Study Guides (248,421)
Canada (121,525)
Biology (423)
BIOL 202 (38)

Biology 202 April Exam study notes.docx

24 Pages
Unlock Document

BIOL 202
Victoria L Friesen

Chapters 23 – 29: Vertebrate Physiology Embryogenesis - Four main steps in embryonic development o Cleavage: zygote divides to from a blastula (fluid filled ball), cells at the top (containing animal – animal pole) are smaller than those at the bottom (contains yolk –vegetal pole) and remain unspecialized o Gastrulation: blastula cells move inward at the blastopore forming the gastrula (fluid filled ball with three cell layers) = ectoderm  epidermis and nervous system, endoderm gut lining and derivatives, mesoderm  everything else Three axes now defined – blastopore forms the anus and the mouth forms the opposite end (deuterostome) – animal pole forms the back and the vegetal pole forms abdomen, cells still unspecialized but fates now determined o Neurulation: dorsal mesoderm cells aggregate into a rod-like structure (i.e. the notochord), and this induces the dorsal ectoderm to fold  forms dorsal neural tube and neural crest cells (CNS + rest) Mesoderm flanking the notochord becomes segmented into somites (skeleton and skeletal muscles) Pharyngeal pouches form along pharynx  gills and thyroid, ectodermal placodes form at head  ears, eyes, nostrils; final product is the same for all verterbrates (NEURULA) o Organogenesis: embryonic cells specialize forming tissues, organs and systems, differential cell division, growth and death results in different body shapes Integumentary systems - Integument = external covering of animals – hypodermis, dermis (from mesoderm), epidermis (from ectoderm) - Protects animal from chemical, mechanical injury and microorganisms - Largest organ – contains blood vessels, nerves, mucous glands, connective tissues, adipose tissues, - Functions in protection, communication, respiration, excretion, osmoregulation, separates skin from deeper tissues - Jawless fish: thick skin, secrete protective cuticle with slime glands that covers the entire body surface – helps protect from external parasites - Cartilaginous fish: multilayered and contain mucous and sensory cells – bone in form of denticles (placoid scales) – contain blood vessels and nerves - new ones produced as old ones lost (sandpapery texture) - Bony fish: scales composed of dermal bone – scales not shed, grow at margins over lower surface, epidermis contains mucous glands – prevent fungal/bacterial infection and reduce friction, some have photophores (light) attract prey and communication - Amphibians: sratified epidermis, dermis with mucous and serous glands + pigmentation cells, KERATIN in outer layers, slimy, moist body – help gas exchange and escape from prey, some have poison glands - Reptiles: thick skin, lacks glands, modified into keratinized scales, scutes (thick scales – snakes, turtles), beaks (turtles), rattles, claws, plaques, spiny crests – resists abrasion, dehydration, protects like armor, MOLTING - Birds: very thin, keratinized outer layer (very soft), FEATHERS, dermis similar to reptiles, air spaces in skin (part of the respiratory system) – also involved with thermal regulation - Mammals: hair, greater variety in glands, highly stratified, dermis very thicnk compared to epidermis – keratinized cells = outer layer, dermis (thickest) = blood vessels, lymph vessels, nerves, hair follicles, sensory receptors, small muscles + glands (sudoriferous = sweat, sebaceous oil = sebum) , hypodermis = loose connective tissues, adipose, skeletal muscles, nails/claws/hooves/horns/baleen plates = modifications of epidermis Skeletal systems - Cartilage o Specialized connective tissue – provides site for muscle attachment, support, movment at joints, transmits muscular force to different areas – made of chondrocytes - Bone/osseous tissue o Provides point of attachment for muscles and transmits force to different areas for movement o Store reserve inorganic salts – calcium and phosphate, manufacture red and white blood cells o Rigid, homogeneous, made up of bone cells = osteocytes - Fish: jawed fish have axial skeleton – include: notochord, ribs, cartilaginous or bony vertebrae - Tetrapods: modified for support on land, specializations of the intervertebral disks that articulate with adjoining vertebrae - hold the vertebral column together, changes in the shoulder allow for more neck movement and flexibility - Mammals (human): endoskeleton in two parts – axial (=skull, vertebral column, sternum, ribs) and appendicular skeleton (=appendages, pectoral girdle, pelvic girdle) Muscular systems - Ability to contract and shorten - 3 important properties: o Excitability – receive and respond to a stimulus o Extensibility – can stretch o Elasticity – can return to original shape - Three types: o Smooth: single nucleus, controls ANS organs and systems, spindle shaped, arranged in parallel pattern forming sheets, o Cardiac: striated fibres, single nucleus, heart muscles, pacemaker cells, branched o Skeletal: striated fibres, multinucleated – work in opposing pairs, muscles can only pull not push - Fish have segmental myomeres - Tendons attach the muscle to the bones - Made up of myofibrils and sarcomeres Sensory systems - Main concepts: o Communication, integration and coordination of the internal systems (external systems too) o Info flow = collection  processing  response o Info transmitted with neurotransmitters, evolution gave rise to organization of nerve cords and centralization of nerve centres - Unit = neron (cells) – excitability (respond t stimuli) and conductivity (ability to conduct signal) o Sensory neuron = receptor, interneuron = receive signal from sensory, motor neuron = response - Vertebrate evolution = development of a notochord and a tubular nerve chord - Central nervous system (CNS) = brain + spinal cord, site of information processing - Peripheral Nervous System (PNS) = sensory neurons, motor neurons = somatic nervous system (SNS) autonomic nervous system (ANS) = sympathetic, parasympathetic and enteric (digestive) systems - CNS o Spinal cord: connecting link between the brain and most of the body – involved with spinal reflex actions o Spinal nerves: number of nerves related to the number of segments in the trunk and tail of the vertebrae o The brain:  Hindbrain: medulla oblongata (contains reflex centres for breathing, swallowing, cardiovascular function and gastric function), cerebellum (coordinates the motor activity associated with limb movement, maintaining posture, spatial orientation), pons (bridge of transverse nerve tracts – connects both sides of the brain and the forebrain to the spinal cord)  Midbrain: coordinates the reflex responses for visual input – functions relating to tactile (sensory/touch) and auditory input – integrates visual and auditory input  Forebrain: diencephalon = pineal gland (controls some body rhythms), pituitary gland (major endocrine gland) hypothalamus (regulates many fucntions – body temps, sex drive, hunger, thirst…) and thalamus (relays sensory info to higher brain centers) and telecephalon = cerebrum (lobes and functions) - Cranial nerves: paired - ANS: in two parts that act antagonistically o Parasympathetic: functions during relaxation – secretion of digestive enzymes o Sympathetic: fight or flight – inhibition of secretion of digestive enzymes o Enteric = all the digestive system parts – peristalsis, smooth muscle contraction, liver - Receptors: o Chemoreceptors – chemicals (taste) o Photoreceptors - vision o Proprioreceptors – knowing your spacial orientation o Tactile receptors – mechanoreceptors – touch and sensory structures on skin (movement of skin) o Thermoreceptors – heat and cold o Lateral-line system (electrical sensing) – sense electrical currents in water o Lateral-line system (mechanorecption) – pressures or distortion of water (neuromasts) o Specialized cells for  Hearing (tympanum, ears…)  Smell (olfactory receptors) o Nocireceptors – pain receptors for tissue damage o Echolocation – sensing objects from sound waves o Magnetoreception – sensing magnetic fields Endocrine systems - Chemical messegners to communicate between cells and within the entire body = hormones - Information transfer is slow, general and long-lasting (internal: hormones, External: pheromones) - Responses to various stimuli – work in nerves and transport in the blood system - Major endocrine glands = hypothalamus, pituitary, thyroid, adrenal, pineal, thymus, pancreas, gonads, but other tissues secrete hormones too - Originally only included the pituitary, pineal, thyroid and scattered cells - Two types of glands o Exocrine: secrete chemicals into ducts and then into a special area/cavity (outside or another duct) o Endocrine: secretes into vascular system to reach other parts of the body (hormones) – no ducts Circulatory systems and gas exchange - Blood = plasma, red cells, white cells, platelets, is a transport system for all types of chemicals, ions a solutes in the body - Closed system in vertebrates, was a single circuit, now more complicated; Pg 467 – circulation of species - Arteries>arterioles>capillaries>venules>vein - Respiratory surfaces: o Cutaneous: skin gas exchange – amphibians, capillary network lies under the skin, slimy mucous layer to keep skin moist o Gills: thin, moist vascularized dermis, blood and water move in opposite directions creating a diffusion gradient for O and CO (o goes in, co2 goes out) 2 2 o Lungs: blind pouches for air to travel in – increased surface area, air drawn or forced in, lung wall = thin vascularized, large number of small units - Lymphatic system takes up excess water and fluid from the circulatory system (capillaries) - Originally had four “chambers” of the heart but only one ventricle and one atrium Nutrition and digestion - Contains: o Buccal cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum, cloaca/anus - Tongues – specialized mouthpart – helps with type of food they eat (frogs, cats…) - Teeth – reflect nature of diet – heterodont v homodont, gringing v tearing… - Salivary glands – exocrine glands – help with digestion, fish don’t have them (lampreys = anticoagulant) - Esophagus – moves food to stomach (some with peristalsis) – birds = crop, stores food for longterm energy - Stomach = holding station, digestive enzymes (HCl and pepsinogen), breaks down food, gizzards in some animals (all birds) helps crush the food, grind the food with stones, rumens (=some mammals, allows regurgitation of food to be chewed again and allows for more energy to be taken out of herbivory diets), flow controlled by the pyloric sphincter – chyme moves down - Ceca- microorganisms in the rumens helping to break down the cellulose - Livers and gallbladders- manufacture and store blie to emulsify fats breaking it down into globules, liver has cells (hepatocytes) that take up nutrients from the small intestine and release into the blood stream and manufacture blood proteins - Pancreata – secretes fluid containing enzymes into small intestine – helps break down food (carbohydrates and fats) – also secretes bicarbonate to neutralize food - Intestines: absorb nutrient and fluids, large = water, small = nutrients, structure: villi and microvilli, folding of the walls to increase surface area (not in l.i.) - Path: ingestion  peristalsis  segmentation  secretion  digestion  absorption  defecation  - Peristalsis – movement of food by muscle contractions - Sphincters – separate the segments (gateways, control the speed of digestion) and prevent backflow - Oral cavity – mouth and lips and teeth and tongue and saliva - Pharynx – common passage for food and air, epiglottis prevents food getting into trachea Reproduction and development - Functions in the production and release of gametes – creates offspring - Develops embryos – ovi/vivi/ovivivi parous - Females = ovaries , male = testes - Fertlilization was originally external but developed internally - Hormones released to control reproductive cycles Excretory System - Functions in osmoregulation and elimination of metabolic and nitrogenous waste , originally started with just the kidney, skin, gills, and intestine - Functional unit is the nephron – in the kidney = tubule lined with specialized cells for filtering wastes from the blood – reabsorbs water and maximizes the waste excretion – balances the salts in the body - Kidney developed from the somites - Originally pronephros served in the embryo and the opisthonephros in the adult - Nitrogenous wastes was probably elimitaed as ammonia (highly soluble and cheap to produce) - Animals eliminate either urea (uric acid) or ammonia Origin of vertebrates - Vertebrates are not more evolved than one another – just adapted differently - Fossil evidence suggests that they developed over 550 mya - Pikaia gracilens – described from mid-cambrian deposists in burgess shale by CD Walcott in 1911  polychaete - re-examined by A. Simonetta in 1962, chordate but it had a cuticle and tenticles so was rexamined and determined to be a stem chordate (notochord, dorsal nerve chord, myometes, and cephalization) - SJ Gould – vertebrates are survival of the luckiest – Cambrian life forms were the most diverse, but most left no modern descendents - Probably originated by paedomorphosis – sexual maturation of the larval form or a urochordate- like ancestor, underwent a duplication of the HOX genes which control development at the time of their origin Hemichordata - Jawless fish = lampreys, hagfish Hyperotreti – hagfish (class: Myxini) - Have most of the basic characteristics except vertebrae - Several derived traits including: mucous glands and thread cells, degenerate eyes, teeth on their tonge, unique feeding - About 20 species known, deep sea scavengers - No vertebrae, Fishlike, skull consisting of cartilaginous bars, no jaws, no paried appendages, mouth with four pairs of tentacles, olfactory sacs open to mouth cavity, 5-15 pairs of pharyngeal slits, ventrolateral slime glands Vertebrata Petromyzontomorphi Petromyzontida – lampreys - Includes over 40 species, parasitic, have basic vertebrae design as a larvae but adults become more specialized - Digestive system specialized for parasitism (eat blood) and tidal ventilation - Several are pests in sport fishing - Marine and freshwater environments – develop in mud of freshwater then move to marine, come back to freshwater to spawn then die - Mouth is sucker-like surrounded by epidermal teeth, tongue rasps away scales then injects anticoagulant to drink blood of victim Gnathostomata - Likely originated in the mod Ordovician – 480mya, underwent second duplication of the Hox genes - Many specialized characteristics: o Skeletal: jaws derived from pharyngeal arches– more efficient ventilation and prey capture, teeth, two pairs of appendages likely derived from skin folds – used to counter rolling and control tilt/perch/steering o Respiratory: gills with counter-current exchange o Reproductive: gametes excreted from an archinephric (sperm) duct or oviduct (eggs) o Nervous: myelinated axons, lateral-line (canal with groups of hair cells) for sensing motion in water, magnetoreceptors Locomotion: skeletal and muscular adaptations - Streamlined shape, mucoid secretions to lubricate skin for less friction with water - Fish expends little energy against gravity (bc of the water buoyancy) - Uses fins and body wall to push against the incompressible surroundin water - Muscle bundles in zigzag pattern – contraction allowing it to act on the whole body wall of a side (better/stronger movement through water) - Vertical caudal tail – tall and forked, reduces surface area that could cause turbulence Nutrition and Digestion: - Earliest were probably filter feeders, and scavengers, now theyre predators and prey vary immensely - Usually swallow prey whole and only use teeth to catch prey, some modified to crush shells – fish often use suction that closing operculum and rapidly opening mouth creates to catch fish, some are herbivores - Sharks and other elasmobranchs have spiral valve and bony fish have outpockets of intestine = pyloric ceca which increase the aborption and secretory surfaces Circulation and gas exchange: - Closed circulatory system with a ventricle as the primary pump - Fish pass a lot of water over their gills to get as much oxygen as they can, some have a pumping mechanisms that allows them to “inhale the water over their gills” others do ram ventilation (swim with open mouth) - Gill arches support the gills, and filaments extend from each gill arch and include vascular folds of skin - Countercurrent exchange mechanisms allows the fish to keep a gradient for the oxygen and the CO2 - Swim bladders pneumatic sacs - help the fish stay buoyant and control their depth – can inhale water or gas regulated by internal system, some sacs function as lungs as they might have a vascual bed surroudnign them - 4 ways to stay buoyant = low density tissues and buoyant oils, fins provide lift, reduction of heavy tissues, swim bladder Nervous and sensory system: - CNS = brain and spinal cord, general sensory structures along body for touch, olfaction, vision, hearing, equilibrium, balance and water movemtn detection - Eyes are lidless - Lateral-line system: sensory pits in the epidermis of the skin and connect to canals, stimulated by water running over them to detect water currents, predators, objects, - Electroreception: detect the magnetic field of other organisms – detects prey or predators by the apullary organs - Some can generate electrical currents Excretion and osmoregulation: - Done by the kidneys and the gills - Freshwater = never drink, short tubule system for little water reabsorption, large quatities fo dilute urine, active transport of ions - Marine = drink water, eliminate excess ions by excretion, defecation, active transport, small glomeruli and long tubules - Elasmobranchs - convert nitrogenous wastes into urea in the liver, most fish excrete ammonia, but urea concentrated all over body – allows an iso-osmotic relation with the sea water, also possess a rectal gland that removes excess salts form blood excretes it into the cloaca - Diadromous fish migrate between fresh and salt – most ammonia secreted from the gills and rest are secreted as urea, creatine or creatinine (produced in liver and excreted via kidneys) Reproduction and development: - Fish produce millions of eggs but most don’t survive, some oviparous (eggs develop outside the female from a stored yolk), ovoviviparous (embryos develop ina modified oviduct of the female) or viviparous ( placenta-like outgrowth of a modified oviduct diverting nutrients to the embryo’s yolk sac) - Male elasmobranchs have claspers that fertilize internally Chondrichthyes - Cartilaginous fish = sharks, skates, rays, ratfish - Elasmobranchii: active predators and planktivores, jaw opening mechanism enables jaw protrusion and suction, stiff fins and heterocercal tail providing lift, multiple gill slits - Holocephali: feed on crustaceans, upper jaw fused to the cranium and teeth a modified into grinding plates, single gill slit Integumentary systems: - Tough skin with dermal placoid scales that project posteriorly to allow less friction with water and gives sandpaper texture - Teeth are modified placoid scales, and are replaced continuously as they wear down and are lost - Skates and rays have blunt teeth for grinding Skeletal systems: - Skeleton may be calcified but not ossified, fins supported by keratinized rods - Cartilaginous endoskeleton - Skates and rays have a lateral expansion for life on the sea floor – sting ray has modified defensive tail Sensory systems: - Well developed electroreception, reflective layer in retina allows vision in dim light, strong olfactory sensitivity - Ventral mouth, intestine with spiral valve, liver oil-filled fro buoyancy - Carnivores or scavengers, most are marine Temperature and body fluid regulation: - Osmoregulation by urea Reproduction and development: - Eggs generally develop ina protein sac (oviparous) but some species are ovoviviparous (females retain eggs during development) or viviparous (internal fertilization via claspers) Ostreichthyes - Bony fish = lobe finned and ray finned - Some bone in their skeleton, bony operculum covering over the gills, lungs or a swim bladder for buoyancy or gas exchange - Bony ridge scales and fins supported by scales - Skull and shoulder girdle composed largely of dermal bone with teeth rooted in jaws - Coiled intestine and ceca - Sacropterygii o Muscular lobes associated with their fins and usually have lungs for gas exchange ~ lungfishes, live in regions with drought but normally use gills and cannot withstand total drying, live in the mud with 3-chambered heart – early forms gave rise to tetrapods o Heavy scale, double circulation o Lungfish and the coelacanth - Actinopterygii o Ray-finned fish – no muscular lobes in the fins, possess swim bladders (gas filled sacs that regulate buoyancy o Account for nearly a third of the species o Some primitive forms with heavy scales and simple jaws – bichirs, sturgeons, bowfin o Teleosts = normal fish you see everyday ~ tangs, triggerfish, eels, pikes, tuna, perch, salmon…  share several adaptations: protrusible upper jaw, pharyngeal jaw with teeth and homocercal tail  diverse habitats = salty, fresh, depth, dessication…  scales vary in size an color, modification and skin has many derivatives  bodies vary in size and shape location and function  various feeding habits and reproductive modes (courtship, fertilization, parental care, fecundity)  migration habitatas vary between fresh and salt – anadromous (f-o), catadromous (o-f) o Examples: mudskipper, pupfish, tetra, viper fish, flying fish, ice fish, porcupine fish, corydoras, lion fish, goosefish, catfish, tuna, oarfish, dragin fish, ocean sunfish, flounder, scripps fish, sword tail, angler fish, sardine, butterfly fish, baracude, cichlid, electric eels, stickleback, clown fish, seahorse, box fish, cardinal fish, eel, lumpfish, toothfish, killifish, salmon o Amphibia - First terrestrial vertebrates, tetrapods – invasion of the land required many adaptions: o Skeletal: axial skeleton that can support the weight of the body and limbs for support,
More Less

Related notes for BIOL 202

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.