Carnivoran Pes & Paw Anatomy PDF

Carnivoran Pes & Paw Learning Objectives Ari Grossman, Ph.D. Office: AGD Science Hall 250-T ​Know the basic osteology of the carnivoran pes Email: [email protected] Understand the os...

Carnivoran Pes & Paw Learning Objectives Ari Grossman, Ph.D. Office: AGD Science Hall 250-T ​Know the basic osteology of the carnivoran pes Email: [email protected] Understand the osteology and ligaments of the distal phalanx with emphasis on the feline retractable claw 1. Ashdown et al. 2011. Color Atlas of Veterinary mechanism Anatomy Vol.2 2nd ed. (Ash) 2. Done et al. 2009. Color Atlas of Veterinary Know the nerves of the carnivoran pes Anatomy Vol.3 2nd ed. (Done) 3. Dyce et al. 2010. Textbook of Veterinary Anatomy Describe the blood supply of the pes 4th ed. (Dyce) 4. Evans & de Lahunta. 2010. Guide to the Dissection of the Dog (EDL) 5. Evans & de Lahunta. 2013. Miller’s Anatomy of the Dog (4th Edition)(Miller) © 2024 Ari Grossman PhD © 2024 Midwestern University  Position and Proportions of the Pes The pes (= hind paw) is the portion of the pelvic limb distal to the tarsus. The tarsus includes the tarsal bones, while the pes includes the metatarsals and phalanges Movement of the hind paw and digits is achieved via muscles of the leg that cross the ankle and insert on the phalanges as well as muscles intrinsic to the paw. Many of these muscles will attach onto the long digital flexors and extensors from the leg  Variations of the Pes The pes of different animals is adapted to their particular locomotor strategy and other important behaviors Plantigrade Digitigrade Unguligrade “flat-footed”  Osteology of the Pes Dog Pes – dorsal view Metatarsals Longer (by about 20%) than the metacarpals More rounded in cross section MT I is rudimentary in the dog Few breeds consistently possess a dewclaw in the hindlimb Phalanges MT I Proximal Intermediate Distal Metatarsal and Phalanges Base Body Head Proximal sesamoid bones Dorsal sesamoid bones Unguicular process http://www.flickr.com/photos/jrochester/14570533591/in/photostrea m/ part of distal phalanx covered by claw Dyce 92 Adaptations of the Integument – Foot Pads highly keratinized Stratum Corneum Connective tissue core of Eccrine sweat dermal papilla glands Tarsal pad Dermis of Metatarsal pad footpad sweat glands Adipose tissue Adipose tissue Digital pad Coarse collagen fibers Claw foot pad makes contact with substrate Adipose tissue  Adaptations of the Integument – Foot Pads Dog Cat Tarsal pad Digital pad is thick Digital pad is thin 1. Epidermis is heavily keratinized 1. Epidermis: stratified squamous keratinized Metatarsal pad 2. Dermal papillae project into epidermis epithelium 3. Hypodermis: Loose connective tissue w/ 2. Dermis: connective tissue sweat glands 3. Hypodermis: Loose connective tissue foot pad can thin depending on where the dog walks 4. Adipose tissue Digital pad 5. Sweat glands Claw Adaptations of the Integument – Claws  Adaptations of the Integument – Claws Extensor tendon Flexor tendons bone Phalanx I Unguicular crest bone Ungual process Wall epidermis Cornified epidermis Phalanx III Noncornified Digital epidermis pad Cornified flexor digitorum superficialis goes to phalanx 2! SC – Stratum corneum of epidermis of claw wall epidermis flexor digitorum profundus goes to phalanx 3 D – Dermis of claw Noncornified DP – Distal phalanx stratum corneum becomes cornfied aka horn-like epidermis DR – Dorsal ridge dorsal aspect S – Sole plantar portion of claw  Muscles of the Pes Dorsal Pes Dorsal Pes Plantar Pes Superficial Deep Extesnor digirotum brevis – Fibular n. aids extensor digitorum longis in extending Plantar Pes EDL The long tendons of the digital flexors travel within a TL synovial sheath. The annular ligaments protect the sheath and prevent the tendons from “bowing” when Extensor the forepaw is flexed. digitorum brevis Large number of intrinsic pes muscles. Interosseous muscles most of the fleshy part of the paw Lumbricales Deeper Interflexorii Tibial n. Adductores digiti II et V Quadratus plantae Abductor digiti V only know interosseous muscle Muscles of 1st digit if present Abductor digiti I flexor digiti I brevis Adductor digiti I Dorsal Elastic Lig.  Important Ligaments of the Pes metatarsal phalangeal Collateral lig. Of MTP joint proximal interpharangeal Collateral lig. Of PIP joint Lateral sesamoidean lig. Dorsal elastic ligament Collateral lig. Of DIP joint distal interphalangeal Miller 174  Important Ligaments of the Manus Dorsal elastic ligaments Extend from the proximal ends of the middle phalanges to the unguicular crests of the distal phalanges Keep the claws elevated – prevent claws getting caught in substrate retracts claw Dorsal elastic ligament Protrusion of the claws is achieved by contraction of Flexor digitorum profundus MP DP Flexor digitorum profundus  Retraction of the Claws in Cats In cats: Medial dorsal elastic ligament Lateral dorsal elastic 1. The dorsal elastic ligaments differ in length and attachments ligament Medial DE ligament – longer Extend from proximal interphalangeal joint to sides of distal phalanx Lateral DE ligament- short Extends from distal end of middle phalanx to top of unguicular crest FDP 2. The distal phalanx is oriented obliquely to the middle phalanx normal state This combination of traits retracts the claws so that the distal phalanx lies lateral to the middle phalanx, with its distal end in a dorsal position. Protracting the claw requires action by the Flexor digitorum profundus lateral dorsal elastic ligament retracts the claw and medial dorsal elastic ligament holds it in place  Onychectomy / ‘Declawing’ – Amputation of Distal Phalanx and Claw Excision/removal of a nail or nail bed Remove the DISTAL PHALANX Disarticulate the Distal Interphalangeal Joint  Blood Supply of the Pes Dorsal The pes has an extensive blood supply Cranial branch Superficial branch of External iliac a. saphenous artery cranial tibial Femoral a. Deep femoral a. Saphenous a. Dorsal pedal artery Cranial branch of the saphenous a.anastomose with superficial branch of cranial tibial Dorsal metatarsal aa. Dorsal common digital aa. sends a branch to adjacent digits Proper digital aa. Caudal branch of the saphenous a. Medial and lateral plantar & metatarsal aa. Dorsal common digital, II, III, IV Popliteal a. Cranial tibial a. Dorsal metatarsal II, III, IV Dorsal pedal a. (Bovine - Dorsal metatarsal) a. Axial dorsal proper digital III Abaxial dorsal proper digital III common means they will branch into other parts! proper goes to exact digits  Blood Supply of the Pes Palmar Superficial Deep The pes has an extensive blood supply Caudal branch Caudal branch saphenous artery External iliac a. saphenous Femoral a. artery Deep femoral a. Saphenous a. Medial plantar a. Cranial branch of the saphenous a. Dorsal metatarsal aa. Proximal perforating Lateral Dorsal common digital aa. branch of dorsal plantar a. Proper digital aa. metatarsal artery II Caudal branch of the saphenous a. Plantar metatarsal Medial and lateral plantar & metatarsal aa. Plantar arteries II, III, IV Popliteal a. common digital Cranial tibial a. arteries II, Plantar Dorsal pedal a. (Bovine - Dorsal metatarsal) a. III, IV common digital arteries cranial and caudal branch of the saphenous are the main blood suppliers II, III, IV Anastomoses via perforating branches of dorsal metatarsal arteries comes through the dorsal and anastomose with plantar metetarsal arteries  Cutaneous Innervation of hindlimb Autonomous zones of the cutaneous Lateral cutaneous innervation of the canine hindlimb femoral n. Caudal cutaneous femoral n. Sciatic nerve Genitofemoral n. plantar dorsal Saphenous n. Fibular (Peroneal) n. Tibial n. medial © 2024 Ari Grossman PhD © 2024 Midwestern University lateral