Chapter 11: Muscles of the Body
The arm muscle that flexes the forearm at the elbow and supinates it is the:
Biceps brachii
If the name of a spinal tract begins with the root "spino-",
It is a sensory pathway
A muscle that contributes to the posterior axillary fold is the:
Latissimus dorsi
The major muscles used in the up portion of a chin-up are the:
Latissimus dorsi and brachialis
Most skeletal muscles of the body operate at a mechanical disadvantage. What are the advantages of this arrangement?
Levers that operate at a mechanical disadvantage allow for greater speed and larger distance of movement for a given muscular effort. In addition, in these arrangements, muscles insert close to the joint, providing better stability to the joint.
Triceps Brachii:
Limb extensor group
Biceps Brachii:
Limb flexor group
What immune disorder results in deterioration of the myelin sheath in the CNS?
Multiple sclerosis
Nissl bodies are located in the _____ of a neuron.
Soma
Biceps brachii and brachialis both flex the forearm. These muscles, which work together, function as _________.
The biceps brachii and brachialis function as synergists.
The word "hallucis" in the name of a muscle pertains to:
The big toe
Where does the spinal cord end?
The cauda equina
The right and left cerebral hemispheres are joined mainly by:
The corpus callosum
Phineas Gage was a railroad worker who suffered an unfortunate accident where a metal rod went through his skull. After the accident he experienced a drastic change in personality. What part of his brain was affected?
The frontal lobe
In a skeletal/muscular lever system, what structure is the fulcrum?
The fulcrum of a skeletal/muscular lever system is the joint.
The integrative function of the nervous system is associated especially with:
The interneurons
What is the neurilemma?
The outermost layer of a Schwann cell
There is a "homunculus" on the precentral gyrus. The reason why the hand region of the homunculus is so large relates to the fact that:
We have numerous motor units associated with finger movement
Identify the muscle that elevates the larynx:
Geinohyoid
A prime mover of thigh flexion at the hip is the:
Iliopsoas
What is a connective tissue band on the lateral thigh that helps stabilize the knee?
Iliotibial tract
What muscles attach to the hyoid bone?
- Geniohyoid - Stylohyoid - Mylohyoid - Sternohyoid - Thyrohyoid
What are the muscles of mastication?
- Masseter - Temporalis - Lateral pterygoid - Medial pterygoid
Which types of levers operate at a mechanical advantage?
- Second class levers always operate at a mechanical advantage. - First class levers operate at a mechanical advantage when the length of the effort arm is longer than the length of the load arm.
Name the fascicle arrangement in a muscle whose fibers extend along its long axis from origin to insertion.
A muscle with fibers aligned along its long axis has a parallel arrangement of its fascicles.
A muscle that helps an agonist by causing a similar movement or by stabilizing a joint over which the agonist acts is:
A synergist
A muscle that abducts the thigh would cross the hip on which side of the joint? What action would the antagonist muscles produce?
A thigh abductor crosses the hip on the lateral side of the joint. The antagonist muscles produce adduction.
Which structure(s) is/are found only in the PNS? A. Ganglia B. Astrocytes C. Myelin D. Lipofuscin E. Unmyelinated axons
A. Ganglia
Which muscle is not part of the suprahyoid group? A. Omohyoid B. Digastric C. Geniohyoid D. Mylohyoid E. Stylohyoid
A. Omohyoid
The white matter of the cerebellum constitutes its:
Arbor vitae
Blood capillaries of the brain are covered by:
Astrocytes
Which muscle listed is part of the quadriceps femoris group? A. Biceps femoris B. Rectus femoris C. Rectus abdominis D. Quadratus femoris E. Pronator quadratus
B. Rectus femoris
Which is not an infrahyoid muscle? A. Sternothyroid B. Sternohyoid C. Mylohyoid D. Omohyoid E. Thyrohyoid
C. Mylohyoid
The brain and spinal cord constitute the _____ nervous system.
Central
Where are upper motor neurons located?
Cerebral cortex or brainstem
The corpus callosum is composed of:
Commissural fibers
The anatomical snuff box:
Contains the styloid process of the radius
One of the functions associated with the limbic system is: A. Hearing. B. Reading comprehension. C. Stimulus filtering. D. Feelings of contentment, fear, or anger. E. Motor control of the limbs.
D. Feelings of contentment, fear, or anger.
The spinal cord is divided into all of the following regions except: A. Cervical. B. Thoracic. C. Lumbar. D. Pelvic. E. Sacral.
D. Pelvic.
Which muscle flexes the knee? A. Rectus femoris B. Soleus C. Gluteus maximus D. Semimembranosus E. Iliopsoas
D. Semimembranosus
The hypothalamus plays a role in controlling all of the following except: A. Sex drive. B. Hunger. C. Sleepiness. D. Speech. E. Blood pressure.
D. Speech.
All of the following move the mandible except A. The masseter. B. The lateral pterygoid. C. The medial pterygoid. D. The thyrohyoid. E. The temporalis
D. The thyrohyoid.
In a ____ neuronal circuit, input to one neuron leads to output from multiple neurons.
Diverging
Because of ___, one motor neuron in the brain can ultimately cause thousands of muscle fibers to contract.
Diverging circuits
From superficial to deep, the meninges occur in the order:
Dura mater, arachnoid, pia mater.
Which muscle from the list is most important for push-ups? A. Pectoralis minor B. Latissimus dorsi C. Trapezius D. Biceps brachii E. Pectoralis major
E. Pectoralis major
Which muscle inserts on the mastoid process? A. Omohyoid B. Sternohyoid C. Posterior scalene D. Trapezius E. Sternocleidomastoid
E. Sternocleidomastoid
The ______ acts synergistically with the masseter. A. Levator scapulae B. Spenius capitus C. Buccinator D. Zygomaticus major E. Temporalis
E. Temporalis
Which muscle inserts on the coronoid process of the mandible? A. Zygomaticus major B. Omohyoid C. Masseter D. Lateral pterygoid E. Temporalis
E. Temporalis
______ line the ventricles in the brain.
Ependymal cells
Someone who sticks out a thumb to hitch a ride is ___ the thumb.
Extending
Which abdominal muscle is most superficial?
External oblique
Tongue Muscles:
From head (occipital) myotomes
Erector Spinae:
From trunk (nonlimb) myotomes
At most joints (the knee and ankle are exceptions), what movement is produced by muscles that cross the posterior side of the joint?
Muscles that cross on the posterior side of a joint generally produce extension.
What does the lateral horn of the spinal cord contain?
Neurons of the sympathetic nervous system
What are the gaps between myelinated segments of an axon?
Nodes of Ranvier
A bipolar neuron has:
One axon and one dendrite arising from the soma
A muscle whose fascicles are arranged at an angle to a central longitudinal tendon has this arrangement:
Pennate
Chewing Muscles:
Pharyngeal arch muscles
Myelin consists mainly of:
Phospholipid
When you see the word _____, you know it must have something to do with the thumb.
Pollicus
The nonvisual awareness of the body's position in space is _____.
Proprioception
Tendinous insertions divide the ______ into segments externally visible on a well-muscled person.
Rectus abdominus
The teres major and teres minor originate on the _____ and insert on the ____.
Scapula; humerus
Two prominent tendons you can palpate at the popliteal fossa arise from the:
Semitendinosus and biceps femoris.
A somatic motor neuron carries:
Signals to skeletal muscle fibers
Why are pennate muscles more powerful than parallel muscles?
The power of a muscle depends on the total number of muscle fibers. Pennate muscles pack more muscle fibers into a unit area than parallel muscles; thus, they are able to generate greater force.
The upper motor neurons that control the skeletal muscles are found in:
The precentral gyrus of the cerebrum
The chewing muscles that protract the mandible and grind the teeth from side to side are:
The pterygoids
The deepest muscle of the abdominal wall is:
Transversus abdominus
