BIOL 204 - Lab Final

Scales

Scales

shark covered w/ tiny structures: placoid scales

• made of enamel, dentin and have pulp score

in rat, epidermal scales are present on feet and tail

Claw

in the rat; end of feet their nails

Cutaneous respiration

frogs can breathe with lungs (pulmonary respiration) and also with skin (______)

Pelvic fins

posterior shark fins

Pectoral fins

shark fins closer to anterior

Claspers

in males and intersex sharks

• mating: one of these of pelvic fins is inserted into cloaca of female to transfer sperm for internal fertilization of eggs

Lateral line

along each side of body; used to sense vibrations and movement in the water

Cloaca

chamber between pelvic fins of shark

• receives feces, urine, and products of reproductive system (same in bullfrog)

Cloacal vent

opening of cloaca chamber

Ampullae of Lorenzini

fluid-filled pits that sense depth and low-level electrical stimuli

• look like dark pin holes in skin and vsisible on face of shark

Nares

allows water to flow over olfactory sac so shark can smell odors in water

• water doesn’t flow from nares to the respiratory system

for bullfrog: it opens and closes during pulmonary respiration and are closed during vocalization

Tympanic membrane

located posterior to the bullfrog eyes; relatively larger in mature males

Scrotum

contains the testes

Nipples

in a band under these in the female: between skin and muscles = granular mammary gland tissue

Skeletal muscle

• striated muscle; striped appearance

• myotome epimere mesoderm of the somites (axial appendicular and hypobranchial muscles)

• branchiomeric from undifferentiated somitomeres

• voluntary muscle

• have many nuclei

• cells = long, cylindrical, unbranched

Cardiac muscle

• muscle only found in heart

• involuntary

• splanchnic hypomere mesoderm

• striated

• single nucleus

• cells often branched

• cells linked to each other by intercalated discs

Smooth muscle

• from splanchnic hypomere mesoderm

• forms visceral/involuntary muscles of structures like blood vessels and digestive tract

• each has single nucleus

• single-shaped fibers dovetail tgt

• don’t have striations; smooth appearance

Antagonists

muscles that work tgt to produce movement in opposing movements

• often work tgt in antagonistic pairs

Agonists

muscles that work tgt to produce movement in same direction

Abductor

move body part away from ventral midline of body

Adductor

move body part towards ventral midline of body

Extensor

increase angle between 2 body parts

Flexor

reduce angle between 2 body parts

Protractor

move a limb or other body part forward (towards anterior)

Retractor

move a limb or other body part backward (towards posterior); withdraw body part

Levator

elevate a body part

Depressor

lowers a body part

Origin

a fixed structure; insertion will move relative to this

Insertion

relatively mobile structure; moves relative to the origin

• when muscle contracts, if it contracts with sufficient force it’ll move the structure onto which it’s inserted (bone, cartilage, connective tissues)

Tendon

muscles attach to site of insertion on bone / cartilage via these

• they are composed of sheets of dense collagen fibers

Ligaments

composed of collagenous connective tissue; connect bone - bone, cartilage-cartilage

Horizontal septum

muscles divided by this into the dorsal epaxial and ventral hypaxial muscles

Linea alba

• shark: ventral hypaxial muscles meet at midline forming raphe

• frog: connective tissue connecting left and right sides of abdominal muscles

• rat: hypaxial muscles composed of 3 sheets of muscles joined ventrally here; on either side is rectus abdominus

Axial

• myotomes of somites of the trunk region

• form skeletal muscles of trunk and tail

• in gnathostomes: muscles divided by horizontal septum into the dorsal epaxial and ventral hypaxial muscles

Appendicular

• also from myotomes of somites of trunk region

• shark: abduct and adduct pelvic and pectoral fins

• tetrapods: lie over many of the axial muscles

• typically form in embryo as dorsal and ventral muscle groups but subdivide in development

Hypobranchial

• group of muscles supplying the jaw

• formed from myotomes of somites located posterior to the pharyngeal slits

• myotomes move anteriorly and ventrally to ventral region of pharynx

Branchiomeric

• myotomes of the somitomeres

  • somitomeres also extrinsic muscles of eye

• muscles attached to pharyngeal arches of splanchnocranium

• in fish: becomes muscles of jaw, hyoid arch and gills

• amniote+ amphibians: more posterior muscles are lost / contribute to muscles of larynx and shoulder

Superior oblique

origin: anterior-medial corner of orbit

• dorsal oblique muscle of eye

• helps look up I think

Inferior oblique

origin: anterior-medial corner of orbit

• ventral oblique muscle of eye

• helps with looking down I think

Superior rectus

part of 4 rectus muscles

• dorsal rectus of eye

• biggest of the 3 rectus group across top of eye

Lateral rectus

part of 4 rectus muscles of eyeball

• smallest little muscle posterior of eyeball; moves shark eye right and towards back of body

Medial rectus

part of 4 rectus muscles of eyeball

• origin: posterior-medial corner of orbit

of 3 rectus muscles it’s the one in the middle with the superior oblique on the left and superior rectus on the right

Inferior rectus

part of 4 rectus muscles of eyeball

• ventral rectus of eye

• origin: posterior-medial corner of orbit

• helps with looking down i think

Adductor mandibulae

large muscle below the spiracle elevating Meckel’s cartilage; closing mouth

• homologous to masseter and temporalis in frog + mammal

Intermandibularis

on the ventral surface posterior to lower jaw; each of these muscles originates on Meckel’s and inserts on central raphe

• elevates floor of mouth for swammlowing

Mylohyoideus

branchiomeric muscle

• frog: extends from mandible to central raphe and floor of mouth elevates when it contracts, decreasing the volume of buccal cavity

• mammal: homologous to digastric

• shark: homologous to intermandibularis

Cucullaris

located dorsal to the gills; elevates the scapular process of the pectoral girdle and also the branchial arches; only hyoid and superficial constrictors can be seen

• for rats it’s homologous to the trapezius and sternomastoideus

Masseter

• frog: inserts onto lower jaw to close mouth; branchiomeric

• rat: lies ventral to eye; elevates lower jaw for complex chewing

Temporalis

• frog: also inserts onto lower jaw to close mouth

• rat: located posterior to eye; elevates lower jaw

Digastric

• rat: depresses lower jaw; lies medially between left and right dentary bone of lower jaw

Trapezius

• rat: muscles of pectoral girdle; 3 muscles, 2 on scapula to adduct and move it forward and up, third on clavicle which protracts humerus

• shark: homologous to cucullaris muscle of dogfish

Sternomastoideus

• rat: derived from cucullaris muscle and serves to turn head

Latissimus dorsi

appendicular muscle

• rat: originates on thoracic vertebrae and inserts on humerus; below trapezius

• frog: on ventral side

• shark: homologous to pectoral abductors

Pectoralis

appendicular muscles

• shark: homo to pectoral adductors

• frog: help with complex movements like adduction, flexion, rotation; they’re on the ventral part of frog like around the rectus abdominus (3 muscles)

• rat: large and include the major and minor; some adduct / pull forelimbs to midline and others retract forelimb; on the underside and kinda crosses horizontally

Triceps brachii

appendicular muscle

• rat: 3 muscles originating on scapula / humerus and inserting tgt on olecranon process of ulna to extend arm

• frog: on the upper arm; abducts the upper arm

• shark: homologous to pectoral abductors

Biceps brachii

Pectoral adductor

• shark: ventral of pectoral fin; appendicular muscle

Pectoral abductor

• shark: dorsal of pectoral fin; appendicular muscle

Coracoarcuals

located ventral to the gills attached to coracoid of pectoral girdle

• depress Meckel’s opening mouth

hypobranchial muscle

• in frog and rat: homologous to sternohyoid and others

Sternohyoid

• rat: hypobranchial muscle; lies on top of larynx

Epaxial

axial muscle

• shark: these muscles dorsal to horizontal septum

• rat: long bundles that extend the trunk and stabilize vertebral column; deep muscles on either side of vertebral column and are hidden by other muscles

• frogs: basically same muscle assortment as rats for this muscle

Hypaxial

• shark: these muscles ventral to horizontal septum

• frogs: these muscles contribute to exhalation phase of pulmonary respiration

• rat: composed of 3 sheets of muscles joined ventrally at linea alba (external + internal oblique, transversus abdominus)

External oblique

• rat: one of 3 layers of hypaxial muscles; support abdominal viscera in muscular sling

• frog: layers of visible abdominal muscles

• shark: homologous to hypaxial muscles

Transverse abdominus

axial muscle

• rat: one of 3 layers of hypaxial muscles; support abdominal viscera in muscular sling

• shark: homologous to hypaxial muscles

• frog: I guess it’s inside somewhere too

Rectus abdominus

axial muscle

• shark: homologous to hypaxial muscles

• rat: on either side of linea alba is this band of longitudinal muscle

• frog: on ventral side of trunk; they depress the sternum

Intercostals

• rat: deeper hypaxial muscle not seen; along with supracostals it attaches to rib cage

Peritoneum

lines the inside of the posterior cavity; serous membrane that secretes lubricating fluid allowing for movement of organs

• parietal: attaches to muscles of body wall and overlies urogenital system

• visceral: surrounds digestive tract and other orgs

Mesentery

where the peritoneum forms a double layer; suspends organs and joins them with each other

• running from organ to organ = ligaments (not the same as the ligaments connecting tissue)

Serous membrane

Peritoneal cavity

in mammals this is the posterior cavity

Thoracic cavity

in mammals this is the anterior cavity

Pericardial cavity

in sharks and bullfrog the coelomic space divided into this and pleuroperitoneal cavity by the transverse septum

• this is the more anterior one

Pleural cavity

Pleuroperitoneal cavity

in sharks and bullfrog the coelomic space divided into pericardial and ____ cavity by the transverse septum

• this is the more posterior one

Transverse septum

divides the anterior pericardial cavity and posterior pleuroperitoneal cavity

Diaphragm

separates the anterior and posterior cavities in mammals

Fat bodies

in frog; store large amounts of energy that may be required for hibernation, emergencies and reproduction

• they require lots of energy to produce gametes and for prolonged mating behaviours where they can’t hunt and eat

Buccal cavity

the oral cavity; mouth

Pharynx

• shark: located posterior to the buccal cavity and can be identified by 5 pairs of gill slits; water exits through the slits

• frog: small opening; there is glottis on the floor which conducts air to trachea

• rat: extends from buccal cavity to larynx allowing passage of food and air

Esophagus

• rat: food travels down here when swallowed; lies dorsal to larynx

• frog: extensible; and transports food from pharynx to stomach

• shark: extends posterior leg from pharynx at transverse septum and is lined with papillae in Squalus

Stomach

• frog: extensible like pharynx and size depends on last meal

• shark: U shaped w/ anterior cardiac limb and posterior pyloric limb

• rat: esophagus ends at cardiac sphincter and opens into this

Rugae

folds of inside stomach lining

Small intestine

anterior portion = duodenum and posterior = ileum

• shark ileum has spiral valve

Duodenum

anterior region of small intestine

Ileum

posterior end of small intestine

Caecum

in rat, ileum ends in T junction with large intestine and large blind ended sac of T junction is this

Large intestine

• rat: ileum ends in T junction with caecum at one end and this at the other (ascending portion)

• shark: shorter than the small intestine and has rectal gland attached

• frog: follows ileum of small intestine

Pancreas

an accessory organ

• shark: has 2 lobes; ventral lobe in curve of duodenum and dorsal lobe in ligament not projecting towards gastrosplenic ligament

• frog: lies in ligament located between stomach and duodenum; an exocrine gland producing digestive enzymes and endocrine gland that secretes hormones

• rat: two lobes also; dorsal lobe extends along ligament thay projects toward gastrosplenic ligament and ventral lobe in curve of duodenum

Liver

accessory organ

• shark: in posterior cavity of shark; 3 lobes; extending posteriorly from transverse septum

• frog: anterior region of pleuroperitoneal cavity; size varies by season

• rat: five dark, reddish brown lobes attached to diaphragm

Gallbladder

accessory organ

• rat: rat doesn’t have

• shark: bile duct leads from here to duodenum; greenish, found on central lobe of the liver (that has 3 lobes)

• frog: on central lobe of liver and stores bile produced from liver

Bile duct

• shark: leads from gallbladder to duodenum along with hepatic vessels

• frog: connects to duodenum but hard to see

• rat: leads to anterior duodenum

Cardiac sphincter

rat: esophagus ends at this sphincter and opens into the stomach

Pyloric sphincter

sphincter marks end of stomach region

Spiral valve

ileum of shark has this internal subdivision

Plicae

folds of internal surface of the small intestine that increase surface area for increased absorption of nutrients

Rectal gland

for salt excretion for osmoregulation

• shark: this gland connected to large intestine ; secretes salt to maintain osmotic balance

Rectum

• shark: most posterior portion of intestine and empties into cloaca

• rat: colon empties into this which is hidden under pelvic girdle and opens at anus

• frog: empties into cloaca

Anus

• rat: located at base of tail and controlled by sphincter muscles

Cloaca

• shark: rectum empties into this

• frog: rectum also empties into this; urine in the arcinephric ducts empty into this; urinalysis bladder located on coelom floor opens into this; oviducts also empty into here

Cloacal vent

• frog: when closed urine backs up into urinary bladder