Lab Exam April Flashcards
Chondrocranium (lamprey)
Formed from endocranial elements
Partly encloses the brain and sense organs and has cartilages that extend anteriorly to support the annular cartilage
Annular Cartilage (lamprey)
Ring-like structure that forms the main skeletal element of the oral funnel
Lingual Cartilage (lamprey)
Median cartilage that extends posteriorly from the annual cartilage, ventral to the chondrocranium
Supports the rasping tongue
Branchial Basket (lamprey)
Network of cartilages that extends posterior and connected to the chondrocranium
Supports the pharyngeal region
Pericardial Cartilage (lamprey)
Crescent-shaped cartilage at the posterior end of the branchial basket
- Lies on the posterior wall of the pericardial cavity
Main differences between lamprey and higher fish pharyngeal skeletons
- In lampreys, the structure is a connected network, not separate arches
- In lampreys, it is connected to the pericardial cartilage
- Branchial basket in lampreys lies superficially, just beneath the skin and lateral to the gills, rather than deep and medial to the gills
Notochord (lamprey)
Axial support for the body
Extends from beneath the posterior part of the brain to the tip of the tail
Arcualia
Representation of vertebrae in the lamprey
Lie dorsal to the notochord on either side of the spinal cord
Operculum
Large, triangular bony plate on the pharyngeal region, covers the gills
Preoperculum
J-shaped bone that lies anterior to the operculum
- Has a fringe of serrations on the posterior edge
Suboperculum
Bone that lies posteroventral to the operculum
Interoperculum
Rounded bone that lies ventral o the preoperculum
Branchial Arches (fish)
Lie deep to the opercular bones and support the gills
Frontal (fish)
Forms much of the skull roof and roofs the orbit
Parietal (fish)
Bone that lies posterior to the frontal
Lacrimal (fish)
Large (ish) bone that forms the anteroventral margin of the orbit
Maxilla (fish)
Slender bone that articulates to the anteroventral part of the lacrimal and the posterior part of the dentary; posterior end is embedded in soft tissue
Edentulate
Premaxilla (fish)
Most anterior bone of the upper jaw that articulates with the other premaxilla and the nasal and maxilla
Bears teeth on the anteroventral sideIs projected forward during opening of the mouth in derived actinopterygians
Nasal (fish)
Thin bone that extends anterior from the frontal
Comparison of bones in fish and other vertebrates
Should be noted that bones with the same name are not homologous with one another
- Frontal in fish = parietal in tetrapods
- Parietal in fish = postparietal in tetrapods
Suspensorium
Supports the jaw onto the rest of the skull in fishes
Consists of three bones:
- Hyomandibular (dorsal)
- Metapterygoid
- Quadrate (ventral, articulates with lower jaw)
Anguloarticular
Forms most of the posterior end of the lower jaw, articulates with the quadrate of the upper jaw
Two parts:
- Angular is large, flat, superficial component
- Articular is medial and endochondral
Dentary (fish)
Can be seen anterior to the anguloarticular
Bears teeth
Retroarticular
Small endochondral ossification that lies posteroventrally on the lower jaw
Vertebral Column (Fish)
Consists of trunk and caudal vertebrae
- Each vertebra has a centrum as its main body
- All vertebrae have elongated dorsal neural spines
Caudal Vertebrae
Vertebrae of the tail- Have elongated hemal spines ventrally
Trunk Vertebrae
Vertebrae anterior to the tail
- Bear ribs, both dorsal and ventral
Fish Ribs
Ventral Ribs
- Prominent
- Curve ventrally and form the myosepta adjacent to the body cavity
Dorsal Ribs
- Extend laterally
- More delicate, are attached via ligaments to the posterior surface of more anterior ventral ribs
- Often missing in prepared specimens
Dorsal Fins
Anterior and Posterior
Supported by thin, elongated fin rays
- Termed spines if they are ossified (all anterior rays, first two posterior)
- Termed soft fin rays if not ossified and may branch distally (remaining posterior)
- Each is supported at the base by a radial perygiophore
Radial Pterygiophore
Ventrally tapered bony element that underlies each fin ray in the anterior and posterior dorsal fins
- Extends ventrally into the connective tissue between two neural spines
Anal Fin
Lies along the midventral line, opposite to the posterior dorsal fin
- First two fin rays are spines, remaining are soft rays
- Radial pterygiophores support these rays by extending dorsally; anterior few fuse into large element that attaches to ventral rib(s) behind which hemal spines begin
Caudal Fin
Supported by soft fin rays that form a homocercal tail in the perch
Uroneurals
Last few neural spines
Hypurals
Flattened hemal spines of the last few caudal vertebrae, immediately posterior and ventral to the uroneurals
Provide most of the support for the fin rays of the caudal fin
Epurals
Modified neural spines that are unattached to vertebrae
Provide some support for the dorsal part of the caudal fin
Cleithrum
Dorsoventrally elongated bone that lies deep to the (sub)operculum and extends to the ventral midline to articulate with the opposite cleithrum
Main supporting element of the pectoral girdle
Supracleithrum
Articulates ventrally with the cleithrum and anterodorsally to the posttemporal
Posttemporal
Bone that is attached to the posterior end of the skull and articulates posteroventrally to the supracleithrum
Scapula
Large element of the shoulder girdle that lies dorsal to the procoracoid
Procoracoid
Large element of the shoulder girdle that lies ventral to the scapula
Postcleithrum
Elongated, triangular bone that extends dorsoventrally beneath the pectoral fin
- Widened end lies deep to the cleithrum
- Tapers ventrally, passing medial to the fin and extends towards the pelvic fin
Radial Pterygiophores (Pectoral Fin)
Extend from the scapula or procoracoid and distally articulate with the soft fin rays
Basipterygia
Paired triangular plates of bones that are oriented anteroposteriorly and form the pelvic girdle
- Wide base located posteriorly
- Tapers and passes dorsal to the articulation between the two cleithra anteriorly
Pelvic Fin
Fin rays each attach directly to the posterior end of a basipterygium
- Are all soft fin rays except for the medial ray
Premaxillae (mudpuppy)
Paired, most anterior part of the skull/upper jaw
Frontals (mudpuppy)
Paired, large bones immediately posterior to the premaxillae
Parietals (mudpuppy)
Paired, large bones posterior to the frontals- Has long slender anterior projection that extends lateral to the frontals
Antorbital Processes (mudpuppy)
Paired, cartilaginous
Part of the chondrocranium
Project laterally near the anterior end of the parietal bones
- Project from the trabecular cartilage
Vomer (mudpuppy)
Modified to take on the role of the maxilla (which the mudpuppy lacks)
- Forms the anterolateral margin of the skull
Palatopterygoid (mudpuppy)
Forms the central part of the lateral margin of the skull
- Posterior to the antorbital process
- Compound element formed from the palatine and pterygoid
Prootic (mudpuppy)
Paired bone that contributes to the otic capsule
Lies lateral to the parietal, near the suture of the parietals and frontals
Opisthotic (mudpuppy)
Paired bone that contributes to the otic capsule
Lies posterior to the squamosal
Fenestra Ovalis (mudpuppy)
Contained within a cartilaginous region that lies between the prootic and opisthotic
Squamosal (mudpuppy)
Extends anterolaterally from the opisthotic to form the posterolateral margin of the skull
Quadrate (mudpuppy)
Articulates with the squamosal posteriorly and the palatopterygoid anteriorly
- Inclines anteroventrally
- Forms the jaw joint at its articulation with the mandible
Quadrate Cartilage (mudpuppy)
Cartilaginous bridge from the anterior end of the quadrate to the lateral margin of the parietal
Columella (mudpuppy)
Disc-shaped bone that lies anterior to the opisthotic and covers the cartilaginous region between the opisthotic and prootic
- Covers the fenestra ovalis
- Has a small stylus projecting from its lateral surface
Transmits vibrations to the inner ear
Foramen Magnum (mudpuppy)
Large opening on the posterior surface of the skull
- Spinal cord passes through it
Exoccipitals (mudpuppy)
Paired, form the posterior part of the skull, lateral and ventral to the foramen magnum
- Each contains an occipital condyle
Parasphenoid (mudpuppy)
Large, triangular, plate-like bone that forms most of the skull’s ventral surface
Ethmoid Plate (mudpuppy)
Cartilaginous plate anterior on the chondrocranium
- Visible anterior to the parasphenoid in ventral view
Chondrocranium (mudpuppy)
Consists of:
- Basal plate
- Exoccipital
- Opisthotic
- Synotic tectum
- Prootic
- Parachordal plate
- Quadrate
- Quadrate cartilage
- Fenestra communis
- Ethmoid plate
- Trabecular horn
- Antorbital process
- Trabecular cartilage
Synotic Tectum (mudpuppy)
Thin cartilaginous bridge that connects the left and right otic capsules
Basal Plate (mudpuppy)
Cartilaginous bridge between the left and right exoccipitals
Parachordal Plate (mudpuppy)
Cartilaginous plate that extends anteriorly from each otic capsule
Trabecular Cartilages (mudpuppy)
Slennder, rod-like, cartilaginous elements extending anteriorly from the parachordal plates
Trabecular Horns (mudpuppy)
Small projections anterior to the ethmoid plate that lie between the nasal capsules
Meckel’s Cartilage (mudpuppy)
Cartilaginous structure that extends through the interior of the mandible
- Mostly visible in medial view
- Forms the articular surface for the quadrate of the upper jaw posteriorly
Mentomeckelian (mudpuppy)
Where Meckel’s Cartilage ossifies anteriorly into the mandibular symphysis
Dentary (mudpuppy)
Covers most of the lateral surface of Meckel’s cartilage
- Bears a long row of marginal teeth
Coronoid (mudpuppy)
Is exposed largely on the medial side of Meckel’s cartilage as well as a tiny exposure on the dorsolateral side
- Bears a short row of marginal teeth
Prearticular (mudpuppy)
Covers much of the posterior part of the mandible in medial view
- Tapers anteriorly as a wedge on the dentary
Hyoid Apparatus (mudpuppy)
Large, composed of the hyoid arch and parts of the first three branchial arches
- Hyoid arch is largest, anterior, supports the tongue
Hypohyal (mudpuppy)
Hyoid Arch
- Small, median
- Paired
Ceratohyal (mudpuppy)
Hyoid Arch
- Lateral, elongated
- Paired
Basibranchial 1 (mudpuppy)
Hyoid Arch
- Lies median
- Extends posteriorly from hypohyals to the base of the first branchial arch
Branchial Arch 1 (mudpuppy)
Formed of:
- Ceratobranchial 1 (paired, anterior)
- Epibranchial 1 (paired, posterior)
Basibranchial 2 (mudpuppy)
Extends posteriorly from the left and right ceratobranchial 1
Ceratobranchial 2 (mudpuppy)
Tiny, nodular element at the base of epibranchial 2
Epibranchial 3 (mudpuppy)
Smallest epibranchial, lies posterior to epibranchial 2
Cervical Vertebra (mudpuppy)
Only one!
- Articulates with the occipital condyles of the skull
- Anteroventral process of the atlas projects into the foramen magnum
- Posteriorly articulates with the first of the trunk vertebrae
Trunk Vertebrae (mudpuppy)
Lots of them
- Have transverse processes that extend from the centrum and articulate with small, Y-shaped ribs
Neural Canal (mudpuppy)
Passes dorsal to the centra in vertebrae
- Neural arch forms the roof of the canal; has a neural process
Prezygapophyses (mudpuppy)
Present on each vertebra for articulation with the preceding vertebra
Postzygapophyses (mudpuppy)
Present on each vertebra for articulation with the succeeding vertebra
Sacral Vertebra (mudpuppy)
Just one!
- Articulates to the pelvic girdle through its ribs
Caudal Vertebrae (mudpuppy)
Tail vertebrae
- Each have a hemal arch
- Most lack ribs, but still have transverse processes
Pectoral Girdle (mudpuppy)
Mainly cartilaginous
Left and right halves that overlap ventrally but don’t fuse
Scapula (mudpuppy)
Short bone with the suprascapular process dorsally
- On ventral side, have glenoid fossa, the depression that articulates with the forelimb
Procoracoid Cartilage (mudpuppy)
Slender, elongated, projects anteriorly from the glenoid fossa
Coracoid Cartilage (mudpuppy)
Broad, ventral, plate-like part of the pectoral girdle; they partly overlap
Humerus (mudpuppy)
Brachium of the forelimb
Radius (mudpuppy)
Anteromedial bone of the antebrachium on the forelimb
Ulna (mudpuppy)
Posterolateral bone of the antebrachium on the forelimb
Manus (mudpuppy)
Only has four digits
- Six carpals
- Four metacarpals
- Phalanges
Pelvic Girdle (mudpuppy)
Mainly cartilaginous
Ilium (mudpuppy)
Ossified, extends ventrally from its articulation with the rib of the sacral vertebra to the acetabulum
Acetabulum (mudpuppy)
Depression on the ilium that articulates with the hind limb
Puboischiadic Plate (mudpuppy)
Ventral formation of the pelvic girdle
- Pubic cartilage
- Ischiadic cartilage
- Ischium
Pubic Cartilage (mudpuppy)
Elongated, triangular anterior portion of the puboischiadic plate
Isciadic Cartilages (mudpuppy)
Posterior portion of the puboischiadic plate; contains a pair of ossified ischia
Obturator Foramen (mudpuppy)
Foramina just anterior to each acetabulum
Femur (mudpuppy)
Forms the thigh on the hindlimb
Tibia (mudpuppy)
Anterior part of the crus on the hindlimb
Fibula (mudpuppy)
Posterior part of the crus on the hindlimb
Pes (mudpuppy)
Most distal part of the hindlimb
- Six tarsals (cartilaginous)
- Four digits consisting of metatarsals and phalanges
Skull elements missing in anurans
- Lacrimal
- Prefrontal
- Postfrontal
- Opisthotic
Interpterygoid Vacuities (frog)
Large paired openings on the ventral part of the skull (palate)
Premaxilla (frog)
Small, median bone on the anterior portion of the skull
- Bears a single row of small teeth (premaxillary)
Maxilla (frog)
Long paired bones that make up the lateral sides of the skull
- Bears a single row of small teeth (maxillary)
Quadratojugal (frog)
Short paired bone on the posterolateral sides of the skull
Vomer (frog)
Lies just posterior to the premaxillae
- Bears vomerine teeth
Nasals (frog)
Paired, broad, flattened bones that meet each other at the dorsal midline
- Form the anterior part of the orbits through a narrow process that extends lateroventrally
Nares (frog)
Lie anterior to each orbit
Frontoparietals (frog)
Paired, elongated bones that meet along the dorsal midline and form much of the cranial roof
Sphenethmoid (frog)
Forms most of the lateral and ventral sides of the braincase
- Mostly tubular, with lateral expansion anteriorly
- Small wedge can be seen dorsally wedged between the nasal and frontoparietal
Palatines (frog)
Extend as transverse bars on either side of the sphenethmoid to reach the maxillae
Parasphenoid (frog)
Cruciate bone on ventral side of skull
- Anterior part of “stem” covers the sphenethmoid in ventral view
- Posterior part of stem projects to the exoccipitals
- Each transverse arm extends laterally towards a pterygoid
Exoccipitals (frog)
Paired bones that form the posterior part of the skull
- Each has an occipital condyle ventrally
Pterygoid (frog)
Paired, Y-shaped bone
- Anterior arm connects with maxilla and nasal
- Posterior arm curves gently laterally to contact the angle of the jaw
- Medial arm is shortest and extends to the prootic and transverse arm of the parasphenoid
Squamosal (frog)
Paired, T-shaped
- Top of T slightly curved, extends diagonally
- Long stem of T angled towards angle of the jaw
Annular Cartilage (frog)
Cartilage that covers a large portion of the squamosal (if in tact) and supports the tymapanic membrane
Quadrate (frog)
Main element that forms the upper part of the jaw joint
- Usually cartilaginous in anurans
- Usually covered laterally by the ventral squamosal and medially by the posterior arm of the pterygoid
Prootics (frog)
Paired, irregularly-shaped bones that contain the inner ear
- Between the squamosal, frontoparietal and exoccipital
- Forms the posterior part of the orbit
- Usually fuses with the exoccipital
Optic foramen (frog)
Foramen on the medial side of the orbit
Trigemial Foramen (frog)
Foramen on the posterior side of the orbit
- Passage for the trigeminal and facial nerves
Foramen Ovale (frog)
Foramen beside the occipital condyle
- Passage for the glossopharyngeal and vagus nerves
- Formed by the prootic and exoccipital
Mandible (frog)
Edentulate
- Meckel’s cartilage is covered by dentary anterolaterally and agulosplenial medial & posteriorly
Missing mandibular bones in anurans (present in non-mammalian tetrapods)
- Coronoid
- Articular
- Prearticular
Dentary (frog)
Thin, flange-like
Angulosplenial (frog)
Large
- Posteromedial surface has medially pointed coronoid process
- Articulates with the quadrate posteriorly
Mentomeckelian (frog)
Ossifies the mandibular symphysis
Hyoid Apparatus (frog)
X-shaped cartilaginous plate that lies on the floor of the oral cavity and supports the tongue and larynx
- Two anterior cornua project anteriorly, curved
- Two posterior cornua are bony rods that project posteriorly
Vertebral Column (frog)
Only nine free vertebrae
- First is the atlas
- Last is a sacral vertebra
- All have prominent transverse processes but no ribs
Urostyle (frog)
Rod-like bone that extends posteriorly from the sacral vertebra
- Formed from the fusion of serveral postcranial vertebrae
Suprascapula (frog)
Extends dorsomedially from the scapula
- Has a prominent, (usually) calcified cartilaginous portion medially
Clavicles (frog)
Slender, extend almost directly medially from the scapula anterior to the procoracoid
Procoracoid (frog)
Large paired bones that form a plate-like base to the pectoral girdle
Omosternum (frog)
Rod-like bone that lies anterior to the clavicles
Episternum (frog)
Cartilaginous extension anterior to the omosternum
Sternum (frog)
Posterior to the procoracoids
Xiphisternum (frog)
Cartilaginous extension posterior to the sternum
Radio-Ulna (frog)
Fusion of the radius and ulna into a single element
Prepollex/prehallux (frog)
Small bone that extends medially from the carpals/tarsals, may be a reduced metacarpal/tarsal
Ilium (frog)
Elongated, anteriorly-directed element of the pelvic girdle that has a prominent iliac crest
Ishium & Pubis (frog)
Form a semi-circle in lateral view
- Ishium is more posterior
- Part of the pelvic girdle
Tibiofibula (frog)
Fusion of the tibia and fibula into a single element
Tibiale (frog)
Elongated proximal tarsal
- Medial
Fibulare (frog)
Elongated proximal tarsal
- Lateral
- Homologous with the calcaneum
Supraspinatus
- Origin: supraspinous fossa of scapula
- Insertion: greater tuberosity of humerus
- Action: extends humerus
Infraspinatus
- Origin: infraspinous fossa of scapula
- Insertion: greater tuberosity of humerus
- Action: rotates humerus laterally
Teres major
- Origin: posterior border of scapula, dorsal third
- Insertion: medial surface of humerus via tendon in common latissimus dorsi
- Action: flexes and medially rotates the humerus
Teres minor
- Origin: posterior border of scapula, distal to glenoid fossa
- Insertion: greater tuberosity of humerus
- Action: flexes and laterally rotates humerus
Rhomboideus
- Origin: posterior cervical and anterior thoracic vertebrae
- Insertion: distal border of scapula, distal portion
- Action: draws scapula toward vertebral column
Rhomboideus capitis
- Origin: medial portion of nuchal crest
- Insertion: dorsal border of scapula, anterior
- Action: rotates and draws scapula anteriorly
Serratus ventralis
cervicis
- Origin: transverse processes of C3-C7
- Insertion: medial surface of scapula, near dorsal border
- Action: draws scapula anteroventrally
thoracis
- Origin: lateral surface of R1-R9/R10
- Insertion: medial edge of scapula, near dorsal border
- Action: draws scapula ventrally, helps support trunk on forelimb
Subscapularis
- Origin: subscapular fossa of scapula
- Insertion: lesser tuberosity of humerus
- Action: adducts humerus
Coracobrachialis
- Origin: coracoid process of scapula
- Insertion: media surface of proximal end of humerus
- Action: adducts humerus
Biceps brachii
- Origin: small tubercle at dorsal margin of glenoid fossa of scapula (via tendon)
- Insertion: bicipital tuberosity of radius (by tendon)
- Action: flexes antebrachium
Medial head of the triceps brachii
- Origin: shaft of humerus
- Insertion: olecranon process of ulna (common tendon with lateral and long heads)
- Action: extend antebrachium
Digastric
- Origin: mastoid process of temporal and jugular process of occipital
- Insertion: venteromedial surface of dentary
- Action: depresses mandible
External intercostals
- Origin: posterior margin of a rib
- Insertion: anterior margin of the adjacent posterior rib
- Action: protracts ribs, increasing the diameter of the thorax
External oblique
- Origin: posterior 9-10 ribs and lumbodorsal fascia
- Insertion: mainly linea alba (sternum to pubis, via aponeurosis)
- Action: constricts abdomen
Genioglossus
- Origin: medial surface of dentary
- Insertion: tongue, posterior fibers on basihyoid and ceratohyoid
- Action: depresses tongue, draws root anteriorly, curls tip of tongue ventrally
Geniohyoid
- Origin: ventromedial surface of dentary (just posterior to symphysis)
- Insertion: ventral surface of basihyoid
- Action: draws hyoid anteriorly
Hyoglossus
- Origin: lateral part of ventral surface of basihyoid
- Insertion: tongue
- Action: depresses and retracts tongue
Iliocostalis
- Origin: lateral surface of ribs
- Insertion: lateral surface of more anterior ribs
- Action: draws ribs together
Internal intercostals
- Origin: anterior margin of a rib
- Insertion: posterior margin of the adjacent anterior rib
- Action: retracts ribs, decreasing diameter of thorax
Internal oblique
- Origin: lumbodorsal fascia and iliac crest
- Insertion: linea alba (via aponeurosis)
- Action: constricts abdomen
Lingualis proprius
Intrinsic musculature of the tongue
- Bundles arranged in longitudinal, transverse and vertical groups
- Responsible for complex movements
Longissimus capitis
- Origin: prezygapophyses of C4-C7
- Insertion: mastoid process of temporal
- Action: flexes head laterally
Longissimus dorsi
medial division
- Origin: sacral and caudal vertebrae
- Insertion: more anterior lumbar/sacral/caudal vertebrae
- Action: extends vertebral column
lateral division
- Origin: ilium and deep layer of lumbodorsal fascia
- Insertion: more anterior lumbar and thoracic vertebrae
- Action: extends vertebral column
Longus colli
- Origin: ventral surface of T1-T6; slips from cervical vert.
- Insertion: transverse processes of all cervical vertebrae
- Action: flexes neck laterally and ventrally
Masseter
- Origin: zygomatic arch
- Insertion: ventral part of masseteric fossa of dentary
- Action: elevates mandible
Multifidus
- Origin: more posterior sacral, lumbar, thoracic and cervical vertebrae
- Insertion: neural processes of more anterior vertebrae
- Action: (singly) flexes vertebral column laterally; (with other side) extends vertebral column
Mylohyoid
- Origin: medial surface of dentary
- Insertion: midventral raphe, posterior fibres to basihyoid bone
- Action: elevates floor of oral cavity; draws hyoid anteriorly
Pterygoid
- Origin: pterygoid blade of skull
- Insertion: medial surface of angular region of dentary
- Action: elevates mandible
Rectus abdominis
- Origin: pubis
- Insertion: costal cartilages of sternum
- Action: compresses abdomen; flexes the trunk (draws ribs and sternum posteriorly)
Scalenus
- Origin: ribs
- Insertion: transverse processes of all cervical vertebrae
- Action: flexes neck or draws ribs anteriorly
Semispinalis capitis
- Origin: prezygapophyses of C3-C7 & T1-T3
- Insertion: medial third of nuchal crest
- Action: elevates head
Semispinalis cervicis
- Origin: neural processes of C7, T1-T3; prezygapophyses of T2-T5
- Insertion: medial third of nuchal crest
- Action: Elevates head
Serratus dorsalis caudalis
- Origin: middorsally from neural processes of lumbar vertebrae
- Insertion: posterior 4-5 ribs
- Action: draws ribs posteriorly
Serratus dorsalis cranialis
- Origin: middorsal raphe between axis and T10 (via aponeurosis)
- Insertion: lateral surface of the first 9 ribs
- Action: Draws ribs anteriorly
Spinalis dorsi
- Origin: neural spines of T10-T13
- Insertion: cervical and more anterior thoracic vertebrae
- Action: extends vertebral column
Splenius
- Origin: anterior middorsal line
- Insertion: nuchal crest
- Action: (singly) flexes head laterally; (with other side) elevates head
Sternohyoid
- Origin: 1st costal cartilage and manubrium
- Insertion: basihyoid
- Action: draws hyoid posteriorly
Sternomastoid
- Origin: manubrium, anterior surface
- Insertion: nuchal crest, lateral portion; mastoid process
- Action: (singly) flexes neck laterally; (with other side) depresses snout
Sternothyroid
- Origin: first costal cartilage
- Insertion: thyroid cartilage of larynx, posterolateral surface
- Action: draws larynx posteriorly
Styloglossus
- Origin: mastoid process; stylohyoid
- Insertion: tongue
- Action: elevates and retracts tongue
Temporalis
- Origin: temporal fossa of skull; temporal fascia
- Insertion: coronoid process of dentary
- Action: elevates mandible
Thyrohyoid
- Origin: thyroid cartilage of larynx, lateral surface
- Insertion: thyrohyoid
- Action: draws hyoid posteriorly and dorsally
Transverse abdominis
- Origin: costal cartilages; transverse processes of lumbar vertebrae; ventral margin of ilium
- Insertion: linea alba
- Action: constricts abdomen
Transverse costarum
- Origin: sternum, lateral margin
- Insertion: first rib and costal cartilage
- Action: draws ribs anteriorly
Transverse thoracis
- Origin: sternum, dorsolateral margin between R3-R8
- Insertion: costal cartilages near rib attachments
- Action: draws ventral portion of ribs anteriorly
Parotid Gland
Largest salivary gland
- Lies ventral to the ear
- Irregular with obvious lobules and an elongated, tapered ventral portion
Mandibular Gland
Small salivary gland
- Lies posterior to the ventral portion of the parotid gland
- Smooth and nearly oval
Maxillary Vein
Crosses the anterior part of the mandibular gland and passes deep to the parotid gland
Lymph nodes
Small, smooth (no lobules), present in the same area as the salivary glands
- Two are present ventral to the parotid and mandibular glands
Linguofacial Vein
Passes between two lymph nodes ventral to the parotid and mandibular glands
Parotid Duct
Thick, whitish strand that passes over the middle portion of the masseter, extends toward upper lip
Facial nerve
Two branches cross the masseter
Mandibular Duct
Emerges from the anteroventral part of the mandibular gland
- Whitish strand
- Passes ventral to a small glandular mass
Sublingual Gland
Small gland that lies deep to the mandibular gland and ventral part of the parotid gland
Labia
Lips
Vestibule
Portion of the oral cavity between the lips and teeth
Oral Cavity Proper
Portion of the oral cavity, bounded by the teeth anteriorly and laterally, extending just beyond the hard palate
Palatal Rugae
Roughened transverse ridges on the epithelial covering of the hard palate
Lingual Frenulum
Vertical median flap that anchors the tongue to the floor of the oral cavity
Lingual Papillae
- Filiform: most numerous
- Fungiform: rounded, interspersed among filiform papillae
- Vallate: on posterodorsal surface
- Foliate: along the side of the posterior end of the tongue
Tonsillar Fossae
Located at the posterior end of the oral cavity
- Paired palatine tonsils are located within
Palatoglossal Arches
Lateral folds just anterior to the tonsillar fossae
Soft Palate
Fleshy posterior continuation of the hard palate
Nasopharyx
Region dorsal to the soft palate
- Exclusively used in respiration
Oropharynx
Region ventral to the soft palate
- Dominantly digestive
- Lies posterior to the oral pharynx
Laryngopharynx
Posterior continuation of the naso- and oro- pharynx; posterior to soft palate
- Communicates with the larynx posteroventrally and esophagus posterodorsally
Auditory Tube
Tube that leads from the dorsolateral wall of the nasopharynx to the middle ear
Larynx
Chamber at the anterior end of the trachea
- Formed from several cartilages
Glottis
Opening into the larynx
- Guarded by the epiglottis
Epiglottis
Plough-like, cartilaginous structure at the base of the tongue
- Supported by an epiglottal cartilage
- Flipped back to cover the glottis during swallowing
Laryngeal Cartilages
- Thyroid: largest, incomplete dorsally and contacts the thyrohyoid anteriorly
- Cricoid: lies slightly distal to the thyroid, complete ring, narrower ventrally than dorsally
- Arytenoid: small, multiple, complete larynx dorsally anterior to cricoid
- Epiglottal: rests on anteroventral part of the thyroid
Cricothyroid Muscle
Extends between the cricoid and thyroid cartilages
Vocal Cords
Posterior folds on either side of the larynx
- Extend between arytenoid and thyroid
- Glottis lies between them
False Vocal Cords
Accessory pair of folds on either side of the larynx
- Extend between arytenoid and epiglottal
- Larger and looser than the vocal cords, lie anterior to them
Tracheal Cartilages
C-shaped, dorsally incomplete cartilaginous elements
- Keep the trachea open
Thoracic Cavity
Anterior part of the coelom
Subdivisions
- Left and right pleural cavities
- Median mediastinum
Abdominopelvic Cavity
Posterior part of the coelom
Diaphragm
Muscular partition that separates the thoracic and abdominopelvic cavities
Pleural Cavities
Contain the left and right lungs
Mediastinum
Contains other structures (besides the lungs) that lie in or pass through the thorax
- Heart
- Esophagus
- Trachea
- Nearly all vessels and nerves
Pleura
Serosa of the thoracic cavity
- Parietal pleura lines the inside of the cavity
- Visceral pleura envelops the lungs
Mediastinal Septum
Double layer of pleura near the midline
- Formed by the meeting of right and left pleura
Lungs
Right Lobes
- Anterior
- Middle
- Posterior
- Accessory
Left Lobes
- Anterior
- Middle
- Posterior
Caval Fold
Pocket-like expansion of the mediastinal septum, just posterolateral to the heart
Pulmonary Ligament
Flat, broad, sheet-like connective tissue that suspends the lung in the pleural cavity
Primary Bronchii
Bifurcations of the trachea near the level of the sixth rib- Each subsequently branches into secondary and tertiary bronchii
Pericardial Cavity
Space, enveloped within the lungs, in which the heart sits