Superficial structures of the thorax Flashcards
Named pleura
costal, diaphragmatic, mediastinal, visceral
costal pleura
lines ribs
diaphragmatic
lines diaphragm
mediastinal pleura
lines mediastinum
visceral pleura
touches lungs
pericardium
Mediastinal parietal pleura, fibrous pericardium, parietal pericardium, visceral pericardium
surgeons pericardium
aka the pericardium: parietal pericardium, fibrous pericardium, mediastinal parietal pleura
cupula pleura
on both sides of cr mediastinum; where costal pleura reflects back and becomes mediastinal pleura; extends cr to 1st rib on R side
clinical significance cupula pleura
extends beyond 1st rib on R side so if horse injures itself here then it can -> pneumothorax
costodiaphragmatic recess
cd to basal border of lung where costal and diaphragmatic pleura rest against each other
clinical significance costal diaphragmatic recess
try to enter abdominal cavity during expiration where this space is bigger
Lobation of equine lung
less distinct than dogs but R and L cr and cd lobes and R accessory lobe around cd vc; lobes connected by CT after tracheal bifurcation at 5th rib or IC space
location of cardiac notch
divides lung lobes crly and cdly
L cardiac notch
between 3rd and 6th rib
R cardiac notch
between 3rd and 4th IC space
Line of pleural reflection
divides pleural and peritoneal cavity; represents where costal parietal pleura reflects back to become diaphragmatic parietal pleura; closely follows attachements of diaphragm
line of pleural reflection landmarsk
starts 8-9th costal cartilage, curves dorsocaudally along rib cage to 18th rib; reflects cranially to end at 17th IC space
boundaries of basal border of the lung
triangle shape
- one side dorsal along back v to epaxial muscles
- one side line drawn from olecranon to junction scapular cartilage with scapula
- 6, 11 ,16: 6th costochondral junction, middle 11th rib, dorsal extend 16th rib
where to auscult lung field in relation to basal border of lung
3-4cm cr to this line
chambers of the heart
L atria, L ventricle, R atria, R ventricle; separated by AV valves
papillary muscles
muscles located in ventricles heart attach to cusps of AV valves via chord tendinae and contract preventing inversion or prolapse of these valves on systole
chordae tendinae
attach papillary muscles to AV vales
septomarginal bands
help transmit electrical signals down purkinje fibers
atrial surface of the heart
R side, subsinusosal IV groove
Subsinusosal IV groove
on atrial surface (R side) of heart; contains R coronary artery, middle cardiac vein
Auricular surface of the heart
L side; Paraconal IV groove
paraconal IV groove
on auricular surface (L side) of heart; contains L coronary artery and great cardiac vein
sternopericardiac ligament
v large in horse; anchors fibrous pericardium to sternum
Cardiac embryonic remnants
ligamentum arteriosum and fossa ovalis
ligamentum arteriosum
remnant of ductus arterioles; L recurrent laryngeal nerve wrap around ligament arteriosum
fossa ovalis
depression in R atrium of heart at level of intertribal septum (wall btwn L and R atrium); remnant of foramen ovale
abdominal cavity boundaries
cr: diaphragm
cd: pelvic inlet
dorsal: lumbar vertebrea and hypoxia muscles
ventral: rectus abdominus muscle
lateral: int and ext abd obliques and transversus abdominus
diaphragm attachments
cr extend can be up to 6th rib attachments: 1. Dorsally via crura v aspects T18- L4 2. medial aspect of ribs 9-18 3. ventrally to sternum
openings of diaphragm D -> V
- aortic hiatus (aorta, azygous vein, thoracic duct)
- Esophageal hiatus (esophagus, D vagal trunk, V vagal trunk)
- Caval foramen (cd vena cava)
4 major abdominal body wall muscles
external abdominal obiques, internal abdominal obliques, transversus abodminus, rectus abdominus
External abdominal obliques fiber direction
cd ventral
external abdominal obliques contribute to
external rectus sheath
external abdominal obliques attachments
tuber coxae, linea alba, prepubic tendon (mostly rectus but some contribution from ext abdominal oblique), lateral aspect of ribs from triceps to 18th rib
internal abdominal obliques attachnents
tuber coxae, dorsal part of inguinal ligament to last rib, costal cartilages, lines alba
internal abdominal obliques fiber direction
cr ventral
internal abdominal obliques continue to
cremaster muscle and external rectus sheath
transversus abdominus attachments
lumbar transverse process to medial surface costal cartilages and linea alba
transversus abdominus contributes to
internal rectus sheath
rectus abdominus attachments
cranially as far as rib 4 and xiphiod process to prepubic tendon
rectus abodminus fiber direction
cranially caudal
superficial inguinal ring
slit in aponeurosis of external abdominal obliques
deep inguinal ring boundaries
- Inguinal ligament= cd boundary
- Internal abdominal oblique= cd free edge of internal abdominal oblique makes boundary of deep inguinal ring
- Rectus abodminus= medial boundary
what runs through the deep inguinal ring
external pudendal ___
abdominal wall muscle innervation sensory
receive innervation from D and V branches of spinal nerves T18-L2; test sensory innervation in thoracolumbar region via cutaneous reflex utilized in neuro exam, sensory info transmitted by D branches of segmental spinal nerves
abdominal wall muscles innervation motor
lateral thoracic nerve innervates cutaneous tunci
-> cutaneous muscle contraction; LMN cell bodies in T1 and C8
prepubic tendon rupture
gives massive sagging of belly b/c loose attachment of rectus tends to happen in older mares; can -> inability to give birth w/o assistance; horse with this should not be bred again bc can’t birth foal without assistance; painful
abdominal wall hernia
can be congenital or acquired from trauma; chance of repair low in adults; painful
heave line
heaves= lung inflamation= equine asthma = issues breathing -> forced expiration with external abdominal oblique -> line where muscle and aponeurosis meet called heave line
Components of nuchal ligaments
funicular and lamellar portions
lamellar portion nuchal ligament
attached to CV; elastic fibers allow head to lower for grazing and raise with lower energy expenditure
funicular portion of nuchal ligament
2x cord of CT running dorsally, starts at ext. occipital protuberance and runs to withers caudally and continues as supraspinous ligament; helps horse support its head
supraspinous ligament
continuation of nuchal ligament form T4 to sacrum
bursae associated with nuchal ligament
cr nuchal bursa, cd nuchal bursa, supraspinous bursa; bursa formed dorsal to C1, C2, T2/T3 to minimize pressure as furnicular portion of nuchal ligament passes over bony provinces; bursa= synovial surface where ligament runs over bone; can become inflamed and infected
cr nuchal bursa
btwn nuchal ligament and C1
cd nuchal bursa
btwn funicular portion and C2
supraspinous bursa
over withers T2-T3
poll evil
cr and cd nuchal bursa inflamed/ infected
fistulous withers
supraspinous bursa inflamed/ infected
path of supraspinous ligament
before reaching withers supraspinous ligament widens at T4 and is continued on each side of midline by funiculars nuchal (yellow elastic cord which extends to skull); at withers funiculars wide and flat covering dorsal border of rhomboideus throacius; thoracolumbar fascia is thick hre
path thoracic lumbar fascia
origin is supraspinous ligament, thick around withers where it gives rise to dorsoscapular ligament from lateral surface continues to level of T1 where continued by splenius; gives off semispinalus capitis from its deep lamina
path dorsoscapular ligament
origin suprascapular ligament around withers, extends venture lateral to insert on deep surface of scapula where it interdigitates with elastic lamellae with scapular insertion serratus ventalis
clinical significance of line of pleura reflection
divides pleural and peritoneal cavities
how does the line of pleural reflection relate to the basal border of the lung
the line of pleural reflection is caudal to basal border or the lung?
intercostal nerves are
ventral branches of thoracic spinal nerves
intercostal neuromuscular bundle (vessels and nerves) location in association with each rib
follow caudal border or ribs
internal intercostal muscle fx and fiber direction
muscle of expiration; fibers run cranioventrally
external intercostal muscle fx and fiber direction
muscle of inspiration; fibers run caudoventrally