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Flashcards in lecture 18 Deck (31):
1

body temperature

-thermoregulation is the maintenance of body temp within a tolerable range
-most of life's processes are very sensitive to body temp
-every animal species has a optimal temp range
-important to keep temp within this range
-humans: 37 degrees
-endotherms are warmed and heated by their own metabolism
-ex) humans and birds
-ectotherms gain most of their heat from the environment and other external sources
ex) amphibians and fish

2

heat can be exchanged with the environment in four ways

1. conduction
2. convection
3. radiation
4. evaporation

3

conduction

-transfer of heat in between molecules by direct contact
-heat always moves from the hotter object to the colder object

4

convection

-transfer of heat by the movement of fluid across a surface

5

radiation

-emission of electromagnetic waves
-can transfer heat in between objects that are not in direct contact

6

evaporation

-loss of heat from the surface of a liquid
-happens when a molecule obtains enough energy to leave the liquid and become gas

7

adaptation for thermoregulation

1.metabolism
2. insulation
3. circulation
-evaporative cooling
-behavioural repsonses

8

metabolism

-hormonal changes in cold weather boost the metabolic rate of mammals, increasing heat production
-additionally moving around more increases heat production
-shivering: contraction of skeletal muscles

9

insulation

-hair, feathers, or fat
-raising or fur or feathers in response to cold traps heat against the surface of the body (goose bumps: humans)

10

circulation

-heat loss can be controlled by the changing the amount of blood flowing to the skin surface
-blood vessels near the surface of the skin dilate and constrict
-conserves heat in the bodies trunk when necessary

11

evaporative cooling

-painting, sweating, and spreading saliva on bodily surfaces all act to decrease body temp
-humans sweat

12

behavioral responses

-migration of birds to different climates
-basking in the sun when cold or seeking shade when hot
-bathing functions to cool immediately

13

excretion

-animals must dispose of nitrogenous wastes
-excretion is the disposal of metabolic wastes
-nitrogenous wastes are products of protein metabolism
-ammonia is poisonous
-water soluble and easily disposed of in animals
-it is converted to urea which is less toxic and much safer to store within the body
-urea and uric acid require energy to produce

14

reproduction:asexual

-can be sexual or asexual
-asexual reproduction results in offspring genetically identical to the parent
-allows for the production of many offspring very quickly
-binary fission: two equally sized cells are produced from one parent cell
-budding: two cells of unequal size are produced from one parent cell
-parthenogenesis: development of an unfertilized egg
-regeneration: entire body parts of some animals can be regenerated
-in humans regeneration is limited to healing and tissue repair
-liver has extensive regenerative capacity

15

reproduction: sexual

-sexual reproduction: fusion of haploid gametes from two parents forms a diploid zygote
-results in extensive genetic variation within offspring
-some animals exhibit hermaproditism
-both male and female reproductive organs are present on the same animals
-in humans this can sometimes occur by mistake

16

reproduction: external fertilization

-occurs in many fish and amphibians
-eggs and sperm are released into water for fertilization to take place
-often physical contact is not required
-timing is very important because the eggs must be ripe

17

reproduction: internal fertilization

-sperm are deposited within or close to the female reproductive tract and gametes unite within the tract
-an adaptation the omits the need for water
-requires copulation: sexual intercourse

18

nervous system: radial symmetry

-the organization of the animals nervous system correlates with form of body symmetry
-animals that are radially symmetrical:
-have web-like nervous systems
-ex) nerve net in hydra
-diffuse throughout the animal body
-no central or peripheral nervous system

19

nervous system: bilateral symmetry

-bilateral symmetry:
-these organisms tend to move through their environment
-requires a head with concentrated sensory organs
-two major adaptions are found within this group:
-cephalization:concentration of the nervous system st the head end
-centralization: a central nervous system(CNS) distinct from the peripheral nervous system

20

nervous system: vertebrate nervous system

-highly specialized
-CNS: brain and spinal cord
-PNS: peripheral nerves
-vertebrate and skull function to protect nerves

21

senses

-senses are important for animal function
-guide movement
-salmon use senses to find their breeding areas
-bears use their senses to locate salmon
-collectively these senses gather info that facilitates feeding, migrating, and other behaviors
-sensory info arrives as a sensation to the brain
-how the brain interprets this info is referred to as perception
-sensory receptors:
-detect stimuli and convert the info into an action potential that is then sent to the brain
-these receptors are highly specialized to pick up stimuli and are located within sensory organs:
-eyes, nose taste buds
-the stimulus energy is transmitted into an action potential which is what will then be sent to the brain

22

five categories of sensory receptors

-many types of receptors can be found on the skin alone
1. pain receptors
2. thermoreceptors
3. mechanoreceptors
4. chemoreceptors
5. electromagnetic receptors

23

pain receptors

-detect stimuli that are considered dangerous

24

thermoreceptors

-detect heat or cold, monitors body temp

25

mechanoreceptors

-respond to any changes in mechanical energy such as touch, pressure, and sound

26

chemoreceptors

-repsond to chemicals
-the nose and the mouth detect chemicals in the enviornment and those about to enter the body
-internal receptors detect chemicals within the body

27

electromagentic receptors

-respond to electricity, magnetism, and light (detected by photoreceptors)

28

vision

-a number of different eyes types have developed in vertebrates
1. simple eye:
-these are cups that sense light intensity and direction
-does not detect an image
2. many-lens compound eyes of insects:
-each unit of the animal has a lens and picks up light from a small portion of the field view
-generates an image from that area only
-all of the lenses together generate the entire picture which is pixelated
3. single-lens eyes of squid:
-similar to a camera
-single lens focuses the image using special muscles in the eye

29

vertebrate eye

-single lens
-cornea and the flexible lens focus the light (via bending) on the retina which contains photoreceptor cells
-light passes through the lens which bends the light ray such that is falls on the retina
-near sighted individuals are only able to see things that are close
-the object is focused within the eye and not on the retina
-far-sighted individuals are only able to see things that are far away
-the object is focused behind the retina

30

locomotion

-locomotion is the active travel from one place to another
-the animal must be able to overcome both gravity and friction
-animals that swim are supported by the body of water but are also slowed by drag created in the water
-animals that move on land are less opposed by friction (air is lighter than water) but they must support their body weight against the force of gravity:
1. hopping
2. running
3. walking
4. crawling

31

skeletal support

-skeletons provide important structure for movement, protection and support
-muscles pull against the skeleton during movement
-protects internal organs within the cavity
-hydrostatic skeletons:
-fluid held under pressure in a body cavity
-worms and cniadrians
-exoskeleton:
-hard, external cases
-chitinous, jointed exoskeletons of arthropods
-includes shells of some molluscs
-endoskeletons:
-hard or leathery supporting elements within the soft tissue of an animal
-vertebrate endoskeleton is composed entirely of cartilage and bone
-sharks have an endoskeleton composed entirely of cartilage