Disection Lab Flashcards
Functional Groups for muscles of thoracic body wall
Epaxial, Extrinsic Forelimb Muscles, muscles of ventilation
Epaxial muscles
Dorsal to transverse process of vertebrae, function to extend vertebral column and help support weight three columns of epaxial muscles lateral iliocostalis system, the intermediate longissimus system, and the medial transversospinalis system
Extrinsic forelimb muscles
Extend from one attachment along the axial skeleton to another attachment on the bone of the forelimb generally the scapula or humorous. Move limb relative to body or body relative to limb. Ex. Latissimus dorsi, superficial pec, deep pec, serratus ventral is.
Muscles that form muscular sling supporting the trunk
Superfical and deep pectoral muscles, latissimus dorsi, and serratus ventralis
Coastal Arch
Costal cartilages of 10 11 12th ribs
Xiphoid Process
The last sternebrea flattened dorsoventrally, caudal end continued by thin plate, xiphoid cartilage
Cutaneous turnci muscle
Cutaneous muscles of the neck, thorax, and abdomen The most supperfical muscle of thoracic body wall. Innervation by lateral thoracic nerve (C8,T1) Responsible for making skin twitch
Latissimus Dorsi
Extrinsic limb muscle Digging muscle Lies deep to cutaneous turn I Runs from transverse process of lumbar vertebrea and thoracolumbar fascia to teres major tuberosity of humorous. Innervation- thoracodorsal nerve (C7,C8,T1) Direction-Caudodorsal
Superfical pectoral muscle
Lie on cranial part of sternum and humorous under skin Descending pectoral- smaller, superfical to transverse pectoral Transverse pectoral- arises from first 2 or 3 sternebrea inserts on crest of greater tubercle of humorous, related on deep surface to deep pectoral muscle Origin- first 2 sternebrea, usually part of the third; the fiber opus rap he between adjacent muscles Insertion- whole crest greater tubercle of humorous Action- adduct limb when not weight bearing, prevent adduct on of limb when weight bearing Innervation- Ventral branch of spinal nerves c7 and c8 Direction- medial- lateral
Deep pectoral muscle
Extrinsic limb muscle Originates from the sternum Inserts into lesser tubercle of humorous and on greater tubercle of humorous via aponeurosis Innervation- Caudal pectoral nerves C8 T1 Direction- Caudoventral
Serratus Ventralis
Fan Shapped, acts as sling to depress scapula and support trunk. Originates from transverse process of cervical vertebrea and from lateral aspects of ventral half of first 7-8 ribs. Attaches to dorsomedial one-third of scapula Innervation- Ventral branches of cervical spinal nerves and long thoracic nerve (C7) Direction- caudodorsal
Muscles of ventilation thorax
Scalenus, internal and external intercostal muscles, rectus abdominus, external abdominal oblique
Trapezius
Extrinsic limb muscle Thoracic and cervicle parts Runs from supraspinous ligament and median raphe of neck to spine of scapula Thoracic part is superfical to dorsal portion of lat dorsi Innervation by accessory spinal nerve (Cranial nerve XI)
External abdominal oblique
Originates from last 6 or 7 ribs Terminates at lineal alba and pubic tendon Function: Maintain integrity of abdominal wall and as muscle of expiration Direction- Caudoventrally Medial crus attaches to lineal alba, smaller lateral crus attaches to pelvic brim; Attach by 2 aponeurotic crura the space between the 2 crura forms superfical inguinal ring (Exit of inguinal canal)
Superfical inguinal ring
Aponeurotic crura of external abdominal obliques form this Medial crus attaches to lineal alba Smaller lateral crus attaches to pelvic brim These two crura form exit of inguinal canal ie superfical inguinal ring Vaginal process (outpocketing of peritoneum) leaves abdomen through inguinal canal in female
Internal abdominal oblique
Arises with external abdominal oblique from thoracolubar facia caudal to last rib Attach to lineal alba via aponeurosis, this aponeurosis will join that of external abdominal oblique to for external laminate of rectus sheath Direction: Cranioventral
Rectus Sheath
External lamina Formed by the aponeurosis attaching internal abdominal oblique to linea alba and aponeurosis of external abdominal oblique
Linea Alba
FIberous cord formed by the midline fusion of the aponeurosis of muscles of abdominal wall. Runs from xiphoid cartilage to carnival end of pelvic symphysis Surgical land mark for ventral midline entry into peritoneal canal
Abdominal body wall innervation
Innervation by caudal intercostal nerves and ventral branches of lumbar spinal nerves.
Blood Supply of abdominal wall
Cranial epicanthic artery Cranial abdominal artery, Caudal epigastric artery, deep circumflex iliac artery
Cranial Epigastric artery
From internal thoracic artery, branch of subclavian artery
Cranial abdominal artery
From common cranial abdominal/ Caudal phrenic trunk, A branch from the aorta
Deep circumflex iliac artery
From the aorta
Rhomboideus
Extrinsic limb muscles, 3 parts names according to osseous attachments Rhomboideus thorasicus- attaches to spinous process of first 7 thoracic vertebrea Rhomboideus cervicus- attaches to median raphe of the neck Rhomboideus capitals- attaches to nucal crest of occipital bone All three parts insert along dorsal border of scapula
Serratus dorsalis
Has cranial and Caudal parts Serratus dorsalis cranialis Muscle of inspiration that arises by aponeurosis from thoracolumbar fascia Insert on craniolateral surfaces of ribs Direction- Caudoventral Serratus dorsalis Caudal is Originates from aponeurosis of thoracolumbar fascia Fibers run in cranioventral direction Insert on caudal boarder of last three ribs Function- Draws last 3 ribs caudally during expiration
Rectus abdominis
Has distinct tendinous intersection that runs transversely. Attaches by aponeurosis to first few ribs and to sternum Attaches caudally to pelvic brim to form pubic tendon In abdominal region covered superficially by external laminitis of rectus sheath (which is formed by aponeuroses of external and internal abdominal obliques) Covered on deep surface by aponeuroses of transvese abdominus Direction- Cranial Caudal
Transverse abdominus
Attaches to medial surface of last few ribs and transverse process of lumbar vertebrea Fibers run transversely to attach by aponeuroses to linea alba Aponeurosis of transverse abdominus forms internal lamina of rectus sheath in abdominal region. In pubic region aponeurosis becomes superficial to the rectus
Three main surgical approaches to peritoneal cavity
Ventrally through linea alba, laterally through flank incision, over inguinal rings
Surgical approach via linea alba
Cuts no muscle fibers only aponeurosis, easier to put back together b/c strength of connective tissue vs frailty of muscle fibers
Flank incision
usually for large animals Ideally through grid incisions Caudoventral through external abdominal oblique Cranioventral through internal abdominal oblique Transversely through transversus abdominous
Incision over inguinal ring
Done to find cryptorchid testicle
Epaxial muscles
In cervical, thoracic, and lumbar regions these lie between transverse and spinous process of adjacent vertebrea. Function- important in motion and weight bearing Most lateral (and ventral) system is iliocostalis, intermediate is longissimus, most medial and dorsal is transversospinalis
Splenius
Supperfical epaxial muscle in neck region Muscle is deep to the trapezius, rhomboideus capitis, and serratus dorsalis cranialis. Superfical to semispinalis capitis Attaches caudally in region of third thoracic vertebrea and rostrally in occipitomastoid region of skull
Longissimus thoracis et lumborum
Superfical epaxial muscle. Originates in ilium Iliocostalis and longissimus are fused in lumbar region Craniocaudal direction Muscles are covered by thick thoracolumbar fascia
Visceral (pulmonary) Pleura
Serous membrane that intimately covers the surface of each lung in the mediastinum
Parietal pleura
Serous membrane that lines the internal surface of the thoracic cavity Includes Costal parietal pleura, diaphragmatic parietal pleura, and mediastinal parietal pleura
Costal parietal pleura
Lines the thoracic wall along the ribs
Diaphragmatic parietal pleura
Covers the thoracic surface of the diaphragm
Mediastinal parietal pleura
Forms the walls of the mediastinum (the central compartment between the two pleural cavities)
Structures in the mediastinum
Cranial vena cava, caudal vena cava, thymus, aorta, azygous vein, esophogous, trachea, heart, phrenic nerves
Phrenic nerve
Runs from the thoracic inlet to the diaphragm, which it innervates (runs from c5,c6,c7). Runs ventral to the hills of the lung Primarily made of somatic efferent axons arising from cervical spinal chord segments providing voluntary motor innervation to the diaphragm NOT PART OF THE AUTONOMIC NERVOUS SYSTEM
Plica venae cava
Serous membrane fold of the medistinal pleura surrounding the caudal vena cava
Pulmonary ligament
Double fold of connecting pleura that holds the caudal left lung lobe in place, making it harder to move than its cranial counter part. Runs between the caudal lobe of the lung and the mediastinum at the level of the esophagus
Extrinsic thoracic limb muscles
Muscles with an attachment on the limb and another on the axial skeleton
Internal intercostal muscles
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External intercostal muscles
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Brachial plexus
Collection of nerves supplying motor and sensory innervation to the thoracic limb, located in the axillary space
Axilla
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Intercostal muscles function
Change the size of the thoracic cavity during respiration
Esophageal hiatus
Passage through diaphragm, muscle fibers of left and right crura make this. This is passage through diaphragm for esophagus and vagal trunk
Aortic hiatus
Tendenous component of crura make this up. This goes around aorta, azygous vein, and thoracic duct
Sympathetic trunk
Bundle of nerve fibers deep to the parietal pleura, ventral-lateral to bodies of thoracic vertebrea
Vagus nerve
Runs dorsal to hill us of each lung
Lung Lobation: Left
The left lung is divided into cranial and caudal lobes (cranial lobe is subdivided into cranial and caudal parts)
Lung Lobation (Right)
Cranial, middle, caudal, and accessory lobes
Cardiac notch
Right lung, 4th and 5th intercostal space. This is between cranial and middle lung lobes. Accommodates position of left ventricle of heart
Hilus
Point on an organ where structures enter and exit
Accessory lobe of lung
Part of the right lung, wraps around caudal vena cava
Peripheral autonomic system
Peripheral circuitry of autonomic circuit arranged similarly to somatic system Axons of afferent (sensory) neurons relay info about external environment or internal homeostatic states to CNS which integrates and processes info; Axons of efferent (motor) neurons then transmit info from CNS back to the body Every nerve that is grossly visible will have some sensory and some motor axons
Afferent
Sensory
Efferent
Motor
Efferent limb nervous set up
For both sympathetic and Parasympathetic the following is true: 2 neurons in a linked series Cell body of first neuron located with in CNS, axon of this neuron exists CNS travels peripheral nerve, synapses on dendritic zone or cell body of 2nd neuron continues upon peripheral course to synapse on target cell
Sympathetic system cell bodies
Cell bodies of first neurons reside in intermediate grey column of all thoracic and first 4 or 5 lumbar spinal cord segments
Parasympathetic system cell bodies
Cell bodies of first neurons located with in specific nuclei within brain stem or within intermediate grey column of sacral spinal chord segments
Thoracolumbar system
Sympathetic system
Craniosacral system
Parasympathetic system
Ansa subclavia
Discrete fiber tract connecting cervicothorasic ganglion to ventrally positioned middle cervicle Anglian. This completes a circle around the subclavian artery
Vagosympathetic trunk
FIbers of the vagus nerve and sympathetic trunk which leave the middle cervical ganglion together to go to the head. It runs parallel to common carotid artery (on each side). Contain both sympathetic and parasympathetic structures
Vagus nerve sympathetic or parasympathetic or both
Parasympathetic
Sympathetic trunk, sympathetic, parasympathetic, or both
Sympathetic
Axon type phrenic nerve
Primarily somatic efferent axons arising from cervical spinal cord segments and provide voluntary motor innervation to the diaphragm. THIS IS NOT PART OF THE AUTONOMIC SYSTEM
Is the phrenic nerve part of the ANS?
NO
Synovial joint
Designed to allow for controlled movements in certain planes
Non-synovial joints
Designed primarily to restrict unwanted movement
Structural stability of a joint
Primarily due to ligaments and muscles and associated tendons. Also affected by congruity of articulated surfaces of bones and joint capsule which increases stability as well
Intrinsic muscles
Those that have both attachments on the limb itself
Tres Major
Other major shoulder flexor. Proximal attachment seen at caudal angle of scapula, distal attachment is on proximal medial aspect of humerus. Distally this attaches to latissimus dorsi
Veins of the heart
Cranial vena cava, caudal vena cava, pulmonary veins, great cardiac vein, azygous vein
Arteries of heart
Aorta, pulmonary trunk, coronary arteries, right and left pulmonary aa
Chambers of the heart
Right artium, right ventricle, left atrium, left ventricle
Valves
Aortic valve, left a-v valve, right a-v valve, pulmonic valve
Topographical regions of the heart
Base and apex
Auricles
Small roughly triangular flaps on canine heart, pulmonary trunk runs between them. If you open the left lateral body wall to expose heart you see auricular surface
Open dog up from right lateral body wall
Open to atrial surface of the heart, if open dog up from left lateral body wall then you are opening to auricle surface
Azygous vein
Facilitates venous return from dorsal body wall (empties directly into r atrium or cranial vena cava
Great cardiac vein
Final venous return from heart’s own structural blood supply. Vein lies in cardiac groove, externally marks separation of atria from ventricles
Intraventricular grooves
Venous tributaries that feed into great cardiac vein run superficially in these on either side of heart
Structural blood supply
Blood supply and drainage to an organ itself, for heart supplied by coronary arteries and drained by great cardiac vein
Functional blood supply
Blood within the heart chambers is volume of blood used to fulfill its own function
Intervenous tubercle
Crest that diverts blood from cranial and caudal vena cava as it enters right atrium, keeps blood from sloshing into turbulent wave when entering. Sends blood to right AV opening. Intervenous tubercle looses prominence with right atrium has been opened
Coronary sinus
Venous return to heart from great cardiac vein is through coronary sinus
Right auricle
Blind pouch internal surface ( as well as the lateral surface on right atrium) characterized by elaborate muscular bands (pectinate muscles)
Pectinate muscles
Muscular bands that make up internal surface right auricle and lateral surface of right atrium
Sinus venarum
Smooth walled part of right atrium, opening for the veins
Pulmonary trunk
Takes blood from right ventricle to the lungs; splits into left and right pulmonary arteries
Left and right pulmonary veins
Brings blood back to left atrium
Ligamentum arteriosum
Cord like structure that spans distance from pulmonary trunk to aorta
Right AV valve
Opens and closes 80-100 times per minute as venous. Blood moves from sinus venarum into chamber of right ventricle
Papillary muscles
Extend from muscular ventricular walls and connect to valve leaflets via chordae tendinae
Trabeculae carnae
Muscular developments and irregularities of right ventricular wall
Conus arteriosus
Directs blood flow through pulmonary valve
Carina
Each principle bronchus branches from trachea at Carina
Lobar bronchi
Principle bronchi branch from trachea at craina and then divide into lobar bronchi (supplying individual lung lobes)
Pulmonary veins
Pulmonary vein from each lung lobe drains directly into left atrium
Pulmonary artery
Each lung is supplied with a single pulmonary artery
Valve or the foramen ovale
Located at the fossa oval is this is a thin flap of tissue on the cranial aspect of interatrial septal wall
Fossa ovalis
Defines the position where during fetal development blood was shunted from right atrium to left atrium through foramen ovale
Systole
Phase of heart beat where heart muscles contract and pump blood into arteries
Diastole
Phase of heartbeat where muscles relax and allow chambers to fill with blood
Left and right coronary arteries
Heart gives itself the most oxygen and nutrient rich blood using left and right coronary arteries. They leave the ascending position of the aorta at the dilated sinus of the aorta distal to cusp of aortic valve.
Scalenus
Muscle of inspiration Attaches cranially to transverse process of cervical vertebrea, attaches caudally to first few ribs Brachial plexus emerges from its ventral border
Brachial plexus
Collection of crossing and intermingling fibers from ventral roots of spinal nerves C6-T2 Emerge ventral to the scalenus Nerves arising from this plexus supply motor innervation to thoracic limb, pectoral muscles, lat dorsi, and cutaneous trounci Additionally they carry sympathetic motor fibers to forelimb and carry sensory information from forelimb to spinal cord
Axillary artery
Found ventral to scalenus Continuation of subclavian artery and is main blood supply to thoracic limb
External intercostal muscles
Fibers run caudoventrally, cover dorsal 2/3 of each intercostal space
Vagus nerve
Vagus is the sole path by which all thoracic and most abdominal viscera are provided with parasympathetic motor innervation Vagosympathetic trunk merges with middle cervical ganglion; Vagus is a complex cranial nerve with both somatic and visceral components each of with contains both somatic and visceral components, each of which contain both sensory and motor fibers
Middle cervical ganglion
Merges with vagosympathetic trunk. Region of middle cervical ganglion contains extensive intermingling of parasympathetic axons and sympathetic axons and cell bodies .
Vagus caudal to middle cervical ganglion
Parasympathetic fibers pass through this region to develop motor innervation to the heart
Recurrent laryngeal nerve
Branches from vagus and passes around the aortic arch; made up of axons of both efferent and afferent somatic neurons, these fibers provide motor and sensory innervation to specific striated muscles of larynx and to the striated muscle with in the wall of the cervical portion of the esophagus
Id structures at arrows

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