Unit 2 Flashcards
(63 cards)
Ways to categorize muscle
location, appearance, control.
Red muscle, white muscle, and pink muscle
Red: high concentration of hemoglobin. Slow twitch, meant for sustainable use, less powerful, aerobic, used for things like swimming or jogging.
White: Fast twitch, meant for short bursts and burn out quickly. More powerful and anaerobic (uses glycosis). Used in sprinting or heavy weightlifting.
Pink: mixture of red and white muscle.
What happens when muscles are longer? Wider?
Longer: Muscles have longer muscle fibers, faster, more sacromeres.
Wider: More sacromeres parallel to each other, increases amount of power available.
Functions of the digestive system
Obtain food, process food, absorb nutrients, pass digested food.
Alimentary Canal
Tube from the mouth to the anus.
Includes: mouth + esophagus, stomach, intestines, cloaca.
Buccal Cavity
Jaws, teeth: acquisition and processing.
Tongue, glands: lubricate food, begin digestion, specialized feeding functions.
chemoreceptors: Detect nutrients and signal toxins.
Pharynx (Anterior-most foregut)
Pharyngeal arches and their derivatives (gills, hyoid arch, eustachian tubes), powerful muscles for swallowing.
Accessory organs (digestive system)
Liver, gallbladder, pancreas.
Abduction vs Adduction
Ab: Moving away from the midline.
Ad: Moving towards the midline.
Flexion vs Extension
Flex: Bending decreases the angle between two bones.
Extension: Increases or straightens out the angle between two bones.
Circumduction
Movement of a body region in a circular manner.
Protraction vs Retraction
Protract: Moves anterior to the body.
Retract: Moves medial to the body.
Elevation vs Depression
Elevation: Moves vertically up, superiorly, elevates.
Depression: Moves down, inferiorly, decreases.
Axial Musculature (Agnathans)
Arranged into myomeres and separated by myosepta; origin in the notochord and inserts in the connective tissue under the skin.
Epaxial Muscles
Dorsal to septum vertebrae and aid in stride length while supporting the head, body, and move tail.
Hypaxial Muscles
Located below the septum of the vertebrae, ventrally, are dominant in tetrapods and aid in respiration.
What happened to muscles as organisms evolved from aquatic habitats to terrestrial habitats?
Muscles specialization increases, external and internal obliques further aid movement, muscles differentiate and become more prominent as need for locomotion increases.
Appendicular Musculature
Limb Specializations: Pectoral and Pelvic Girdles
Pectoral: Brachial adaptations: rhomboideus, pectoralis (attaches limbs to trunk, brings limb forward, backward, and towards body), serratus ventralis (supports trunk, carries trunk forward and back). Trapezius: elevates shoulder and moves scapula towards head and tail.
Muscle differentiation in pectoralis for tetrapods
Present in early tetrapods as large sheet of muscle, need for more mobility causes selective pressure that causes muscle differentiation, facilitates increased control and fine movements around a joint.
What becomes the neck muscles in tetrapods?
The myomeres in the heads of agnathans; hypobrachial muscles become incorporated into the tongue.
Some important human muscle evolutions
constrictor colli (facial muscles), thumb muscles, and the glutes.
Integument and Functions
Beneath the skin (Epidermis: epiderm, dermis: mesoderm, and basement membrane: epiderm) = superficial facia (connective tissue, muscles, adipose tissue).
Functions: Gas exchange facilitation and protection, facilitate movement, house specialized structures and sensory adaptations, communication.
Pigment cells
Cells which synthesize and assemble pigments, often into membrane bound organelles.
Color change mechanism in vertebrates
Facilitated by melanosome transport; more spread out = more light absorbed = darker pigment.
Iridophore orientation - overlapping or angling can change the light being reflected.