1. Animal Kingdom Evolution
5 Defining characteristics of the animal kingdom:
1) Heterotrophic eukaryotes; ingestion
2) Lack cell walls; collagen
3) Nervous & muscular tissue
4) Sexual; diploid; cleavage; blastula; gastrulation; larvae; metamorphosis
5) Regulatory genes: Hox genes

2. Animal phylogeny *Monophyletic; colonial flagellated protist ancestor
First split
1- Parazoa vs. Eumetazoa dichotomy:
*(Parazoa)~ no true tissues example sponges
*(Eumetazoa)~ true tissues
all other animals

3. Parazoa *Parazoa: No true tissues Invertebrates
No true tissues, unspecialized cells:
*Sponges Closest lineage to protists
Phylum Porifera

4. Phylum: Porifera (“pore bearer”)
*Sessile (attached to bottom)
Spongocoel (central cavity)
*Osculum (large opening)
Choanocytes (flagellated collar cells)
*Hermaphroditic (produce both sperm and eggs)

5. Eumetazoa: True Tissues: Everything but sponges
2nd split – Body Symmetry
Radiata vs.Bilateria dichotomy:
1) *radial body symmetry
*Cnidaria (hydra; ‘jellyfish’; sea anemones) & *Ctenophora (comb jellies)
2) *bilateral body symmetry (also: **cephalization)
all other animals

6. Eumetazoa The Radiata, Diploblastic
Radial symmetry
Phy: Cnidaria (hydra, jellies, sea anemones, corals)
*No mesoderm; gastrovascular cavity (GVC)(sac with a central digestive cavity)
Hydrostatic skeleton (fluid held under pressure)
Polyps and medusa
Cnidocytes (cells used for defense and prey capture)
Nematocysts (stinging capsule)
Phy: Ctenophora (comb jellies)

7. 3. Gasturlation: diploblastic vs. triploblastic
3- Gastrulation: germ layer development; ectoderm (outer), mesoderm (middle), endoderm (inner)
diploblastic-2 layers; no mesoderm;
Radiata
Phy: Cnidaria (hydra, jellies, sea anemones, corals)
triploblastic-all 3 layers
*bilateria symmetry
All others

8. 4- Acoelomate, Pseudocoelomate, and Coelomate
All are triploblastic animals
*acoelomates solid body, no body cavity
(Platyhelminthes-flatworms)
mesoderm but, GVC with only one opening
*Some cephalization
*pseudocoelomates body cavity, but not lined with mesoderm called
(Rotifers); *1st with a complete digestive track
Parthenogenesis: type of reproduction in which females produce offspring from unfertilized eggs
Coelomate: true coelom (body cavity) lined with mesoderm called
Phy: Nematoda (roundworms)
Complete digestive track; no circulatory system

9. Animal phylogeny 5 *Protostomes Phylogenetics debated….
1)Phy: Nemertea (proboscis and ribbon worms)
*Complete digestion and closed circulatory system (blood)
2) Phy: the lophophorates (sea mats, tube worms, lamp shells)

10. The Coelomates: Protostomes, II
3) Phy: Mollusca (snails, slugs, squid, octopus, clams, oysters, chiton)
Soft body protected by a hard shell of calcium carbonate
Foot (movement), visceral mass (internal organs); mantle (secretes shell); radula (rasp-like scraping organ)
Ciliated trochophore larvae (related to Annelida?)

11. The Coelomates: Protostomes, III
4) Phy: Annelida (earthworms, leeches, marine worms)
True body segmentation (specialization of body regions)
Closed circulatory system
Metanephridia: excretory tubes
“Brainlike” cerebral ganglia
*Hermaphrodites, but cross- fertilize

12. The Coelomates: Protostomes, IV
5) Phy: Arthropoda trilobites (extinct); crustaceans (crabs, lobsters, shrimps); spiders, scorpions, ticks (arachnids); insects (entomology)
*2 out of every 3 organisms (most successful of all phyla)
*Segmentation,
*hard exoskeleton (cuticle)~ molting,
*jointed appendages; open circulatory system (hemolymph);
*extensive cephalization

13. Insect characteristics
Outnumber all other forms of life combined
Malpighian tubules: outpocketings of the digestive tract (excretion)
Tracheal system: branched tubes that infiltrate the body (gas exchange)
*Metamorphosis…...
*•incomplete: young resemble adults, then molt into adulthood (grasshoppers)
*•complete: larval stages (looks different than adult); larva to adult through pupal stage

14. The Coelomates: *Deuterostomes, I
1) Phy: Echinodermata (sea stars, sea urchins, sand dollars, sea lilies, sea cucumbers, sea daisies)
Spiny skin; sessile or slow moving
Often pentaradial
Water vascular system by hydraulic canals (tube feet)

15. Deuterostomes Chordates Next branch
*Notochord: longitudinal, flexible rod located between the digestive and the nerve cord
*Dorsal, hollow nerve cord; eventually develops into the brain and spinal cord
*Pharyngeal slits; become modified for gas exchange, jaw support, and/or hearing
*Muscular, postanal tail

16. Invertebrate chordates
Both suspension feeders…..
Subphy: Urochordata (tunicates; sea squirt); mostly sessile & marine
Subphy: Cephalochordata (lancelets); marine, sand dwellers
*Importance: vertebrates closest relatives; in the fossil record, appear 50 million years before first vertebrate
*Paedogenesis: development of sexual maturity in a larva (link with vertebrates?)

17. Subphylum: Vertebrata
Retain chordate characteristics with specializations….
*Neural crest: group of embryonic cells near dorsal margins of closing neural tube
*Pronounced cephalization: concentration of sensory and neural equipment in the head
*Cranium and vertebral column
*Closed circulatory system with a ventral chambered heart

18. Vertebrate diversity Phy: Chordata Subphy: Vertebrata
Superclass: Agnatha jawless vertebrates (hagfish, lampreys)
*Most primitive, living vertebrates

19. Vocabulary
tetrapods (‘4-footed’)
amniotes (shelled egg)

20. Superclass Gnathostomata, I
Placoderms (extinct): first with hinged jaws and paired appendages
Class: Chondrichthyes~ *Sharks, skates, rays
*Cartilaginous fishes; well developed jaws and paired fins; continual water flow over gills (gas exchange); lateral line system (water pressure changes)
*Life cycles:
*Oviparous- eggs hatch outside mother’s body
*Ovoviviparous- retain fertilized eggs; nourished by egg yolk; young born live
*Viviparous- young develop within uterus; nourished by placenta

21. Superclass Gnathostomata, III
Class: Amphibia
*1st tetrapods on land
Frogs, toads, salamanders, caecilians
Metamorphosis; lack shelled egg; moist skin for gas exchange

22. Superclass Gnathostomata, IV
Class: Reptilia
Lizards, snakes, turtles, and crocodilians
*Amniote (shelled) egg with extraembryonic membranes (gas exchange, waste storage, nutrient transfer);
absence of feathers, hair, and mammary glands; *ectothermic; scales with protein keratin (waterproof); lungs; ectothermic (dinosaurs endothermic?)

23. Superclass Gnathostomata, V
Class: Aves
Birds
*Flight adaptations: wings (honeycombed bone); feathers (keratin); toothless; one ovary
*Evolved from reptiles (amniote egg and leg scales); endothermic *(4-chambered heart)
Archaeopteryx (stemmed from an ancestor that gave rise to birds)

24. Superclass Gnathostomata, VI
Class: Mammalia
*Mammary glands; hair (keratin); endothermic; 4-chambered heart; large brains; teeth differentiation
*Evolved from reptilian stock before birds
*Monotremes (egg-laying): platypus; echidna
*Marsupials (pouch): opossums, kangaroos, koalas
*Eutherian (placenta): all other mammals

25. Order: Primates (evolution)
*Characteristics: hands & feet for grasping; large brains, short jaws, flat face; parental care and complex social behaviors
Suborder: Prosimii •lemurs, tarsiers
Suborder: Anthropoidea •monkeys, apes, humans (opposable thumb)
*45-50 million years ago
*Paleoanthropology: study of human origins
*Hominoid: great apes & humans
Hominid (narrower classification): √ australopithecines (all extinct) *√ genus Homo (only 1 exant, sapiens)

26. Human evolution Misconceptions:
1- Chimp ancestor (2 divergent branches)
2- Step-wise series (coexistence of human species)
3- Trait unison(all traits at once) vs. mosaic evolution(over time) (*bipedalism, upright, enlarged brain)

27. The first humans Ape-human split (5-7 mya)
Australopithecus; “Lucy” (4.0 mya)
Homo habilis; “Handy Man” (2.5 mya)
Homo erectus; first to migrate (1.8 mya)
Neanderthals (200,000 ya)
Homo sapiens (100,000 ya?)
Multiregional model (parallel evolution)
“Out of Africa” (replacement evolution)

28. Tissues: groups of cells with a common structure and function (4 types)
Anatomy: structure
Physiology: function
Type 1- Epithelial: outside of body and lines organs and cavities; held together by tight junctions
basement membrane: dense mat of extracellular matrix
Simple: single layer of cells
Stratified: multiple tiers of cells
Cuboidal (like dice)
Columnar (like bricks on end)
Squamous (like floor tiles)
Glandular (can secrete) mucous membrane

29. Connective Tissue (6 kinds)
Type 2- Connective Tissue: bind and support other tissues; scattered cells through matrix kinds of fibers:
A-Collagenous fibers (collagen protein) non elastic B-Elastic fibers (elastin protein) C-Reticular fibers (thin branched collagen fibers)
Loose connective tissue: binds epithelia to underlying tissue; holds organs (has all 3 fiber types)
Two types of cells dominate
1-Fibroblasts- secretes the protein for extracellular fibers
2-Macrophages- amoeboid WBC’s; phagocytosis
Adipose tissue (specialized form)- fat storage; insulation

30. Connective Tissue, Type II
Fibrous connective tissue: parallel bundles of cells
1-Tendons- muscles to bones
2-Ligaments- bones to bones; joints (BOBOLI)
Cartilage: collagen in a rubbery matrix (chondroitin); flexible support
Bone: mineralized tissue by osteoblast cells
Blood: liquid plasma matrix; erythrocytes (RBC’s) carry O2; leukocytes (WBC’s) immunity

31. Nervous Tissue, Type III
3-Nervous: senses stimuli and transmits signals from 1 part of the animal to another
*Neuron: functional unit that transmits impulses
*Cell body (contains nucleus)
*Dendrites: transmit impulses from tips to rest of neuron
*Axons: transmit impulses toward another neuron or effector

32. Muscle Tissue (3 kinds)
4- Muscle: capable of contracting when stimulated by nerve impulses; myofibrils composed of proteins actin and myosin; 3 types:
A- Skeletal: voluntary movement (striated)
B- Cardiac: contractile wall of heart (branched striated)
C- Smooth: involuntary activities (no striations)

33. Internal regulation
Interstitial fluid: internal fluid environment of vertebrates; exchanges nutrients and wastes
*Homeostasis: “steady state” or internal balance
*Negative feedback: change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation; i.e., body temperature
*Positive feedback: physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change; i.e., uterine contractions at childbirth

34. Metabolism: sum of all energy-requiring biochemical reactions
*Catabolic processes of cellular respiration
Calorie; kilocalorie/C
*Endotherms: bodies warmed by metabolic heat
*Ectotherms: bodies warmed by environment
Basal Metabolic Rate (BMR): minimal rate powering basic functions of life (endotherms)
Standard Metabolic Rate (SMR): minimal rate powering basic functions of life (ectotherms)

35. Chapter 48 ~ Nervous System

36. The Nervous System Neurons Glial cells Axon Dendrite Synapse
Neurons
Glial cells
Axon
Dendrite
Synapse
Neurotransmitters
Action potential
Motor neurons
Interneurons
Sensory neurons
Myelin sheath
Schwann cells
Reflex arc

37. Nervous systems Effector cells~ muscle or gland cells
Nerves~ bundles of neurons wrapped in connective tissue
Central nervous system (CNS)~ brain and spinal cord
Peripheral nervous system (PNS)~ sensory and motor neurons

38. Structural Unit of Nervous System
Neuron~ structural and functional unit
Cell body~ nucelus and organelles
Dendrites~ impulses from tips to neuron
Axons~ impulses toward tips
Myelin sheath~ supporting, insulating layer
Schwann cells~ PNS support cells
Synaptic terminals~ neurotransmitter releaser
Synapse~ neuron junction

41. Simple Nerve Circuit
Sensory neuron: convey information to spinal cord
Interneurons: information integration
Motor neurons: convey signals to effector cell (muscle or gland)
Reflex: simple response; sensory to motor neurons
Ganglion (ganglia): cluster of nerve cell bodies in the PNS
Supporting cells/glia: nonconductiong cell that provides support, insulation, and protection

43. Neural signaling
Membrane potential (voltage differences across the plasma membrane)
*Intracellular/extracellular ionic concentration difference
K+ diffuses out (Na+ in); large anions cannot follow….selective permeability of the plasma membrane
Net negative charge of about -70mV

44.
Neural signaling
Excitable cells~ cells that can change membrane potentials (neurons, muscle)
Resting potential~ the unexcited state of excitable cells
Gated ion channels (open/close response to stimuli): photoreceptors; vibrations in air (sound receptors); chemical (neurotransmitters) & voltage (membrane potential changes)
Graded Potentials (depend on strength of stimulus):
1- Hyperpolarization (outflow of K+); increase in electrical gradient; cell becomes more negative
2- Depolarization (inflow of Na+); reduction in electrical gradient; cell becomes less negative

45. Neural signaling
Threshold potential: if stimulus reaches a certain voltage (-50 to -55 mV)….
The action potential is triggered….
Voltage-gated ion channels (Na+; K+)
1-Resting state •both channels closed
2-Threshold •a stimulus opens some Na+ channels
3-Depolarization •action potential generated •Na+ channels open; cell becomes positive (K+ channels closed)
4-Repolarization •Na+ channels close, K+ channels open; K+ leaves •cell becomes negative
5-Undershoot •both gates close, but K+ channel is slow; resting state restored
Refractory period~ insensitive to depolarization due to closing of Na+ gates

46. Neural signaling “Travel” of the action potential is self-propagating
Regeneration of “new” action potentials only after refractory period
Forward direction only
Action potential speed:
1-Axon diameter (larger = faster; 100m/sec)
2-Nodes of Ranvier (concentration of ion channels); saltatory conduction; 150m/sec

47. Synaptic communication
Presynaptic cell: transmitting cell
Postsynaptic cell: receiving cell
Synaptic cleft: separation gap
Synaptic vesicles: neurotransmitter releasers
Ca+ influx: caused by action potential; vesicles fuse with presynaptic membrane and release….
Neurotransmitter

48. Neurotransmitters Acetylcholine (most common) •skeletal muscle
Acetylcholine (most common) •skeletal muscle
Biogenic amines (derived from amino acids) •norepinephrine •dopamine •serotonin
Amino acids
Neuropeptides (short chains of amino acids) •endorphin

49. Nervous System (know this slide)
Central Nervous System
Crainial Nerves
Spinal Nerves
Peripheral Nervous System
Sensory (afferent) Division
Sensing external environment
Sensing internal environment
Motor (Efferent) Division
Autonomic Nervous System
Sympathetic Nervous System
increase energy consumption
Parasympathetic Nervous System
conservation of energy
Somatic Nervous System
voluntary, conscious control, muscles

50. Vertebrate PNS

54. Vertebrate Skeletal Muscle
*Contract/relax: antagonistic pairs w/skeleton
*Muscles: bundle of….
Muscle fibers: single cell w/ many nuclei consisting of….
*Myofibrils: longitudinal bundles composed of….
*Myofilaments:
Thin~ 2 strands of actin protein and one strand of a regulatory protein
Thick~ staggerd arrays of myosin protein

55. Vertebrate Skeletal Muscle
Sarcomere: repeating unit of muscle tissue, composed of….
Z lines~sarcomere border
I band~only actin protein
A band~actin & myosin protein overlap
H zone~central sarcomere; only myosin

56. **Sliding-filament model
Theory of muscle contraction
Sarcomere length reduced
Z line length becomes shorter
Actin and myosin slide past each other (overlap increases)

57. **Actin-myosin interaction
1- Myosin head hydrolyzes ATP to ADP and inorganic phosphate (Pi); termed the “high energy configuration”
2- Myosin head binds to actin; termed a “cross bridge”
3- Releasing ADP and (Pi), myosin relaxes sliding actin; “low energy configuration”
4- Binding of new ATP releases myosin head
Creatine phosphate~ supplier of phosphate to ADP

58. **Muscle contraction regulation
Relaxation: tropomyosin blocks myosin binding sites on actin
Contraction: calcium binds to toponin complex; tropomyosin changes shape, exposing myosin binding sites

59. **Muscle contraction regulation
Calcium (Ca+)~ concentration regulated by the….
Sarcoplasmic reticulum~ a specialized endoplasmic reticulum
Stimulated by action potential in a motor neuron
T (transverse) tubules~ travel channels in plasma membrane for action potential
Ca+ then binds to troponin

60. The Vertebrate Brain (know this slide)
Forebrain
•*cerebrum~ memory, learning, emotion
•*cerebral cortex~ sensory and motor nerve cell bodies
•*corpus callosum~ connects left (analytical) and right (creative) hemispheres
•*thalamus (main input/output from cerebrum); *hypothalamus (hormone production)
Midbrain
•inferior (auditory) and superior (visual) colliculi
Hindbrain •*cerebellum~coordination of movement •*medulla oblongata/ pons~ autonomic, homeostatic functions

61. Emotion

62. Cerebrum Cerebral hemispheres Cerebral cortex—”gray matter”
Know that there are different lobes for different purposes. You do not need to memorize this information.
Cerebral hemispheres
Cerebral cortex—”gray matter”
Convolutions
Cerebral lobes
Frontal lobe—conscious thought and muscle control.
Parietal Lobes—receive information from skin receptors.
Occipital Lobe—receives visual input.
Temporal Lobe—has areas for hearing and smelling.

65. Pituitary Gland
Corpus Callosum