Anatomy Flashcards
The thoracic skeleton consists of:
- Sternum
- The 12 pairs of ribs and the associated costal cartilages
- The 12 thoracic vertebrae and their associated intervertebral (IV) discs
- Intervertebral (IV) discs are joints located between the vertebrae
The sternum is composed of 3 parts:
Manubrium
Body
Xiphoid process
(The sternal angle is the articulation between the manubrium and the body)
The ______ is the articulation between the manubrium and the body
sternal angle
The sternal angle marks the articulation site for the ____ rib and its ____
The sternal angle marks the articulation site for the 2nd rib and its costal cartilage
The sternal angle is directly opposite the approximate level of the ____ thoracic vertebra
The sternal angle is directly opposite the approximate level of the 4th thoracic vertebra
(or about T4/T5 level)
The ____ is the easily palpable concave notch along the superior border of the manubrium
Jugular notch
The thoracic cage has superior and inferior openings called _____
apertures
The ____ aperture is considered the doorway between the thoracic cavity and the neck
The superior thoracic aperture is considered the doorway between the thoracic cavity and the neck
clinicians generally reger to the superior thoracic aperture as the “thoracic outlet”
The _____ closes the inferior thoracic aperture, separating the thoracic cavity from the ____ cavity
The muscular diaphragm closes the inferior thoracic aperture, separating the thoracic cavity from the abdominal cavity
A typical thoracic vertebra consists of 3 major features:
- Vertebral body- for weight bearing
- Vertebral (neural) arch consisting of pedicles and laminae- protection of the spinal cord
- Numerous (7) processes for muscular attachment and joint surfaces
What portion of the vertebra is used for weight bearing?
The vertebral body
Which portion of the vertebra serves to protect the spinal cord?
The vertebral (neural) arch
(Consists of pedicles and laminae)
What portion of vertebra serves for muscular attachment and joint surfaces?
The numerous (7) processes
______ are heart-shaped and have 2 costal facets- (superior and inferior) on each side of the body for articulation with the head of a rib
Vertebral bodies are heart-shaped and have 2 costal facets- (superior and inferior) on each side of the body for articulation with the head of a rib
_________ are long and slender and have a transverse costal facet for articulation with the tubercle of a rib
Transverse processes are long and slender and have a transverse costal facet for articulation with the tubercle of a rib
Transverse processes are long and slender and have a _________ for articulation with the tubercle of a rib
Transverse processes are long and slender and have a transverse costal facet for articulation with the tubercle of a rib
Spinous processes are long and slant ______
inferiorally
_______ and their associated joint surfaces (facets) serve for articulation with adjacent vertebrae
Articular processes (4) and their associated joint surfaces (facets) serve for articulation with adjacent vertebrae
Articular processes (4) and their associated joint surfaces (facets) serve for articulation with _________
Articular processes (4) and their associated joint surfaces (facets) serve for articulation with adjacent vertebrae
What are the 3 types of ribs?
1.Vertebrocostal (True) - articulates directly with sternum via its own costal cartilage (1-7)
2.Vertebrochondral (False) - indirect articulation with sternum via costal cartilage of the superior rib (8-10)
3.Vertebral (Floating) - do not articulate with sternum, end in the posterior abdominal wall (11-12)
These ribs articulate directly with the sternum via their own costal cartilage:
Vertebrocostal (true) ribs
(1-7)
These ribs articulate indirectly with the sternum via costal cartilage of the superior rib:
Vertebrochondral (False) ribs
(8-10)
These ribs do not articulate with the sternum, and end in the posterior abdominal wall:
Vertebral (floating) ribs
(11-12)
The head of a typical rib has two facets (____ and ____) for articulation with the bodies of two vertebrae. There is a ___ between these two facets.
The head of a typical rib has two facets (superior and inferior) for articulation with the bodies of two vertebrae. There is a crest between these two facets.
The ___ is the slightly constricted area just distal to the head of a typical rib
The neck is the slightly constricted area just distal to the head of a typical rib
The ____ is the portion of the rib located at the junction of the neck and the shaft. It has a ____ for articulation with corresponding transverse process of the vertebra
The tubercle is the portion of the rib located at the junction of the neck and the shaft. It has a facet for articulation with corresponding transverse process of the vertebra
The ____ is the portion of the rib located at the junction of the neck and the shaft. It has a facet for articulation with the corresponding _______ of the vertebra
The tubercle is the portion of the rib located at the junction of the neck and the shaft. It has a facet for articulation with the corresponding transverse process of the vertebra
The ____ has a costal angle where rib turns anterolateral and a costal groove inferiorly for neurovascular structures
The shaft has a costal angle where rib turns anterolateral and a costal groove inferiorly for neurovascular structures
The shaft has a costal angle where rib turns anterolateral and a costal groove inferiorly for ______ structures
neurovascular
The head of typical ribs articulates with two vertebrae:
The body of the numerically corresponding vertebra
and
the body of the vertebra superior to it
e.g. rib 5 articulates with the body of T5 and T4
The tubercle of a typical rib articulates with the ______ transverse process
The tubercle of a typical rib articulates with the numerically corresponding transverse process
e.g. rib 5 articulates with the transverse process of T5
Rib 5 articulates with (3):
Transverse process of T5
Body of T5
Body of T4
Costochondral joint:
cartilaginous joints between the rib and its costal cartilage
Sternocostal joint:
synovial joints between the costal cartilage and the sternum
Costovertebral joints:
synovial joints between the ribs and the vertebral column
the upper limit of the heart reaches as high as the ____ costal cartilage on the right side of the sternum and the ____ intercostal space on the left side of the sternum.
the upper limit of the heart reaches as high as the 3rd costal cartilage on the right side of the sternum and the 2nd intercostal space on the left side of the sternum.
The heart rests on the diaphragm and is covered anteriorly by the _______ and approximately the _____ costal cartilages of both sides.
The heart rests on the diaphragm and is covered anteriorly by the body of the sternum and approximately the 3rd-6th costal cartilages of both sides.
The right margin of the heart extends from approximately the right ____ costal cartilage to near the right ___ costal cartilage.
The right margin of the heart extends from approximately the right 3rd costal cartilage to near the right 6th costal cartilage (at the 6th chondro-sternal junction).
The left margin of the heart descends laterally from the ____ intercostal space to the apex located near the midclavicular line in the ___ intercostal space.
The left margin of the heart descends laterally from the 2nd intercostal space to the apex located near the midclavicular line in the 5th intercostal space.
The lower margin of the heart extends from the sternal end of the right ____ costal cartilage to the apex in the ____ intercostal space near the midclavicular line
The lower margin of the heart extends from the sternal end of the right 6th costal cartilage to the apex in the 5th intercostal space near the midclavicular line
The arch of the aorta lies behind the ______ of the manubrium. The left brachiocephalic vein courses obliquely behind the ____ just above the aortic arch
The arch of the aorta lies behind the sternal angle/lower portion of the manubrium. The left brachiocephalic vein courses obliquely behind the manubrium just above the aortic arch
What is the weakest part of the ribs?
Just anterior to its angle
What ribs are the most commonly fractured?
Middle ribs (5-9) via e.g. auto accidents or sports injuries
Pectus excavatum:
(aka funnel chest) is a condition in which a person’s sternum is sunken into his or her chest
More common in males than females
If the depth of the sternum is severe, it may reduce the ability of the lungs to expand
Severe compression can also squeeze the heart, reducing its ability to fill/pump efficiently
The exact cause is unknown…it may be an inherited (genetic) and/or associated with some syndromes (i.e. Marfan Syndrome
Pectoralis major:
Large fan-shaped muscle in superior thorax
Two heads of origin: clavicular and sternocostal
Inserts into the humerus
Powerful adductor; flexor, and medial (internal) rotator of the arm
Innervated by the medial & lateral pectoral nerves
Pectoralis Minor:
Originates from anterior surface of the 3rd - 5th ribs
Inserts into the coracoid process of the scapula
Stabilizes the scapula against thoracic wall (accessory respiratory muscle also)
Innervated primarily by the medial pectoral nerve
Serratus Anterior Muscle:
Originates on the surface of the 1st - 8th ribs
Inserts into the medial border of the scapula
Stabilizes and protracts the scapula (shoulder blade)
Serratus Anterior…“Boxer’s Muscle”
Innervated by long thoracic nerve
What are the 3 intrinsic muscles of the thorax?
External intercostals
Internal intercostals
Innermost intercostals
The intercostal muscles are all accessory muscles of ____
respiration
What is the order of the neurovascular structures within the costal groove?
VAN:
Intercostal Vein
Intercostal Artery
Intercostal Nerve
Intercostal nerve blocks:
Local anesthetic infiltrated around one or several intercostal nerves to provide anesthesia to thoracic wall
Can be used for reducing pain associated with fractured ribs or to reduce pain associated with bone cancer within the rib cage
How many intercostal muscles are there?
11 on each side (one in each intercostal space)
_____ intercostal muscles course “down and in” and are visualized more laterally
External
_____ intercostal muscles course “down and out” and are visualized more medially
Internal
____ intercostals are located on the inside of the thoracic wall
Innermost intercostals
The neurovascular plane is located between the _____ layer AND the _______ layer. This is where the intercostal nerves, arteries, and veins traverse
The neurovascular plane is located between the internal intercostal muscle layer AND the innermost intercostal layer. This is where the intercostal nerves, arteries, and veins traverse.
The _______ is located between the internal intercostal muscle layer AND the innermost intercostal layer. This is where the intercostal ___, ___, and ____ traverse.
The neurovascular plane is located between the internal intercostal muscle layer AND the innermost intercostal layer. This is where the intercostal nerves, arteries, and veins traverse.
Transversus thoracis muscle:
A particular innermost intercostal
Located on the inside of the thoracic wall, just deep to the sternum
Origin: posterior surface of the sternum
Inserts onto the internal surface of costal cartilages of ribs 2-6
Intercostal arteries arise from two major arteries:
Thoracic (descending) aorta
Internal thoracic arteries (which are branches of the subclavian arteries)
_____ arteries arise from the aorta and course between the ribs where the anastomose with the anterior intercostals
Posterior intercostal arteries
Posterior intercostal arteries arise from the aorta and course between the ribs where the anastomose with the ______
anterior intercostals
The internal thoracic arteries divide into the _____ and _____ arteries
musculophrenic
superior epigastric
The _____ vein from the leg is routinely used as a graft for CABG. It is surgically connected to the aorta and also to a site distal to the occlusion of the coronary artery
Great saphenous vein
What is the primary choice for CABG surgery?
Internal thoracic artery (ITA)
ITA is dissected from the thoracic wall and its distal portion is sutured to the coronary artery downstream of the occlusion/obstruction
This graft essentially detours blood directly from the subclavian to downstream of the occluded or blocked vessel
Intercostal veins drain venous blood from the _______.
They drain into (2):
Drain blood from the thoracic wall.
Drain into the Azygos system of veins and internal thoracic veins.
Each intercostal nerve courses in the costal groove (along the inferior surface of the rib) innervating the ________ and the _______.
Each intercostal nerve courses in the costal groove (along the inferior surface of the rib) innervating the anterior and lateral body wall and the intrinsic thoracic wall muscles (i.e. intercostal muscles)
There are ___ intercostal nerves which are branches of the _______.
There are 12 intercostal nerves (T1-T12) which are branches of the thoracic spinal nerves.
An intercostal nerve is simply the ____ ramus of a thoracic spinal nerve
VENTRAL
What are the 3 compartments that the thoracic cavity is divided into?
Two lateral compartments which contain the lungs and the pleurae (serous membranes surrounding the lungs)
The central compartment aka the mediastinum that contains many major thoracic structures (heart, great vessels, and portions of the trachea, esophagus, and thymus)
The mediastinum extends from the ____ to the ____
The mediastinum extends from the superior thoracic aperture to the diaphragm
The division between the superior and the inferior mediastinum is called the _____
transthoracic plane
The transthoracic plane is an imaginary line drawn from the _____ to the _____.
The transthoracic plane is an imaginary line drawn from the sternal angle to the T4/T5 vertebral column level.
What is the anterior mediastinum?
The anterior mediastinum is a small space just beneath the sternum.
In children, the thymus gland occupies much of the anterior mediastinum. The gland regress in adulthood. Nonetheless this is the area that the thymus is contained in.
The middle mediastinum contains the:
Pericardium (a fibro-serous membrane that surrounds and protects the heart)
The Heart
Roots (or origins) of the great vessels (ascending aorta, SVC, Pulmonary trunk)
What is the posterior mediastinum? What does it include?
The posterior mediastinum is a small area posterior to the heart/pericardium and anterior to the 5th through the 12th thoracic vertebrae.
Contents include:
- Esophagus
- Descending aorta
- Azygos veins
- Thoracic duct
- Autonomic nerves
The right atrium (choice D) forms the right border of the heart. Its anterior surface is on the right side of the sternum from approximately the third rib to the sixth rib.
Correct answer is D. The right ventricle forms most of the anterior wall of the heart and extends from approximately the right border of the sternum to approximately 2 inches to the left of the sternum at the level of the fourth/fifth intercostal spaces.
The left ventricle (choice B) forms most of the left border of the heart and the diaphragmatic surface of the heart. It forms the anterior wall of the heart in a region from approximately 2-3 inches from the left border of the sternum from the third to the fifth intercostal space.
A 52 year-old-male is brought to the emergency department for evaluation of fever, chills, and malaise. Cardiac examination reveals a heart murmur that radiates toward his axilla (armpit). Blood cultures are obtained and he undergoes transesophageal echocaridiography. The ultrasound probe is placed in the mid-esophagus facing anteriorly and the cardiac chambers are interrogated (imaged). Anatomically, which of the following chambers is closest to the ultrasound probe?
A. Right atrium
B. Left atrium
C. Right ventricle
D. Left Ventricle
Transesophageal Echocaridiography: a flexible thin tube that passes through your mouth, down your throat, and into your esophagus. Anatomically, the left atrium of the heart is positioned posteriorly within the pericardial sac. The TEE probe facing anteriorly can effectively image the overlying left atrium (as well as other chambers/structures of the heart)
What is the pericardium and what is it composed of?
It is a double-walled fibroserous sac that encloses the heart and roots of great vessels
External sac = fibrous pericardium
Internal sac = serous pericardium
The ____ pericardium is the outer layer of the pericardium. It is made of _____ tissue.
The fibrous pericardium is the outer layer of the pericardium. It is made of tough connective tissue.
The fibrous pericardium is continuous with adventitia of _____ and attached to _____ of diaphragm as well as sternum
The fibrous pericardium is continuous with adventitia of great vessels and attached to central tendon of diaphragm as well as sternum
How is the fibrous pericardium supplied blood?
Supplied by internal thoracic (including pericardiacophrenic and musculophrenic) and inferior phrenic arteries as well as the aorta itself.
How is pain in the fibrous pericardium conveyed?
By general sensory fibers of the phrenic nerve
What are the layers of the serous pericardium?
Parietal layer – Lines the inner surface of the fibrous pericardium
Visceral layer (epicardium) – Adheres to the heart and forms its outer covering
(The parietal and serous layers are continuous with one another around the large arteries and around the large veins)
Coronary (atrioventricular) sulcus:
Encircles the heart, dividing the atria from the ventricles
Anterior and posterior interventricular sulci:
Separate the two ventricles
The right border of the heart is defined by the:
right atrium
The left border of the heart is defined by the:
Left appendage (auricle)
Left ventricle
The anterior surface of the heart is defined by:
the right ventricle
The posterior surface of the heart is defined by:
The left atrium
How is the heart removed during dissection?
Cut the:
- Superior vena cava
- Inferior vena cava
- Pulmonary veins
- Aorta
- Pulmonary trunk
Transverse pericardial sinus:
Separates the arteries from the veins
Oblique pericardial sinus:
Formed by reflection onto the pulmonary veins of the heart
What are the 4 circulations of the body?
- coronary circulation
- pulmonary circulation
- systemic circulation
- portal circulation
What is the right coronary artery?
Located in the atrioventricular, or coronary, sulcus
- branch to SA node
- marginal branch (acute marginal)
- posterior descending/interventricular artery (PDA)
Left ventricular artery:
aka left main
- Left anterior descending artery (ant. interventricular)
- circumflex branch (LCX)
Marginal branch (obtuse marginal)
Label the following arteries:
What does the right coronary artery supply?
R atrium
R ventricle
SA node
AV nodes
Interatrial septum
L atrium (part)
IV septum (part)
L ventricle (part)
What does the left coronary artery supply?
L atrium (mostly)
Left ventricle (mostly)
IV septum (mostly)
AV bundle/branches
85% of people have a ___-dominant coronary circulation, where the PDA arises from the ____.
85% of people have a right-dominant coronary circulation, where the PDA arises from the RCA.
8% of people have a ___-dominant coronary circulation, where the PDA arises from ____
8% of people have a left-dominant coronary circulation, where the PDA arises from LCX
7% of people have a __-dominant circulation, where the PDA arises from the _____
7% of people have a co-dominant circulation, where the PDA arises from the LCX and RCA
The great cardiac vein and most other cardiac veins drain into the ______.
Coronary sinus
(returns blood to the right atrium)
Label the drawing of the right atrium:
What structure is indicated in the image?
right atrium
Label the right ventricle:
What is the septomarginal trabecula?
The moderator band + the septal limb
Describe the tricuspid valve:
- An atrioventricular (AV) valve
- Has 3 cusps or leaflets
- Anterior
- Septal
- Posterior
•Papillary muscles and chordae tendineae prevent eversion of valves.
- Septal
- Posterior
- Anterior
Describe the pulmonary valve:
- A semilunar valve
- Has 3 semilunar cusps
- Left
- Anterior
- Right
What structure is indicated in this image?
Right ventricle
What is indicated in this image of the left atrium?
The valve of the foramen ovale
What is indicated in this image?
Left atrium
Describe the mitral (biscuspid) valve:
- An atrioventricular (AV) valve
- Has 2 cusps or leaflets
- Anterior
- Posterior
Describe the aortic valve:
- A semilunar valve
- Has 3 semilunar cusps
- Right
- Posterior
- Left
What is indicated in this image?
left ventricle
What is the cardiac skeleton?
- Collection of dense, fibrous connective tissue in the form of 4 rings
- Helps maintain the integrity of the valves
- Provides attachment sites for cusps
- Separates atrial musculature from ventricular musculature
- Electrically isolates atria from ventricles
Describe the lub and dub heart sounds:
What are the 4 auscultatory locations of the heart?
The actual valves are located behind the sternum, but the sound is carried by the bloodflow to more peripheral locations where one auscultates.
Pulmonary valve – Left 2nd intercostal space just lateral to sternum
Tricuspid valve – Lower part of sternum
Aortic valve – Right 2nd intercostal space just lateral to sternum
Mitral valve – Left 5th intercostal space away from sternum
Heart rate is ____ by the autonomic nervous system
modified
What is the cardiac plexus?
–Is a collection of sympathetic and parasympathetic nerves located at bifurcation of trachea just superior to heart
–Sends nerve fibers along coronary arteries to reach heart
–Modifies heart rate, force of contraction, and cardiac output
Sympathetic nerves:
–Come from sympathetic chain
- Sup. cervical cardiac nerves
- Middle cervical cardiac nerve
- Inf. cervical cardiac nerves
- Thoracic cardiac nerves
–Visceral motor fibers raise heart rate and force of contraction
–Visceral sensory fibers convey cardiac pain signals
Parasympathetic nerves:
–Come from vagus (X)
–Visceral motor fibers lower heart rate and force of contraction
–Visceral sensory fibers transmit cardiac reflexes (alterations in BP and blood chemistry)
Broadly describe the innervation of the heart:
Visceral sensory fibers paralleling ______ visceral motor fibers convey pain.
Visceral sensory fibers paralleling sympathetic visceral motor fibers convey pain.
Visceral sensory fibers paralleling ______ visceral motor fibers convey reflexes.
Visceral sensory fibers paralleling parasympathetic visceral motor fibers convey reflexes.
What is referred pain?
The CNS perceives (confuses) visceral pain from the heart to be somatic pain from the T1-T4 dermatome.
What are these vessels?
A = ascending aorta
B = superior vena cava
C = right pulmonary artery
D = left pulmonary artery
E = descending aorta
What heart chambers are shown in these MRIs?
A = right ventricle
B = left ventricle
C = right atrium
D = left atrium
What chambers and vessels are shown in this MRI?
A - superior vena cava
B - right atrium
C - aortic arch
D - left ventricle
E - pulmonary trunk
F - right ventricle
How many spinal nerves compose the spinal cord?
31 total nerves compose the spinal cord
8 cervical
12 thoracic
5 lumbar
1 coccygeal
Ventral root:
Contains axons of motor nerves that convey impulses away from the spinal cord
Dorsal root:
Contains axons of sensory nerves that convey impulses toward the spinal cord
The dorsal root and the ventral root unite to form a ____ which conveys both motor and sensory axons
spinal nerve
Dorsal ramus:
Conveys nerve axons to and from the muscles of the back and the overlying skin of the back
Ventral ramus:
Conveys nerve axons to and from the body wall (torso) and/or the upper and lower limbs
The motor nerves (called “somatic motor nerves”) ultimately innervate ______. The cell bodies of the somatic motor nerves reside in the ____ of the spinal cord.
The motor nerves (called “somatic motor nerves”) ultimately innervate skeletal or striated muscles. (I.e. intercostal muscles and limb muscles) The cell bodies of the somatic motor nerves reside in the ventral horn of the spinal cord.
The ____ nerves convey sensations like pain, touch, and temperature into the spinal cord/CNS. The cell bodies of these nerves reside in the ______.
The sensory nerves (called “general” or somatic sensory nerves) convey sensations like pain, touch, and temperature into the spinal cord/CNS. The cell bodies of the somatic sensory nerves reside in the dorsal root ganglion (DRG) - a swelling located on the dorsal root of all spinal nerves
It is the ______ of thoracic spinal nerves that ultimately innervate the muscles and skin along the thoracic wall
It is the ventral rami of thoracic spinal nerves that ultimately innervate the muscles and skin along the thoracic wall
The ventral ramus of a thoracic spinal nerve is called a(n) _______.
The ventral ramus of a thoracic spinal nerve is called a(n) intercostal nerve (i.e. runs between the ribs).
In a dermatome map, the thoracic nerves innervate _____ segments along the body wall. These dermatomes correspond to a specific _______.
In a dermatome map, the thoracic nerves innervate successive segments along the body wall. These dermatomes correspond to a specific spinal nerve/spinal cord segment.
Important landmarks for dermatome maps:
T4 dermatome corresponds to the level of the nipples
T10 dermatome corresponds to the level of the umbilicus
Somatic motor nerves convey impulses from the ___ to the ____.
The cell body is located _____.
Somatic motor nerves convey impulses from the CNS to the skeletal (voluntary) muscles.
The cell body is located within the ventral horn.
Somatic sensory nerves convey sensations from the ____ to the _____.
The cell body is located _____.
Somatic sensory nerves convey sensations (pain, touch, temperature) from the body to the CNS.
The cell body is located within the dorsal root ganglion.
The ventral ramus conveys motor and sensory nerves to the _____.
Body wall (intercostal muscles and skin)
Somatic motor nerves convey impulses from the ____ to the _____.
Somatic motor nerves convey impulses from the CNS to the skeletal muscle.
Somatic sensory nerves convey sensations from the ___ to the ____.
Somatic sensory nerves convey sensations from the body to the CNS.
