Unit 3 Anatomy

What is involved in the thoracic cage

Ribs 12 (each side)
Sternum
Thoracic Vertebrae T1-T12

Thoracic Superior Aperture

Smaller
T1
First ribs
Manubrium

Thoracic Inferior Aperture

Larger
T12
11th and 12th ribs
7-10 ribs
Xiphisternal joint

Commonalities of Intercostals

SA: Inferior border of rib above
IA: superior border of ribs below
N: intercostal nn.

3 types of intercostals

Internal
External
Innermost

Action of external intercostals

Forced inspiration; elevate ribs

Direction of external intercostal mm

Inferior and anterior

Action of internal and innermost intercostal mm.

Forced respiration
Interosseous part: depress rib
Interchondral part: elevates rib

Origin of Transversus thoracis m.

Posterior surface of inferior sternum

Insertion of transversus thoracis m.

Internal surface of ribs 2-6

Action of transversus thoracis m.

Depress rib weakly and proprioception

Innervation of transversus throacis m.

Intercostal nn.

Origin of diaphragm

Inferior internal surface of ribs, sternum and lumbar vertebrae

Insertion of diaphragm

Central tendon

Action of diaphragm

Inspiration (primarily)

Innervation of diaphragm

Phrenic n. (C3-5)

Posterior neurovasculature

Intercostal n.
Posterior intercostal a. And v.

Anterior neurovasculature

Internal thoracic a. /v.
Anterior intercostal a. And v.

Boundaries of mediastinum

Superior and Inferior

The boundary line of the superior mediastinum

Sternal angle to vertebrae of T4/T5

Inferior boundary of mediastinum

Xiphosternal junction to T9/T10

Compartments of the inferior mediastinum

ANterior: anterior to the heart
Middle: which is the heart
Posterior: posterior to the heart

Contents in the superior mediastinum anterior to posterior

1. Thymus
2. Veins
3. Arteries
4. Trachea
5. Esophagus
6. Lymphatics
And nerves

Contents of anterior mediastinum

Thymus
Lymph nodes
Fat

Contents of the middle mediastinum

Heart
Lungs
Phrenic n.

Contents of posterior mediastinum

Thoracic aorta
Thoracic duct (lymph)
Azygos and hemi-azygos veins
Esophagus
NErves

What arteries branch from thoracic aorta

Posterior intercostal aa.

Where do the lymphatics originate

Cisterna chyli

What are the lymphatics between

Esophagus and azygos v.

Where do the lymphatics empty

Into the L internal jugular and subclavian v.

Where do the lymphatics drain

Lower extremity, pelvis, abdomen, thorax, and L head and L upper extremity

Veins in the thoracic cage

Azygos v.
Left superior intercostal v. 2-4
Accessory hemi-azygos v 5-8
Hemi-azygos v. 9-12 and superior abdomen

Where does the esophagus lie

Right of aorta; posterior to pericardium

What direction does the esophagus deviate

Left

Three constrictions of esophagus

-arch of the aorta
-left main bronchus
-Diaphragm

The duck between two gooses

Azyogus v.
Thoracic duct
Esophagus

What does the sympathetic nervous system do

Prepares the body for intense physical activity

Sympathetic site of origin

Lateral horns (T1-L2)

Sympathetic relative lengths

Short pre and long post

Sympathetic location of their ganglia

Sympathetic chain and abdominal aorta

parasympathetic function

Relaxes the body and inhibits or sloes many high energy functions

Site of origin for parasympathetic

Brain stem and sacral region (S2-4)

parasympathetic relative lengths of fibers

Long pre and short post

parasympathetic location of their ganglia

Near the target organ

Nerves CN X (Vagus n.)

-Recurrent laryngeal n.
-PS for heart
-PS for lungs
-Ps for esophageal plexus

Sympathetic Chain

Greater splanchnic n.
Lesser sphanchnic n.
Least sphalnchnic n.

What is the superior border of the heart

Pulmonary trunk
Superior vena cava
Ascending aorta
R and L atrium

What is the left border of the heart

L ventricle
L auricle

What is the apex border of the heart

Left ventricle

What is the base border of the heart

R ventricle (more)
L ventricle

What is the right border of the heart

R atrium
SVC
IVC

What are the two types of pericardium in the heart

Fibrous
Serous (around the heart)

What are the two layers in the serous pericardium

Parietal layer (out)
Visceral layer (in)

External anterior features of the heart

Pulmonary trunk
Ascending aorta
SVC

What branches from the arch of the aorta

Brachiocephalic trunk a.
Left common carotid a.
Left subclavian a.

External posterior features of the heart

Arch of the aorta
SVC
R and L pulmonary a.
Left atrium
4 Pulmonary v.

Artery takes blood

Away from the heart (oxygenated)
To the heart (deoxygenated)

Is the pulmonary trunk oxygenated or deoxygenated blood

Deoxygenated

What are the great vessels

SVC
IVC
Ascending aorta (Aortic arch and 3 branches)
Pulmonary trunk

What fraction of people are right coronary artery dominant

2/3

What fraction of people are left coronary a. Dominant

1/3

What is always in the right coronary a.

AV nodal a.
Right marginal a.

What is always in the left coronary a.

Anterior interventricular a.
Circumflex a.

What varies in R and L coronary a.

SA nodal a. (60% R and 40% L)
Posterior interventricular a.

What determines dominance of coronary a.

The posterior interventricular a.

What are the 4 most important cardiac veins

Great cardiac v.
Middle cardiac v.
Small cardiac v.
Coronary sinus v.

Where does coronary sinus drain into

Right atrium

What a. Does the great cardiac v. Run with

Anterior interventricular a.

What a. Does the small cardiac v. Run with

Right marginal a.

What a. Does the middle cardiac v. Run with

Posterior interventricular a.

Right side is

Deoxygenated blood

Left side is

Oxygenated blood

Contents of the right atrium

Oval fossa
Crista terminalis
Pectinate muscles
SVC
IVC
Coronary sinus

What valve is used when blood goes from RA to RV

Tricuspid

Contents of R ventricle

Tendinous cords
Papillary muscle
Trabeculae carneae
Cusps of tricuspid valve

Valve that takes blood from RV to pulmonary trunk

Pulmonary semilunar valve

What takes the blood from pulmonary trunk to the left atrium

4 pulmonary v.
R superior
R inferior
L superior
L inferior

Contents of L atrium

Oval fossa
4 pulmonary veins
LEft auricle
Pectinate mm.

Valve that takes blood from LA to LV

Bicuspid valve (Mitral)

4 Valves of the heart

Bicuspid
Pulmonary semilunar
Tricuspid
Aortic semilunar

Contents of left ventricle

Tendinous cords
Papillary muscle
Mitral valve
Fibrous ring
Trabeculae carneae

What valve takes blood from left ventricle to ascending aorta

Aortic semilunar

Two embryonic remnants in the heart

Fossa ovales (Forament ovale)
Ligamentum arteriosum (ductus arteriosus)

Results of both embryonic remnants not closing

Mixing of oxygenated and deoxygenated blood

Ligamentum arteriosum tearing is

Deadly

How is blood oxygenated for baby in uterus

Placenta

Two ways the blood is oxygenated to bypass the use of lungs

Foramen ovale
Ductus venosus

Is R or L primary bronchi longer

L

Hoe many lobes does the left lung have

2 Superior
Inferior
Oblique fissure on lung

How many lobes does right lung have

3 (superior, middle, and inferior)
Has horizontal and oblique fissure

Contents of L Lung

4 Grooves
-Descending aorta
-Arch of the aorta
-subclavian a.
-Cardiac impression
Pulmonary v.
LEft main bronchus
Pulmonary a.
Lingula
Hilum

Contents of R lung

4 Grooves
-Cardiac impression
-Groove for SVC
-Groove arch of azygos
-Esophageal groove
Right main bronchus
Pulmonary aa.
Pulmonary vv.
Hilum

How can you tell the difference between R and L lung medial view

R the Pulmonary a. Is anterior to bronchus
L the pulmonary a. Is superior to bronchus
RALS

External oblique m. Origin

Outer surface of lower 8 ribs

External oblique m. insertion

Linea alba; pubic crest

External oblique m. Action

Bilateral: flex the vertebral column
Unilateral: Trunk rotation
Compress abdominal wall

Recuts abdominis m. Origin

Pubic crest and symphsis

Rectus abdominis m. Action

Flex the vertebral column
Increase intra abdominal pressure

Rectus abdominis m. Insertion

Xiphoid process and ribs 5-7

Rectus abdominis m. Innervation

Intercostal nn.