Thorax (skeletal muscles) Flashcards
What structures make up the thoracic cage?
Thoracic vertebrae
Ribs
Sternum
What is the anatomical term for the breastbone?
Sternum
From superior to inferior, what are the three main parts of the sternum?
Manubrium
Body
Xiphoid process
What are the depressions on the sternum for the articulation of the clavicles?
Clavicular notches
What is the shallow, superior depression on the sternum?
Suprasternal notch
What depressions on the sternum do the ribs articulate with?
Costal notches
What palpable feature lies at the articulation of the manubrium and the body of the sternum?
Sternal angle
How many ribs are there?
12 pairs
What ribs have their costal cartilages directly articulated with the sternum? What are their numbers?
True ribs (1-7)
What ribs do not have their costal cartilages directly articulated with the sternum? What are their numbers?
False ribs (8-12)
What type of rib has no connection with the sternum? What are their numbers?
Floating ribs (11-12)
What part of a rib articulates with the body (bodies) of a vertebra(e)?
Head
What part of a rib articulates with the transverse process of a vertebra?
Tubercle
What part of a rib lies between the head and tubercle?
Neck
Ribs project posterolaterally from the vertebral column. What is the region of a rib where it changes if direction and begins curving toward the sternum?
Angle
What is the main part of a rib?
Body/shaft
What feature on the inferior side of a rib marks the path of an artery, a vein, and a nerve?
Costal groove
What is the structure, function, and an example of sternoclavicular joints?
Structurally: Synovial
Functionally: Diarthrodial
One of three examples of a saddle joint in the body.
The joint between the anteriomedial aspect of the ribs and the costal cartilages
Costochondral Joints.
Contain hyaline cartilage
Functionally: Snyarthrodial
Structurally: Cartilagenous
Sternocostal Joints
The 1st sternocostal joint is cartilaginous
(The 2nd through 7th are synovial joints)
Identify: Pectoralis major
Origin: Clavicular head: Anterior surface of medial half of clavicle
Sternocostal head: Anterior surface of sternum, superior six costal cartilages and aponeurosis of external abdominal oblique
Insertion: Crest of greater tubercle of humerus (Lateral lip of intertubercular groove)
Action: Adducts and medially rotates humerus. Draws shoulder joint anteriorly and inferiorly. Acting alone: Clavicular head flexes humerus and sternocostal head extends it
Identify: Pectoralis minor
Origin: Sternal ends of the 3rd, 4th, and 5th ribs
Insertion: Coracoid process of the scapula
Action: Pulls scapula forward and downward
Identify: Serratus anterior
Origin: External surfaces of lateral parts of ribs 1-8/9
Insertion: Anterior vertebral border of the scapula
Action: Pulls scapula forward and downward
Identify: External Intercostals
Origin - Inferior border of a rib from costal tubercle to end of rib at articulation with costal cartilage.
Insertion - Superior border of rib just inferior to rib of origin
Identify: Internal intercostals
Origin - Superior border of a rib from costal angle to sternum.
Insertion - Inferior border of rib just superior to rib of origin.
Action - Interchondral portion: elevates and draws ribs together during inspiration as needed. Interosseous portion: depresses and draws ribs together during expiration as needed.
Identify: Diaphragm
Origin - Xiphoid process, costal cartilages of last six ribs and lumbar vertebrae.
Insertion - Central tendon.
Action - Pulls central tendon inferiorly.
What part of the vertebrate nervous system innervates smooth and cardiac muscle and glandular tissues and governs involuntary, vital functions?
The autonomic nervous system
By this definition the ANS is
Purely motor
The somatic and autonomic divisions (SNS & ANS) are
functional divisions of the nervous system with components in both the CNS and PNS.
If we follow a nerve impulse from the CNS to an effector within the SNS (Somatic), how many motor neurons would be involved?
One
If we follow a nerve impulse from the CNS to an effector within the ANS, how many motor neurons would be involved?
Two
A motor neuron within the ANS that lies between the CNS and a ganglion is what type of neuron?
Preganglionic neuron
A motor neuron within the ANS that lies between a ganglion and an effector is what type of neuron?
Ganglionic neuron
What is the axon of a ganglionic neuron within the ANS?
Postganglionic axon
What are the two divisions of the ANS?
Parasympathetic and Sympathetic
What division of the ANS is primarily concerned with conserving energy and replenishing nutrient stores and has been nicknamed the “rest-and-digest” division?
Parasympathetic
What division of the ANS is primarily concerned with preparing the body for emergencies and is often referred to as the “fight-or-flight” division?
Sympathetic
What is another term for the parasympathetic division?
Craniosacral division
Where are the cell bodies of the preganglionic neurons for the parasympathetic division located?
Brainstem
Gray regions of S2-S4 spinal cord segments
Where are the ganglia of the parasympathetic division found?
Next to or within the organs they innervate
What is another term for the sympathetic division of the ANS?
Thoracolumbar division
From what regions of the CNS does the sympathetic division arise?
The lateral horns of the T1-L2 regions of the spinal cord
What part of spinal nerves do the preganglionic sympathetic axons travel within as they leave the lateral horn of the spinal cord?
Anterior root
What sympathetic ganglia lie on the left and right sides of the vertebral column from T1-L2?
Sympathetic trunk/Paravertebral ganglia
What are the connections between the spinal nerves and the sympathetic trunks?
Rami communicates (communicating rami)
What structures carry preganglionic sympathetic axons from the T1-L2 spinal nerves to the sympathetic trunk?
White rami communicantes (white rami)
What structures carry postganglionic sympathetic axons from the sympathetic trunk to the spinal nerves?
Gray rami communicates (gray rami)
What pathway is a postganglionic axon within if it travels through a gray ramus that is at the same level as the ganglionic neuron to innervate blood vessels or arrector pili muscles or sweat glands?
Spinal nerve pathway
What pathway is a postganglionic axon within if the preganglionic neuron synapses with a ganglionic neuron in a sympathetic trunk ganglion, but the postganglionic axon DOES NOT leave the trunk via a gray ramus, but instead the postganglionic axon extends away from the sympathetic trunk ganglion and goes directly to the effector organ?
Postganglionic sympathetic nerve pathway
