Production of body heat, Communication, Contraction of organs and vessels, and Contraction of the heart.
The terms used to best describe skeletal muscles that respond to stimuli and recoil are?
Excitability- respond to stimulus
Elasticity- recoil
What is the muscular fasica?
Bundle of muscle fibres.
What are the names of the connective tissue that surrounds muscle fibres?
Endomysium
The region of the muscle that contains the T-tubes is called?
Sarcolemma
What is the function of Sarcoplasmic Reticulum?
Holds all Ca and releases it.
Calcium binds to this region on actin?
Troponin
Resemble golf clubs?
Myosin
How would you best describe the following Z disk, A band, and H zone?
Z disk are protein fibres that form attachment site for actin.
H zone is the center of sarcomere and contains only myosin.
I band contains only actin.
A band is where actin and myosin overlap.
M line is where myosin are anchored.
During a muscle contraction the following regions of _______ and _______ shorten but ___________ stays the same.
During a muscle contraction, H zone and I band shorten but A band stays the same.
Define synaptic cleft.
Space between presynaptic terminal and postsynaptic membrane.
What is the underlining cause of rigor mortis?
When a person dies and there is no ATP left available to release cross-bridges.
T or F, ATP can only be made in the mitochondria under aerobic respiration?
False. ATP can be made under both Anaerobic and aerobic respiration.
Define the terms threshold and twitch.
Threshold is the weakest stimulus needed to produce a response and Twitch is the contraction and relaxation of a muscle fibre in response to a stimulus.
What is the difference between slow and fast twitch fibres?
Slow twitch fibres happen under aerobic and fast twitch fibres happen under anaerobic.
What is the role of myoglobin in muscle?
Myoglobin helps O2 bind in muscle.
Define the terms agonist and fixator?
Agonist- prime mover, a muscle that accomplishes a certain movement.
Fixation- a muscle or group of muscles that hold a body part in place so another one can move.
List the muscles of the head and neck? What are their major functions?
Occipitofrontalis- raises eyebrows (forehead)
Orbicularis Oculi- allows blinking (eyes)
Orbicularis Oris- kissing muscle (mouth)
Zygomaticus- smiling muscle (cheek)
Masseter- chewing (mastication) muscle
List the muscles of the abdomen originating from the skin layers?
Rectus abdominis, External abdominal oblique, Internal abdominal oblique, Transverse abdominis.
What muscle flexes the elbow?
Biceps Brachii
List the muscles of the hips and thighs?
Iliopsoas, Gluteus maximus, Gluteus medius
What is the muscle that is responsible for flexing the foot and leg?
Gastrocnemius
T or F, Cardiac muscle cells are rich in both mitochondria and nuclei?
False.
What is the functional role of the intercalated disks?
Special cell junctions that allow cells to act as a unit.
What muscle is responsible for allowing the eye to blink?
Orbicularis oculi
