.. ng; use tissue rich in Mit/blood supply and Thermogenin. COLD vs HOT- Fig. 37.21 THERMAL INSULATION AND RATE OF HEAT LOSS = Thermal energy is release by body to it’s environment = Muscle contraction or change blood flow to skin; WOLF-constrict Blood vessel in its feet at above 0 C = Elephant, Rhinos, water Buffaloes have thick layer of fur; so they wallow in water = Sweating, panting are last resort use bu animals in hot climate or habitat (H2O evaporate quickly) THE VERTEBRATE THERMOSTAT- Fig 37.22/37.23 = All animals that thermoregulate must have a regulatory system; Info get from Hypothalamus-integration center In Humans: If glands is cool BT rises (constriction of Blood vessels and increase rate); Hypo temp is – feedback = Amount of increase in heat is proportional to how much the glands is cooled below the Set point. = Hypothalamus receive info from sensor in skin to shift the set point for responses; Higher when skin is cold FEVER Fever is a rise in BT in response to substance called Pyrogens; heat production above set point cause chills, shiver = Macrophages attack antigen then secretes interleukins; Interleukin stimulate prostaglandin and raise the set point ANIMAL AND THEIR THERMOSTAT Hypothermia- condition in which BT is below normal (starvation, illness, anesthetic) = Can cause unconsciousness, weaker contraction, nerve impulse, slow metabolism, cell damage/O2) Torpor-condition in which an animal lowers its BT during the time of inactivity (Air temp, mice, hummingbird) = Willow tit lowers it Bt at night; the brain of the willow is it’s integrated center for the thermostat.
Hibernation -is the hyptherming to low temp for days of weeks; = It assures maximum energy conservation; BT is maintain at freezing pt. = Metabolic rate 1/5 basal (Ex bats, bears, squirrel, poor will); occur when temp is low and food scarce = Control by biological clock(Circannual rhythm); rhythm cycle of squirrel include active season; Hib-spring to fall Active season -Animal breed, raise young, prepare nest, fatten bodies and store food Hibernation season -occur in bouts; lose body weight; at end sex organs become functional CHAPTER 44 MUSCLE CONTRACTION: Actin/myosin interaction Effectors-adaptation in response to info that is sensed, integrated & transmitted by its neuron & endocrine = Muscle contraction is the most important effector mechanism in animal in response to Environment cues = All physiological and behavioral response depend on muscle cells Muscle Cells- have high density microfilament and myosin = Account for movement in earthworm, jelly fish, limb movement in Anthropods/vertebrates = Found in blood vessel, gut, bladder and heart or where ever tissue contracts = Smooth, Skeleton and Cardiac Smooth Muscles = Provides contraction for internal organs under control of autonomic Nervous System (involuntary control) = Move food through digestive tracts; involve in blood flow and empties the urinary bladder = Simpliest cell- long spindle-shaped w/single nuclei; actin/myosin not regularly arrange In digestive tracts: arrange as sheet of attach by Gap junction (electrical conduction) = Stretching the tract depolarize it’s membrane potential- result in contraction; longer contract more stretch SKETETAL MUSCLES -straited muscle = Control all voluntary movement: running, playing the piano, generate movement of breathing = Highly regular arrangement of Actin/myosin; Muscle fiber are large & multi-nucleated = Biceps compose of muscle fibers bundled together by connective tissues (Fig. 44.1) Muscle fibers- compose of myofibrils Myofibrils- are bundles of contractile filament; each thick filament is surrounded by thin filament = Band pattern of myofibril due to its repeated units called Sarcomeres-the unit of contraction. Contraction = The I-band- the region b/w A-bands and the Z-line ; contain only thin filament (light) = A-band region of thick filament (center); H-zone- M-line and region where thick/thin do not overlap = Sliding of Filament theory-propose by Andrew and Hugh Huxley = Shorten of the H-zone and I-band; Z-line moves towards the A-band as if Actin is slide over myosin MYOSIN- made of 2 polypeptide chain coils ending in a globular head (contain ATPase) = Myosin filament compose of myosin molecules arranged parallel w/the head protruding MICOFILAMENT- consist of helically arranged polypeptide chain consisting of G-actin globular protein = Contain tropomyosin (2 chain) twist around Actin helix & Troponin- binds Ca, Actin, Tropomyosin Interaction = Head of myosin filament interact w/Actin cause 5-10 nm shift relative to the other; ATP return the system Rigor mortis -stiffness on muscle after death; no ATP no release of filament = Muscle at different part of body soften at different times (lose integrity); estimate time of death Interaction and Calcium Motor Unit- all fibers innervated by a single motor neuron which triggers it to contract (1) Contraction is initiated by nerve impulses at neuromuscular junction; receptor binding of molecules (2) Molecules is release in the synapsis by neurons via action potential (open channel) along it (3) Polarization of Plasma membrane of fibers send message throughout fibers & T-tubule system (4) Ca is pump into Sarcoplasmic Recticulum (SR) from Sarcoplasm (contact with T-tubule system) (5) Hi conc of Ca in SR is release into Sarcoplasm by opening of channels via the action potential (6) Binding of Ca to Troponin induce change in Tropomyosin which expose Actin-myosin bind site SMOOTH MUSCLE CONTRACTION = Contain no Troponin-Tropomyosin mechanism but use Ca; stimulated by Ca in cytoplasm = Stimulated by stretching, hormones level, action potential; Ca binds to Calmodulin protein Ca-Calmodulin complex- activate protein Kinase; Phosphorylation activate actin/myosin interaction = Repolarization of muscle fibers occurs through the pumping of Ca back into the SR (muscle relaxes) Muscle twitches In skeleton Muscle- the spread of impulse along fibers that cause a minimum contraction, a twitch = Twitch measured in terms of tension or the force it generates = If the twitch is generated over an adequate time period – ALL-or-None response or discrete twitch = Rapid firing cause summation of twitches; tension increase and contraction is continuous = Hi level of stimulation result in Tetanus- maximum contraction (no Ca from SR to S) Strength of the contraction depend on : (1) of motor neuron firing (2) rate of firing = some muscle have low level of tension, called Tonus when body at rest; neck, trunk and limb =Muscle Tonus arise from activity of many motor units; time in contract & time relax; regulate by NS Muscle fibers, Aerobic condition and strength = A single muscles may contain different fibers types: SLOW and FAST-Twitch Slow-twitch- called Red muscle; contain many myogloblin, glycogen, fats and mitochondria & well supported blood vessels = They are resistant to fatigue so make of low tension fibers; found in most athletes Fast-twitch- called white muscle; fatigue rapidly; high myosin-ATP activity; sprinters and weightlifters. CARDIAC MUSCLES = Cell appear striated and are branched; so resistance to tear and high pressure = Also contain intercalated disc-mechanical adhesion and arrangement b/w cells (gap junction) = Conduct electricity due to low resistance to ion; they depolarize rapidly = Also contain special cell that are pacemakers (sinus node); so heartbeat is myogenic-beat it’s own = Rate pacemaker cell is modified by Autonomic NS; not responsible for its continuous heart beat rhythm SKELETAL SYSTEM = Provide rigid support and attachment of muscles; 3 type of Skeleton; Hydrostatic, exo & endoskeleton Hydrostatic Skeleton = Found in cnidarian (sea anemone), annelids (earthworms) and soft-bodied invertebrates.
= Contain incompressible fluid enclosed in a cavity surrounded muscles Movement: Usually involves muscle arrange longitudinal (retract) and circular (extension, fig. 44.13) = Alteration of contraction cause movement; Also found in Squid and Octopus. Exoskeleton Exoskeleton- is a harden outer surface to which internal muscles are attach. Joints move relative to other Mollusk-shell grow with animal (note rings); Snails-shell made w/CaCO3 and protein = Molluscan shell use for protein: Soft part of body is for Locomotion (hydrostatic skeleton) Antropod-(soft-shell crab) made of cuticle but not at joints; will not grow with animal; Crustacian-CaCo3 Cuticle- 2 layers: Outer-the Epicuticle is thin prevent drying out; Inner-Endocuticle, thicken, Protein chitin Vertebrate Skeleton = Compose of bones connected by various joints; 206 bones; rodlike, platelike and tubelike = Divide into 2-skeleton-Axial (Ribs, sternum, skull and vertebral column and Appendicular skeleton- bones of the Arm, leg, feet & hands, pectoral girdle. = Endoskeleton- grows with organism; contain 2 kind of connective tissue: Cartilage and Bones CONNECTIVE TISSUE CELLS- large matrix of protein(collagen) and polysaccharides Cartilage- found where stiffness and resiliency is required (surface of joints) = Found in Larynx, nose, ears, shark and rays and embryonic skeleton during development Bones-mostly Collagen and CaPO4; reservoir for Ca for the body; In equil with Ca in the Matrix = Under calcitonin and parathyroid control = Cell of Bones–Osteoblast, Osteocytes, Osteoclast Osteoblast-lay down new matrix on bone surface until cavitize (lucunae) in the bone. Osteocytes-Cavitize osteoblast cells; remain in contact by communicating Osteoclasts- erode and reabsorb bones; derive from WBC producing cells; for cavity and tunnel in bones = They proceed osteoblast so involve in remodeling BONES and CONNECTIVE Tissues–2 types Membranous bones- form on scaffolding of connective tissue membrane; outer bone of skull Cartilage bone- form on cartilaginous structures until gradually ossified (limb); can grow -center outward Compact-good for compression/bending; called Haversian bone in mammal(made of unit of Haversian sys) Cancellous bones- spongy bone; can stand compressive force BONES And JOINTS = Muscle work as antagonist pairs; contract and relax; Flexor-flex joints; Extensor- extend joint Ligament- bands of connective tissue that hold joint bones together Tenons- Connective tissue that attach muscles to bones; may span the joint Quadriceps (in knee jerk reflex) Types of joint- Hinge, ball-in the socket, Saddle joints, Pivotal joint, Ellipsoid joint, plane joint Hinge- knee; allow no rotation & flex in one direction; Saddle-b/w carpel bones; Plane -b/w tarsal bone Ellipsoid-b/w phalanges; Ball-in-socket-at hips; allow movement in most direction Pivotal- b/w 2 bones of the forearms at elbow; allow radius to rotate when wrist move side to side.
LEVER SYSTEM- demonstrate the translation of force into fast movement or over short distance. Ratio=load arm/power arm; Arm-small ratio; much for over short distance: LEG-large; less force/short Dist EFFECTORS of Animal kingdom = Muscle are effector; not all effector are muscles; Function- as specialize for other function = Defense, communication, capture and avoidance Nematocyst-Hydra and Portuguese-man-of-war = Coiled structure produce by cell in tentacle; Hydra-contain a spine shape trigger projectile to capture prey = Once trigger it entangle and penetrate the prey Chromatophores-pigment containing cell; under NS/Hormonal control; In Squids and Chameleon = Can be use for mating or for terrestrial rivaling in some species; There are 3 types Fixed cell- contain pigment granules-move by microfilament; high concentration means animal is pale Some capable of Amoeboid movement; Cephalopods-muscle contractions GLANDS- produce chemical involve in communication, defense or to capture prey Poison glands -snakes, frogs, fish, spiders; Dendrotoxin produce from skin of frog (use by arrow of tribe) Venom- bungarotoxin, inactivate acetylcholine receptor Puffer fish-tetrodotoxin, blocks Na/voltage gated channel; Mollusk-Conotoxin- interferes with Ca-channel NON-poisonous Glands = Mercaptan release by skunk ; Pheromone-sex hormone; use as communication in some animals/ protist = Gland are also involve in digestion (salivary) and heat regulation (sweat glands) Electric Organs = Electric eel (600 volts) and Torpedo ray and Catfish = The electric field is use to sense environmental cues, communication, capture prey; evolve from muscles CHAPTER 36 Plants reproduce both sexually and asexually; both are important in agriculture Grain crops such as: millet, rice, cereal & wheat all grow from seed (sexual). The nasal orange however grows from a seedless orange seed (asexual). SEXUAL REPRODUCTION–genetic diversity = Meiosis and mating shuffles genes in a population; this produce diversity = Diversity serve as environmental changes or expansion into a new environment. Flower- a modified leaf Carpel-stigma, style, ovary; Stamen- anthers & filament; petals and sepals; calyx- collection of sepals.
Carpel- bears the megasporangia(ovary and integument)–which produce the megasporangium Corolla-is collection of petals ; Tepals- series of petals and sepals = Flowers is where alternation of generation lives (gametophytes, Fig 36.1) Gametophyte- a gamete producing generation that develop from haploid spores or sporangia. Megasporangia- Produce the female gametophyte or megagametophyte or embryo sac. Microsporangia–produce the male gametophyte or microgametophyte or pollen grain. Megasporocyte in megasporangia (ovule); produce 4 megaspores (meiosis);one spore survive. = The megaspore undergo 3 mitosic division in a single cell (3 top, 3 bottom, 2 middle); megagametophyte = cell wall formation lead to 7-celled gametophyte with 8 nuclei = 3 cell at micropyle-1 egg/2 synergid cells; 3 at top-called antipodal; 2 center-produce endosperm. The anther’s (microsporangia) microsporocyte produce microspores by meiosis-divide once then release. POLLINATION- transfer of pollen from anther to stigma.
= In gymnosperm/angiosperm the sperm travels in pollen grains. 2 types; self-pollination (legumes, peas) and cross- pollination (wind, insect, animals and water). In wind pollinated flowers the stigma is sticky or featherlike. Acceptance Essays.