ch.21 poisonous and allergy plants

Question 1

toxicon G arrow poison

Answer 1

• contains active ingredients mainly alkaloids and glycosides.
• curare: arrow poison of the neotropics, variety of preparations, blown with as a dart
• today: used as a muscle relaxant during surgery

Question 2

strychnine

Answer 2

• origin: from Asian- Strychnos nuxvomica
• CNS stimulant
• used as rodent poison, deadly at high doses

Question 3

what are the two common poisonous plants found in North America?

Answer 3

• Poison hemlock and water hemlock
• native to Europe
• common in the midwest and found in uncultivated grounds
• member of the carrot family, gets confused with wild carrot and parsnip
• deadly poison, was used to kill Socrates

Question 4

milkweeds

Answer 4

• cardiac glycosides: poison livestock and children
• deadly
• primary food source of monarch butterflies, so monarchs are immune to the poison. viceroy have evolved to look like monarchs but don NOT feed on milkweed.
• unpalatable to birds

Question 5

TC: milkweed pods are a traditional food of Omaha Indians- cooking makes them nontoxic. how were poisonous plants first identified? why find methods to detoxify so they can be eaten?

Answer 5

• they were accidentally eaten
• if they are detoxified, they can be another food source for survival. could possess chemical compounds that benefit health.

Question 6

backyward poisons

Answer 6

• yews (NOT pacific yew), with red arils; shrub like gymnosperm
• attract children, 2 seeds may be fatal
• red aril: ovulate cone

Question 7

castor bean Ricinus communis

Answer 7

• not a true bean, member of the spurge family
• has toxic poinsettia leaves
• oil is grown commercially to act as a laxative
• 3 seeds are fatal for adults
• toxic protein ricin disables ribosomes, decreases protein synthesis
• potential bioterrorism agent

Question 8

other livestock poison: white snakeroot

Answer 8

• common native plant, found in forests
• causes trembles in cattle
• once it advances, it can contaminate the milk in cattle and cause sickness in humans

Question 9

photodermitis/ St.John’s Wort

Answer 9

• skin irritant activated by light
• St. John’s Wort: causes bighead in sheep. effects the skin first, light activates it, then the face swells. common in grazing animals.

Question 10

Allelopathy

Answer 10

• inhibition of plant growth by plants
• Black walnut tree: releases juglone ( juglans nigra). inhibits plants growing beneath and around it
• less competition for resources and space
• volatile terpenes create allelopathic vapor cloud in sage brush

Question 11

plants that can cause mechanical injury

Answer 11

• cacti
• stinging nettle hairs: trichome breeches the skin, causing histamine release, leading to dermatitis
• can soothe with aloe

Question 12

plant derived insecticides and piscicide

Answer 12

• pyrethrum from ground chrysanthemum cinerariaefolium: garden dust that repels flees and ticks
• rotenone from tuba root: paralyze fish and acts as an insecticide. blocks ETC. from Malaysia
• BOTH break down rapidly

Question 13

plant allergies

Answer 13

• pollen, contact dermatitis, and food allergies
• foreign substance (antigen) induces antibody production

Question 14

allergic reactions

Answer 14

• involve IgE which do not circulate in blood; attach to mast cells lining respiratory tract, skin and intestines
• histamines are leased from mast cells cause symptoms

Question 15

allergic rhinitis

Answer 15

• 10-30% of population worldwide
• cause hay fever, induced by allergens
• common symptoms: eye inflammation, swollen sinus lining, stuffy or runny nose, itchy or sore throat
• severe symptoms: asthma

Question 16

allergic rhinitis causing plants

Answer 16

• ragweeds (Amrosia): found in the midwest
• nonshow flowers, wind pollinated
• common in allergens: make a lot of pollen to assist in pollination
• peaks in August-September in NE
• male: have a stock with anthers and pollen grains inside. chemicals of the exterior exine of pollen cause allergies.

Question 17

other common plant pollen allergens

Answer 17

• trees: oak and maple during the spring
• grasses: early summer
• mainly nonnative: bermuda, kentucky blue grass, johnson grass

Question 18

contact dermititis

Answer 18

• poison ivy, poison oak, and poison sumac
• poison ivy: found in east US
• Rydberg’s poison ivy: central and northern US
• Poison sumac: Southeast US
• Poison oak: west and southeast

Question 19

urushial

Answer 19

• found in poison ivy, poison sumac, poison oak
• cause dermatitis
• hydrophobic
• can’t wash off with water, need to avoid scrubbing off

Question 20

food allergies: response and treatment

Answer 20

• affects 4% of US population
• extreme response: anaphylaxis- swelling of respiratory tissues, drop in bp, cardiac arrest
• immediate treatment: epinephrine reduces allergic response

Question 21

common plant allergens:

Answer 21

peanuts, wheat, tree nuts, strawberries