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Thorax & Lungs/Respiration Histology
LECOM Yr 1
161
Anatomy
Graduate
08/24/2011

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Cards

Term
in males, where are the nipples typically located?
Definition
in the 4th intercostal spaces
Term
the majority of the lungs are located superior to what region?
Definition
a horizontal line passing through the nipples
Term
much of the liver lies under which dome of the diaphragm?
Definition
right dome
Term
the stomach and spleen lie under which dome of the diaphragm?
Definition
the left dome
Term
the left kidney lies anterior to which vertebrae?
Definition
lies anterior to T11-L3 vertebrae
Term
the right kidney lies next to which vertebrae?
Definition
T12-L4; one vertebrae lower than the left kidney
Term
what is the mediastinum?
Definition
central compartment of the thorax that houses the thoracic viscera, except the lungs
Term
what does the diaphragm enclose?
Definition
the thoracic cavity inferiorly
Term
describe the thoracic skeleton
Definition
osteocartilaginous; includes 12 pairs of ribs and costal cartilages, intercostal spaces, 12 thoracic vertebrae and IV discs, and the sternum
Term
what are the parts of the sternum?
Definition
manubrium, body, sternal angle (angle of louis) and jugular notch
Term
what are the 3 types of ribs?
Definition
true, false and floating
Term
which ribs are true ribs?
Definition
the first 7 ribs, attach directly to the sternum via costal cartilages
Term
which ribs are false ribs?
Definition
ribs 8-10; attach to the costal margin
Term
which ribs are the floating ribs?
Definition
ribs 11 and 12; do not attach to the sternum
Term
describe features of the first rib
Definition
has grooves for subclavian vessels; has one articular facet on its head
Term
describe features of the 2nd rib
Definition
2 articular facets; tubercles for muscle attachment
Term
describe features of ribs 11 and 12
Definition
are floaters, have no necks or tubercles
Term
the superior angle of the scapula is at the level of which vertebral spinous process?
Definition
T2 spinous process
Term
the inferior angle of the scapula is at the level of which vertebral spinous process?
Definition
T7 spinous process
Term
the jugular notch is at the level of which vertebrae?
Definition
the T2 vertebral body
Term
where is the sternal angle located?
Definition
where the 2nd costal cartilages attach; it lies at the level of the IV disc between T4 and T5
Term
the breast is supported by which ligaments?
Definition
suspensory ligaments
Term
describe characteristics of the breast
Definition
Composed mainly of subcutaneous fat, glands, and ligaments
Usually, only women have well developed mammary glands
Mammary glands are modified sweat glands that form lobules
Each lobule drains into a lactiferous ducts that opens on the nipple
Supported by suspensory ligaments
Usually situated vertically over the 2nd – 6th ribs
Two-thirds of the breast overlies the pectoralis major m., the remaining third overlies the serratus anterior m.
The retromammary space lies between the pectoral fascia and the breast. It allows movement.
Male nipple is usually at the 4th intercostal space
Lateral region can form an axillary tail
Term
the blood supply to the breast occurs via which routes?
Definition
The lateral thoracic artery (Lateral Mammary Branches)
The internal thoracic artery (Medial Mammary Branches)
Posterior intercostal arteries (2nd, 3rd, and 4th intercostal spaces)
Term
describe the venous drainage of the breast
Definition
Venous drainage is to the axillary vein via lateral mammary veins
Medial mammary veins drain into the internal thoracic veins
Note: Venous drainage can reach the azygous system via intercostal veins
Term
which nerves innervate the breasts?
Definition
the anterior and lateral cutaneous branches of the 2nd and 6th intercostal nerves
Term
the nipple is innervated by which nerve?
Definition
the 4th intercostal nerve
Term
describe some key features of lymphatic drainage in the breast
Definition
Lymph passes from the nipple, areola, and lobules to the subareolar lymphatic plexus

Most lymph (75%), drains laterally and superiorly into axillary nodes. Eventually, these drain into the right lymphatic or thoracic ducts

Most of the medial quadrant drains into parasternal nodes. From here, it can travel across to the contralateral breast or drain to the lymphatic or thoracic duct.

Some lymph drainage follows the lateral branches of posterior intercostal vessels (not depicted). This eventually drains into the right lymphatic or thoracic ducts.

There is some drainage to the subdiaphragmatic nodes & liver
Term
during radical mastectomy, which nerves are at risk of being damaged?
Definition
the long thoracic nerve (because of its location on the lateral thoracic wall) and the thoracodorsal nerve
Term
what are the 3 layers of the intercostal muscles?
Definition
the external, internal and innermost intercostals
Term
the 3 layers of intercostal muscles are innervated by which nerves?
Definition
intercostal nerves
Term
describe the external intercostals
Definition
membranous anteriorly; continuous with external oblique (abdomen)
Term
describe the internal intercostals
Definition
membranous posteriorly; continuous with internal oblique (abdomen)
Term
describe the innermost intercostals
Definition
membranous anteriorly and posteriorly
Term
which muscles are the major contributors to respiration?
Definition
the 3 layers of intercostal muscles; other contributors include the scalene muscles, posterior serratus muscles, deep muscles (levator costrum, transverse thoracic muscles)
Term
True or false: the subcostal muscles posteriorly span 2-3 intercostal spaces and can be considered a counterpart of the transversus thoracis muscle
Definition
True
Term
True or false: transversus thoracis muscles span more than one intercostal space
Definition
True
Term
what are the 2 major sources of blood supply to the thorax?
Definition
posterior intercostal and anterior intercostal arteries
Term
where does the posterior intercostal artery originate from?
Definition
originate from the thoracic aorta
Term
where do anterior intercostal arteries originate from?
Definition
originate from internal thoracic arteries
Term
the musculophrenic arteries supply which space?
Definition
the lower space
Term
the internal thoracic arteries terminate into what 2 arteries?
Definition
superior epigastric and musculophrenic
Term
the upper two posterior intercostal arteries originate from which artery?
Definition
originate from the superior thoracic artery, a branch from the costocervical trunk
Term
True or false: venous drainage of the thorax basically parallels arterial supply, except for the azygous system
Definition
True
Term
blood in the thorax ultimately drains back to the venous system through what 2 routes?
Definition
the internal thoracic veins and the azygos system
Term
where do the internal thoracic veins drain into?
Definition
the brachiocephalic veins
Term
where does the azygous system drain into?
Definition
the superior vena cava
Term
collateral nerve branches are found near which border of the ribs?
Definition
superior
Term
what is the arrangement of vessels and nerves from superior to inferior in the intercostal space?
Definition
veins, arteries and nerves
Term
what protects the veins, arteries and nerves in the intercostal space?
Definition
costal grooves in the inferior edge of the ribs
Term
what does the diaphragm cover and what does it separate?
Definition
Covers the inferior thoracic aperture, separating the thoracic & abdominal cavities
Term
where do muscle fibers converge in the diaphragm?
Definition
at the central tendon
Term
which structures traverse the diaphragm?
Definition
The inferior vena cava & right phrenic nerve and pericardiacophrenic artery pass through the central tendon at vertebral level T8

The esophagus and vagus nerves pass through the muscular part at vertebral level T10

The thoracic aorta and thoracic duct pass posterior through the aortic hiatus at vertebral level T12
Term
the largest blood supply to the diaphragm is from where?
Definition
the branches of the abdominal aorta; other supply is via pericardiacophrenic, musculophrenic, branches from intercostals and branches from thoracic aorta
Term
what nerve innervates the diaphragm?
Definition
the phrenic nerve; they penetrate the diaphragm and supply it from underneath
Term
describe what happens to the rib cage during inspiration
Definition
the rib cage expands vertically, laterally, and in the anteroposterior dimension
Term
describe what happens to the diaphragm during expiration
Definition
the diaphragm relaxes and the rib cage contracts
Term
what contracts and what expands during normal inspiration?
Definition
during normal inspiration, the diaphragm and intercostal muscles contract; the rib cage expands laterally, anteriorly, and vertically
Term
is the lung in the pleural cavity?
Definition
no
Term
where is the cervical pleura located?
Definition
extends into the root of the neck
Term
where is the costal pleura located?
Definition
adjacent to ribs and intercostal spaces
Term
what does the mediastinal pleura cover?
Definition
the mediastinum
Term
what does the diaphragmatic pleura cover?
Definition
the diaphragm
Term
what happens to the pleura at spinal levels T5-T7?
Definition
the pleura reflects back on itself; this reflection forms the hilum of the lung; the structures entering through this region make up the root of the lung; an extension of the 2 pleural layers continues inferiorly as the pulmonary ligament
Term
the pulmonary ligament has what function?
Definition
allows for movement of the lung
Term
what is the endothoracic fascia?
Definition
a loose connective tissue layer separating the parietal pleura from the internal surface of the thoracic wall
Term
what type of connective tissue is the endothoracic fascia composed of?
Definition
loose connective tissue
Term
where is the costodiaphragmatic recess located?
Definition
below the 6th rib in the midclavicular line and the 8th rib in the midaxillary line
Term
where is the costomediastinal recess located?
Definition
anteriorly where the costal pleura and mediastinal pleura meet
Term
how many lobes does the right lung have?
Definition
3; separated by horizontal and oblique fissure
Term
how many lobes does the left lung have?
Definition
2 lobes; separated by oblique fissure
Term
which lung has the main bronchus inferior to the pulmonary artery?
Definition
the left lung
Term
in which lung is the main bronchus posterior to the pulmonary arteries?
Definition
the right lung
Term
what is a bronchopulmonary segment?
Definition
the largest subdivision of a lobe
Term
what are the functions of bronchial arteries and veins?
Definition
arteries supply the lungs, veins drain the lung tissue
Term
the right side of the bronchial vein drains into what vein?
Definition
the azygous vein
Term
the left side of the bronchial vein drains into which vein?
Definition
the hemiazygous system
Term
why can blood oxygenation never reach 100%?
Definition
Bronchial veins unite within the lungs with pulmonary veins. This delivers low oxygenated blood back to the left atrium. For this reason, blood oxygenation cannot reach 100%.
Term
what is pneumothorax?
Definition
the entry of air into the pleural cavity; may be due to trauma
Term
True or false: there is always negative space in the inflated lung
Definition
True
Term
what is hydrothorax?
Definition
the accumulation of fluid in the pleural cavity that may be due to pleural effusion
Term
what is hemothorax?
Definition
the accumulation of blood in the pleural cavity; usually due to injury of the intercostal vessels
Term
what are the contents of the superior mediastinum from anterior to posterior?
Definition
Thymus
Superior vena cava
Brachiocephalic veins
Arch of aorta
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery

Vagus & phrenic nerves
Cardiac nerve plexus
Left recurrent laryngeal nerve
Trachea
Esophagus
Thoracic duct
Prevertebral muscles
Term
where is the thymus oriented in the superior mediastinum?
Definition
most anterior in sup. mediastinum; just posterior to the sternum
Term
blood supply to the thymus is from which arteries?
Definition
from the internal thoracic and superior thyroid arteries
Term
the brachiocephalic veins are formed by the union of which veins bilaterally?
Definition
the subclavian and internal jugular veins
Term
what are the 2 major divisions of the respiratory system?
Definition
the conducting portion and the respiratory portion
Term
what are the 7 components of the conducting portion of the respiratory system?
Definition
nasal cavity
nasopharynx
larynx
trachea
bronchi
bronchioles
terminal bronchioles
Term
what are the 3 components of the respiratory portion of the respiratory system?
Definition
respiratory bronchioles
alveolar ducts
alveoli
Term
what is a nasal cavity?
Definition
paired chambers separated by a bony and cartilagenous septum
Term
each chamber of a nasal cavity is divided into what 3 regions?
Definition
vestibule; respiratory segment; olfactory segment
Term
what is a vestibule?
Definition
site of communication with the external environment via the external nares (nostrils)
Term
what is the vestibule lined with?
Definition
lined with stratified squamous epithelium that contains hairs
Term
what is the function of the hairs in the vestibules?
Definition
hairs prevent large particulates from entering the nasal cavities
Term
when the vestibule ends, the stratified squamous epithelium is replaced by which type of epithelium?
Definition
replaced by respiratory epithelium, pseudostratified columnar ciliated epithelium with goblet cells
Term
a respiratory segment is lined by which type of epithelium?
Definition
lined by pseudostratified columnar ciliated epithelium with goblet cells (respiratory epithelium)
Term
the medial wall of the respiratory segment is what structure?
Definition
the nasal septum
Term
the lateral wall of the respiratory segment is composed of what structure?
Definition
conchae or turbinates (3 shelf like bony prominences)
Term
what is the function of turbinates (conchae) in the respiratory segment?
Definition
They increase surface area and cause a turbulence in air flow to allow for better warming and moisterizing of the air.
The turbinates also cause eddies in the airflow that help remove particulate matter by trapping it in the mucus of the cavity.
Term
describe the characteristic features of the nasal cavity lamina propria
Definition
Very vascular.
Warms the inspired air nearer to body temperature.
Vessels become excessively engorged and leaky during allergic reactions and viral infections.
consequent distention of the lamina propria makes breathing more difficult.
Contains mucous glands with serous demilunes.
Demilune cells secrete lysozyme, an antibacterial
Term
what type of epithelium lines the olfactory segment?
Definition
olfactory epithelium
Term
the entire area of olfactory mucosa in humans is measured in ____ _____ _____.
Definition
mere square centimeters
Term
what are the 4 types of cells found in an olfactory segment?
Definition
olfactory cells, supporting or sustenacular cells, basal cells, brush cells
Term
what are olfactory cells?
Definition
special visceral sensory cells
Term
what are supporting or sustenacular cells?
Definition
provide mechanical and metabolic support for olfactory sensory cells; role is similar to that of glial cells
Term
what are basal cells?
Definition
mitotic cells that renew the sensory and sustenacular cells
Term
what are brush cells?
Definition
general sensory cells innervated by the trigeminal nerve (cranial nerve V); signal touch from the olfactory epithelium; they are also found in the respiratory epithelium
Term
which neurons are the only neurons that regenerate in an adult human?
Definition
olfactory cells
Term
describe olfactory cells
Definition
bipolar neurons.
span the thickness of the olfactory epithelium.
At their apical surface, they have a knob-like structure, the olfactory vesicle.
The vesicle has a number of non-motile cilia on its surface. The cilia are the sites of olfactory receptors.
The basal end of the cell gives rise to an axon.
The axon joins others to form the olfactory nerve (cranial nerve I).
The olfactory axons penetrate the cribiform plate of the ethmoid bone to synapse in the olfactory bulb.
These neurons, unlike others in adult humans, can regenerate.
Term
what is an olfactory vesicle?
Definition
located at the apical surface of olfactory cells; have a knob-like structure; the vesicle has a number of non-motile cilia on its surface; the cilia are the sites of olfactory receptors
Term
where is the nasopharynx located?
Definition
located posterior to the nasal and oral cavities; the portion above the soft palate and behind the nasal cavities is the nasopharynx
Term
what is the nasopharynx lined by?
Definition
lined by respiratory epithelium and its posterior wall contains the pharyngeal tonsil (adenoids)
Term
describe the epiglottis
Definition
has a core of elastic cartilage; projects into the pharynx from the rim of the larynx
Term
the lingual surface (facing the tongue) of the epiglottis is lined with what type of epithelium?
Definition
stratified squamous epithelium
Term
the laryngeal surface of the epiglottis is lined with what type of epithelium?
Definition
pseudostratified columnar epithelium
Term
true or false: the lamina propria contains mixed mucous and serous glands
Definition
true
Term
what is the larynx?
Definition
Complex structure that connects the pharynx with the trachea.
Lamina propria of the larynx is characterized by the laryngeal cartilages (thyroid, cricoid and arytenoid cartilages).
The cartilages are essential to the maintenance of the patency of the larynx. They also play a major role in vocalization.
Term
describe the false vocal folds (ventricular folds) in the larynx
Definition
Upper of two pairs of folds found in the larynx.
Usually covered by pseudostratified columnar epithelium, the lamina propria of which contains numerous serous glands.
Term
describe the true vocal folds (vocal cords) in the larynx
Definition
lower pair of folds in the larynx.
Covered by stratified squamous epithelium.
Contain parallel bundles of elastic fibers that form the vocal ligaments.
Vocalis muscles lie parallel to the vocal ligaments. They are skeletal muscles innervated by the vagus nerve (cranial nerve X).
Term
describe the trachea
Definition
The trachea is a short tubular structure about an inch in diameter and 5 inches long. It extends from the larynx to the mid thorax where it branches into the two primary bronchi
The epithelium rests upon a very thick basement membrane made up of densely packed collagen fibers that lie immediately beneath the epithelial basal lamina.
actually, a very thick reticular lamina and as such is a part of the lamina propria.
In smokers, chronic coughing causes this membrane to thicken.
The lamina propria itself is a loose connective tissue with the typically found cells such as mast cells, plasma cells and macrophages. Lymphatic tissue, both diffuse and nodular can characterize this layer
Term
what is the tracheal mucosa composed of?
Definition
composed of pseudostratified ciliated columnar epithelium and an elastic-rich lamina propria. The epithelium is similar to respiratory epithelium in other parts of the conducting system
It has ciliated cells, goblet cells, brush cells (sensory cells), small granule cells (a cell similar to enteroendocrine cells) and basal cells that repopulate the epithelium. The cilia of the epithelial cells beat in unison upward to move mucus toward the oropharynx.
Term
describe the cartilagenous layer of the trachea
Definition
hyaline cartilage; 16-20 C-shaped cartilages that form the cartilagenous layer.
They allow for flexibility of the trachea while at the same time maintaining its patency.
In older individuals, there may be some calcification and bone formation.
Posteriorly, the C-shaped cartilage is attached by the trachealis muscle (smooth muscle). Contraction of the muscle can increase the velocity of expelled air during the cough reflex and thereby aid in clearing the passageway
Term
where are primary bronchi located?
Definition
outside the lungs (extrapulmonary)
Term
describe the bronchi
Definition
Primary bronchi are extrapulmonary (outside the lungs).
Initially, bronchial structure is similar to that of the trachea except that there are rings of cartilage rather than C-shaped cartilages.
As the bronchi enter the lungs, the cartilagenous rings are replaced by irregular plates. Plates are distributed circularly around the entire circumference of the bronchus.
Term
what are bronchioles?
Definition
Air conducting tubes measuring a millimeter or less in diameter.
Larger bronchioles initially have pseudostratified ciliated columnar epithelium (typical respiratory epithelium).
Further down the epithelium becomes simple ciliated columnar, then simple cuboidal.
Goblet cells are found in the largest bronchioles, but typically are absent in the smaller ones.
Term
cartilage is replaced by thick ______ muscle in bronchioles
Definition
smooth
Term
what distinguished bronchioles from bronchi?
Definition
absence of cartilage distinguishes bronchioles from bronchi and is a major criterion used for the histological identification of these structures
Term
are there subepithelial glands in bronchioles?
Definition
no
Term
what are clara cells?
Definition
first cells found in the bronchioles; They secrete a lipoprotein that prevents adhesion of adjacent walls during expiration.
Clara cell protein (CC16) is used to assess damage to lungs.
Decreases in bronchoalveolar fluids when lung is damaged.
May appear in blood, signalling lung damage.
Term
if clara cell protein is found in the blood, what can be indicated?
Definition
lung damage
Term
what is the function of the protein secreted by clara cells?
Definition
prevents adhesion of adjacent walls during expiration
Term
are there macrophages in the lung?
Definition
yes, many of them which take up particulate matter
Term
what are terminal bronchioles?
Definition
smallest bronchioles with purely conducting function; have clara cells in their epithelium which is a simple cuboidal epithelium; this is visceral pleura
Term
what are respiratory bronchioles?
Definition
Transitional structures and are the first part of the respiratory tree where gas exchange occurs
Term
narrow lumens of respiratory bronchioles are lined with which type of epithelium?
Definition
simple cuboidal; Initial portion contains both ciliated and Clara cells.
More distally, Clara cells predominate in the epiithelium
Term
scattered thin-walled outpouchings of the respiratory lumen are ______.
Definition
alveoli
Term
why do chronic alcoholics frequently have pneumonia?
Definition
alcohol effects ciliary movement
Term
describe how smoking affects the trachea and bronchi
Definition
Smoking impairs ciliary motility and increases mucus production in the trachea, bronchi. Goblet cells can be found further down the bronchioles in smokers
Term
which drugs are used to relax smooth muscle during asthma attacks?
Definition
epinephrine and sympathomimetic drugs
Term
what occurs during an asthmatic attack
Definition
Mast cells in the lamina propria release histamine and other vasoactive substances in response to allergens.
Cause the constriction of smooth muscle in bronchioles
Term
what is cystic fibrosis?
Definition
Autosomal recessive disorder.
Genetic defect in Cl- channel protein which results in abnormal transport of Cl- in exocrine gland epithelium.
Results in decreased Cl- secretion and increased Na+ and water resorption.
Mucus become very thick and viscous.
Eventually bronchioles become obstructed and later bronchi.
Average lifespan is 32 years with aggressive daily therapy.
Term
what are the site for gas exchange?
Definition
alveoli
Term
how many alveoli are there in the lung?
Definition
Somewhere around 300 million alveoli in the human lung that function to dramatically increase gas exchange surface area
Term
what are alveolar ducts?
Definition
elongate airways with almost no walls, only alveoli as their peripheral boundaries
Term
what are alveolar sacs?
Definition
spaces surrounded by clusters of alveoli
Term
what are type I pneumocytes?
Definition
extremely thin, squamous cells and form 95% of the alveolar lining. They are attached to surrounding cells by tight junctions.
involved in gas exchange and cannot divide
Term
what are type II pneumocytes?
Definition
secretory cells.
cuboidal cells interspersed among the type I pneumocytes.
Although as numerous as type I cells, they only cover about 5% of the alveolar lining because of their taller stature
At the electron microscopic level, the type II cells are seen to contain lamellar bodies.
The lamellae are rich in phospholipids among which is the surface active agent surfactant.
The lamellar bodies are released into the alveolar spaces and the surfactant forms a monomolecular layer over the surface of the lining cells.
The surfactant reduces the surface tension at the air-epithelium interface.
Without surfactant, the alveoli would collapse on exhalation.
This is a problem in premature infants that haven't developed sufficiently to produce surfactant. This is called respiratory distress syndrome.
Term
what composes the air-blood barrier?
Definition
septal components and the monomolecular layer of surfactant
Term
what are the components of the alveolar septum in the air-blood barrier?
Definition
alveolar epithelial cells
the basal lamina of those cells
the basal lamina of capillary endothelial cells
endothelial cells
Term
where is the site of gas exchange between the air and the blood?
Definition
the alveolar septum
Term
at the electron microscopic level, the type II pneumocytes are seen to contain _____ _____.
Definition
lamellar bodies
Term
what is the function of the surfactant in the lamellar bodies of type II pneumocytes?
Definition
reduces the surface tension at the air-epithelium interface; forms a monomolecular layer over the surface of the lining cells
Term
what is respiratory distress syndrome?
Definition
lack of surfactant causing the alveoli to collapse on exhalation; problem in premature infants that haven't developed sufficiently to produce surfactant
Term
what is goodpasture syndrome?
Definition
Antibodies are made to type IV collagen.
Antibodies to type IV collagen can affect the basal laminae of the alveolar septae in the lungs.
Also can affect renal glomerular basal lamina.
Goodpasture syndrome is most common in males with an average age of 29
Term
what causes emphysema?
Definition
Characterized by a permanent dilation of the air spaces distal to the terminal bronchiole.
Caused by chronic obstruction of the airflow due to narrowing of the bronchioles
Term
what happens during COPD/Emphysema?
Definition
Alveolar walls are destroyed and gas exchange becomes severely impaired.
Cigarette smoking is the most common cause of emphysema although there are occupations with higher incidence of emphysema, e.g. coal miners.
One treatment for emphysema is to collapse the dilated, damaged portions of the lung to allow room within the thoracic cavity for expansion of the remaining normal lung tissue during inspiration
Term
where do alveolar macrophages function?
Definition
in the connective tissue and air spaces
Term
what do alveolar macrophages do?
Definition
scavenge the surface of the epithelium and remove inhaled particulates; often referred to as dust cells
Term
true or false: connective tissue alveolar macrophages may remain in the connective tissue for an extremely long time
Definition
true
Term
what is the destination of engorged alveolar macrophages?
Definition
engorged macrophages are carried up the respiratory tree in the mucus which is moved by the cilia in the tract; at the pharynx, they are swallowed or expectorated
Term
what happens during congestive heart failure?
Definition
the lungs become congested with blood
Red cells (erythrocytes) are forced into the alveolar spaces from damaged capillaries.
Alveolar macrophages phagocytose the red cells and contain the iron pigment, hemosiderin.
Hemosiderin-filled macrophages are often called heart failure cells
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