The interactive dog atlas · for the classroom
33 cards, six per A4 sheet, to cut along the lines. Choose the set and, if you want an exercise, hide the name (the student writes it) or the text (the student writes the definition). No student names, no score.
cor · heart
On a lateral radiograph, the dog's heart usually lies between thoracic vertebrae 3 and 8, with the middle of its base at the level of the carina, near the 5th-6th intercostal space, and with the apex resting on the sternum. It measures 2.5-3.5 intercostal spaces: closer to 2.5 in deep-chested dogs, to 3.5 in broad-chested ones. It is wrapped in the pericardium.
Where: In the middle mediastinum, between thoracic vertebrae 3 and 8, with the apex toward the sternum.
pulmones · lungs
The left lung has a cranial lobe, with a cranial part and a caudal part, and a caudal lobe; the right has cranial, middle, caudal and accessory lobes, with the cardiac notch between the cranial and middle lobes. The number of lobes is established by the lobar bronchi, not by the outer appearance. The caudal border follows the cupola of the diaphragm.
Where: They fill the thoracic cavity from the thoracic inlet to the diaphragm; the left lung is drawn here.
trachea · trachea
The trachea is the tube with cartilage rings that carries air from the larynx into the thorax. On the lateral radiograph it shows as a radiolucent tube that ends at the carina, the bifurcation into the two main bronchi, in the center of the thorax; the middle of the base of the heart is at the same level. In the thorax it lies slightly to the right of the midline.
Where: From the larynx, beneath the cervical spine, to the carina, in the middle of the thorax.
oesophagus · esophagus
The esophagus links the pharynx to the stomach. In the neck it lies dorsal to the trachea; in the thorax it passes through the cranial mediastinum, then dorsal to the heart and to the tracheal bifurcation, in the middle mediastinum, and leaves the thorax between the two crura of the diaphragm, through the esophageal hiatus, next to the aorta, which has its own hiatus.
Where: Dorsal to the trachea in the neck, then through the mediastinum to the esophageal hiatus of the diaphragm.
larynx · larynx
The larynx is the cartilaginous box at the start of the trachea: the epiglottic, thyroid and cricoid cartilages form its wall, and the intrinsic muscles (for example the cricothyroideus) move its parts. It is suspended from the hyoid apparatus, to which the hyoid muscles attach: the sternohyoideus, thyrohyoideus and mylohyoideus.
Where: At the entrance to the trachea, below the pharynx, suspended from the hyoid apparatus.
thymus · thymus
The thymus is a two-lobed organ of the mediastinum, placed cranial and ventral to the heart. Its size depends on age: it is large in young animals, when immune function is being built, and shrinks gradually with age, so that in the adult it can be hard to find. The drawing shows it at the size of a puppy's.
Where: In the cranial and ventral mediastinum, in front of the heart.
hepar · liver
The liver lies against the caudal face of the diaphragm and, in the healthy dog, sits entirely within the costal arch. Its caudal border reaches the spleen on the left and the stomach in the center, and the right kidney lies in the renal fossa of the caudate lobe. It has right medial and lateral, quadrate, left medial and lateral, and caudate lobes; the gallbladder is on the right.
Where: Immediately caudal to the diaphragm, entirely within the costal arch.
ventriculus (gaster) · stomach
The dog's stomach is an organ of the left side, placed caudal to the liver, in the center of the cranial abdomen, with its long axis perpendicular to the vertebral column. The cardia lies slightly to the left of the median plane, at the level of thoracic vertebra 11; the pylorus slightly to the right. It has a cardia, fundus, body and pyloric part (antrum, canal, pylorus). Its shape and position change with filling.
Where: On the left, immediately caudal to the diaphragm and the liver, with its long axis perpendicular to the spine.
lien (splen) · spleen
The spleen lies on the left abdominal wall, cranial and ventral, parallel to the greater curvature of the stomach, in the greater omentum. Being held only by the gastrosplenic ligament, its position varies with the filling of the stomach and with its own size; the stomach is cranial and medial to it, the left kidney dorsal, medial and caudal. Its size varies greatly between breeds.
Where: Along the left abdominal wall, cranial and ventral, parallel to the greater curvature of the stomach.
pancreas · pancreas
The pancreas has a right lobe, a body and a left lobe. The right lobe lies in the mesoduodenum, medial and dorsal to the descending duodenum and ventral to the right kidney; the left lobe lies next to the greater curvature of the stomach and extends toward the cranial pole of the left kidney; the body is at the pyloroduodenal junction. The pancreatic duct opens on the major duodenal papilla.
Where: V-shaped: the right lobe next to the descending duodenum, the left lobe next to the greater curvature of the stomach.
duodenum · duodenum
The duodenum leaves the pylorus, makes the cranial flexure, descends on the right side of the abdomen as the descending duodenum, next to the right kidney and lateral to the ascending colon, turns back through the caudal flexure and climbs toward the duodenojejunal flexure. It receives bile and pancreatic juice through the major duodenal papilla. Being on the right, in the view from the left it is drawn with a dashed outline.
Where: The first part of the small intestine, on the right side (dashed outline).
jejunum et ileum · jejunum and ileum
The jejunum and ileum are the long, mobile part of the small intestine, in loops held by the mesentery; the mesenteric lymph nodes lie in the mesojejunum and mesoileum. For veterinary anatomists, the ileum is only the short terminal segment, which opens into the large intestine through the ileal orifice, unlike the 40/60 division of human anatomy.
Where: The loops of the small intestine in the ventral abdomen, held by the root of the mesentery.
caecum · cecum
The dog's cecum is a blind pouch at the start of the large intestine, lying caudoventral to the ascending colon, on the right side of the root of the mesentery. The ileum opens into the large intestine through the ileal orifice, and the cecum communicates with the colon through the cecocolic orifice. In the left-side view it is drawn with a dashed outline.
Where: On the right side, caudoventral to the ascending colon (dashed outline).
colon ascendens · ascending colon
The ascending colon is the first segment of the colon: short and straight in the dog, it runs from the cecocolic junction up to the right colic flexure, on the right side of the root of the mesentery, medial to the descending duodenum, with the cecum caudoventral to it. Being on the right, it is drawn with a dashed outline.
Where: Short, on the right of the root of the mesentery, medial to the descending duodenum (dashed outline).
colon transversum et descendens · transverse and descending colon
After the short ascending colon, the transverse colon crosses from right to left, cranial to the root of the mesentery, and the descending colon runs along the left side of the abdomen, dorsally, continuing as the rectum at the pelvic inlet. The descending colon is retroperitoneal for part of its length and is the caudal and medial landmark of the spleen.
Where: The transverse colon crosses from right to left, cranial to the root of the mesentery; the descending colon runs down the left side to the rectum.
rectum · rectum
The rectum is the last part of the large intestine, the continuation of the descending colon into the pelvic cavity, where it lies dorsal to the urinary bladder and the prostate (in the male) or the uterus and vagina (in the female) and ends in the anal canal. It is held by the mesorectum and belongs to the pelvic viscera, together with the bladder and the urethra.
Where: In the pelvis, dorsally, from the pelvic inlet to the anal canal.
ren sinister · left kidney
The left kidney lies retroperitoneally, against the dorsal wall of the abdomen, usually at the level of lumbar vertebrae 1-3, more caudal than the right one. On a ventrodorsal radiograph, a normal kidney measures 2.5-3.5 times the length of the second lumbar vertebra. It is the dorsal, medial and caudal landmark of the spleen; the ovary (in the female) lies caudal to it.
Where: Retroperitoneal, dorsal, at the level of lumbar vertebrae 1-3.
ren dexter · right kidney
The right kidney usually lies more cranially than the left one, roughly between the last thoracic and the second lumbar vertebra, with its cranial pole in the renal fossa of the caudate lobe of the liver. Masses of this kidney push the descending duodenum and the ascending colon medially and ventrally, a sign that these organs lie beside it, on the right. In the left-side view it is drawn with a dashed outline.
Where: More cranial than the left, roughly T13-L2, with its cranial pole in the renal fossa of the liver (dashed outline).
glandulae suprarenales · adrenal glands
The adrenal glands are two small endocrine organs, one cranial and medial to each kidney; the apparent position of the left one shifts when the kidney is pushed by the ultrasound probe. They are described in the endocrine system entry. In the drawing, the left one is the orange dot at the cranial pole of the left kidney, in front of the outline of the right kidney.
Where: Cranial and medial to each kidney.
vesica urinaria · urinary bladder
The urinary bladder lies in the caudal abdomen, at the border with the pelvis: it appears both among the abdominal viscera and among the pelvic ones. In a quadruped, the weight of the urine pulls it cranially, into the abdomen, away from the urethra, and when empty it draws back toward the pelvic inlet. It is held by the median ligament and the lateral ligaments; the urethra leaves from its neck.
Where: In the caudal abdomen, toward the pelvic inlet; its size depends on filling.
prostata · prostate gland
In the male dog, the prostate is a large, bilobed gland that completely surrounds the prostatic urethra, the first part of the pelvic urethra, immediately after the neck of the bladder. Unlike the cat, the dog has no preprostatic urethra and no bulbourethral glands. It lies at the pelvic inlet, ventral to the rectum; its position changes as the bladder fills.
Where: In the male, immediately caudal to the neck of the bladder, around the prostatic urethra, at the pelvic inlet.
uterus et ovaria · uterus and ovaries
In the female, the uterus has a cervix, a body and two long horns, held by the broad ligament (mesometrium). The ovaries lie caudal to the kidneys (on ultrasound they were found there in all the bitches of a group of 50) and are attached to the dorsal abdominal wall by the suspensory ligament, which must be broken at spaying so the ovary can be brought to the incision.
Where: The ovaries caudal to the kidneys, attached to the dorsal wall; the uterine horns run down to the uterine body and cervix, dorsal to the bladder.
encephalon · brain
The brain lies in the cranial cavity, behind the orbits, protected by the bones of the neurocranium; together with the spinal cord it forms the central nervous system, while the cranial and spinal nerves form the peripheral system. According to UMN, the hemispheres have frontal, parietal, temporal and occipital lobes, with the rhinencephalon underneath: the olfactory bulb, tract and piriform lobe. In the drawing it is schematic; the path of scent is in “Journey of a Scent”.
Where: In the cranial cavity, protected by the neurocranium.
medulla spinalis · spinal cord
The spinal cord continues the brain through the foramen magnum and runs down the vertebral canal, protected by the vertebral arches; from it the spinal nerves leave for the trunk and the limbs. Together with the brain it forms the central nervous system. In the drawing it is the violet line below the crests of the vertebrae, drawn schematically.
Where: In the vertebral canal, from the foramen magnum backward, below the crests of the vertebrae.
glandula thyroidea · thyroid gland
The thyroid has two long, narrow, flattened lateral lobes, lying on the lateral faces of the trachea, close to the larynx, along the first six or seven tracheal rings. The isthmus joining them is inconstant: in large dogs it may be a glandular band about a centimeter wide, in small ones it is usually absent. The parathyroids, usually four, lie on the lobes.
Where: On the sides of the trachea, immediately behind the larynx, along the first 6-7 tracheal rings.
cerebellum · cerebellum
The cerebellum lies in the caudal part of the cranial cavity, above the brainstem, to which it is joined by peduncles; it has a median vermis and two hemispheres, with a surface furrowed into folia. It coordinates movement and balance. In awake dogs scanned with fMRI, its activation rose with the concentration of the odor; the authors link it to the control of sniffing and to the detection threshold.
Where: In the back part of the braincase, behind the hemispheres, above the brainstem.
truncus encephali · brainstem
The brainstem joins the hemispheres to the spinal cord; in the UMN nomenclature it includes the diencephalon, mesencephalon, pons and myelencephalon. Most cranial nerves leave through it, and the motor and sensory pathways of the body pass through it. The tractography of Andrews et al. (2022) described in the dog a ventral tract running from the olfactory bulb, along the base of the brain, into the brainstem; its function is not demonstrated.
Where: Below the cerebellum, between the hemispheres and the spinal cord.
bulbus olfactorius · olfactory bulb
The olfactory bulb is the ventral structure of the hemisphere, part of the rhinencephalon, resting on the cribriform plate of the ethmoid, through which the olfactory nerves enter; the olfactory peduncle attaches it to the brain. Here the axons of the neurons from the nose synapse in glomeruli with the mitral cells, whose axons leave through the olfactory tract. In the dog it takes up about 0.31 % of brain volume, measured on five fixed brains (Kavoi and Hassanali 2011).
Where: At the front end of the brain, below the frontal lobes, on the cribriform plate.
hypophysis · hypophysis (pituitary)
The hypophysis, the pituitary gland, hangs from the ventral face of the hypothalamus by an infundibulum and sits in the hypophyseal fossa on the dorsal face of the basisphenoid, on the floor of the cranial cavity. In the dog it is circular and rather small, and the fossa is shallow. It releases hormones that command the thyroid, the adrenals and the gonads.
Where: Below the brain, in the hypophyseal fossa of the base of the skull.
lingua · tongue
The tongue has a root, a body and an apex and lies on the floor of the mouth, attached to the hyoid apparatus by the hyoglossus and to the chin by the genioglossus. In the dog it is wide and thin in front, thicker toward the root, very mobile, unpigmented, bright red, with a median groove; on its underside, beneath the mucosa, lies the lyssa, a fibrous cord peculiar to carnivores. Taste from the front two thirds travels through the facial nerve.
Where: On the floor of the mouth, between the rami of the mandible, attached to the hyoid and to the chin.
glandula parotidea · parotid gland
The parotid gland lies in the retromandibular region, between the ramus of the mandible, the base of the ear and the superficial part of the masseter; its upper end is wide and notched by the base of the ear. The parotid duct crosses the masseter and opens into the mouth, opposite the upper cheek teeth. The sources do not agree on its size relative to the mandibular gland, so the atlas does not compare them.
Where: At the base of the ear, between the ramus of the mandible and the masseter.
glandula mandibularis · mandibular gland
The mandibular gland, called submandibular in humans, lies ventrocaudal to the parotid, in a fibrous capsule, in the angle between the jugular vein and the facial vein, where it can be palpated. It is round and yellowish; its duct runs forward, toward the floor of the mouth. Next to it, in the same capsule, lies the caudal part of the sublingual gland.
Where: Below and behind the angle of the mandible, next to the jugular vein.
lymphonodi mandibulares · mandibular lymph nodes
The mandibular lymph nodes lie near the angle of the mandible, in the caudal half of the region between the two rami of the jaw, separated from the skin only by the platysma; they drain the regions of the face. They are easy to palpate, especially when inflamed, and belong to the mandibular lymph center, a constant group in carnivores.
Where: Below the angle of the mandible, immediately under the skin.