Visceral Organs Flashcards
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Visceral Organs
Diaphragm
Action:
- Dome of diaphragm flattens during inspiration.
- Contraction increases vertical dimension of thoracic cavity.
Origin:
- Sternal part (not always present): xiphoid process.
- Costal part: ribs 5-10 and their costal cartilages.
- Lumbar part: Arcuate ligaments and L1-3 vertebral bodies
Insertion:
- Central tendon
Innervation:
- Phrenic nerve
Pulmonology
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Visceral Organs
Left Lung
Location:
- Pulmonary cavity (in lateral thoracic cavity)
- Surrounded by pleural cavity
Description:
- Two lobes: upper (or superior) and lower (or inferior), separated by oblique fissure
- Medial surface has hilum with airway and pulmonary vessels
- Surface of lung covered with visceral pleura
Function:
- Primary organ of respiration
Comment:
- Thoracic cavity divided into three parts: mediastinum, and right and left pulmonary cavities
Pulmonology
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Visceral Organs
Left Lung - Superior Lobe
Location:
- Left lung
Description:
- Dominates anterior surface of lung
- Dome-shaped apex posterior and superior to clavicle (in root of neck)
- Separated from inferior lobe by oblique fissure
- Receives lobar (secondary) bronchus
- Surface of lung covered with visceral pleura
Function:
- Primary organ of respiration
Comment:
- Left lung has two lobes: superior and inferior
Also known as:
- Upper lobe of left lung
Pulmonology
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Visceral Organs
Left Lung - Inferior Lobe
Location:
- Left lung
Description:
- Concave base rests on diaphragm
- Separated from superior lobe by oblique fissure
- Receives lobar (secondary) bronchus
- Surface of lung covered with visceral pleura
Function:
- Primary organ of respiration
Comment:
- Left lung has two lobes: superior and inferior
Also known as:
- Lower lobe of left lung
Pulmonology
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Visceral Organs
Left Lung - Oblique Fissure
Location:
- Left lung
Description:
- Deep, narrow cleft
- Separates superior and inferior left lobes
- Passes through hilum
Comment:
- Surface projection follows line connecting spinous process of T2 (posteriorly) with left 6th costal cartilage (anteriorly)
Pulmonology
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Visceral Organs
Left Lung - Cardiac Notch
Location:
- Left lung (upper lobe)
Description:
- Anterior, indented region of upper lobe
- Adjacent to left side of heart
Pulmonology
Visceral Organs
Left Lung - Lingula
Pulmonology
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Visceral Organs
Right Lung
Location:
- Pulmonary cavity (in lateral thoracic cavity).
- Surrounded by pleural cavity
Description:
- Three lobes: upper (or superior), middle, and lower (or inferior), separated by two fissures - oblique and horizontal.
- Medial surface has hilum with airway and pulmonary vessels.
- Surface of lung covered with visceral pleura.
Function:
- Primary organ of respiration
Comment:
- Thoracic cavity divided into three parts: mediastinum, and right and left pulmonary cavities.
Pulmonology
Visceral Organs
Right Lung - Superior Lobe:
Location:
- Right lung
Description:
- Dominates anterior surface of lung
- Dome-shaped apex posterior and superior to clavicle (in root of neck)
- Separated from middle lobe by horizontal fissure
- Separated from inferior lobe by oblique fissure
- Receives lobar (secondary) bronchus
- Surface of lung covered with visceral pleura
Function:
- Primary organ of respiration
Pulmonology
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Visceral Organs
Right Lung - Middle Lobe:
Location:
- Right lung
Description:
- Separated from superior lobe by horizontal fissure.
- Separated from inferior lobe by oblique fissure.
- Receives lobar (secondary) bronchus
- Surface of lung covered with visceral pleura.
Function:
- Primary organ of respiration
Comment:
- Right lung has three lobes: superior, middle, and inferior.
Pulmonology
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Visceral Organs
Right Lung - Inferior Lobe:
Location:
- Right lung
Description:
- Concave base rests on diaphragm
- Separated from middle lobe and superior lobe by oblique fissure
- Receives lobar (secondary) bronchus
- Surface of lung covered with visceral pleura
Function:
- Primary organ of respiration
Comment:
- Right lung has three lobes: superior, middle, and inferior
- Also known as:
- Lower lobe of right lung
Pulmonology
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Visceral Organs
Right Lung - Oblique Fissure:
Location:
- Right lung
Description:
- Deep, narrow cleft
- Separates superior from inferior lobe
- Separates middle from inferior lobe
- Passes through hilum
Comment:
- Surface projection follows line connecting spinous process of T2 (posteriorly) with left 6th costal cartilage (anteriorly).
- Joined by horizontal fissure at midaxillary line.
Pulmonology
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Visceral Organs
Right Lung - Horizontal Fissure:
Location:
- Right lung
Description:
- Short, deep cleft
- Separates superior and middle right lobes
- Joins oblique fissure laterally (at midaxillary line)
- Surface projection: right 4th rib and costal cartilage
Pulmonology
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Visceral Organs
Regions (Both Lungs) - Apex
Location:
- Right and left lung
Description:
- The blunt region that is most superior aspect of the right and left lungs
- The apex is superior to rib 1
- The apex is covered superiorly by cervical pleura (pleural cupola)
Pulmonology
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Visceral Organs
Regions (Both Lungs) - Base:
Pulmonology
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Visceral Organs
Regions (Both Lungs) - Costal Surface
Pulmonology
Visceral Organs
Regions (Both Lungs) - Mediastinal Surface:
Pulmonology
Visceral Organs
Regions (Both Lungs) - Diaphragmatic Surface
Pulmonology
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Visceral Organs
Pleura - Parietal Pleura:
Location:
Thorax
Description:
- Thin, serous membrane
- Lines pulmonary cavity
- Fused to internal walls of thoracic cavity and lateral surface of mediastinum.
- Continuous with visceral pleura at root of lung.
- Regions include mediastinal, cervical, diaphragmatic, and costal.
Comment:
- Pleural cavity created by narrow space between parietal and visceral layers of pleura
- Thorax has three subdivisions: mediastinum and right and left pulmonary cavities
- Costal and peripheral diaphragmatic pleura innervated by intercostal nerves.
Pulmonology
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Visceral Organs
Pleura - Visceral Pleura
Location:
- Thoracic cavity
Description:
- Thin, serous membrane.
- Fused to surface of lung.
- Continuous with parietal pleura at root of lung.
- Separated from parietal pleura by pleural cavity.
Comment:
- Thoracic cavity divided into midline mediastinum and right and left pulmonary cavities.
Pulmonology
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Visceral Organs
Trachea
Location:
- Neck
- Thoracic cavity (mediastinum)
- Between larynx and tracheal bifurcation
Description:
- Rigid tube held open by a series of “C-shaped” cartilaginous rings (open end of rings directed posteriorly)
- Cartilaginous rings connected by anular ligaments of trachea
- Posterior aspect of tracheal rings closed by fibroelastic trachealis muscle
Also known as:
- “Windpipe”
Comment:
- Tracheotomy is surgical procedure to open trachea in neck to bypass an airway obstruction
Pulmonology
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Visceral Organs
Trachea - Left Main Bronchi
Location:
- Thorax
Description:
- Formed at bifurcation of trachea
- Longer, more narrow, and less vertical than right main bronchus
- Component of root and hilum of left lung
Also known as:
- Left primary bronchus
Comment:
- Foreign bodies that enter trachea tend to pass to right main bronchus
Pulmonology
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Visceral Organs
Trachea - Right Main Bronchi
Location:
- Thorax
Description:
- Formed at bifurcation of trachea
- Shorter, wider, and more vertical than left main bronchus
- Component of root and hilum of right lung
Also known as:
- Right primary bronchus
Comment:
- Foreign bodies that enter trachea tend to pass to right main bronchus
Pulmonology
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Visceral Organs
Right Atrium
Location:
Heart
Description:
- One of four heart chambers
- Thin, smooth, posterior wall
- Thin, rough anterior wall (pectinate muscles)
- Receives superior and inferior venae cavae and coronary sinus
- Internal features include interatrial septum, fossa ovalis, and crista terminalis
Comment:
- Forms right surface of heart
- Separated from right ventricle by atrioventricular (tricuspid) valve.
Cardiology
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Visceral Organs
Right Atrium - Opening for Coronary Sinus
Drainage:
- Receives venous blood from heart
Tributaries:
- Great, middle, and small cardiac veins
Course:
- Passes from left to right in posterior portion of coronary (atrioventricular) sulcus
Termination:
- Right atrium
Cardiology
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Visceral Organs
Right Ventricle
Location:
- Heart
Description:
- One of four heart chambers
- Rough, muscular walls (trabeculae carneae).
- Muscle wall thicker than either atrium, and thinner than left ventricle.
- Internal features include papillary muscles, chordae tendineae, interventricular septum, and conus arteriosus.
Comment:
- Separated from right atrium by atrioventricular (tricuspid) valve.
- Separated from pulmonary trunk by pulmonary valve.
- Responsible for pumping oxygen-poor blood to lungs.
Cardiology
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Visceral Organs
Right Atrioventricular Valve
Location:
- Heart (between right atrium and right ventricle).
Description:
- Valve with three cusps
- Chordae tendineae attach free edges of cusps to papillary muscles
Also known as:
- Tricuspid valve
Comment:
- Valve is open during ventricular diastole
Cardiology
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Visceral Organs
Tricuspid Valve - Cusps (Anterior, Posterior, and Septal)
Cardiology
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Visceral Organs
Chordae Tendonae
Cardiology
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Visceral Organs
Papillary Muscle - (Anterior, Posterior, and Septal):
Location:
Heart ventricles
Description:
- Conical elevations of myocardium in ventricular chambers.
- Chordae tendineae attached to apex
A type of trabeculae carneae.
Function:
- Regulates movement of atrioventricular valve cusps
Helps assure proper closure of atrioventricular valves
Comment:
Right ventricle has three, left ventricle has two (number corresponds to number of respective atrioventricular valve cusps)
Cardiology
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Visceral Organs
Trabecula Carnae:
Location:
- Heart ventricles
Description:
- Irregular, muscular elevations on internal surface of both ventricles.
Comment:
- Absent in aortic vestibule and conus arteriosus.
- Papillary muscles are a type of trabeculae carneae.
Cardiology
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Visceral Organs
Left Atrium
Location:
- Heart
Description:
- One of four heart chambers
- Thin, smooth wall
- Receives four pulmonary veins
- Internal features include interatrial septum.
Comment:
- Forms most of base of heart
Separated from left ventricle by left atrioventricular (bicuspid or mitral) valve
Only its auricle seen in anterior view of heart.
Cardiology
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Visceral Organs
Left Auricle:
Location:
- Heart
Description:
- Small, conical, pouch-like extension of left atrium.
- Thin, rough wall (pectinate muscles).
Comment:
- Only portion of left atrium seen in anterior view of heart.
- Latin: auricula = small ear
Cardiology
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Visceral Organs
Left Ventricle
Location:
- Heart
Description:
- One of four heart chambers
- Thick, muscular walls
- Internal features include papillary muscles, chordae tendineae, trabeculae carneae, interventricular septum, and aortic vestibule.
Comment:
- Separated from left atrium by left atrioventricular (bicuspid or mitral) valve
- Separated from aorta by aortic valve
- Walls twice as thick as right ventricle
- Forms apex of heart
- Responsible for pumping oxygen-rich blood to body (except lungs)
Cardiology
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Visceral Organs
Bicuspid (Mitral) Valve -
Location:
- Heart
Description:
- Valve with two cusps between left atrium and ventricle.
- Chordae tendineae attach free edges of cusps to papillary muscles.
Function:
- Prevents reflux of blood into left atrium
- Also known as: Bicuspid or mitral valve (shaped like a hat (miter) of a Roman Catholic Bishop).
Comment:
- Valve is open during ventricular diastole.
Cardiology
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Visceral Organs
Aortic Valve
Location:
- Heart
- At junction of left ventricle (aortic vestibule) and ascending aorta
Description:
- Valve with three semilunar cusps
Function:
Prevents reflux of blood into left ventricle.
Comment:
- Valve closed during ventricular diastole.
- Coronary arteries branch from ascending aorta just distal to aortic valve.
Cardiology
Visceral Organs
Regions - Apex
Cardiology
Visceral Organs
Regions - Base
Cardiology
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Visceral Organs
Ascending Aorta
Origin:
- Left ventricle (aortic vestibule)
Course:
- Ascends short distance (approx. 5 cm) within pericardium
- Distribution:
- Heart (via coronary arteries)
Branches:
- Right and left coronary arteries
- Continues as arch of aorta
Comment:
- Has aortic valve at origin
- Large arteries do not by themselves supply structures, but do so through their branches
Angiology
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Visceral Organs
Right Coronary A.
Origin:
- Ascending aorta
Course:
- Passes between pulmonary trunk and right auricle
- Lies in coronary (atrioventricular) sulcus
Distribution:
- Right atrium
- Right ventricle
- Interventricular septum
- Left ventricle
Branches:
- Right atrial
- Right marginal
- Posterior interventricular
Comment:
- Large arteries do not by themselves supply structures, but do so through their branches.
Angiology
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Visceral Organs
Posterior Interventricular A.
Origin:
- Right coronary artery
Course:
- Courses through posterior interventricular sulcus
Distribution:
- Left ventricle
- Right ventricle
- Interventricular septum
Comment:
- Accompanies middle cardiac vein in posterior interventricular sulcus.
- Right dominant heart: Posterior interventricular artery derived from right coronary artery (80%).
- Left dominant heart: Posterior interventricular artery derived from circumflex branch of left coronary artery (20%)
Angiology
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Visceral Organs
Left Coronary A.
Angiology
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Visceral Organs
Circumflex Branch
Origin:
- Left coronary
Course:
- Passes from anterior to posterior surface of heart in left portion of coronary sulcus
Distribution:
- Left atrium
- Left ventricle
Branches:
- Left marginal
- May continue as posterior interventricular branch
Angiology
Visceral Organs
Aortic Arch
Origin:
- Ascending aorta
Course:
- Arches diagonally and posteriorly to the left
Distribution:
- Head, including brain
- Neck
- Upper extremities
Branches:
- Brachiocephalic trunk
- Left common carotid
- Left subclavian
- Continues as descending (thoracic) aorta
Comment:
- Ligamentum arteriosum attached to concave surface of arch
- Large arteries do not by themselves supply structures, but do so through their branches
Angiology
Visceral Organs
Brachiocephalic Trunk
Angiology
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Visceral Organs
Common Carotid A.
Origin:
- Right: brachiocephalic trunk from arch of aorta
- Left: arch of aorta
Course:
- Exits thorax and ascends in neck
Distribution:
- Structures of head and neck
Branches:
- Internal and external carotid arteries (at level of C4 vertebra)
Comment:
- Has no branches before terminal branches
- Enclosed in carotid sheath
- Carotid sheath is a fascial sleeve which contains common and internal carotid arteries, internal jugular vein, vagus nerve (CN X), and lymphatic channels
- Large arteries do not by themselves supply structures, but do so through their branches
Angiology
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Visceral Organs
Subclavian A.
Origin:
- Right: brachiocephalic trunk from arch of aorta
- Left: arch of aorta
Course:
- Arches over rib 1
Branches:
- Vertebral
- Internal thoracic
- Costocervical trunk
- Thyrocervical trunk
- Suprascapular (sometimes)
- Continues as axillary artery at lateral border of rib 1
Comment:
- Large arteries do not by themselves supply structures, but do so through their branches
Angiology
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Visceral Organs
Pulmonary Trunk
Origin:
- Right ventricle
Course:
- Ascends within pericardium
- Initially anterior to ascending aorta and then to its left and slightly posterior.
Distribution:
- Lungs
Branches:
- Right pulmonary artery
- Left pulmonary artery
Comment:
- Conveys oxygen-poor blood from right ventricle of heart
- Has pulmonary (semilunar) valve at its origin
- Large arteries do not by themselves supply structures, but do so through their branches
Angiology
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Visceral Organs
Right and Left Pulmonary A.
Origin:
- Pulmonary trunk
Course:
- Left: laterally, inferior to arch of aorta and anterior to left main bronchus.
- Right: laterally, posterior to ascending aorta and superior vena cava.
- Through root and hilum of respective lungs
Distribution:
- Lung
Branches:
- Lobar arteries to lung lobes
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Angiology
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Visceral Organs
Right and Left Pulmonary V.
(L) Drainage:
- Lungs
Tributaries:
- Lobar veins
Course:
- Two veins pass through root of each lung (i.e., four pulmonary veins in total) and directly into left atrium
Termination:
- Left atrium
Comment:
- Carry oxygen-rich blood
(R) Drainage:
- Lungs
Tributaries:
- Lobar veins
Course:
- Two veins pass through root of each lung (i.e., four pulmonary veins in total) and directly into left atrium
Termination:
- Left atrium
Comment:
- Carry oxygen-rich blood
Angiology
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Visceral Organs
Coronary Sinus
Drainage:
- Receives venous blood from heart
Tributaries:
- Great, middle, and small cardiac veins
Course:
- Passes from left to right in posterior portion of coronary (atrioventricular) sulcus.
Termination:
- Right atrium
Angiology
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Visceral Organs
Great Cardiac V.
Drainage:
- Left atrium
- Left ventricle
- Right ventricle
Course:
- Ascends in anterior interventricular sulcus
- Enters coronary sulcus
Termination:
- Coronary sinus
Also known as:
- Anterior interventricular vein
Comment:
- Companion to anterior interventricular artery
Angiology
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Visceral Organs
Middle Cardiac V.
Drainage:
- Right ventricle
- Left ventricle
Course:
- Ascends in posterior interventricular sulcus from apex of heart
Termination:
- Coronary sinus
Also known as:
- Posterior interventricular vein
Comment:
- Companion to posterior interventricular artery
Angiology
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Visceral Organs
Superior Vena Cava:
Drainage:
- Head
- Upper limbs
- Posterior thoracic walls
- Mediastinal structures
- Tributaries:
- Formed by union of right and left brachiocephalic veins
- Arch of azygos vein
Course:
- Descends in mediastinum from level of right 1st costal cartilage.
Termination:
- Right atrium
Angiology
Visceral Organs
Brachiocephalic V.
Drainage:
- Head and neck
- Upper limb
- Tributaries:
- Internal jugular
- Subclavian
Course:
- Left: descends obliquely to the right from junction of internal jugular and subclavian veins, posterior to manubrium it crosses midline.
- Right: descends vertically from junction of internal jugular and subclavian veins; it does not cross midline.
Termination:
- Superior vena cava
Also known as:
- Innominate veins (Latin: innominatus = nameless)
Comment:
- Lacks valves
Angiology
Visceral Organs
Internal Juglar V.
Drainage:
- Cranial cavity, including brain
- Face
- Neck
Tributaries:
- Sigmoid sinus
- Inferior petrosal sinus
- Facial
- Lingual
- Pharyngeal
- Superior and middle thyroid
Course:
- Formed in jugular foramen of skull
- Descends through neck in carotid sheath
- Enters thorax
- Termination:
- Posterior to sternum unites with subclavian vein to form brachiocephalic vein.
Comment:
- Enclosed in carotid sheath
- Carotid sheath is fascial sleeve containing common and internal carotid arteries, internal jugular vein, vagus nerve (CN X), and lymphatic channels
Angiology
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Visceral Organs
Subclavian V.
Drainage:
- Upper limb
- Superficial back and neck
- Tributaries:
- Continuation of axillary
- External jugular
- Dorsal scapular
- Anterior jugular (sometimes)
- Thoracic duct (left side only)
- Right lymphatic duct (right side only)
Course:
- Begins at lateral border of rib 1
- Arches over rib 1 to enter thoracic cavity
- Termination:
- Joins internal jugular vein posterior to sternum to form brachiocephalic vein
Angiology
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Visceral Organs
Inferior Vena Cava
Drainage:
- Everything inferior to diaphragm, except posterior abdominal wall, which drains into azygos system
Tributaries:
- Common iliac
- Lumbar
- Right testicular/ovarian
- Renal
- Right suprarenal
- Inferior phrenic
- Hepatic
Course:
- Ascends from level of L4 vertebral body, through diaphragm, to heart
Termination:
- Right atrium of heart
Comment:
- Largest vein of body
Angiology
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Visceral Organs
Submandibular gland
Location:
- Neck (inferior to body of mandible)
- Head (medial to body of mandible)
- Description:
- “C” shaped salivary gland (around posterior edge of mylohyoid muscle)
- Has capsule
- Has superficial and deep parts
- Has single duct
Function:
- Produces and secretes components of saliva
- Produces 60-70% of saliva
Comment:
- Serous (primarily) and mucous secretions/
- Functions of saliva include: moistening and lubrication of food before swallowing; secretion of amylase for initial digestion of polysaccharides; dissolving some food molecules to aid in taste; and secretion of lysozyme, which has antibacterial activity.
- Three major, paired salivary glands: parotid, submandibular, and sublingual.
Gastroenterology
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Visceral Organs
Esophagus
Location:
- Cervical part: neck (inferior)
- Thoracic part: thorax (posterior mediastinum)
- Abdominal part: abdomen (left upper quadrant)
Description:
- Muscular tube
- Superior third: striated muscle
- Middle third: striated and smooth muscle
- Inferior third: smooth muscle
- Passes through diaphragm (esophageal hiatus)
Function:
- Conveys food from pharynx to stomach
- Peristaltic (wave-like) contractions during swallowing
Comment:
- “Heartburn” (reflux esophagitis) results from regurgitation of stomach contents
Gastroenterology
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Visceral Organs
Liver
Location:
- Abdomen
- Immediately inferior to diaphragm
- In upper abdominal quadrants; in epigastric and right hypochondriac regions.
Description:
- Accessory digestive organ
- Four lobes: right, left, quadrate, and caudate
- Largest visceral organ
- Suspended from diaphragm by peritoneum
Function:
- Produces and secretes bile and plasma proteins
- Stores glycogen, minerals, and vitamins
- Detoxifies drugs and alcohol
- Modifies hormones
- Removes (phagocytizes) bacteria
Comment:
- Adult liver typically does not project inferior to costal margin
- Alcoholism, drug abuse, and liver disease can lead to destruction of hepatocytes (liver cells) resulting in cirrhosis
Gastroenterology
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Visceral Organs
Gallbladder
Location:
- Abdomen (right upper quadrant)
- Inferior to liver in shallow fossa on quadrate lobe
- In right upper abdominal quadrant; in epigastric and right hypochondriac regions
Description:
- Pear shaped, hollow, muscular organ
- Cystic duct connects to neck of gallbladder
- Function:
- Storage, concentration, and release of bile
Comment:
- Bile passes from the liver to gallbladder for storage and from the gallbladder to the duodenum for emulsification and digestion of lipids
- Precipitation of bile salts or cholesterol forms gallstones (cholelithiasis)
Gastroenterology
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Visceral Organs
Abdominal Aorta
Origin:
- Thoracic aorta
- Course:
- Parallels vertebral column, slightly left of midline
- Divides into common iliac arteries on body of L4 vertebra
Distribution:
- Abdominal and pelvic viscera
- Walls of abdomen and pelvis
- Ovaries and testis
Branches:
- Celiac
- Superior mesenteric
- Inferior mesenteric
- Middle suprarenal
- Renal
- Gonadal
- Inferior phrenic
- Lumbar
- Median sacral
- Continues as right and left common iliac
Gastroenterology
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Visceral Organs
Stomach
Location:
- Abdomen
- In upper abdominal quadrants; in epigastric and left hypochondriac regions
Description:
- Hollow, muscular organ
- Characteristic “J” shape
- Four parts (proximal to distal): cardia, fundus, body, and pyloric part
- Between esophagus and duodenum
Function:
- Initiates digestion of protein
- Mixes gastric contents
- Peristaltic contractions move contents toward pyloric sphincter
Comment:
- Concave superior border forms lesser curvature
- Convex inferior border forms greater curvature
- Pyloric part of stomach includes an antrum, canal, and pylorus (the latter includes a sphincter and orifice)
Gastroenterology
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Visceral Organs
Spleen
Location:
- Abdomen
- In contact with diaphragm and lower ribs on left
- In left upper abdominal quadrant; in left hypochondriac region
Description:
- Largest lymphatic organ
- Highly vascular tissue surrounded by capsule
Function:
- Initiates immune response to blood antigens
- Reservoir for red and white blood cells
- Phagocytoses (removes) old and damaged blood cells and bacteria and other foreign material
Comment:
- Protected posteriorly by rib cage
- Spleen monitors blood for antigens whereas lymph nodes monitor lymph
Gastroenterology
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Visceral Organs
Duodenum
Location:
- Abdomen (right upper quadrant)
- Between pylorus of stomach and jejunum
Description:
- “C-shaped” with concavity directed toward left
- First and shortest part (25 cm) of small intestine
- Adjacent to head of pancreas
- Four parts (proximal to distal): superior (first), descending (second), horizontal (third), and ascending (fourth)
Function:
- Receives ingested material (chyme) from stomach
- Bile and pancreatic juices enter second part
- Carbohydrate, protein, and lipid digestion
- Absorbs nutrients
- Peristaltic contractions move contents toward jejunum.
Gastroenterology
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Visceral Organs
Jejunum
Location:
- Abdomen
- Between duodenum (proximal) and ileum (distal)
Description:
- Jejunum (2.5 meters in length): second part of small intestine.
Function:
- Chemical digestion and nutrient absorption
Comment:
- Jejunum makes up two-fifths of small intestine; ileum makes up three-fifths of small intestine
Gastroenterology
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Visceral Organs
Ileum
Location:
- Abdomen
- Between jejunum (proximal) and cecum (distal)
- Pelvis
Description:
- Third (terminal) part of small intestine
- 3.5 meters in length
- Wall contains abundant Peyer’s patches (lymphoid nodules)
Function:
- Final stages of nutrient absorption
- Protection against microorganisms (Peyer’s patches)
Gastroenterology
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Visceral Organs
Cecum
Location:
- Large intestine
- In right lower abdominal quadrant; in right inguinal region
Description:
- Portion of large intestine on right side
- Pouch (“blind-ended” sac) inferior to ileocecal junction
- Approximately 6 cm in length
- Continuous with vermiform appendix (inferior) and ascending colon (superior)
Function:
- Water and electrolyte absorption
- Absorption of vitamin B and vitamin K produced by bacteria in colon (normal gut flora)
Comment:
- Latin: cecum = blind
Gastroenterology
?
Visceral Organs
Ascending Colon
Location:
- Abdomen (right upper and lower quadrants)
- Between cecum (inferior) and transverse colon (superior)
Description:
- Portion of large intestine on right side
Approximately 15 cm in length
Function:
- Water and electrolyte absorption
- Absorption of vitamin B and vitamin K produced by bacteria in colon (normal gut flora)
Gastroenterology
?
Visceral Organs
Transverse Colon
Location:
- Abdomen
- Between ascending colon at right colic flexure (proximal) and descending colon at left colic flexure (distal)
Description:
- Part of large intestine
- Variable in length; usually approximately 50 cm in length
- Passes horizontally across abdominal cavity
- Suspended from posterior abdominal wall by transverse mesocolon
Function:
- Water and electrolyte absorption
- Absorption of vitamin B and vitamin K produced by bacteria in colon (normal gut flora)
- Store feces
Comment:
- Most mobile part of large intestine
Gastroenterology
?
Visceral Organs
Descending Colon
Location:
- Abdomen (left upper and lower quadrants)
- Between transverse colon (superior) and sigmoid colon (inferior)
Description:
- Portion of large intestine on left side
- Approximately 25 cm in length
Function:
- Water and electrolyte absorption
- Absorption of vitamin B and vitamin K produced by bacteria in colon (normal gut flora)
Gastroenterology
?
Visceral Organs
Sigmoid Colon
Location:
- Pelvis
- Begins in left iliac fossa
- Ends at S3 vertebra (sacrum)
Description:
- Part of large intestine
- Characteristic “S”-shape
- Continuous with descending colon (superior) and rectum (inferior)
Function:
- Water and electrolyte absorption
- Storage of feces
Gastroenterology
?
Visceral Organs
Appendix
Gastroenterology
?
Visceral Organs
Thyroid Gland
Location:
- Neck (anterior inferior)
Description:
- Bilobed endocrine gland
- Normally composed of left and right lateral lobes connected across midline by isthmus of gland.
- An additional, superiorly-directed, conical pyramidal lobe present 50% of the time.
Function:
- Follicular cells: synthesize and secrete thyroid hormones T3 (triiodothyronine) and T4 (thyroxine).
- Parafollicular cells: synthesize and secrete calcitonin.
Other Structures
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Visceral Organs
Kidney
Location:
- Abdomen (posterior wall)
- Retroperitoneal
- Left kidney higher than right
Description:
- Paired, bean-shaped organ
- Concave, medial border is point of entrance/exit of renal vessels and ureter
- Contains cortex, medulla, and renal sinus
Function:
- Removes excess water, electrolytes, and wastes of protein metabolism from blood.
- Urine formation
- Synthesizes calcitrol, a form of vitamin D, which stimulates uptake of calcium and phosphate by intestinal cells.
- Releases erythropoietin (EPO) in response to low blood oxygen (EPO causes increased production and maturation of erythrocytes).
- Produces renin, an enzyme that helps form angiotensin II, a hormone involved in blood pressure regulation and water (fluid) balance.
Comment:
- Surrounded and supported by layers of connective tissue and fat.
Other Structures
?
Visceral Organs
Renal a.
Origin:
- Abdominal aorta
Course:
- Passes laterally to enter kidney
- Distribution:
- Kidney
- Ureter (upper part)
- Suprarenal gland
Branches:
- Four or five branches near hilum of kidney.
Comment:
- Right renal artery longer than left renal artery.
Other Structures
?
Visceral Organs
Renal vein
Drainage:
- Kidney
- Ureter (upper part)
- Suprarenal (adrenal) gland (left side only)
- Gonad (left side only)
Tributaries:
- Gonadal vein (left side only)
- Suprarenal vein (left side only)
Course:
- Passes medially from kidney
- Anterior to renal arteries
- Termination:
- Inferior vena cava
Comment:
- Left renal vein three times longer than right.
Other Structures
?
Visceral Organs
Ureter
Location:
- Abdominal cavity (posterior abdominal wall)
- Lateral pelvis
- Description:
- Muscular tube
- 25-30 cm in length
- Begins at hilum of kidney
- Enters base of urinary bladder as ureteric orifice
Function:
- Transport urine from kidney to urinary bladder
Comment:
- Lies anterior to bifurcation of common iliac artery
- In female: passes inferior to uterine artery
- In male: crossed by vas deferens
Flow of urine from kidney:
- collecting duct >
- renal papilla >
- minor calyx >
- major calyx >
- renal pelvis >
- ureter >
- urinary bladder >
- urethra
Other Structures
