Vasculature and Nerves Flashcards
1
Q
How many cervical spinal nerves in the dog?
A
Eight
2
Q
Where does the first cervical spinal nerve pass through?
A
Lateral vertebral foramen of the atlas (Transverse foramen in wing of the caudal vertebral body of the atlas)
3
Q
Where does the eight cervical spinal nerve pass through?
A
The intervertebral foramen between the 7th cervical vertebra and 1st thoracic vertebra.
4
Q
Which are larger - dorsal or ventral branches of the spinal nerves?
A
Ventral
5
Q
What do dorsal branches of the spinal nerves innervate?
A
Structures dorsal to the vertebrae.
6
Q
Where will you find the 2nd cervical nerve?
A
Between: Mastoid part of the cleidocephalicus Omotransversarius Deep to platysma Dorsal to external jugular vein
7
Q
What does the 2nd cervical nerve innervate?
A
Branches into two:
Great auricular nerve: skin of the neck, the ear, and back of the head.
Transverse cervical nerve: Skin of the cranioventral part of the neck
8
Q
What vessels is the external jugular vein formed by?
A
Facial components: Linguofacial (ventral) and maxillary (dorsal) veins. Maxillary can be distinguished by mandibular lymph nodes lying on either side.
Brachial components: Omobrachaial (dorsal) and cephalic (ventral) veins
9
Q
Mandibular salivary gland
A
Dorsal to the mandibular LNs.
10
Q
Mandibular lymph nodes
A
Receive lymph drainage from the cutaneous areas of the head, neck, and thoracic limb
Ventral to the mandibular salivary gland, deep to the cleidocephalicus and omotransversarius.
11
Q
Where do you find the accessory cranial nerve?
A
Also called the 11th cranial nerve
Emerges below the sternocephalicus, runs along the dorsal border of the omotransversarius, terminates in the trapezius
12
Q
What does the accessory cranial nerve innervate?
A
Only motor nerve of the trapezius. Also supplies: Omotransversarius Cleidocephalicus (mastoid and cervical parts) Sternocephalicus
13
Q
Third, Fourth, and Fifth cervical spinal nerves
A
Distributed segmentally to the muscles and skin of the neck
14
Q
Vagosympathetic nerve trunk
A
Within the carotid sheath, medial to the common carotid artery.
15
Q
Medial retropharyngeal lymph node
A
Lies ventrolateral to the carotid sheath
Opposite the larynx
16
Q
Branching pattern of the dorsal intercostal arteries
A
Do not confuse with dorsal branch of the artery
First three dorsal arteries: from branch of the costocervical trunk
Last 9 dorsal arteries: from aorta
Two lateral cutaneous branches (one dorsal, one ventral) that perforate both intercostal muscles
17
Q
Ventral intercostal arteries
A
Ventral intercostal artery anastomoses with the dorsal intercostal artery
Perforating branch that perforates just the internal intercostal muscles near the sternum.
18
Q
Dorsal branch of the arteries of the intercostal space
A
Supplies the epaxial muscles
Do not confuse with dorsal intercostal arteries.
19
Q
Ventral branch of the arteries of the intercostal space
A
Anastomoses with the dorsal intercostal artery.
20
Q
Veins of the intercostal spaces
A
Will follow in the same pattern as the arteries of the intercostal spaces.
21
Q
What do the lateral branches of the dorsal intercostal arteries supply?
A
Cutaneous structures
Example: thoracic mammae
22
Q
What do the perforating branches of the ventral intercostal arteries supply?
A
Cutaneous structures
Example: thoracic mammae
23
Q
Branching pattern of the intercostal nerves
A
Dorsal, lateral, and ventral branches
Dorsal: innervates epaxial muscles.
Lateral: Becomes the dorsal lateral cutaneous branch
Ventral: A lateral branch that perforates both intercostal muscles and a ventral cutaneous branch that perforates just the internal intercostal near the sternum.
24
Q
What are the cranial thoracic mammae supplied by?
A
Fourth, fifth, and sixth ventral and lateral cutaneous vessels and nerves (from the intercostals)
Branches of the lateral thoracic vessesls (from the axillary vessels)
25
What are the caudal thoracic mammae supplied by?
Sixth and seventh cutaneous nerves and vessels
| Cranial superficial epigastric vessels
26
What do the intercostal vessels and nerves become after they pass through the intercostals?
Cutaneous vessels and nerves.
27
Axilla
Armpit.
Bounded by: Pectorals and serattus ventralis.
Contains: brachial plexus
28
Where do you find the lateral thoracic vessels and nerve?
In the axilla
| Between the latissiumus dorsi and deep pectorals
29
What does the lateral thoracic nerve innervate?
Motor to the cutaneus trunci.
30
What does the lateral thoracic nerve consist of?
Branches of the 8th cervical and 1st thoracic spinal nerves.
31
What do the lateral thoracic vessels consist of?
Branches of the axillary artery and vein.
32
What do the lateral thoracic vessels supply?
Muscle, skin, subcutaneous tissue, and cranial thoracic mama.
33
Axillary lymph node
Drains the afferent lymph vessels of the thoracic wall and deep structures of the limb.
Dorsal to the deep pectoral
34
Cranial epigastric artery
Terminal branch of the internal thoracic artery
Emerges from costal arch
Runs caudally on the deep surface of the rectus abdominis
Gives rise to cranial superficial epigastric artery
35
Cranial superficial epigastric artery
From the cranial epigastric artery
Perforates the rectus abdominis
Runs caudally over external surface of rectus abdominis
Branches terminate in rectus abdominus.
36
What does the cranial superficial epigastic artery supply?
Skin over the rectus abdominis
Caudal thoracic mammae
Cranial abdominal mammae
37
Transversus thoracis
Flat muscle on deep ventral surface of costal cartilage 2-8.
| Attachments: chostochondral junctions and sternum
38
Internal thoracic artery
3rd lateral branch off the brachiocephalic artery.
Supplies the phrenic nerve, the thymus, the mediastinal pleurae and the dorsal intercostal spaces.
Branch from the subclavian artery
Runs ventrocaudally through the cranial mediastinum
Anastomoses with ventral intercostal arteries on the medioventral surface of the thoracic cavity.
Terminatees in the musculophrenic and cranial epigastric arteries.
39
Pleurae
Serous membranes that cover the lungs and line the walls of the thorax.
40
Visceral pleura
Also called pulmonary pleura
| Closely attach to the surfaces of the lungs and separate the two lobes.
41
Parietal pleura
Attached to the thoracic wall by endothoracic fascia
| Three contiguous parts: costal, diaphragmatic, and mediastinal
42
Costal pleura
Covers inner surface of the ribs and associated intercostal and transverses thoracis muscles.
43
Diaphragmatic pleura
Covers cranial surface of the diaphragm.
44
Mediastinal pleura
Covers the sides of the partition between the two pleural cavities
45
Mediastinum
Two mediastinal pleurae and the space between them
Encloses the heart, lymph nodes, thymus, heart, aorta, trachea, and esophagus, as well as the vagus nerve and other nerves/vessels.
Can be divided into cranial, middle, dorsal, ventral, and caudal parts with the middle covering the heart and the others in relation to the heart.
46
Pericardial mediastinal pleura
Portion of the mediastinal pleura covering the heart.
47
Esophageal hiatus
Where the esophagus passes through the diaphragm
| Connected by connective tissue, pleura, and peritoneum.
48
Plica venae cavae
Loose fold of pleura from the right caudal mediastinal portion of the pleural sac.
Surrounds the caudal vena cava.
49
Root of the lung
Also called the hilus of the lung.
| The pleura, bronchi, vessels, and nerves that are all entering into the lung.
50
Pulmonary ligament
Between the caudal lung lobe and the mediastinum at the level of the esophagus.
51
Thymus
Bilobed compressed structure in the cranial mediastinum, over the surface of the pericardium when large.
Largest in young animals and atrophies with age.
52
Musculophrenic artery
Runs caudodorsally in the angle formed by the diaphragm and the lateral thoracic wall.
53
What artery supplies the thymus?
Internal thoracic artery.
54
What nerve innervates the trapezius?
Accessory cranial nerve.
55
Left lung lobes
Two:
Cranial lobe with cranial and caudal parts
Caudal lobe
56
Right lung lobes
```
Four:
Cranial lobe
Middle lobe (most lateral)
Caudal lobe
Accessory lobe (most medial)
```
57
Cardiac notch
On the right lung
Between the cranial and middle lobes of the lung
The fourth and fifth intercostal space
58
Principal bronchi
Bifurcation of the trachea to supply each lung.
59
Carina
Partition between the principal bronchi in the trachea.
60
Lobar bronchi
Divisions of the principal bronchi to supply the lobes of the lungs.
61
What is the clinical significance of the cardiac notch?
Heart is accessible for cardiac puncture here.
62
Aortic impression on the left lung
Most marked on the accessory lobe.
63
Tracheobronchial lymph nodes
Located at the bifurcation of the trachea and further down on the bronchi.
Do not confuse with mediastinal lymph nodes.
64
Where do the pulmonary veins drain? Do they carry oxygenated or deoxygenated blood?
Drain into the left atrium of the heart
| Carry oxygenated blood
65
Pulmonary trunk
Supplies each lung with a pulmonary artery. Right pulmonary artery will be ventral to right principal bronchus.
66
Cranial vena cava
Drains into the right atrium
| Formed by the union of the left and right brachiocephalic veins, and the right azygos vein.
67
Thoracic inlet
Union of the left and right brachiocephalic veins draining into the cranial vena cava.
68
Brachiocephalic veins
Formed by external jugular and subclavian veins
69
Azygos vein
Only the right vein develops in the dog
The last branch entering the cranial vena cava
Winds ventrocranially around the right lung
Collects blood from all of the dorsal intercostal veins as far cranially as the 3rd/4th intercostal space
70
Thoracic duct
```
Drainage from:
lymphatic capillaries
ducts to the venous system
left thoracic limb
left tracheal trunk
Drains into the left brachiocephalic vein
```
71
Cisterna chyli
Dilated structure that receives lymph drainage from the abdominal and pelvic viscera and the pelvic limbs.
Caudal to the thoracic duct and the thoracic duct continues from it.
72
Left tracheal trunk
Lymph drainage from the left side of the head and neck
| Drains into the thoracic duct
73
Right tracheal trunk
Lymph drainage from the right side of the head and neck
| Drains into the venous system at the right brachiocephalic vein.
74
Aorta
Large unpaired vessel from left ventricle
Two main parts:
Cranial aorta (to the diaphragm): Ascending aorta, aortic arch, and descending aorta
Caudal aorta (to the diaphragm
75
Coronary arteries
Branches of the ascending aorta that supply the heart muscle
76
Vessels from the ascending aorta
Coronary arteries
77
Vessels from the aortic arch
Brachiocephalic trunk
| Left subclavian artery
78
Vessels from the descending aorta
8-9 dorsal intercostal arteries (first 3 from the costocervical trunk)
79
Brachiocephalic trunk
First branch from the aortic arch
| Gives rise to left carotid artery and then terminates as the right carotid artery and the right subclavian artery.
80
Common carotid arteries
Both left and right come from the brachiocephalic trunk
81
Subclavian arteries
Right comes from the brachiocephalic trunk
Left is the second branch of the aortic arch
Both have similar branching after this point.
82
Vertebral artery
1st branch off of the subclavian artery
| Supplies the cervical muscles and spinal branches spinal cord and its coverings via intervertebral foramina.
83
Costocervical trunk
2nd branch off the subclavian artery
Supplies the 1st/2nd/3rd intercostal spaces, muscles at the base of the neck, and muscles dorsal to the first few thoracic vertebrae.
84
Superficial cervical artery
3rd medial branch of the subclavian artery.
| Supplies the base of the neck and the scapular region.
85
Bronchoesophageal artery
Supplies the esophagus
Arises from the 5th intercostal artery
Terminates in the bronchial arteries
86
Bronchial arteries
Supply the lungs
87
Phrenic nerves
Arises from the ventral branches of the 5th/6th/poss.7th cervical nerves
Innervate the diaphragm
Have both sensory and motor functions.
88
Central Nervous System
Brain and spinal cord
89
Peripheral Nervous System
Anything outside of the CNS
| Cranial nerves, spinal nerves, and what they become.
90
Sensory nerves
Afferent nerves
| Always pseudounipolar
91
Motor nerves
```
Efferent nerves
Somatic efferents (conscious, to skeletal muscle) are pseudounipolar
Visceral/autonomic efferents (unconscious, to smooth muscle) parasympathetic (rest and digest) or sympathetic (fight or flight) are multipolar and need two to reach the effector tissue
```
92
Ganglion
Gross enlargement of a nerve
| Contains neuronal cell bodies
93
What are groups of neuronal cell bodies within the CNS called?
Nuclei
94
What are the two autonomic efferent neurons called as they travel to the effector tissue?
Preganglionic and postganglionic neurons.
95
What is another name for the sympathetic nervous system?
Thoracolumbar system
96
What is another name for the parasympathetic nervous system?
Craniosacral system
97
What humoral transmitter substance is released at sympathetic nerve endings?
Norepinephrine
98
What humoral transmitter substance is released at parasympathetic nerve endings?
Acetylcholine
99
Where are parasympathetic ganglia typically located?
In the wall of the structure being innervated.
100
Where are sympathetic ganglia typically located?
A short distance from the spinal cord.
101
Ventral root of the spinal cord
Efferent neurons
102
Dorsal root of the spinal cord
Afferent neurons
103
Spinal nerve
Joining of the ventral and dorsal roots of the spinal cord just at the edge of the vertebra at the level of the intervertebral foramen.
104
Ramus communicans
Also called the communicating branch
Leaves the ventral branch of the spinal nerve just after it starts
Joins the sympathetic trunk
Like all other nerves, multiple types of nerves. Mostly pre and post ganglionic sympathetic GVEs in these branches but may be others.
105
Sympathetic trunk ganglion
Peripheral nerve just lateral to the spinal column
A sympathetic trunk ganglion located at each point where a ramus communicants joins with the trunk, with cell bodies of postganglionic sympathetic neruons.
106
Splanchic nerves
Run through the sympathetic trunk
Form plexuses around the main blood vessels of the abdominal organs
Additional sympathetic ganglion within the plexuses (postganglionic cell bodies of the neurons that formed these nerves located here)
107
Describe the movement of a pair of sympathetic GVE neurons that innervate smooth muscles, sweat glands, and other strucutures located above the spinal cord.
1. Run down the ramus communicans
2. Synapse either with the first sympathetic trunk ganglion that they come across or move one or two ganglia cranially or caudally.
3. Postganglionic neuron runs back over through the ramus comminicans in the segment where the synapse occurred
4. Runs with a spinal nerve to the structures to be innervated.
108
What verterbrae have spinal nerves that feed into the sympathetic nervous system?
T1 - L4 or L5
109
Cranial cervical ganglion
Synapses of the preganglionic sympathetic neurons that supply the head.
110
Cervicothoracic ganglion
Enlargement of the sympathetic trunk lateral to the longus colli at the first intercostal space
Fusion of the caudal cervical ganglion and the first two or three thoracic ganglion.
111
Brachial plexus
Pathway through the axilla for the postganglionic axons to reach the thoracic limb.
Formed by the ventral branches of the (sometimes 5th)/6th/7th/8th cervical and 1st/2nd thoracic spinal nerves.
These intermix and differently named intermixed nerves leave from the plexus.
112
Vertebral nerve
From the cervicothoracic ganglion through transverse foramina to the heart and other thoracic structures.
113
Ansa subclavia
Division of the sympathetic trunk for it to loop around the subclavian artery. Unite at the middle cervical ganglion.
Many nerves leave this to supply the heart.
114
Middle cervical ganglion
Junction of the nasa and the vagosympathetic trunk. Many nerves leave this to supply the heart.
115
Cardiac nerves
Numerous
| Leave the ansa subclavia and middle cervical ganglion to course to the heart.
116
Vagosympathetic trunk
Lies in the carotid sheath
Cranial cervical ganglion at its cranial end.
Combines with the vagus nerve (tenth cranial nerve).
117
Left and right recurrent laryngeal nerves
Left curves around the arch of the aorta
Right curves around the right subclavian artery
Both then run up the trachea and supply the larynx
Innervate the heart, esophagus, and trachea.
Longest peripheral nerves in the body, so early peripheral neuropathy is typically seen with trouble barking or swallowing.
118
Caudal laryngeal nerve
Termination of the recurrent laryngeal nerves in the larynx.
119
Ventral vagal trunk
Cranial termination of the dorsal and ventral vagus nerves on the esophagus, cranial to the heart.
120
Dorsal vagal trunk
Caudal termination of the dorsal and ventral vagus nerves dorsal to the esophagus near the diaphragm.
121
Dorsal and ventral vagus nerves
Division of each vagus nerve near the base of the heart.
122
Pericardium
```
Fibroserous covering of the heart
Three layers:
Outer: Pericardial mediastinal pleura
Fibrous pericardium
Inner: Parietal serous pericardium
```
123
Serous pericardium
Two layers
parietal layer - adheres to the fibrous pericardium (forms part of the pericardium)
visceral layer - adheres to the heart (considered part of the heart)
124
Pericardial cavity
Contains pericardial fluid between the parietal serous pericardium and visceral serous pericardium.
125
Phrenicopericardial ligament
Continuation of the fibrous pericardium to the sternum and the diaphragm.
Usually associated with adipose tissue.
Located in the ventral mediastinum.
126
Epicardium
Another name for visceral serous pericardium.
127
Auricular surface of the heart
Left side of the heart, can see both auricles from this side.
128
Atrial surface of the heart
Right side of the heart. Can generally only see the right auricle here.
129
Dorsal surface of the heart
Attachments of the great vessels
130
Apex of the heart
Ventrocaudal and slightly to the left in most hearts, part of the left ventricle.
131
Coronary Groove
Separates the ventricles from the atria on the atrial side of the heart.
132
Interventricular grooves
Paraconal interventraicular groove (auricular surface, oblique)
Subsinuosal interventricular groove (atrial surface)
133
Cranial surface of the heart
Right ventricle covers the left ventricle here.
134
Parts of the right atrium
```
Sinus venarum (main)
right auricle
```
135
How many openings into the right atrium? What are they?
Four.
1. Caudal vena cava
2. Coronary sinus
3. Cranial vena cava
4. Right atrioventricular orifice (holds the valve)
136
Interatrial septum
Medial wall of the heart separating the left and right atria.
137
Intervenous tubercle
Transverse ridge between the two caval openings in the right atrium
Serves to channel blood towards the right atrioventricular orifice.
138
Fossa ovalis
Slitlike depression caudal to the intervenous tubercle
| Formed the foramen ovale between the right and left atria in the fetus (no need to send blood to the lungs)
139
Pectinate muscles
Interlacing muscular bands in the auricles and atria
140
Endocardium
Grossly: glistening surface on the inner surface of the heat
Microscopically: Simple squamous epithelium lining the inner part of the vessel.
141
Crista terminalis
Thick, semilunar smooth portion of the right atria at the entrance into the auricle. Pectinate muscles radiate from this band.
142
Pulmonary trunk
Leaves the right ventricle at the conus arteriosus to continue to the lungs.
At the left craniodorsal aspect of the heart.
Will then bifurcate into the left and the right pulmonary arteries.
143
Atrioventricular valve
Right and left
Both have two cusps, a septal and a parietal cusp.
Subsidiary leaflets found at the end of both cusps in the left and just the septal cusp in the right.
144
Chordae tendineae
Connect the cusps of the atrioventricular valves with the walls of the ventricles via the papillary muscles.
145
Papillary muscles
Conical muscle projections in the ventricles
Usually three or four
Attachments for the chordae tendineae.
146
Trabeculae carnae
Muscular irregularities of the interior of the ventricular walls.
More numerous in the right ventricle than in the left.
147
Trabecula septomarginalis
Muscular strand extending across the lumen of the right ventricle from the septal to the parietal wall, also anchored by a papillary muscle.
148
Pulmonary valve
Between the conus arteriosus and the pulmonary trunk
| three semilunar cusps, each with a small fibrous nodule in the middle of them.
149
Valve of the foramen ovale
Remnant of the foramen oval
| In the left atrium, directly across from the fossa ovalis in the right atrium.
150
ligamentum arteriosum
Fibrous connection between the pulmonary trunk and the aorta
| Remnant of the patent ductus arteriosus to bypass the lungs in the fetus (funneled blood straight into the aorta).
151
Aortic valve
Between the left ventricle and the aorta.
| Three semilunar cusps with fibrous nodules like the pulmonary valve.
152
Sinus of the aorta
Slight expansion of the aorta just cranial to the aortic valve.
153
Right coronary artery
Leaves the right sinus of the aorta.
| Passes through coronary groove and often part of the subsinuosal interventricular groove.
154
Left coronary artery
Twice as large as the right coronary artery.
Leaves the left sinus of the aorta.
Two branches: circumflex branch and paraconal inter ventricular branch.
155
Circumflex branch of the left coronary artery
Passes through the subsinuosal interventricular groove and in the coronary sulcus.
156
Paraconal interventricular branch of the left coronary artery.
Passes through the paraconal interventricular groove.
Sends large rami over the surface of the left ventricle.
Septal branch that runs into the interventricular septum and supplies this.
157
Coronary sinus
Dilated terminal end of the great cardiac vein.
158
Great cardiac vein
Drains the coronary vessels back to the heart.
| Starts in the paraconal interventricular sulcus.
159
Subclavian artery branches
1. Vertebral artery
2. Costocervical artey
3. Internal thoracic artery and superficial cervical artery
4. Continues as the axillary artery
160
What does the superficial cervical artery supply?
Superficial muscles of the base of the neck, superficial cervical lymph nodes, and the muscles of the scapula and shoulder.
161
What is the function of the superficial cervical lymph nodes?
Drain the afferent lymph vessels from the superficial part of the neck, caudal surface of the head, ear, and pharynx, and the thoracic limb.
162
What are the branches off the axillary artery?
External thoracic artery
Lateral thoracic artery
Subscapular artery
Cranial circumflex artery
163
What are the nerves that come out of the brachial plexus?
```
Suprascapular nerve
Subscapular nerve
Axillary nerve
Musculocutaneous nerve
Radial nerve
Median nerve
Ulnar nerve
Thoracodorsal nerve
Lateral thoracic nerve
Pectoral nerve
```
164
External thoracic artery
1st branch off the axillary artery.
(normal variation: may be off the same trunk as the lateral thoracic artery or superficial cervical artery)
Supplies the superficial pectorals.
165
Lateral thoracic artery
2nd branch off the axillary artery.
(normal variation: may be distal to the subscapular artery).
Supplies the latissimus dorsi, deep pectorals, cutaneus trunk, and thoracic mammae.
166
Subscapular artery
```
3rd branch off the axillary artery.
Three branches:
Thoracodorsal artery
Caudal circumflex humeral artery
Continuation of the subscapular artery (supplies the scapula).
```
167
Cranial circumflex artery
4th branch off the axillary artery.
(normal variation: may be distal or proximal to the subscapular artery).
Supplies the biceps brachia and the joint capsule of the shoulder
168
Thoracodorsal artery
Supplies the trees major and latissimus dorsi
169
Caudal circumflex humeral artery
Wraps around the cranial side of the humerus (can be seen under the deltoideus on the lateral side).
Supplies the triceps, deltoids, coracobrachialis, infraspinatus, and shoulder joint capsule.
170
Brachial artery
```
Continuation of the axillary artery over the humerus. Terminates in the median artery after the branch off of the common interosseous artery.
Branches into:
Collateral ulnar artery
Superficial brachial artery
Transverse cubital artery
Common interosseous artery
```
171
Collateral ulnar artery
1st branch off the brachial artery (across from a smaller bicipital artery)
Supplies the triceps, ulnar nerve, and the elbow
172
Superficial brachial artery
2nd branch off the brachial artery
More distally will anastomose with the cranial superficial antebrachial artery.
Supplies the dorsum of the forepaw
173
Transverse cubital artery
3rd branch off the brachial artery.
| Supplies the elbow.
174
Cranial pectoral nerves
Derived from branches of the 6th/7th/8th cervical spinal nerves
Innervate superficial pectoral muscle.
175
Suprascapular nerve
Derived from 6th/7th cervical spinal nerves (Brachial plexus)
Passes directly across the scapular notch and so very susceptible to injury (sweeny in horses)
Innervates supraspinatus and infraspinatus
176
Subscapular nerve
Derived from 6th/7th cervical spinal nerves (Brachial plexus)
Innervates the subscapularis
177
Musculocutaneous nerve
Derived from 6th/7th/8th cervical spinal nerves (Brachial plexus)
Innervates coracobrachialis, biceps brachii, brachialis.
A branch off the musculocutaneous joins with the median nerve.
178
Axillary nerve
Derived from 7th/8th cervical spinal nerves (Brachial plexus)
Innervates
179
Thoracodorsal nerve
Derived from 8th cervical spinal nerve (Brachial plexus)
| Innervates the latissimus dorsi
180
Radial nerve
Derived from 7th/8th cervical and 1st/2nd thoracic spinal nerves (Brachial plexus)
Innervates all the extensor muscles of the elbow, carpal, phalangeal joints, triceps, tensor fasciae antebrachii, and anconeus.
Terminates as a deep and superficial branch.
181
Median nerve
Derived from 8th cervical and 1st/2nd thoracic spinal nerves. (Brachial plexus) Common trunk with the ulnar nerve.
Receives a branch from the musculocutaneous nerve.
Innervates most of the muscles of the forearm and skin of the palmar surface of the paw -
Pronator teres
Pronator quadratus
Flexor carpi radialis
Superficial digital flexor
Parts of deep digital flexor
182
Ulnar nerve
Derived from 8th cervical and 1st/2nd thoracic spinal nerves (Brachial plexus) Common trunk with the median nerve.
Innervates the skin of the distal medial aspect of the brachium and the caudal aspect of the antebrachium -
Flexor carpi ulnaris
Parts of deep digital flexor
183
Caudal pectoral nerves
Derived from 8th cervical and 1st and 2nd thoracic spinal nerves.
Innervates the deep pectoral muscle.
184
Lateral thoracic nerve
Derived from from 8th cervical and 1st thoracic spinal nerves. (Brachial plexus)
Innervates the cutaneus trunci.
185
Cephalic vein
Begins on palmar surface of paw and runs over the cranial surface of the antebrachium.
Enters the external jugular vein near the thoracic inlet.
186
Accessory cephalic vein
Arises from small veins on the dorsum of the paw and joins the cephalic on the distal third of the antebrachium.
187
Median cubital vein
Forms connection between the cephalic and brachial veins over the flexor surface of the elbow.
188
Axillobrachial vein
Leaves the cephalic vein at the middle of the antebrachium.
| Joins the axillary vein near the deltoideus.
189
Omobrachial vein
Arises from the axillobrachial vein and enters the external jugular vein cranial to the cephalic vein.
190
Median artery
Termination of the brachial artery after the branch of the common interosseous artery. Runs with the median vein.
Extends to the superficial palmar arch in the paw.
Branches:
Deep antebrachial artery
Radial artery
191
Common interosseous artery
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Short branch off the brachial artery.
Branches into:
Ulnar artery
Caudal interosseous artery
Cranial interosseous artery
```
192
Ulnar artery
Courses caudally from the common interosseous artery and continues with the ulnar nerve.
Supplies the ulnar and humeral heads of the deep digital flexor and flexor carpi ulnaris.
193
Caudal interosseous artery
Course distally from the common interosseous artery between the radius and ulna under the pronator quadratus.
Supplies many structures around the radius and ulna with small branches then joins with radial and median arteries to supply the palmar surface of the forepaw.
194
Cranial interosseous artery
Third branch off of the common interosseous artery, difficult to visualize.
195
Superficial palmar arch
Formed by the anastomosis of the median artery and caudal interosseous artery.
Gives rise to the palmar common digital arteries that supply the palmar surface of the forepaw.
196
Radial artery
Arises from the median artery in the middle of the leg and follows medial border of the radius.
197
Deep antebrachial artery
Caudal branch of the median artery just under the common interosseous artery.
Supplies the flexor carpi radialis, deep digital flexor, flexor carpi ulnaris, and superficial digital flexor.
198
Radial nerve
Supplies the extensors of the elbow, carpus, and digital joints.
Divides into superficial and deep branches, superficial divides again to medial, lateral, and lateral cutaneous branches.
199
Deep branch of the radial nerve
Courses with the brachial into the forearm.
Innervates the extensor carpi radialis, common digital extensor, supinator, lateral digital extensor, the abductor digiti I longus, and the ulnaris lateralis.
200
Medial and lateral branches of the radial nerve
Follow the medial and lateral sides of the cephalic vein.
Innervate (sensory to) the skin on the cranial and lateral surface of the forepaw and dorsal surface of the carpus, metacarpus and digits.
Terminate in the dorsal common digital nerves.
201
Palmar branch of the ulnar nerve
Sensory to the palmar surface of the forepaw and motor to the intrinsic muscles of the forepaw.
202
Dorsal and palmar common digital vessels and nerves
Superficial nerves and vessels of the forepaw
| Each common trunk divides to branches medial and lateral to each digit.
203
Dorsal and palmar metacarpal vessels and nerves
Deep nerves and vessels of the forepaw
| Each common trunk divides to branches medial and lateral to each digit.
204
Cutaneous area of a nerve
Entire area of skin innervated by a nerve. May overlap with the cutaneous area of other nerves.
205
Autonomous zone of a nerve
The area of skin innervated solely by one nerve with no overlap by the adjacent nerves.
206
External pudendal artery
Emerges from the superficial inguinal ring. Courses caudally near the gracialis.
207
Caudal superficial epigastric artery
Continuation of the external pudendal artery that courses cranially over the rectus abdominus.
Supplies the prepuce, caudal abdominal mammae, inguinal mammae, labia, and scrotum.
208
Superficial inguinal lymph nodes
Drain the mammae, prepuce, scrotum, and the ventral abdominal wall as far cranially as the umbilicus
209
Cranial abdominal arteries
Arises with the caudal phrenic artery off the aorta
| Perforate abdominal musculature and supply the skin.
210
What are the four main arteries that supply the abdominal wall?
Cranial abdominal artery
Cranial epigastric artery
Caudal epigastric artery
Deep circumflex iliac artery
211
Patterning of the ventral branches of the first four lumbar nerves
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Run ventrocaudally from their vertebra of origin to the area of skin innervated.
(Names:
T1: Cranial iliohypogastric
T2: Caudal iliohypogastric
T3: Ilioinguinal
T4: Lateral cutaneous femoral nerves)
```
212
Genitofemoral nerve
Arises from the 3rd and 4th lumbar nerves
Bound to external pudendal vein
Innervates cremaster, prepuce, and skin of inguinal thigh in both sexes.
213
Spermatic fascia
Continuation of abdominal and transversus fascia
Surrounds the structures coming through the superficial inguinal ring including the vaginal tunic, spermatic cord, and cremaster muscle.
214
Vaginal process
Diverticulum of the peritoneum present in both sexes
Called the vaginal tunic in males and covers the testes, and spermatic parts.
Consists of parietal, visceral, and connecting parts.
215
Parietal vaginal tunic
Outer layer of the peritoneal diverticulum. Surrounds a portion of the peritoneal cavity between the parietal and visceral tunics. Joins with the visceral layer at the caudal end of the testis.
216
Visceral vaginal tunic
Inner layer of the peritoneal diverticulum, closely fused to the testis, epididymus, and ductus deferens. Joins with the parietal layer at the caudal end of the testis.
217
Mesorchium
Connecting mesentery of the testis that contains nerves and vessels
218
Mesoductus deferens
Fold of the peritoneum that attaches the ductus deferens to the body wall and mesorchium. Contains the artery, vein, and nerve of the ductus deferens.
219
Spermatic cord
The ductus deferens and spermatic artery and vein (everything above the testes)
220
Ductus deferens
Carries the sperm from the tail of the epididymus to the urethra.
221
Deferens artery and vein
Accompany the ductus deferens
222
Patterning of the testicular artery and vein
Veins and nerves are woven around the artery. Important for temperature control of the testes.
223
Cremaster muscle
Arises from the free border of the internal abdominal oblique and attaches to the vaginal tunic near the testes. Comes through the superficial inguinal ring.
224
Pampiniform plexus
Venous plexus of the testicular veins, interwoven with nerves and wrapped around the artery, important for temperature control of the testes.
225
Epididymus
Head: cranial, least mature sperm.
Middle
Tail: caudal, most mature sperm.
226
Ligament of the tail of the epididymus
Connects the tail of the epididymus to the vaginal process.
| Forms the round ligament of the uterus in females.
227
Proper ligament of the testis
Connects the tail of the epididymus to the testis.
228
Scrotum
Skin over the testes divided by an external raphe and an internal median septum.
229
Round ligament of the uterus
Runs with the peritoneal diverticulum out of the superficial inguinal ring in the female. May
extend as far as the fascia.
230
Nerve types in the plexus of the testes
Both autonomic and sensory
| sympathetic axons from the third to 5th lumbar sympathetic ganglia.
231
Inguinal canal
Short fissure filled with connective tissue, bounded by the four abdominal muscles and the superficial and deep inguinal rings. Vaginal tunic/process and spermatic cord/round ligament of the uterus travel through this canal.
232
Abdominal cavity
Formed by the muscles of the abdominal wall, ribs, and the diaphragm. Lined by the peritoneum. Contains all of the abdominal organs.
233
Peritoneal cavity
Closed space lined by a serous membrane, between the parietal and visceral peritoneum. No organs within the cavity.
Derived from somatic and splanchnic mesodermal layers of the embryonic coelom.
234
Parietal peritoneum
Lines the body cavity of the abdomen and scrotum.
235
Visceral peritoneum
Lines the organs of the abdominal cavity and scrotum.
236
Connecting peritoneum
Double sheet of peritoneum that extends between the parietal and visceral peritoneums. Forms the mesentery that suspends the organs, as well as containing their nerves and vessels.
Its folds can form the mesenteries, omenta, or ligaments of the abdominal cavity.
237
Transversalis fascia
Reinforces the parietal peritoneum and attaches it to the abdominal muscles and diaphragm.
238
Falciform ligament
Fold of peritoneum that passes from the umbilicus to the diaphragm.
Connects to the liver between the medial and quadrate lobes.
Accumulation of fat inside this ligament in adults.
Umbilical vein ran through this - may find remnants of the embryonic ventral mesentery here in young animals.
239
Round ligament of the liver
Attached to the free border of the falciform ligament, more prominent in young animals.
240
Median ligament of the bladder
Caudal to the umbilicus, fold of the peritoneum running caudally to the urinary bladder. Umbilical artery and urachus ran through this structure.
241
Vaginal ring
Opening in the parietal peritoneum as it leaves the abdomen and enters the inguinal canal. Contains the spermatic cord and vaginal tunic/process.
242
Deep inguinal ring
Fatty structure formed by the folds of the transversalis fascia and associated adipose tissue on the superficial side of the vaginal ring.
243
Caudal epigastric artery
Course cranially on the deep face of the caudal part of the rectus abdominis.
Origin from the pudendoepigastric trunk.
244
Greater omentum
Also called the epiploon
Extension of the connecting peritoneum, with two layers.
Extends caudoventrally to many of the abdominal organs. (outside of the liver)
245
Superficial leaf of the greater omentum
Lacelike. Layer closer to the peritoneum. Encloses the spleen.
246
Deep leaf of the greater omentum
Layer closer to the viscera. Encloses the left lobe of the pancreas.
247
Omental bursa
Space between the deep and superficial leaf of the greater omentums.
Can cause colic in horses if a loop of intestine becomes entrapped in this sac. May occasionally happen in the small animal but rare (epiploic entrapment).
248
Urinary bladder
Empty: lies on the floor of the abdomen.
Full: Displaces freely moving viscera, frequently reaching a transverse plane through the umbilicus.
249
Uterus
Short cevix
| Two long horns.
250
How does the uterus change shape during pregnancy?
Lies on the floor of the abdomen.
| As pregnancy develops, middle parts of the horns move ventrocranially, causing the uterus to bend on itself.
251
Round ligament of the uterus
May pass through the inguinal canal.
Fold of the peritoneum from the mesometrium which surrounds the uterus.
Remnant of fetal gubernaculum.
Becomes the ligament of the tail of the epididymus in males.
252
Spleen
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Left side of the abdomen
Shape variable (HUGE in our dogs as a result of the barbiturates they were given).
```
253
Gastrosplenic ligament
The part of the greater omentum that attaches to the spleen.
254
Muscular parts of the diaphragm plus their attachments?
Tendinous center: V shaped and small, in the center of the diaphragm, runs between the costal and lumbar parts on each side.
Lumbar part: Left and right crura: attach to the bodies of L3 and L4 by large tendons.
Costal part: Arises from the medial surface of ribs 8-13, interdigitating with the transversus abdominis.
Sternal part: Narrow, from sternum to xyphoid cartilage.
255
Cupula of the diaphragm
Most cranial part of the diaphragm, bulges into the thorax.
256
Where does the aorta pass through the diaphragm?
Aortic hiatus. Dorsal diaphragm.
257
Where does the caudal vena cava pass through the diaphragm?
Caval foramen.
258
Where does the esophagus pass through the diaphragm?
Esophageal hiatus. Right crus of the diaphragm.
259
Where does the thoracic duct pass through the diaphragm?
Aortic hiatus. Dorsal diaphragm.
260
Where does the azygous vein pass through the diaphragm?
Aortic hiatus. Dorsal diaphragm.
261
Liver (lobes)
1. Caudate lobe
2. Right lateral lobe
3. Right medial lobe
Gallbladder!
4. Quadrate lobe
5. Left medial lobe
6. Left lateral lobe
262
What are the two sides of the liver?
Visceral surface (caudal) and parietal surface (cranial).
263
Which lobe of the liver does the right kidney contact?
Caudate lobe, forming the renal impression on the caudate process.
264
Which lobe of the liver does the lesser curvature of the stomach contact?
Caudate lobe, contacting the papillary process of the caudate lobe.
265
Lesser omentum
The omentum that is hidden under the liver and viscera rather than padding the ventral side of the viscera.
266
Hepatoduodenal ligament
Right free edge of the lesser omentum, attaching the liver to the duodenum.
Contains the portal vein, hepatic artery, and the bile duct.
267
Epiploic foramen
Formed by the omenta. Opens in the main peritoneal cavity.
268
Mesoduodenum
Originates at the dorsal abdominal wall and root of the mesentery and attaches to the duodenum. Continuous with the mesentery of the jejunum.
269
Duodenocolic fold
Attachment of the ascending duodenum to the mesocolon of the descending colon.
270
Mesentery
Passageway for nerves and vessels to supply the small intestines. Continuous with the mesocolon of the ascending colon.
271
Root of the mesentary
Attachment of the mesentery to the abdominal wall at the second lumbar vertebra.
272
Mesocolon (parts and function)
Ascending, transverse, and descending parts.
273
Right and left triangular ligaments
Extend from the right and left crus of the diaphragm to the right and left lateral lobes of the liver.
274
Coronary ligament
Sheet of peritoneum continuous with both the right and left triangular ligaments on the dorsal side.
275
Hepatic ducts
Carries bile from microscopic structures out of the liver from each lobe. Joins with the cystic duct to form the bile duct.
Variable arrangements.
276
Gallbladder
Between the quadrate and right medial lobes of the liver
Storage for bile
Neck is continuous with the cystic duct.
277
Cystic Duct
Carries bile to and from the gallbladder.
| Joins with the hepatic ducts to form the bile duct.
278
Bile duct
Ductus choldochus
Created by the joining of the hepatic and cystic ducts
No valves = flow in two directions
Empties into the duodenum at the major duodenal papilla.
279
Major duodenal papilla
Termination of the bile duct and the pancreatic duct.
| Most cranial papilla in the descending duodenum.
280
Parts of the Stomach
1. Cardiac part (near esophagus)
2. Fundus (left side)
3. Body (middle)
4. Pyloric part (right side)
281
Parts of the pylorus
1. Pyloric antrum (initial and thin walled)
2. Pyloric canal (narrower and thicker)
3. Pylorus (sphincter)
282
Lesser curvature of the stomach
Faces mainly to the right
283
Greater curvature of the stomach
Faces mainly to the left
284
How does the position of the empty stomach differ from that of the full stomach?
Empty stomach: Hidden under the liver, strongly curved around the papillary process of the liver.
Full stomach: In contact with the ventral abdominal wall, displacing the intestinal mass.
285
Duodenum and its parts.
Most fixed part of the small intestine, suspended by mesoduodenum.
1. Cranial duodenal flexure near the pylorus
2. Descending part
3. Caudal duodenal flexure
4. Ascending part.
286
Where does the duodenum turn into the jejunum?
Duodenojejunal flexure
| At the root of the mesentary
287
Jejunum
The coils of the small intestine, supplied by the cranial mesenteric artery.
Root of the mesentery attaches the jejunum to the dorsal body wall.
288
Mesenteric lymph nodes
Near the vessels in the mesentery.
289
Ileum
Continuous with the jejunum, recognized by the anti mesenteric iliac artery.
290
Ileocolic orifice
Junction between the ileum and the colon. Sphincter.
291
Cecum
S-shaped blind tube off of the colon.
| Lies to the right of the colon.
292
Cecocolic orifice
Junction between the cecum and the colon.
293
Parts of the colon
1. Ascending colon
2. Right colic flexure
3. Transverse colon
4. Left colic flexure
5. Descending colon
294
Rectum
Continuous with the descending colon
295
Parts of the pancreas
Body: at the pylorus
Left lobe: between the peritoneal layers that form the deep leaf of the greater omentum.
Right lobe: dorsomedial to the descending duodenum.
296
Pancreatic duct
Terminates in the descending duodenum with the bile duct at the major duodenal papilla
297
Accessory pancreatic duct
Terminates in the descending duodenum at the minor duodenal papilla (caudal to the major papilla).
Major pancreatic duct in the dog.
298
Adrenal glands
Light cortex and dark medulla
| Crossed by the common trunk of the caudal phrenic and cranial abdominal veins.
299
What are the locations of the two kidneys?
Right kidney: L1-L3 (cranial)
| Left kidney: L2-L4 (caudal)
300
What are the kidneys considered to be?
Retroperitoneal organs.
301
What passes through the hilus of the kidney?
Renal vessels and nerves and the ureter.
302
Renal pelvis
Expansion of the ureter to collect urine.
303
Renal sinus
Fat filled space that surrounds the renal pelvis and contains the renal vessels.
304
Renal cortex
Light, granular region on the periphery of the kidneys. Contains renal corpuscles and tubules.
305
Renal medulla
Darker, striated central portion of the kidneys that contains collecting ducts.
306
Arcuate branches
Branches of the renal vessels that appear at the corticomedullary junction
307
Renal crest
Ridge of the medulla projecting into the renal pelvis. Collecting tubules of the medulla end here.
308
Renal pyramids
Formed by the medulla and the intersections of the pelvic recesses.
309
Pelvic recesses
Projections of the renal pelvis outwards between the renal pyramids.
310
Where are the ovaries located?
Near the caudal poles of the kidneys.
311
Ovarian bursa
Thin walled peritoneal sac that encloses the ovary.
Slitlike orifice on the medial surface opens to the peritoneal cavity.
Formed by the mesovarium and the mesosalpinx.
312
Uterine tube
Oviduct. Runs through the lateral wall of the bursa from the ovary to the uterine horn.
313
Infundibulum
Dilated ovarian end of the uterine tube.
Fimbriated margin to catch eggs as they leave the ovary
Many fimbriae project through the orifice of the bursa into the peritoneum.
314
Abdominal ostium
The entrance of the infundibulum into the uterus, where fertilization takes place.
315
Tubouterine junction
Junction between the uterine horn and uterine tube.
| Here the transit of sperm and ova are regulated.
316
Broad ligaments of the uterus
Peritoneal folds that attach the uterus to the lateral sublumbar region.
Three parts: mesometrium, mesovarium, and mesosalpinx.
317
Mesometrium
Attaches to cranial end of the vagina, uterine cervix, uterine body, and uterine horn.
318
Uterine horn
Long part of the uterus from the uterine body and cervix to the uterine tube.
319
Mesovarium
Cranial portion of the broad ligament and helps to create the ovarian bursa.
320
Mesosalpinx
Helps create the ovarian bursa and attaches the uterine tube to the mesovarium.
321
Suspensory ligament of the ovary
Holds the ovary in a relatively fixed position by connecting with the transversalis fascia.
322
Proper ligament of the ovary
Attaches the ovary to the cranial end of the uterine horn
323
Round ligament of the uterus
The free border of the mesometrium.
Homologue to the embryonic gubernaculum, which becomes the ligament of the tail of the epididymus in the male. Passes through the inguinal canal.
324
Patterning of the vagus nerve
Travels through the neck in the vagosympathetic trunk (GVE, GVA)
Separates from the sympathetic trunk at the thoracic inlet
RLNs branch off
Branches into dorsal vagal trunk and ventral vagal trunk caudal to the heart
Passes through the esophageal hiatus
Gives off a celiac branch
325
What do the dorsal and ventral branches of the vagus innervate?
The esophagus
326
Where does cranial nerve ten pass through the diaphragm
Vagus nerve; through esophageal hiatus
327
Dorsal vagal trunk
Uniting of the right and left dorsal vagal branches near the diaphragm
328
Ventral vagal trunk
Uniting of the right and left ventral vagal branches caudal to the root of the lung
329
What does the dorsal vagal trunk innervate in the abdomen?
Lesser curvature of the stomach, pylorus, small intestines, and adrenal glands.
330
What does the ventral vagal trunk innervate in the abdomen?
Liver, parietal surface of the stomach, and the pylorus.
331
Psoas minor
Cranial to the psoas major, running along the lumbar vertebrae within the abdomen.
Attachments: Fascia of the quadratus lumborum to T13 and L1-5, inserts on the arcuate line of the ilium.
332
What type of nerves are the splanchnic nerves? What are the types of splanchic nerves?
```
GVE sympathetics.
Branch off of the sympathetic trunk.
Major = First branch off at T12/13
Minor = before the adrenals
Lumbar = after the adrenals
```
333
What does the major splanchnic nerve run towards?
Courses to celiacomesenteric ganglia and plexus.
334
What do the minor splanchnic nerves innervate?
Adrenal glands.
| Terminates in celiacomesenteric ganglia and plexus.
335
How are the lumbar splanchnic nerves distributed?
To aorticorenal, cranial mesentaric, and caudal mesenteric ganglia and plexuses.
336
What does the celiacomesenteric ganglion and plexus consist of?
Celiac ganglia
Cranial mesenteric ganglion
Terminal plexus of celiac artery
337
What do the nerves of the caudal mesenteric ganglion innervate?
A portion of the colon
338
Right and left hypogastric nerves
Leave the caudal mesenteric ganglion and run caudally near the ureters, then enter the pelvic canal.
339
Lumbar arteries
Paired
Penetrated the dura and arachnoid to join with the ventral spinal artery and supply the spinal cord
Also supply muscles and skin above lumbar vertebrae.
340
Celiac artery
From the aorta between the diaphragmatic crura.
Three branches: hepatic, left gastric, and splenic.
Often covered by the celiac plexus.
341
Hepatic artery
First branch off the celiac, directed cranially towards the liver.
Branches into the hepatic branches (1-5), cystic artery, right gastric artery, and gastroduodenal artery.
342
Hepatic branches
Leave the hepatic artery
Supply the liver
One to five branches
343
Cystic artery
Leaves hepatic artery
| Supplies the gallbladder
344
Right gastric artery
Leaves the hepatic artery.
Small artery that passes dorsal to the stomach and then supplies the lesser curvature of the stomach.
Anastomoses with the left gastric artery.
345
Gastroduodenal artery
Leaves the hepatic artery.
Supplies the pylorus.
Terminates with right gastroepiploic artery.
346
Right gastroepiploic artery
Terminal branch of the gastroduodenal artery.
| Anastomoses with the left gastroepiploic artery and supplies the greater curvature of the stomach.
347
Cranial pancreaticoduodenal artery
Terminal branch of the gastroduodenal artery, follows the descending duodenum.
Supplies the duodenum and right lobe of the pancreas.
Anastomoses with the caudal pacreaticoduodenal artery.
348
Left gastric artery
Branch off of the celiac artery
Runs to the lesser curvature of the stomach and supplies both sides of the stomach.
Anastamoses with the right gastric artery near the pylorus.
349
Splenic artery
Branch off of the celiac artery
Crosses and supplies the left lobe of the pancreas
Enters the hilus of the spleen
Gives rise to the short gastric arteries and left gastroepiploic artery.
350
Short gastric arteries
Branches of the splenic artery
| Supply the greater curvarture of the left side of the stomach.
351
Left gastroepiploic artery
Branch of the splenic artery.
Supplies the greater curvature of the stomach.
Anastomoses with the right gastroepiploic artery.
352
Cranial mesenteric artery
Unpaired, leaves the abdominal aorta just caudal to the celiac branch.
Branches into the common trunk of the middle and right colic arteries, the ileocolic artery, the caudal pancreaticoduodenal artery, the jejunal arteries, then terminates in the branches of the ileal arteries.
353
Middle colic artery
Arises from a common trunk with the right colic artery off the cranial mesenteric.
One branch supplies the descending colon and anastamoses with the left colic artery.
Other branch supplies the left colic flexure and transverse colon and anastomoses with the right colic artery.
354
Right colic artery
Arises from a common trunk with the middle colic artery off the cranial mesenteric.
Supplies the ascending colon, right colic flexure, and the transverse colon (anastomosing with the middle colic artery and colic branch of the ileocolic artery)
355
Ileocolic artery
Branch off of the cranial mesenteric artery.
| Branches into the colic branch and the cecal artery, then continues as the mesenteric ileal branch.
356
Colic branch of the ileocolic artery
Supplies the ascending colon, anastomoses with the right colic artery.
357
Cecal artery
Branch off of the ileocolic artery.
Supplies the cecum
Then terminates as the antimesenteric ileal artery supplying the ileum.
358
Mesenteric ileal branch of the ileocolic artery
Termination of the ileocolic branch.
Supplies the ileum.
Anastomoses with the ileal arteries.
359
Caudal pancreaticoduodenal artery
Branch of the cranial mesenteric artery.
Supplies descending duodenum and right lobe of the pancreas.
Anastamoses with the cranial pancreaticoduodenal artery.
360
Jejunal arteries
Branches of the cranial mesenteric artery.
| Form cascades in the mesentery and supply the jejunum.
361
Ileal arteries
Termination of the cranial mesenteric artery.
Supply the ileum, run through the mesentery.
Last branch anastamoses with the ileocolic artery.
362
Common trunk of the caudal phrenic and cranial abdominal arteries
Paired, arise from the abdominal aorta caudal to the cranial mesenteric and cranial to the renal arteries.
363
Caudal phrenic artery
Runs cranially to supply the diaphragm.
364
Cranial abdominal artery
Runs into the abdominal wall through the internal abdominal obliques, can be seen superficially.
365
Renal arteries
Paired, leave the aorta at different levels (right cranial to the left)
Right is longer than the left.
Supply the kidneys.
366
Ovarian arteries
Homologous to the testicular arteries.
Paired, caudal to the renal arteries.
Varies in size, position, and tortuosity depending on the size and the development of the uterus.
Supplies the ovary, ovarian bursa, uterine tube, and uterine horn.
Anastomoses with the uterine artery.
367
Testicular arteries
Homologous to the ovarian arteries.
Also paired, caudal to the renal artery.
Crosses the ventral surface of the ureter.
Lies in the mesorchium with the vein and nerve plexus, then through the vaginal ring.
368
Caudal mesenteric artery
Unpaired, arises from the abdominal aorta near its termination as the iliac arteries.
Runs in descending mesoduodenum and branches to the left colic artery and cranial rectal artery.
369
Left colic artery
Supplies the left colic flexure and anastomoses with the middle colic artery.
370
Cranial rectal artery
Descends along rectum and supplies.
| Anastamoses with the middle rectal artery.
371
Deep circumflex iliac artery
Paired, arises from the abdominal aorta near the external iliac.
Crosses the psoas minor, perforates abdominal wall and supplies skin of the caudal abdomen, flank, and cranial thigh.
372
Portal vein
Returns blood from the GI tract to the liver and then to the caudal vena cava
Gastroduodenal vein: drains pancreas, stomach, duodenum, and greater omentum
Splenic vein: Drains lesser curvature of the stomach, spleen, pancreas, and greater omentum
Cranial and caudal mesenteric veins: drain the small intestine
Separates into a right and left branch as it enters the liver, to right and left three lobes each.
373
Levator ani muscles
Broad thin muscle lying dorsal to the internal obturator on the wing of the ileum.
Attachments: Medial edge of the body of the ileum and caudal vertebrae 3-7.
374
Coccygeus muscle
Lateral to the levator ani - can be seen on the medial surface of the leg next to the internal obturator.
Attachments: ischiatic spine and transverse processes of caudal verterbrae 2-4.
375
Pelvic diaphragm
Formed by the coccygeus and levator ani muscles.
Contract with the abdominal muscles to keep the viscera from moving into the pelvic canal.
In older dogs can become weak and may see perianal hernias.
376
Pelvic plexus
Lies near the colon, dorsal to the prostate, and near the vaginal/prostatic artery.
Joining of the hypogastric nerve (sympathetic) and pelvic nerve (parasympathetic).
377
Pelvic nerve
Parasympathetic preganglionic axons.
Very small, runs from the bladder to the pelvic plexus
Supplies: urogenital organs, rectum, descending colon.
378
Pararectal fossa
Extension of the peritoneal cavity dorsal to the rectum on either side of the mesorectum.
Extends to second caudal vertebra.
379
Rectogenital pouch
Continuous with pararectal fossa, ventral to this. Communicates with the uterus in the female.
380
Vesicogenital pouch
In the female, the pouch between the uterus and the bladder.
381
Iliac artery patterning
External iliac becomes the femoral artery.
Internal iliac branches into the caudal gluteal artery and internal pudendal artery. Also gives off the round ligament of the bladder, the remnant of the umbilical artery.
Small unpaired median sacral artery between the internal iliac.
382
Vascular lacuna
Where the external iliac exits the abdominal cavity and becomes the femoral artery.
383
Pubovesical pouch
Communication of the rectogenital (male) or vesicogenital (female) pouch between the bladder and the ventral body wall and pubis. Divided by the median ligament of the bladder.
384
Caudal gluteal artery
Branch of the internal iliac artery.
| Supplies the muscles on the outside of the pelvis and the caudal thigh.
385
Internal pudendal artery
Branch of the internal iliac artery.
Vaginal/prostatic artery branches off here.
Supplies the pelvic viscera and external genitalia at the ischial arch.
386
Vaginal/prostatic artery
Branch off of the internal pudendal artery.
| Termination = uterine artery or artery of the ductus deferens.
387
Uterine artery
Supplies the uterus, and branches into a caudal vesical artery and middle rectal artery.
388
Caudal vesical artery
Branch off of the uterine or artery of the ductus deferens.
Supplies bladder, urethra (both sexes)
Female - also runs in round ligament of the uterus to supply the uterine body and horn, anastomoses with the uterine branch of the ovarian artery.
389
Middle rectal artery
Branch off of the uterine or the artery of the ductus deferens.
Female: supplies rectum and vagina.
Male: supplies rectum, prostate, and urethra.
390
Artery of the ductus deferens
Branch off the prostatic artery.
Gives off caudal vesicle and middle rectal arteries.
Supplies the ductus deferens.
391
Ventral perineal artery
Termination of the internal pudendal artery after it passes the ischiatic notch with a variable urethral artery and artery of the penis/clitoris.
Branch here for the caudal rectal artery to the rectum and anus.
392
Artery of the penis
Terminates as three branches at the ischial arch:
Artery of the bulb of the penis
Deep artery of the penis
Dorsal artery of the penis
Surrounded by veins that will assist with erection.
393
Artery of the bulb of the penis
Arborizes in the bulb of the penis
| Supplies corpus spongiosum and penile urethra.
394
Deep artery of the penis
Enters the corpus cavernous at the crus.
395
Dorsal artery of the penis
Supplies the prepuce and pars long glandis.
396
Artery of the clitoris
Supplies clitoris and vestibular bulb.
397
Cranial vesical arteries
Remnant artery of the umbilical artery that has not closed all the way to the round ligament of the bladder. Supply bladder.
398
Parts of the urinary bladder
Apex
Body
Neck: no gross sphincter but smooth muscle innervation makes a physiological sphincter
399
Lateral ligament of the bladder
Attaches the bladder to the pelvic wall, often contains adipose tissue.
400
Urethral muscle
Serves as a voluntary sphincter for the urethra
In the pelvic canal and surrounds the urethra.
Innervated by the pudendal nerve
401
Trigone of the bladder
Triangle formed by the urethra and the entrance of the ureters into the bladder.
402
What are the infoldings of the empty bladder called?
Rugae
403
Where is the rectum
Within the pelvic canal. Continuous with the colon and the anal canal.
404
Three zones of the anal canal
Columnar zone: (Mucosa forms longitudinal ridges/anal columns)
Cutaneous zone: Fine hairs, cirucumanal glands, and paranal sinus).
Anus: After the external sphincter muscle.
405
Paranal sinus
Anal sac
| Opens into the cutaneous zone of the anal canal.
406
Where is the external sphincter muscle and what kind of muscle does it contain? What supplies the external sphincter muscle?
Surrounds the anal sac external to the cutaneous zone of the anal canal
Striated muscle
Innervated by the caudal rectal branch of the pudendal nerve
Supplied by the caudal rectal branch of the pudendal artery. `
407
Where is the internal sphincter muscle and what kind of muscle does it contain?
Enlargement of the smooth muscle coat of the anal canal near the anus.
408
Rectococcygeus muscle
Lies between the levator ani and the coccygeus to connect the anus with the tail
Attachments: dorsal surface of the rectum and sphincter muscles to caudal vertebrae.
409
Prostate gland (male)
Surrounds the neck of the bladder, varies in size.
| Thick capsule that is partially divided into right and left lobes by a septum.
410
Uretral parts (male)
Pelvic part
Penile part
Based on location
411
Colliculus seminalis (male)
Hillock into the lumen of the urethra where the ductus deferens opens.
412
Parts of the penis (male)
Root (crura and bulb)
Body (fibrous region that "locks" by bending).
Glans (pars longa glandis and bulbis glandis)
413
Preputial orifice (male)
Opening of the prepuce
| Haired region and smooth region of the prepuce meet here.
414
Fornix (male)
Deepest recess of the prepuce, pocketlike. Eliminated in erection.
415
Urethral crest (male)
Widening of the prostate into the pelvic urethra.
416
What are the crura of the root of the penis formed by? (male)
Corpus cavernosum penis
Vascular cavernous tissue
Extends from the ischiatic tuberosities on each side.
417
What is the corpus cavernosum penis supplied by? (male)
Deep artery of the penis
418
Tunica albuginea (male)
Thick fibrous white tunic surrounding the corpus cavernosum.
419
Ischiocavernosus muscle (male)
Arises from the ischiatic tuberosity and covers the origin of the crus, then inserts on the crus.
420
Retractor penis muscle (male)
Very long and skinny cordlike muscle. Mix of smooth and striated muscle.
Attachments: ventral surface of the sacrum, first 2-3 caudal vertebrae, and anal sphincters to the glans of the penis.
421
Bulbospongiosus muscle (male)
Bulges between the ischiocavernosus and covers the bulb of the penis.
422
Bulb of the penis (male)
Dorsal expansion of the corpus spongiosum.
| Part of the root of the penis between the left and right crura and covered by the bubospongiosus m.
423
Corpus spongiousum (male)
Surrounds the urethra over its entire length.
| Supplied by the artery of the bulb of the penis.
424
Ischiourethralis muscle (male)
Transverse muscle from ischial tuberosity to pelvic symphysis. Encircles the left and right dorsal veins of the penis, helping maintain erection.
425
Bulbis glandis (male)
Expansive vascular structure that surrounds the proximal end of the os penis
Helps retain the penis in the vagina during copulation.
Separated from the pars longa glandis by connective tissue.
426
Pars longa glandis (male)
Overlaps with the bulbis glands and continues to the distal end. Separated from the bulbis glands by connective tissue.
427
Os penis (male)
Forms about 1mo after birth from ossification of corpora cavernosa.
Ends in a pointed cartilagenous tip dorsal to urethral opening.
428
Deep V in the center of the os penis is called?
Which surface is it on?
(male)
The urethral groove
Surrounds the urethra and corpus spongiosum on 3 sides.
Ventral surface
429
Cervix (female)
Constricted caudal portion of the uterus. Small palpable enlargement grossly.
430
Cervical canal (female)
Vertical opening through the cervix.
431
Vagina (female)
Between the cervix and the vestibule. Mucosal lining has transverse folds so that it can expand.
432
Fornix (female)
s
433
Vestibule (female reproductive tract)
Continuous between the vagina and the vulva.
| Contains the vestibular bulbs, fossa clitoris, and the urethral tubercle.
434
Urethral tubercle (female)
Projection of tissue where the vagina and urethra meet the wall of the vestibule.
Dorsal to the vulva.
Contains the external urethral orifice.
435
Vestibular bulbs (female)
Erectile tissue homologous to the bulb of the penis. Small and close to the clitoris in the vestibular walls.
436
Clitoris (female)
Female homologue of the penis. Located in the floor of the vestibule.
437
Glans clitoridis (female)
Two crura attached and a glans body. Very small erectile structure in the fossa clitoridis . May contain an os clitoridis.
438
Fossa clitoridis (female)
Contains the glans clitoridis, in the floor of the vestibule.
Do not mistake with the urethral opening (which is cranial and ventral farther into the vestibule).
439
Vulva parts (female)
Two labia that are joined by dorsal and ventral commissures.
440
Rima pudendi
Orifice formed by the parts of the vulva.
441
Neurons are? Axons are?
Excitable cells that are the functional unit of a nerve. Their axons move signals from one part of the body to another.
442
What are the layers of the meninges?
```
(Epidural/extradural space)
The Dura mater
(Subdural space - more spread out).
The Arachnoid mater
(subarachnoid space)
The Pia mater
```
443
Cerebral spinal fluid cisterns
Cerebellomedullay (can access at the atlantoccipital joint).
| Lumbosacral (can access at the end of L7).
444
What are the functions of cerebral spinal fluid?
Protect the central nervous system
Provide nutrients
Provide a sink for electrons
Provide buoyancy so the CNS weighs very little.
445
Brain epidural space
A potential space - not there unless something is wrong such as a hematoma. Its presence increases inter cranial pressure.
446
Spinal nerve formula for the dog?
C8 T13 L7 S3 Cd5 (36 pairs)
447
Caudal Equina
The combination of nerves L6-Cd5 that branch off of L5/6/7 (spp. dependent) like a horse's tail.
448
Autonomic nervous system.
Synonym for visceral nervous system.
449
How do you test a reflex arc? What is going on in the nerves?
Often with skin pinching. Should see the cutaneus trunci twitch. This is from the afferent neuron communicating via a spinal cord interneuron in the spinal cord before the signal is sent to the brain.
450
How are the spinal nerves numbered in relation to vertebrae?
Cervical - for the vertebrae caudal to the nerve
Thoracic and beyond - for the vertebrae cranial to the nerve.
Nerve segments of the spinal cord starts to not match vertebrae at the lumbar portion.
451
Why can we breathe without thinking about it?
Strong reflex arcs of the diaphragm
| Will cause us to pass out before we can suffocate ourselves.
452
What are some examples of SSAs?
Balance, Vision, Hearing
453
What are some examples of SVAs?
Taste, Olfaction
454
Cortical input
Conscious control
455
What do GVAs sense?
The internal environment mainly.
| Chemical and physical status (temp, pressure, stretch, pH)
456
What do GSAs sense?
The external environment mainly.
| Pressure temp and pain from bones, skin and CT.
457
Name some physiological responses to a sympathetic signal.
Increased:
HR, RR, airway diameter, urination
Decreased:
Pupil size (mydriasis), GI output and movement
Varied:
vascular smooth muscle depending on location
458
Name some physiological responses to a parasympathetic signal.
Decreased:
HR, RR, airway diameter, urination
Increased
Pupil size (miosis), GI output and motility.
459
What types of tissue only have connections to one type of GVE? What type?
Vascular smooth muscle
Piloerector muscles
Sweat glands
Have only sympathetic innervation. Other tissues normally always in flux state between the two.
460
What tissue within the heart carries electrical impulses from Purkinje fibers?
Trabeculae carnae.
461
"Right sided" circulation
Pulmonary, low pressure
462
"Left sided" circulation
Systematic, high pressure
463
What is the general venous return pathway for blood from:
1. The head
2. The front limbs
3. Back/dorsum
4. GI system
5. Hind limbs and kidneys
1. External jugular to cranial v.c.
2. Cephalic vein to cranial v.c.
3. Azygous to cranial v.c.
4. Hepatic portal system to caudal v.c.
5. Caudal v.c.
464
Ductus venosum
Normal fetal shunt for the umbilical artery through the liver.
465
What is the point of the FO and PDA?
To improve efficiency so that the fetal circulation does not have to go through the useless underdeveloped lungs.
466
S1 occurs in which phase of the cardiac cycle? What is it caused by?
Diastole
| Closure of the aortic and pulmonary valves.
467
S2 occurs in which phase of the cardiac cycle? What is it caused by?
Systole
| Closure of the atrioventricular valves
468
What are the stages of the cardiac cycle (5)?
1. Atria contract (top off ventricles)
2. Ventricles contract and pressure increases, AV valves close, Pul/Aortic valves open, and blood is ejected.
(1 and 2 are systole, shorter)
3. Ejection slows and ventricles relax.
4. Aor/Pul valves close and AV valves open as pressure of ventricles drops
5. Atria and ventricles fill (at the same time).
(3,4,and 5 are diastole, longer)
469
In which phase is the heart relaxed?
Diastole
470
What produces heart sounds?
Vibrations from the sudden increase in pressure on inelastic valvular tissue.
471
Puncta maxima localization scheme
P: Pulmonary valve, on the left 3rd intercostal space
A/M: Aortic/mitral valve, on left 4th intercostal space.
R: Right AV, on R 5th intercostal space.
L: Left AV on L 5th intercostal space.
472
Basal/Apical localization scheme
Combine P/A (basal) and R/L (apical)
473
Which heart sound can split? Why?
S2 in very athletic animals.
474
What would cause a murmur?
Turbulent blood flow due to stenosis or valvular insufficiency.
475
In what area can normal lung sounds be heard?
Around the large airways
| Abnormal to hear sounds in smaller airways.
476
Which GVE has more broad coverage of the body?
The parasympathetic - into the brainstem as well.
477
How can you estimate the age of the animal from a thoracic radiograph?
Radiodensity of the thymus
| Older animals have radiolucent (fattier) thymuses
478
What type of nerves is the brachial plexus primarily?
GSE and GSA
| Some GVE for blood supply
479
What vessels supply the extensors of the antebrachium primarily?
Axillary and radial
480
What vessels supply the flexors of the antebrachium primarily?
Median and ulnar
481
What are the major sources of blood to the forepaw?
Median artery and caudal interosseous (radial branch).
482
Collateral circulation
If one blood supply is cut off the other can make up for it.
483
Is an open or closed castration technique preferred for small animals?
Open.
| Peritoneal cavity is open but technique is aseptic so this is okay.
484
Vaginal cavity
Continuous with the peritoneal cavity. Around the testes.
485
Blood supply to the abdominal wall
Dorsal: Cranial abdominal artery and Deep circumflex iliac artery
Ventral: Cranial epigastric artery and caudal epigastric artery (and their superficial branches)
486
What does the diaphragm look like when the dog is in right lateral recumbency?
The right crus is pushed cranial to the left crus.
487
What is the main muscle of inspiration?
```
The diaphragm
(others = muscles that pull the ribs laterally and cranially - external intercostals, serratis doornails, scalenus).
```
488
What is the main muscle of expiration
None - mainly the passive elastic recoil of the lungs and chest wall. Additional muscles recruited only with exertion.
489
Heave line
Mainly seen in horses.
Hypertrophy of the external abdominal obliques because of chronic effort to exhale due to an emphysema like condition caused by allergens.
490
How far does the abdominal cavity extend into the thorax via the cupula?
13th - 8th rib normally.
491
Name five structures on the left side of the abdomen?
```
Liver (both sides)
L kidney
Stomach
Spleen
Descending colon
```
492
Name five structures on the right side of the abdomen?
```
Liver (both sides)
R kidney
Descending duodenum
Cecum
Ascending colon
```
493
Name three structures in the dorsal abdomen?
Root of the mesentery
Transverse colon
Urinary bladder
494
What is found in the ventral abdomen?
The omentum
| Spleen if enormously enlarged.
495
Functions of the omentum
Pads the organs
| With damage forms adhesions with muscles to wall off areas of inflammation.
496
What is a sign of obesity in an abdominal radiograph?
A very clear falciform ligament in the ventral abdomen.
497
Where are the kidneys seen radiographically?
R kidney: L1-L3 (can only see the caudal pole in most radiographs)
L kidney: L2-L4
498
Name the unpaired arteries of the abdomen
Celiac
Cranial mesenteric
Caudal mesenteric
All supply the GI tract primarily
499
Why are splenectomies so time consuming?
Major branches of the splenic artery continue to the stomach and pancreas. Must ligate only the very small arteries next to the capsule of the spleen to avoid cutting off blood supply to those organs.
