1. Umm Al-Qura University
بسم الله الرحمن الرحيم
Umm Al-Qura University
Health Sciences College at Al-Leith
Department of Public Health
Lecture (3)

2. biology of Insects and structure 2- Internal Anatomy

3. Objectives
1/ Recognize of Internal Morphology and biology of arthropods. 2/ Define types of arthropods Metamorphosis .

4. 1- The Respiratory System
Function:
Intake of oxygen
removal of CO2
Spiracles: external openings
(2 pair on Thorax, 8 pair on Abdomen)
Trachea/tracheoles: air tubes
Air sacs: air storage

5. Respiratory System

6. Respiratory System

7. 2- The Circulatory System
An open system (unlike vertebrates)
The only blood vessels are the heart and dorsal aorta
Hemocoele – open blood cavity of insect

8. The Circulatory System
Principle functions:
transport food, waste products, and hormones from one part of the body to another.
other functions:
lubrication of internal structures
act as a hydraulic medium
protect the body form infection
serve as a simple storehouse for metabolic waste products

9. Circulatory system
Aorta portion of

10. 3- Nervous System

12. Features of nervous system:
Brain in head, and a ganglia in each section
Ganglia may coordinate the impulses of specific regions

13. 4- Digestive & Excretory Systems

14. Features of digestive tract:
A tube divided into 3 sections (foregut, midgut, & hindgut)
Many insects are efficient at removing water from food (results in dry fecal pellets, also called frass).
Waste is primarily uric acid.

15. 5- Reproductive System

16. Abdomen – digestion, respiration and reproduction
reproductive & oviposition structures
spiracle
Abdomen has 7-11 segments
Each segment has a pair of spiracles

19. Insects will complete one of two different life cycles:
1- Incomplete Metamorphosis - gradual change.
2- Complete Metamorphosis - complete change.

20. Incomplete Metamorphosis:
Egg.
Early nymph (no wings).
Late nymph (wings developing).
Adult.

22. Complete Metamorphosis:
Egg.
Larva.
Pupa.
Adult.

26. What are the basic characteristics of insects?
Are invertebrates.
Have an exoskeleton.
Segmented; Bilateral.
Breathe through holes called spiracles.
Have 6 legs (3 pairs of legs).
Have compound eyes.
Open circulatory system.
Ventral nervous system.
Don’t live very long lives.

27. 2. Reproductive capacity & adaptibility
WHY ARE INSECTS SO SUCCESSFUL?
1. Ability to fly
2. Reproductive capacity & adaptibility
3. Resist drying - exoskeleton
4. Small size
5. Metamorphosis

28. Thanks
Radia 28