External and Internal Anatomy

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External and Internal Anatomy

• Veterinary Entomology 208
• Spring 2010

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External Anatomy

• Today we will be using the grasshopper as a model
  insect
• Work in pairs
• Read through the handout on external anatomy
• DO NOT CUT INTO THE GRASSHOPPER

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Our Test Subject
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The head
antenna
compound eye
ocelli
labrum
hypopharynx
filler
mandible
maxilla
labium
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Body regions
dorsal
notum
anterior
posterior
pleuron
sternum
ventral
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Body regions

• thorax divided into
• prothorax
• mesothorax
• Metathorax
• 1st pair of legs prothoracic legs
• 1st pair of wings mesothoracic wings
• 2nd pair of wings metathoracic wings

head
thorax
abdomen
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External reproductive structures

• Male claspers (cerci)

• Female ovipositor

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Objectives for external anatomy

• Know the underlined structures
• Pull off the mouthparts to identify them
• Look at the demonstration material
• Make sure you are familiar with both male and
  female external anatomy

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Internal anatomy

1. Read through the handout on internal anatomy
2. We will go through the procedure for dissection
   and what structures will be visible
3. DONT CUT THEM YET

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1. Reproductive System

• The first thing you will see is the reproductive
  system on the dorsal surface of the grasshopper
• Male testes
• Female ovaries
• Make sure you are familiar with both
• Look at the demo

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2. Digestive system
foregut
midgut
hindgut
anus
ileum
colon
crop
gastric caecae
stomach
gizzard
malpighian tubules
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3. Nervous System
connective
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Dissection procedure

• Cut off the head
• Cut off the legs
• Watch out for the esophagus and cut down both
  sides of the grasshopper
• Gently pull the back off
• Observe the reproductive system lying over the
  digestive system
• Observe the digestive system
• Under the digestive system is the delicate
  nervous system
• Clean up

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External anatomy
Mesothoracic wing
Metathoracic wing
antennae
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