Biology Development

Front 1

list the two functions of fertilization?

Back 1

to create genetic variation and fuse a sperm cell with and egg, and form a diploid cell known as a zygote.

Front 2

Describe the acrosomal reaction and explain how it ensures the gametes are conspecific.

Back 2

1.) contents of acrosome are expelled and enzymes are released digest a pathway through eggs jelly layer and allow sperm to reach vitelline envelope of egg. 2.) polmerization of actin into microfilamentast that form acrosomal process. finally, plasma membranes of egg and sperm fuse. sperm nucleus, mitochondria, and centriole enter egg. sperm and eg nuclei fuse--forms zygote.

Front 3

explain the cortical reaction.

Back 3

3. layer splits off of the egg. The egg has a whole series of vesicles at surface that fuse and dumps contents into the vatellin layer. Molecules are there to increase osmolarity to fill with water and pull the surface away. Then hardens and becomes a permanent surface. To get a vesicle to fuse with surface you need a small change in the calcium. It comes from the endoplasmic reticulum that has extra calcium. Need to trigger its release from the ER, the signal comes from the sperm, might take a min to take place from once side of cell to the other side of the cell.

Front 4

explain how the acrosomal and cortical reactiosn function sequentially to prevent polyspermy.

Back 4

4. The entry of a sperm causes calcium ions (Ca2+) to be released from storage areas inside the egg. In response to the dramatic increase in calcium concentration, a series of events occurs in the egg. For example the cortical granules located just inside the membrane fuse with the egg cells plasma membrane and release their contents to the exterior. The contents of the crtical granules include proteases that digest the exterior-facing fragment of the egg-cell receptor for sperm. In addition, other compounds from the cortical granules are trapped between the egg cell’s plasma memebrane and the vitelline envelope and cause water to flow into the space by osmosis. The influx of water then causes the envelope matrix to lift away from the cell and form a fertilization envelope. The fertilization envelope, in turn keeps additional sperm from contacting the egg membrane.

Front 5

describe the changes that occur in an activated egg and explain the importance of cytoplasmic materials to egg activation.

Back 5

5. *The cytoplasmic determinants direct cleavage in the egg. New RNA start to be produced after the twelfth cleavage division. Until then, development is directed by cytoplasmic determinants. The cytoplasmic determinants also orientation the mitotic spindle. The orientation of cleavage is controlled by the mitotic spindle. Different pigment cells might mark individual cells and allow researchers to follow their fate as development progressed. The fate is what the cell is likely to become in the adult individual. (p.455)

Front 6

describe the process of gastrulation and explain its importance.

Back 6

7. Gastrulation radically rearranges cells and results in formation of gastrula, which contains the three embryonic tissue types. The three tissue types are extoderm, mesoderm, endoderm. PROCESS-
• blastula contain cytoplasmic determinants that determine their fate during gastrulation.
• Gastrulation begins with the formation of an opening midway between the poles. Cells from the surface move to the interior through a blastipore.
• The blastocoel shrinks as the surface cells continue to move inward, forming the three embryonic tissue layers
• The three embryonic tissue layers are formed, ready for organogenesis. The blastopore (future anus in frogs*) surrounds a plug of yolk cells.

Front 7

list adult structures derived from each of the primary tissue layers.

Back 7

• Ectoderm
i. Nervous system, cornea and lens of eye, epidermis of skin, epithelial lining of mouth and rectum.
• Mesoderm
i. Skeletal system , circulatory system, lymphatic system, muscular system, excretory system, reproductive system, dermis of skin, lining of body cavity
• Endoderm
i. Epithelial lining of: digestive tract, respiratory tract, reproductive track, and urinary tract.
ii. Liver, pamcreas, thyroid, parathyroids, thymus.

Front 8

distinguish between meroblastic cleavage and holoblastic cleabage.

Back 8

holoblastic- total cleavage
meroplastic- partial cleavage

Front 9

list and explain the functions of the extraembryonic membranes

Back 9

1. amnion
a. thin, ectoderm-derived innermost membrane
b. produces amniotic fluid to bath embryo
c. reptiles, bird, and mammals are referred to as amniotes.
2. yolk sac
a. endoderm-derived
b. associated with nutrition in reptiles and birds
c. retained in mammals because it is the source for primordial germ cells and
original circulating blood cells
3. allantois
a. endoderm-derived
b. reptile/birds – reservoir for wastes and mediates gas exchange
c. mammals – associated with fetal-maternal interface at placenta
4. chorion
EXTRAEMBRYONIC MEMBRANES
Four sets of extraembryonic membranes common to vertebrates.
a. mesoderm-derived, outermost layer
b. reptile/birds – gas exchange
c. mammals – involved in respiration, nutrition, excretion, filtration, and hormone
synthesis by producing fetal placenta

Front 10

differentiation

Back 10

process by which a cell becomes a cell becomes a particular cell type by differential gene expression

Front 11

morphogenisis

Back 11

process of embryonic development during which cells become organized into arecognizable tissues, organs, and other surfaces.

Front 12

fertilization

Back 12

the union of a sperm and egg

Front 13

explain the cortical reaction.

Back 13

3. layer splits off of the egg. The egg has a whole series of vesicles at surface that fuse and dumps contents into the vatellin layer. Molecules are there to increase osmolarity to fill with water and pull the surface away. Then hardens and becomes a permanent surface. To get a vesicle to fuse with surface you need a small change in the calcium. It comes from the endoplasmic reticulum that has extra calcium. Need to trigger its release from the ER, the signal comes from the sperm, might take a min to take place from once side of cell to the other side of the cell.

Front 14

explain how the acrosomal and cortical reactiosn function sequentially to prevent polyspermy.

Back 14

4. The entry of a sperm causes calcium ions (Ca2+) to be released from storage areas inside the egg. In response to the dramatic increase in calcium concentration, a series of events occurs in the egg. For example the cortical granules located just inside the membrane fuse with the egg cells plasma membrane and release their contents to the exterior. The contents of the crtical granules include proteases that digest the exterior-facing fragment of the egg-cell receptor for sperm. In addition, other compounds from the cortical granules are trapped between the egg cell’s plasma memebrane and the vitelline envelope and cause water to flow into the space by osmosis. The influx of water then causes the envelope matrix to lift away from the cell and form a fertilization envelope. The fertilization envelope, in turn keeps additional sperm from contacting the egg membrane.

Front 15

describe the changes that occur in an activated egg and explain the importance of cytoplasmic materials to egg activation.

Back 15

5. *The cytoplasmic determinants direct cleavage in the egg. New RNA start to be produced after the twelfth cleavage division. Until then, development is directed by cytoplasmic determinants. The cytoplasmic determinants also orientation the mitotic spindle. The orientation of cleavage is controlled by the mitotic spindle. Different pigment cells might mark individual cells and allow researchers to follow their fate as development progressed. The fate is what the cell is likely to become in the adult individual. (p.455)

Front 16

describe the process of gastrulation and explain its importance.

Back 16

7. Gastrulation radically rearranges cells and results in formation of gastrula, which contains the three embryonic tissue types. The three tissue types are extoderm, mesoderm, endoderm. PROCESS-
• blastula contain cytoplasmic determinants that determine their fate during gastrulation.
• Gastrulation begins with the formation of an opening midway between the poles. Cells from the surface move to the interior through a blastipore.
• The blastocoel shrinks as the surface cells continue to move inward, forming the three embryonic tissue layers
• The three embryonic tissue layers are formed, ready for organogenesis. The blastopore (future anus in frogs*) surrounds a plug of yolk cells.

Front 17

list adult structures derived from each of the primary tissue layers.

Back 17

• Ectoderm
i. Nervous system, cornea and lens of eye, epidermis of skin, epithelial lining of mouth and rectum.
• Mesoderm
i. Skeletal system , circulatory system, lymphatic system, muscular system, excretory system, reproductive system, dermis of skin, lining of body cavity
• Endoderm
i. Epithelial lining of: digestive tract, respiratory tract, reproductive track, and urinary tract.
ii. Liver, pamcreas, thyroid, parathyroids, thymus.

Front 18

distinguish between meroblastic cleavage and holoblastic cleabage.

Back 18

holoblastic- total cleavage
meroplastic- partial cleavage

Front 19

list and explain the functions of the extraembryonic membranes

Back 19

1. amnion
a. thin, ectoderm-derived innermost membrane
b. produces amniotic fluid to bath embryo
c. reptiles, bird, and mammals are referred to as amniotes.
2. yolk sac
a. endoderm-derived
b. associated with nutrition in reptiles and birds
c. retained in mammals because it is the source for primordial germ cells and
original circulating blood cells
3. allantois
a. endoderm-derived
b. reptile/birds – reservoir for wastes and mediates gas exchange
c. mammals – associated with fetal-maternal interface at placenta
4. chorion
EXTRAEMBRYONIC MEMBRANES
Four sets of extraembryonic membranes common to vertebrates.
a. mesoderm-derived, outermost layer
b. reptile/birds – gas exchange
c. mammals – involved in respiration, nutrition, excretion, filtration, and hormone
synthesis by producing fetal placenta

Front 20

differentiation

Back 20

process by which a cell becomes a cell becomes a particular cell type by differential gene expression

Front 21

morphogenisis

Back 21

process of embryonic development during which cells become organized into arecognizable tissues, organs, and other surfaces.

Front 22

fertilization

Back 22

the union of a sperm and egg

Front 23

zygote

Back 23

fetilized egg

Front 24

acrosome

Back 24

enzymes found on head of sperm cell that helps dissolve zona pellucida or jelly layer on egg.

Front 25

acrosomal reaction

Back 25

a response that is triggered by contact between the sperms head and the jelly layer

Front 26

acrosomal vesicle

Back 26

holds acrosome in sperm

Front 27

acrosomal procerss

Back 27

a protrusion that extens until it makes contact with the viteline envelope

Front 28

bindin

Back 28

protein that is on the head of a sea urching sperm that binds to the surface of the eggs in a species- specific- manner

Front 29

vitelline layer

Back 29

outside plasma membrane, fibrous, mat-like sheet of glycoproteins, surrounds egg, in humans=zona pellucida

Front 30

fast block to polyspermy

Back 30

formation of fertilization envelope

Front 31

cortical granules

Back 31

small vesicles filled with enzymes that are involved in fertilization in egglaying animals. synthesized, transported to cell surface and bound to inner surface of plasma membrane as egg matures

Front 32

cleavage

Back 32

rapid cell divisions that take place in animals after fertilization

Front 33

blastomeres

Back 33

cells created by cleavage divisions

Front 34

vegetal pole

Back 34

yolk-rich reagion

Front 35

meroblastic cleavage

Back 35

cleavage is restricted to only part of the cell

Front 36

holoblastic cldavage

Back 36

cleavage plane cuts through tentire cell, including

Front 37

morula

Back 37

an embryo at an early stage of embryonic development, consisting of approximately 12-32 cells

Front 38

blastocoel

Back 38

cerntral region of a blastula (or blastosphere). It is filled with fluid.

Front 39

blastula

Back 39

sphere of cells that formss when cleavage is complete

Front 40

gastrulation

Back 40

coordinated cell movements that result in a formation of a layered body structure.

Front 41

blastopore

Back 41

small pore of vertebrate embryo, through which cells move during gastrulation

Front 42

gastrula

Back 42

embryo after gastroulation with three germ layers but with no nerve cord

Front 43

invagination

Back 43

indentation in cell that starts gastrulation

Front 44

archentron

Back 44

primitive gut

Front 45

ectoderm

Back 45

outside-skin, epidermis of skin, forms outer covering and nervous system, forms skeletal muscle, and lens of eyeball

Front 46

mesoderm

Back 46

middle skin, gives rise to muscle, internal organs such as blood and cartilage.

Front 47

endoderm

Back 47

inner skin, produces lining of digestive tract or gut, along with organs.

Front 48

notochord

Back 48

long, gelantinous, supportive rod down back of chordate embryo, below developing spinal cord, replaced by vertebrae in adult vertebrates, defining feature of chordates

Front 49

neural plate

Back 49

flat formation in gastroula that preceded the neural crest and tube.

Front 50

neural tube

Back 50

folded tube of ectoderm that forms along dorsal side of vertebrate embryo, gives rise to brain and spinal cord.

Front 51

yolk platelets

Back 51

discs full of yolk

Front 52

dorsal lip

Back 52

...

Front 53

involution

Back 53

find out

Front 54

yolk plug

Back 54

large food-laden endothermal cells surrounded by the blastopore of an amphibian gastrula

Front 55

somite

Back 55

a block of mesoderm on both sides of the developing spinal cord in a vertebrate embryo, gives rise to muscle tissue, vertebrae, ribs, limbs.

Front 56

neural crest

Back 56

group of embryonic cells that separate from the neural plate during neurolation and migrae to give several different lineages of adult cells.

Front 57

determined cell

Back 57

cells that cannot change, they have their function

Front 58

animal pole

Back 58

yolk poor region of an egg cell

Front 59

positional information

Back 59

info that cells use to determine what they are going to be in respect to their relative position

Front 60

morphogen

Back 60

substance governing the pattern of tissue development, positions of the various specialized cell types within a tissue

Front 61

yolk sac

Back 61

amniotic egg, membranebound sac that contains the yolk

Front 62

amnion

Back 62

membrane in amniotic egg that surrouds embryo and encloses it in a protective pool of fluid

Front 63

chorion

Back 63

amniotic egg, highly vascularized membrane across which gas exchange occurs.

Front 64

allantois

Back 64

amniotic egg, membrane-bound sac that holds waste materials.

Front 65

blastocyst

Back 65

thin walled hollow sphere produced by cleavage whose wall is the trophoblast with embryo proper being represented by a mass of cells @ one site

Front 66

inner cell mass

Back 66

group of cells found in the blastocyst, which give rise to embryo, it can make anything (tissues, organs) except trophoblast

Front 67

trophoblast

Back 67

provides nutrients to fetus, eventually forms placenta

Front 68

embryonic disc

Back 68

forms floor of amniotic cavity, derived of inner mass

Front 69

gray crescent

Back 69

gray cytoplasm in zygotes of some frog species opposite the point of sperm entry

Front 70

totipotent

Back 70

capable of dividing and developing to form complete, mature organism

Front 71

cytoplasmic determinant

Back 71

a molecule that exists in eggs and helps early development

Front 72

fate map

Back 72

description of what each cell in the embryo is destined to become.

Front 73

pattern formation

Back 73

events that determine spatial organization of embryo, including major body axes and orientation of limbs

Front 74

retinoic acid

Back 74

vitamin A, cause of cell differentiation, plays part in growth and development in embryo. higher concentration causes growth of extra limbs

Front 75

extramembryonic membranes

Back 75

membrane that connects mother to child

Front 76

induction

Back 76

interaction between a signaling cell and a nearby recipient cell that changes the activity or fate of the recipient cell.

Front 77

organizer

Back 77

region of amphibian embryo that can organize development of entire embryo cells that do recruiting, which come from specific fegion on the embryo's dorsal side.

Front 78

primitive streak

Back 78

where invagination eventually occurs

Front 79

epithelial tissue

Back 79

covers outside of the body, lines surfaces of organs, and forms glands. acts as a barrier and protective layer, typically form layers of closely packed cells. adjacent cells are joined by structures that hold them together (tight junctions and desmosomes).

Front 80

simple epithelial cell

Back 80

one layer of flat cells

Front 81

columnar

Back 81

rectangular cells, epithelial cells whose heights are at least twice their width. divided into simple, or unilayered, and stratified, or multi-layered

Front 82

elastic fiver

Back 82

bundles of proteins (elastin) found n connective tissue, produced by fibroblasts and smooth muscle cells in arteries

Front 83

axon

Back 83

long projection of a neuron that can propagate an action potential

Front 84

chondrocytes

Back 84

only cells found in cartilage

Front 85

leukocytes

Back 85

immune system cells, including neurtrohils, macrophages, b cells and t cells, circulate in blolod or lymph and functin in defense against disease. (white blood cells

Front 86

cardiac muscle

Back 86

tissue of the vertebrate heart, consists of long branched fibers that are electrically connected that initiate their own contractions, not under voluntary control.

Front 87

dendrite

Back 87

short extension from a neurons cell body that recieves neurotransmitters from other neurons

Front 88

connecective tissue

Back 88

cells loosely arranged in a liquid, jellylike, or soldid extracellular matrix

Front 89

stratified epithelia

Back 89

layered epithelial cells

Front 90

squamous

Back 90

flat cells

Front 91

reticular fibers

Back 91

very thin, delicately woven strands of collagen, strands build highly ordered cellular network and provide support

Front 92

organ

Back 92

structure that seves a specialized function and consists of several tissues

Front 93

osteocyte

Back 93

most abundant cell found in bone

Front 94

erythrocyte

Back 94

Red blood cells

Front 95

visceral muscle

Back 95

smooth muscle

Front 96

fibrous connective tissue

Back 96

type of connective tissue which has relatively high tensile strength, due to a relatively high concentration of collagenous fibers

Front 97

muscle tissue

Back 97

tissue consisting of bundles of long, thin contractile cells (muscle fibers)

Front 98

pseudostratified

Back 98

1 layer, which looks like 2 because of the position the nuclei.

Front 99

loose connective tissue

Back 99

contains an array of fibrous proteins in a soft matrix and serves as a packing material between organs or padding under the skin.

Front 100

fibroblast

Back 100

fiber for connective tissue

Front 101

tendon:

Back 101

band of tough, fibrous connective tissue that connects a muscle to a bone.

Front 102

Haversian system:

Back 102

Osteons (also called Haversian system in honor of Clopton Havers) are predominant structures found in some lamellar or compact bone.

Front 103

platelet

Back 103

small membrane-bound cell fragment in vertebrate blood, important in blood clotting

Front 104

nervous tissue

Back 104

tissue consisting of nerve cells (neurons) and various supporting cells, and functioning in rapid transmission of complex information

Front 105

cuboidal

Back 105

cube shaped cells, nucleus in the center of cell

Front 106

collagenous fibers

Back 106

made of collagen, bundles of fibrils that are coils of collagen molecules

Front 107

adipos tissue

Back 107

fat tissue

Front 108

ligament

Back 108

short band of tough fibrous connective tissue composed mainly of long, stringy collagen fibers

Front 109

blood

Back 109

type of liquid connective tissue consisting of red blood cells and leukocytes (white blood cells) suspended in fluid plasma.

Front 110

skeletal muscle

Back 110

(striated muscle): muscle tissue attached to bones of vertebrate skeleton, consists of long, unbranched muscle fibers w/characteristic striped (striated) appearance; voluntary control.

Front 111

neuron

Back 111

: nerve cell, specialized for transmission of nerve impulses, has dendrites, cell body, and long axon that forms synapses with other neurons.

Front 112

monocot

Back 112

plant that has single cotyledon upon germination

Front 113

abscisic acid

Back 113

ABA, plant hormone that inhibits cell elongation, stimulates leaf shedding and dormancy

Front 114

phloem

Back 114

plant vascular tissue conducts sugar, amino acids, chemical signals, contains sieve-tube members and companion cells

Front 115

vascular tissue system

Back 115

parenchyma and sclerenchyma cells specialized for support and long-distance transport of water and nutrients. (xylem, phloem)

Front 116

tropisms

Back 116

involuntary positional growth response to a stimulus

Front 117

indeterminate growth

Back 117

a pattern of growth in which organism continues to increase its overall body size throughout life

Front 118

gravitropism

Back 118

movement or growth of a plant in response to gravity, caused by asymmetrical distribution of auxin in roots

Front 119

stem

Back 119

vertical aboveground part of a plant usually bearing leaves, fruit, flowers

Front 120

node

Back 120

part of stem where leaves or leaf buds are attached

Front 121

internode

Back 121

section of a plant stem between 2 nodes (site where leaves attach)

Front 122

axillary bud

Back 122

lies at the junction of the stem and petiole of a plant

Front 123

apical dominance

Back 123

growth habit in which most of stem’s growth occurs at the apical meristem of the shoot

Front 124

parenchyma cell

Back 124

found in all tissue systems, living cells, capable of further division (totipotent), thin primary wall (found in leaves, centers of stems and roots, fruits. Involved in photosynthesis, starch storage, new growth)

Front 125

collenchyma cell

Back 125

living cell, thicker cell wall, elongated and packed into long ropelike fibers. Provide mechanical support in ground tissue system or elongating plants

Front 126

sclerenchyma cell

Back 126

strengthening and supporting function, dead cells w/thick lignified secondary cell walls, prevent them from stretching as plants grow.

Front 127

dicot

Back 127

plant w/2 cotyledons upon germination

Front 128

xylem

Back 128

plant vascular tissue conducts water and ions from root system to shoot system. Contains tracheids and vessel elements

Front 129

cuticle

Back 129

waxy layer that overlays epidermal cells of shoot system, minimizes water loss, forms barrier that protects plant from virus particles, reduces gas exchange, protects from damaging effects of intense sunlight and attacks from herbivores.

Front 130

leaf abscissin

Back 130

shedding of leaves from a plant

Front 131

root hair

Back 131

outgrowths produced by epidermal cells, greatly increase surface area of dermal tissue, furnish actual sites of water and nutrient absorption

Front 132

indoleacetic acid (IAA)

Back 132

hormone, molecule that produced bending response in decapitated shoots

Front 133

acid-growth hypothesis

Back 133

auxin’s effect on plant cell elongation occurs via installation of proton pumps that make cell wall more acidic, causing cell wall to expand.

Front 134

vessel elements

Back 134

elongated water-conducting plant cell founding xylem. Has gaps thru both primary and secondary cell walls, allowing unconstrained passage of water from one cell to the next.

Front 135

gibberellins

Back 135

plant hormone that stimulates growth

Front 136

apical meristem

Back 136

grp of undifferentiated cells at the tip of stem or root of a vascular plant, responsible for primary growth

Front 137

simple tissue

Back 137

: plant tissues that consist of a single cell type

Front 138

dermal tissue system

Back 138

: plants protective outer covering, facilitates water and ion uptake in roots and regulates gas exchange in leaves and stems

Front 139

ethylene

Back 139

: gaseous plant hormone that induces fruit to ripen, flowers to fade, and leaves to drop. (assoc. w/senescence (process of aging)

Front 140

ground tissue system

Back 140

plant tissue consisting of all cells beneath the outer protective layers of epidermis and cork, expect for vascular tissue.

Front 141

phototropism

Back 141

growth or movement in a particular direction in response to light

Front 142

ground meristem:

Back 142

middle layer of young plant embryo, gives rise to ground tissue

Front 143

procambium

Back 143

group of cells in core of embryo that becomes vascular tissue

Front 144

cytokinins

Back 144

: plant hormones that promote cell division, active cytokinins are synthesized in apical meristems of roots and transported in apical meristems of roots and transported into shoot system thru xylem

Front 145

rootcap

Back 145

protective cells that cover growing region of root

Front 146

zone of cell division

Back 146

contains apical meristem, where cells are actively dividing

Front 147

complex tissue

Back 147

tissues that contain several types of cells

Front 148

stress hormone:

Back 148

cortisol and norepinephrine are released at periods of high stress. The hormone regulating system is know as the endocrine system. Cortisol is believed to affect the metabolic system and norepinephrine is believed to play a role in ADHD

Front 149

taproot system:

Back 149

large vertical main root of a plant

Front 150

auxin

Back 150

indoleacetic acid, plant hormone that stimulates phototropism, involved in cell elongation and apical dominance, promotes cell division and leaf expansion, encourage ethylene production

Front 151

meristem

Back 151

group of undifferentiated plant cells that can produce cells that differentiate into specific adult tissues.

Front 152

protoderm:

Back 152

exterior layer of plant embryo, gives rise to epidermis

Front 153

sieve plates

Back 153

pore-containing structure at one end of a sieve-tube member in phloem

Front 154

petiole

Back 154

stalk of leaf

Front 155

tracheids

Back 155

elongated water-conducting plant cell w/gaps (pits) in secondary cell wall to allow water movement from once cell to next

Front 156

perennial

Back 156

plant that lives for more than 1 year.

Front 157

Angiosperm

Back 157

flowering plant, produces flowers, flowers contain both male and female parts, produces seeds within mature ovaries

Front 158

Monocots

Back 158

monocotyledons dicotyledons
1 cotyledon (inside seed) 2 cotyledons
vascular tissue scattered throughout stem vascular tissue in circular arrangement in stem
parallel veins in leaves (bundles of vascular tissue) branching veins in leaves
flower petals in multiples of 3 flower petals in multiples of 4/5

Front 159

Dicots

Back 159

dicotyledons
2 cotyledons
vascular tissue in circular arrangement in stem
branching veins in leaves
flower petals in multiples of 4/5

Front 160

The importance of root system is to anchor the plant, take in water and nutrients from the soil, and serve as a storage site for starch and carbohydrates. The shoot system harvests light and CO2. The root system provides the shoot system with water and key elements in the form of ions.
Plants grow through primary growth and secondary growth. Primary growth increases the length of roots and shoots through the root and shoot system. The roots college nutrients and water, send it up to the shoot system. Secondary growth is increases the width of the system.

Parenchyma Cells Collenchyma Cells
Structure Living, thin primary cell wall Living, thick cell walls, elongated and packed in long ropelike fibers
Function Wound healing, asexual reproduction, primary site of photosynthesis, storage cells for starch deposits, make up phloem Support
Sclerenchyma cells:
Fibers- form long bundles, assoc w/vascular tissue and extremely elongated, manufacture paper, hemp or jute ropes or fabric
Sclereids- shorter branched cells found in seed coats and fruit, hardest, coat seeds and make up thick cells of nuts

Tracheids and vessel elements are important to plants because they make up the xylem. Both are sclerenchyma cells w/thick secondary cell walls containing lignin. Tracheids are extremely long and thin compared to vessel elements which are short and wide. Both are water-conducting cells found in vascular tissue. Tracheids have pits, interruptions in 2dary cell wall, which help water move both vertically and laterally, because resistance to flow is lowest at pits. Vessel elements have perforations, openings that lack both 1 & 2 cell walls, because they offer so little resistance to flow, they conduct water more efficiently than tracheids do.

Water-Conducting cells (Xylem Sieve-tube members (Phloem)
Structure Tracheids- long, thing
Vessel elements- short wide Long, thin cells
Function Conducts water and ions from root to shoot Conduct sucrose throughout body

Back 160

b

Front 161

Simple tissues

Back 161

plant tissues that consist of single cell type

Front 162

Complex tissues

Back 162

plant tissues that contain several cell typesCuticles are needed for overlaying the epidermal layer of the shoot system.
used to minimize water loss by their wax, which is a lipid and hydrophobic. reduce amount of water that is lost thru evaporation from dermal tissue. protect the plant against pathogens by forming the first line of defense. Reduce gas exchange (open or closed stomata) Protection against sunlight and attacks by herbivores. Roots do not need protection because they are in the ground, therefore no intense sunlight, no herbivores. They have dead cells there that may be eaten

Front 163

Dermal tissue system

Back 163

protective outer covering, facilitates water and ion uptake in roots and regulates gas exchange in leaves and stems

Front 164

: Vascular tissue system

Back 164

xylem and phloem (form continuous vascular system throughout plant), conducts water and solutes between organs and mechanical support

Front 165

5 classes of plant hormones:

Back 165

auxin: bends stems of plants towards light (phototropism), inhibits lateral bud development, cell elongation, organogenisis
ethylene: ripens plants, promotes leaf abscission
gibberellin: promotes seed germination, cell division and elongation, breaks seed dormancy
ABA: inhibits seed germination, promotes seed dormancy and winter dormancy
Cytokinin: promotes cell division and differentiation, inhibits leaf abscission.

Front 166

tropism

Back 166

Light causes a phototropic response by wavelengths in the blue part of the electromagnetic spectrum being detected by photoreceptors (phototropins). It activates the hormones, which is produced in one part of the plant, and transported to target cells in another region of the individual, where it causes physiological responses.

Front 167

Auxin

Back 167

, a hormone, is produced in the shoot tips when phototropins in those cells absorb blue light. Auxin is redistributed to the shady side of the tip, then transported down the shoot, where it binds to the ABP1 receptors in plasma membrane of target cells. Cells elongate when activated ABP1 leads to the installation of additional proton pumps and the activation of the expansin proteins. In this way, auxin acts as the phototropic signal.

Front 168

Small Intestine-

Back 168

first site of the intestine, immediately after the stomach, site of the final stages of digestion and of most nutrient absorption.

Front 169

Pancreas

Back 169

gland attached to the small intestine that secretes digestive enzymes into the intestine and several digestion-related hormones (insulin and glucagons) into the bloodstream.

Front 170

Maltose-

Back 170

a dimer, found in inactive form of maltose

Front 171

Maltase

Back 171

enzyme that breaks down starch.

Front 172

Disaccharid(-ases)-

Back 172

on the brush border.

Front 173

Trypsin-

Back 173

protein-digesting enzyme produced by the pancreas, secreted into the intestine, and activated by enterokinase, activates several other protein-digesting enzymes.

Front 174

Chymotrypsin

Back 174

An enzyme that trypsin activates.

Front 175

- carboxypeptidase’s-

Back 175

An enzyme that trypsin activates.

Front 176

Aminopeptidase

Back 176

breaks up long amino acids into shorter ones.

Front 177

Enterokinase-

Back 177

An intestinal enzyme that converts trypsinogen (from the pancreas) to active trypsin, which then activates protein-digesting enzymes.

Front 178

Chyme-

Back 178

Acid in your stomach. Needs to be carefully controlled b/c it can destroy small intestine cells. It needs a buffer (HCO3-).

Front 179

Microvill(I)-

Back 179

Tiny protrusions from the surface of an epithelial cell that increase the surface area for absorption of substances.

Front 180

Lactase

Back 180

breaks down lactose.

Front 181

Amylase-

Back 181

saliva Breaks down starch so we won’t choke and to keep our teeth healthy

Front 182

Rectum-

Back 182

The last part of the digestive tract; a short tube that hold feces until they are expelled.

Front 183

Pancreatic Amylase

Back 183

- Continues the digestion of carbohydrates that began in the mouth . It is secreted from the pancreas into the small intestine.

Front 184

Bolus

Back 184

The ball of food that the tongue shapes so you can easily swallow it.

Front 185

Esophagus

Back 185

The muscular tube that connects the mouth to the stomach

Front 186

Lacteal-

Back 186

- Lymphatic vessels in the center of villi of the small intestine. Receive chylomicrons containing fat absorbed from food and send them into the lymph system.

Front 187

Bile-

Back 187

A fluid produced by the liver, stored in the gall bladder and secreted into the intestine, where it emulsifies fats during digestion.

Front 188

Emulsification

Back 188

When fat molecules are broken up

Front 189

Jejunum

Back 189

Second part of the small intestine.

Front 190

Peristalsis

Back 190

Rhythmic waves of muscular contractions of muscular contraction that push food along the digestive tract.

Front 191

Lipase-

Back 191

Any enzyme that can digest fats.

Front 192

Salivary amylase-

Back 192

an enzyme within the mouth that softens food and breaks down starch.

Front 193

Feces

Back 193

Waste.

Front 194

Cholecystokinin

Back 194

Intestinal hormone. Stimulates the release of digestive enzymes. From the pancreas.

Front 195

- Stomach

Back 195

A tough, muscular pouch in the digestive tract that breaks up food and delivers it to the intestine.

Front 196

Large stomach (colon)-

Back 196

Compact the wastes that remain and absorb enough water to form feces.

Front 197

Zymogens

Back 197

The inactive forms of enzymes. The enzymes are in inactive form in order to prevent the body from eating itself.

Front 198

Mucus-

Back 198

A slimy mixture of glycoproteins and water, secreted by organs for lubrication.

Front 199

Goblet cells-

Back 199

mucus

Front 200

Cecum

Back 200

A blind sac between the small intestine and the colon. Used in some species as a fermentation vat for digestion of cellulose.

Front 201

Salivary glands

Back 201

Release water and glycoproteins called mucins (when touch water, it forms mucus).

Front 202

Liver-

Back 202

An abdominal organ of vertebrates that performs many biochemical processes, including storage of glycogen, processing and converting of food and wastes, and production of bile.

Front 203

Starch

Back 203

A mixture of polysaccharides amylose and amyl pectin; used primarily for food storage in plants.

Front 204

Cardiac sphincter-

Back 204

Connects the esophagus to the stomach.

Front 205

Pyloric sphincter

Back 205

Connects the stomach to the doudenum (the small intestine).

Front 206

Saliva-

Back 206

a substance within the mouth that contains amylase that softens and breaks down starch.

Front 207

Pepsin

Back 207

The non-harmful form of pepsin(ogen). Digests proteins in the stomach.

Front 208

Secretin

Back 208

A peptide hormone produced by the small intestine in response to the arrival of food from the stomach. Stimulates secretion of bicarbonate from the pancreas

Front 209

Gastrin-

Back 209

A hormone produced by the stomach in response to the arrival of food or to a signal via nerves from the brain. Stimulates other stomach cells to release hydrochloric acid.

Front 210

Villi

Back 210

projections of the lining of the digestive tract. Function to increase surface area for absorption.

Front 211

Bile salts

Back 211

Small lipids in bile that emulsify fats

Front 212

Duodenum

Back 212

The first part of the small intestine.

Front 213

Nucleases

Back 213

Digest the RNA and DNA in food.

Front 214

Sucrase-

Back 214

An enzyme that breaks down starch

Front 215

Ileum-

Back 215

The third part of the small intestine

Front 216

Triglycerides-

Back 216

.
the basic form of lipid when it is broken down for digestion.

Front 217

Chylomicrons

Back 217

- A ball of protein-coated lipids, used to transport the lipids through the bloodstream.

Front 218

Vasopressin (ADH)-

Back 218

Synthesized in the hypothalamus and released from the pituitary gland. Increases the permeability of the kidney’s collecting ducts to water. As a result, water is reabsorbed from the urine and saved. Instrumental in achieving homeostatis.

Front 219

Oxytocin

Back 219

A hormone that is released from the hypothalamus and induces labor and milk production in females.

Front 220

Pituitary

Back 220

Sits below the hypothalamus and has distinct anterior and posterior regions; releases the growth hormone, ACTH, TSH, prolactin, FSH and LH.

Front 221

Gluconeogenesis

Back 221

- - Synthesis of new glucose from non-carbohydrate sources, such as proteins and fatty acids. Occurs in the liver response to low insulin levels and high glucagons levels.

Front 222

Aldosterone

Back 222

Increases reabsorption of sodium by kidneys. Released from the adrenal glands

Front 223

Growth hormone

Back 223

A peptide hormone produced by the mammalian pituitary gland. Involved in lengthening the long bones during childhood and in muscle growth, tissue repair, and lactation in adults.

Front 224

Prolactin-

Back 224

Released from the pituitary gland. Stimulates the mammary gland growth and milk production in females.

Front 225

Giantism

Back 225

A disease where the growth hormone is overproduced. It results in a person being very tall.

Front 226

Pancreas

Back 226

A gland attached to the small intestine that secretes digestive enzymes into the intestine and several digestion-related hormones (notably, insulin and glucagons) into the bloodstream.

Front 227

Insulin-

Back 227

A peptide hormone produced by the pancreas in response to high levels of glucose (or amino acids) in blood. Enables cells to absorb glucose and coordinates synthesis of fats, proteins, and glycogen.

Front 228

Glucagons-

Back 228

A peptide hormone produced by the pancreas response to low blood glucose. Raises blood glucose by triggering breakdown of glycogen and stimulating gluconeogensis

Front 229

Hypothalamus-

Back 229

A part of the brain that regulates the body’s internal physiological state, such as the autonomic nervous system and the endocrine system.

Front 230

Releasing factor-

Back 230

A hormone that stimulates the release of other hormones

Front 231

Inhibiting factors

Back 231

A hormone that inhibits the release of other hormones

Front 232

Adrenal cortex

Back 232

Completely different gland from adrenal medulla. Makes steroid hormones.

Front 233

Adrenal medulla-

Back 233

- Produces two different hormones 1) epinephrine (adrenaline), 2) nor epinephrine.

Front 234

Glucocorticoids-

Back 234

A class of steroid hormones released from the adrenal cortex that increase blood glucose and prepare the body for stress. Its primary role in humans is to ensure the continued availability of fuel molecules to support important body functions.

Front 235

Hormone

Back 235

A signaling molecule that circulates throughout the body in blood or other body fluids; can trigger pronounced responses in distant target cells at very low concentrations.

Front 236

Epinephrine-

Back 236

A catecholamine hormone from the adrenal medulla. Triggers rapid responses relating to the fight-or-flight response. Also known as adrenaline.

Front 237

Calcitonin-

Back 237

Help regulate the blood calcium level. It decreases the calcium in blood. It is released from the Thyroid gland.

Front 238

PTH-

Back 238

A peptide hormone that increases the calcium levels in blood.

Front 239

TSH

Back 239

peptide hormone from the pituitary gland that stimulates release of thyroid hormones from the thyroid gland.

Front 240

ACTH

Back 240

Stimulated from the pituitary gland. It stimulates adrenal glands to secrete glucocorticoids

Front 241

Trophic hormone

Back 241

hormones that control the release of other hormones

Front 242

Thyroid gland-

Back 242

Situated in the neck. Releases thyroxin and calcitonin

Front 243

Thyroxin

Back 243

Regulates the metabolic rate. Increases the metabolic rate and heart rate; promotes growth. It is released from the thyroid gland.

Front 244

Parathyroid gland

Back 244

- Embedded in the thyroid gland; releases PTH (increases the calcium in blood)

Front 245

Adrenal gland

Back 245

Two glands that sit atop the kidney and have an outer cortex and a central medulla. Release epinephrine, cortical and aldosterone.

Front 246

telencephalon

Back 246

- name for a large region within the brain that is attributed many functions.

Front 247

Meninges

Back 247

the system of membranes that envelop the central nervous system

Front 248

White matter

Back 248

one of the two main solid components of the central nervous system . It is composed of myelinated nerve cell processes, or axons, which connect various grey matter areas (the locations of nerve cell bodies) of the brain to each other and carry nerve impulses between neurons.

Front 249

Grey matter

Back 249

major component of the central nervous system, consisting of nerve cell bodies and short nerve cell extensions/processes ( axons and dendrites).

Front 250

Telodendria

Back 250

azon terminal branches

Front 251

Synaptic knobs

Back 251

- The end of a cell membrane where the neurotransmitters are transported to another neuron via exoctyosis

Front 252

Neuropeptides-

Back 252

any of the variety of peptides found in neural tissue; e.g. endorphins, enkephalins. Now, about 100 different peptides are known to be released by different populations of neurons in the mammalian brain.

Front 253

Forebrain

Back 253

the rostral-most portion of the brain.

Front 254

Diencephalons

Back 254

the region of the brain that includes the thalamus, hypothalamus, epithalamus, and subthalamus.

Front 255

Brain-

Back 255

the control center of the central nervous system

Front 256

Spinal cord

Back 256

part of the vertebrate central nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). It consists of nerve cells

Front 257

Cerebral cortex

Back 257

brain structure in vertebrates . In non-living, preserved brains, the outermost layers of the cerebrum has a grey color, hence the name "grey matter".

Front 258

Astrocytes-

Back 258

characteristic star-shaped glial cells in the brain.

Front 259

Temporal summation

Back 259

an effect generated by a single neuron as way of achieving action potential

Front 260

Spatial summation-

Back 260

a way of achieving action potential in a neuron which involves input from multiple cells. Spatial summation is the algebraic summation of potentials from different areas of input, usually on the dendrites.

Front 261

Biogenic amines

Back 261

biogenic amine is a biogenic substance with an amine group. Some prominent examples of biogenic amines include: Histamine, norephrphrine,

Front 262

Hindbrain-

Back 262

a developmental categorization of portions of the central nervous system in vertebrates.

Front 263

Graded potentials

Back 263

the electrical potential difference ( voltage) across a cell's plasma membrane

Front 264

Thalamus

Back 264

the main part of the diencephalon, a portion of the brain.

Front 265

Electrical synapse

Back 265

mechanical and electrically conductive link between two abutting neurons that is formed at a narrow gap between the pre- and postsynaptic cells known as a gap junction

Front 266

Mesencephalon

Back 266

the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. The mesencephalon caudally adjoins the pons and rostrally adjoins the diencephalon.

Front 267

Prosencephalon

Back 267

the rostral-most portion of the brain. The prosencephalon, the mesencephalon (midbrain), and rhombencephalon (hindbrain) are the three primary portions of the brain during early development of the central nervous system

Front 268

- - Brainstem

Back 268

the lower part of the brain, adjoining and structurally continuous with the spinal cord. . Major route for communication.

Front 269

Glial cells

Back 269

non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin, and participate in signal transmission in the nervous system

Front 270

All-or-none event

Back 270

Action potentials can only occur in all or none. They can't occur in partial events.

Front 271

- Oligodendrocytes

Back 271

variety of neuroglia. Their main function is the myelination of nerve cells exclusively in the central nervous system of the higher vertebrates, a function performed by Schwann cells in the peripheral nervous system.

Front 272

Blood-

Back 272

brain barrier- membrane that controls the passage of substances from the blood into the central nervous system.

Front 273

Chemical synapse

Back 273

- specialized junctions through which cells of the nervous system signal to one another and to non-neuronal cells such as muscles or glands

Front 274

Endorphin

Back 274

peptides produced by the pituitary gland and the hypothalamus in vertebrates, and they resemble the opiates in their abilities to produce analgesia and a sense of well-being. In other words, they might work as "natural pain killers."

Front 275

Atria-

Back 275

thin walled chambers of the heart that pump blood in to the ventricles

Front 276

Hydrostatic pressure

Back 276

created by pressure on blood generated by the heart

Front 277

Hemoglobin

Back 277

oxygen-binding protein consisting of four polypeptide subunits, each containing a heme group

Front 278

Chordae tendinae-

Back 278

- cord-like tendons that connect papillary muscles to tricuspid valve and mitral valve in heart.

Front 279

Intercalated disc-

Back 279

physical connections between adjacent heart muscle cells. Contain gap junctions to allow electrical signals to pass between the cells

Front 280

Bundle of his

Back 280

- band of specialized cardiac muscle fibers that originate in the atrioventricular node and extends into the membranous part of the interventricular septum

Front 281

Effects of smoking

Back 281

- numbs cilia in trachea, so it cannot pick up shit you inhale, thus it collects in lung.

Front 282

Trachea

Back 282

- tube found in most mammals through which inhaled air travels and is carried to the lungs

Front 283

Sinus node

Back 283

specialized cardiac muscle fibers that generate cardiac impulses normally acts as a pacemaker(located in the right atrium)

Front 284

Purkinje fibers

Back 284

the inner ventricular walls of the heart, just beneath endocardium fibers are specialized myocardial fibers that conduct an electrical stimulus that enables heart to contract in a coordinated fashion. work with SA node and AV node to control heart rate.

Front 285

Arteriole

Back 285

tiny arteries that deliver blood to the capillaries (has muscular walls)

Front 286

Blood Pressure

Back 286

force that the circulating blood exerts on the walls of the arteries (systolic and diastolic)

Front 287

Respiratory Epithelium

Back 287

ciliated pseudostratified columnar epithelium, encompasses goblet cells, all cells make contact with the basement membrane

Front 288

Plasma

Back 288

consists of serum and clotting factors, fluid portion of the blood that remains after the removal of white blood cells, red blood cells, and platelets

Front 289

Diastole

Back 289

portion of the heartbeat cycle during of which the atria or ventricles of the heart are relaxed

Front 290

Systole

Back 290

portion of the heartbeat cycle during which the heart muscles are contracting

Front 291

Systolic Pressure

Back 291

blood pressure in arteries during ventriclar systole(heart contractions)

Front 292

Ventricles

Back 292

thick walled chamber of the heart that receives blood from an atrium and pumps it to the body or to the lungs

Front 293

Bronchi

Back 293

large tubes that lead from the trachea to each lung

Front 294

Cartilage Rings

Back 294

rings of cartilage that make up trachea

Front 295

Capillary

Back 295

smallest blood vessel where gasses and other molecules are exchanged between blood and tissues

Front 296

Emphysema

Back 296

lung disease caused by breakdown of alveoli and loss of elasticity of the lungs

Front 297

Mitral Valve

Back 297

valve that separates the left atrium from the left ventricle

Front 298

Bohr Effect

Back 298

right ward shift of the oxygen – hemoglobin dissacociation curve that occurs with decreasing pH. Result in hemoglobin being more likely to release oxygen in the acidic environmentof exercising muscle.

Front 299

Alveoli

Back 299

tiny air filled sacs of a mammalian lung

Front 300

Platelets

Back 300

small membrane bound cell fragments in vertebrate that aid in the clotting process

Front 301

Mucus

Back 301

slimy mixture of glycoprotiens and water secreted by organs for lubrication

Front 302

Vein

Back 302

any blood vessel that carries blood from an atrium and pumps it to the body or to the lungs

Front 303

aortic valve

Back 303

lies between left ventricle and aorta. When pressure in left ventricle rises above pressure in the aorta, it opens, allowing blood to exit left ventricle into aorta

Front 304

Atrioventricular node

Back 304

location in the heart between the atria and the ventricles where electrical signals from the atria are slowed before spreading to the ventricles allowing them to fill with blood before contracting

Front 305

Artery

Back 305

any blood vessel that carries blood from the heart to the capillaries, has thick muscular walls that withstand and control blood pressure

Front 306

White Blood Cells

Back 306

immune system cells that circulate in the blood or lymph and functions in the defense against disease

Front 307

Tricuspid valve

Back 307

heart valve named for its three cusps, divides the right atrium and right ventricle

Front 308

Red Blood Cells

Back 308

hemoglobin-containing cells that circulate in the blood and deliver oxygen from, the lungs to the tissues

Front 309

Allosteric

Back 309

allosteric regulation is the regulation of an enzyme or protein by binding an effector molecule at the protein's allosteric site

Front 310

Bronchioles

Back 310

small lungs that carry air from the bronchi to the alveoli.

Front 311

Globulins

Back 311

serum proteins

Front 312

Vagus Nerve

Back 312

only nerve that starts in brainstem (within the medulla oblongata) and extends, thru jugular foramen, down below head, to abdomen, single most important nerve in body

Front 313

Diastolic Pressure

Back 313

blood pressure in arteries during the relaxation of the hearts left ventricle

Front 314

Albumin

Back 314

class of large proteins found in plants and animals (mainly in the albumen of eggs and in blood plasma

Front 315

Transduction

Back 315

movement of ions across membrane

Front 316

Amplification

Back 316

G proteins (molecular). Physical- example hearing. Bones move to enhance hearing by positioning so the sound waves will hit the water better.

Front 317

Transmission

Back 317

action potential going to the central nervous system.

Front 318

Opsin

Back 318

one of several proteins involved in animal vision. An opsin joins with retinal to form the light-detecting pigment rhodopsin in rod cells.

Front 319

Tropomyosin

Back 319

a muscle protein that blocks the myosin-binding sites on actin filaments, preventing muscle contraction. Can be moved out of the way by troponin when intracellular calcium is high.

Front 320

Mechanoreceptors

Back 320

pressure, stretch, touch, motion, sound, *propio (self)

Front 321

Pacinian corpuscles

Back 321

the receptors that are deep in the dermis. Can be 2 cm long, real deep pressure and distortion.

Front 322

Meissners corpuscles

Back 322

very light touch. Ex: finger tips.

Front 323

Merkel’s discs

Back 323

responsible for very light touch

Front 324

Tympanic membrane

Back 324

the eardrum; a membrane separating the middle ear from the outer ear in terrestrial vertebrates, or similar structures in insects.

Front 325

Thermoreceptor

Back 325

thought to be “naked”. Hot-linked to pain- 42 linked to capsacin-heat. Capsacin blocks pain over time. Cold-below 25 degrees linked to menthol, responding with the cold receptor.

Front 326

Stapes

Back 326

a stirrup-shaped bone in the middle ear of vertebrates. Receives vibrations from the tympanic membrane and passes them to the cochlea.

Front 327

Oval window

Back 327

a membrane separating the fluid-filled cochlea from the air-filled middle ear. The stapes, a middle ear bone, transmits sound vibrations to the cochlea by vibrating on the oval window.

Front 328

Sclera

Back 328

(usually) the white outer coating of the eye made of tough fibrin connective tissue which gives the eye its shape and helps to protect the delicate inner parts.

Front 329

Cornea

Back 329

the transparent sheet of connective tissue at the very front of the eye in vertebrates and some other animals. Protects the eye and helps focus light.

Front 330

Pupil

Back 330

the hole in the center of the iris through which light enters a vertebrate or cephalopod eye.

Front 331

Rhodopsin

Back 331

a combination of two molecules (retinal and one of various opsins) instrumental in detection of light by rods and cones of vertebrate eyes.

Front 332

Myofibrils

Back 332

Found within muscle cells, they are the bundles of filaments that run from one end of the cell to the other and are attached to the cell surface membrane at each end.

Front 333

Thin filaments

Back 333

strands of actin found in the middle of a muscle sarcomere. Bind to thin filaments (actin) and cause muscle contraction.

Front 334

Aqueous humor

Back 334

the clear, watery fluid in the eye that fills the space between the back surface of the cornea and the front surface of the vitreous humor.

Front 335

Sarcomere

Back 335

a single contractile unit of a skeletal muscle cell.

Front 336

Rod cells

Back 336

a type of photoreceptor cell with a rod-shaped outer portion. Found in vertebrate retinas. Particularly sensitive to dim light, but not used to distinguish colors.

Front 337

Cone cells

Back 337

(1) a photoreceptor cell with a coneshaped outer portion that is particularly sensitive to bright light of a certain color. Found in eyes of vertebrates and some other animals.

Front 338

Fovea

Back 338

the small region of the vertebrate retina in which the photoreceptors are very tightly packed, producing the most acute vision.

Front 339

Sensory adaptation

Back 339

a change over time in the responsiveness of the sensory system to a constant stimulus.

Front 340

Bipolar cells

Back 340

cells in the vertebrate retina that receive information from one or more photoreceptors and pass it to the other bipolar cells and ganglion cells.

Front 341

Ganglion cells-

Back 341

neurons in the vertebrate retina that collect visual information from one or several bipolar cells.

Front 342

Horizontal cells

Back 342

the laterally interconnecting neurons in the outer plexiform layer of the retina

Front 343

Amacrine cells

Back 343

interneurons in the retina which operate at the Inner Plexiform Layer (IPL), the second synaptic retinal layer where bipolar cells and ganglion cells synapse

Front 344

Olfactory receptor

Back 344

a type of G protein-coupled receptor in olfactory receptor neurons. In vertebrates, the olfactory receptors are located in the olfactory epithelium. In insects, olfactory receptors are located on the antennae. Sperm cells also express odor receptors, which are thought to be in volved in chemotaxis to find the egg cell.

Front 345

Incus

Back 345

is the anvil-shaped small bone or ossicle in the middle ear. It connects the malleus to the stapes. The incus only exists in mammals, and is derived from a reptilian upper jaw bone, the quadrate bone.

Front 346

Pain receptor

Back 346

Nociceptor. A sensory cell or organ specialized to detect tissue damage, usually producing the sensation of pain.

Front 347

Cochlea

Back 347

a coiled, fluid-filled tube in the inner ear of mammals, birds, and crocodilians. Contains nerve cells that detect sounds of different pitches.

Front 348

Endolymph

Back 348

the fluid contained in the membranous labyrinth of the inner ear. The main cation of this unique extracellular fluid is potassium. Disruption of the endolymph due to jerky movements (like driving over bumps while riding in a car) can cause motion sickness.

Front 349

Utricle

Back 349

larger than the saccule, is of an oblong form, compressed transversely, and occupies the upper and back part of the bestibule, lying in contact with the recessus ellipticus and the part below it. The portion which is lodged in the recess forms a sort of pouch or cul-de-sac, the floor and anterior wall of which are thichened, and form the macula acustica utriculi, which receives the utricular filaments of the acoustic nerve. The cavity of the utricle communicates behind with the semicircular ducts by five orifices. From its anterior wall is given off the ductus utriculosaccularis, which opens into the ductus endolymphaticus.

Front 350

Semicircular canals

Back 350

three half-circular, interconnected tubes located inside each ear that are the equivalent of three gyoscopes located in three planes perpendicular. Each canal is filled with a fluid called endolymph and contains a motion sensor with little hairs (cilia) whose ends are embedded in a gelatinous structure called the cupula. The semicircular canals are a component of the Labyrinth.

Front 351

- Myofilaments

Back 351

The filaments of myofibrils constructed from proteins, myofilaments consist of 2 types, thick and thin. Thin filaments consist primarily of the protein actin; thick filaments consist primarily of the protein myosin. The protein complex composed of actin and myosin is sometimes referred to as "actomyosin." In striated muscle, such as skeletal and cardiac muscle, the actin and myosin filaments each have a specific and constant length on the order of a few micrometers, far less than the length of the elongated muscle cell (a few millimeters in the case of human skeletal muscle cells). The filaments are organized into repeated subunits along the length of the myofibril.

Front 352

Tetanus

Back 352

generates smooth muscle contraction. The maximum state of tension that can be achieved in a muscle.

Front 353

Thick filaments-

Back 353

strands of myosin found in the middle of a muscle sarcomere. Bind to thin filaments (actin) and cause muscle contraction.

Front 354

Origin

Back 354

muscle connection where the least amount of motion occurs.

Front 355

Myosin

Back 355

a eukaryotic protein that can be polymerized to form thick filaments that are used in muscle contraction and intracellular movement.

Front 356

Troponin complex

Back 356

a muscle protein that can trigger muscle contraction by moving tropomyosin off the myosin-binding sites on actin filaments. Activated by high intracellular calcium.

Front 357

Hair cell

Back 357

a pressure-detecting sensory cell that has tiny “hairs” (stereocilia) jutting from its surface

Front 358

Lens

Back 358

a transparent, crystalline structure that focuses incoming light onto a retina or other light-sensing apparatus of an eye

Front 359

Pinna

Back 359

visible part of the ear that resides outside the head.

Front 360

Auditory canal

Back 360

The ear canal or 'external auditory meatus' is a tube running from the outer ear to the middle ear. The ear canal extends from the pinna to the eardrum and is about 26 mm in length and 7 mm in diameter.

Front 361

Middle ear

Back 361

the air-filled middle portion of the mammal ear, connecting to the thraot via the Eustachian tube. Transmits and amplifies sound from the tympanic drum

Front 362

Cardiac muscle

Back 362

the muscle tissue of the vertebrate heart. Consists of long branched fibers that are electrically connected and that initiate their own contractions; not under voluntary control

Front 363

Intercalated discs

Back 363

the physical conections between adjacent heart muscle cells. Contain gap junctions to allow electrical signals to pass between the cells

Front 364

Inner ear

Back 364

the innermost portion of the mammalian ear, consisting of a fluid-filled system of tubes that includes the cochlea (which receives sound vibrations from the middle ear) and the semicircular canals (which function in balance)

Front 365

Iris

Back 365

a ring of pigmented muscle just inside the vertebrate eye that contracts or expands to control the amount of light entering the eye.

Front 366

Retina

Back 366

a thin layer of light-sensitive cells (rods or cones) and neurons at the back of a camera-type eye, such as that of cephalopods or vertebrates.

Front 367

Actin-

Back 367

a globular protein that can be polymerized to form actin filaments, which are I nvolved in cell movement

Front 368

Sarcoplasmic reticulum

Back 368

sheets of smooth endoplasmic reticulum in a muscle cell. Contains high concentrations of calcium, whoch can be released into the cytoplasm to trigger contraction.

Front 369

Sliding filament model

Back 369

the hypothesis that the contraction of muscle cells is caused by filaments of actin and myosin sliding past each other

Front 370

Chemoreceptor

Back 370

sensory cell or organ specialized for detection of specific molecules of classes of molecules.

Front 371

Electromagnetic receptor

Back 371

sensory cell or organ specialized to detect electric fields.

Front 372

Myoglobin-

Back 372

an oxygen-binding muscle protein consisting of a single globin and one heme group.

Front 373

Smooth muscles

Back 373

the unstriated muscle tissue that lines the intestine, blood vessels, and some other organs. Consists of tapered, unbranched cells that can sustain long contractions. Not voluntarily controlled.

Front 374

Nociceptor

Back 374

a sensory cell or organ specialized to detect tissue damage, sually producing the sensation of pain