Morphology and Anatomy of Cockroach
External features and the digestive, circulatory, respiratory, excretory, nervous and reproductive systems. (Biology › Structural Organisation in Animals, NEET UG syllabus.)
What is Morphology and Anatomy of Cockroach?
The leathery, opaque forewings of a cockroach, which cover and protect the hindwings when at rest.
Key points
- Describe the external morphology of a cockroach, including body divisions, exoskeleton, and appendages.
- Identify and explain the structure and function of the digestive system.
- Trace the path of hemolymph in the open circulatory system.
- Explain the mechanism of respiration through the tracheal system.
Common exam trap
Confusing anal styles (male only) with anal cerci (both sexes).
Definitions
- Term
Tegmina
- Meaning
The leathery, opaque forewings of a cockroach, which cover and protect the hindwings when at rest.
- Term
Anal styles
- Meaning
Paired, short, unjointed filamentous appendages found exclusively on the 9th abdominal segment of male cockroaches, used in copulation.
- Term
Anal cerci
- Meaning
Paired, jointed filamentous sensory appendages present on the 10th abdominal segment in both male and female cockroaches.
- Term
Hepatic caeca
- Meaning
Finger-like blind tubules located at the junction of the foregut and midgut, responsible for secreting digestive enzymes.
- Term
Malpighian tubules
- Meaning
The primary excretory and osmoregulatory organs in insects, located at the junction of the midgut and hindgut, filtering hemolymph and producing uric acid.
- Term
Uricotelic
- Meaning
Describes animals that excrete nitrogenous waste primarily in the form of uric acid, which conserves water.
- Term
Ootheca
- Meaning
A dark reddish-to-blackish brown capsule, often bean-shaped, secreted by the female cockroach to enclose and protect her fertilized eggs.
- Term
Open circulatory system
- Meaning
A circulatory system where the blood (hemolymph) is not confined to vessels but flows freely within the body cavity (hemocoel), bathing the organs directly.
Learning objectives
Describe the external morphology of a cockroach, including body divisions, exoskeleton, and appendages.
Identify and explain the structure and function of the digestive system.
Trace the path of hemolymph in the open circulatory system.
Explain the mechanism of respiration through the tracheal system.
Describe the excretory system and the nature of nitrogenous waste.
Outline the organization of the nervous system.
Compare and contrast the male and female reproductive systems, highlighting sexual dimorphism.
Recognize key anatomical features from diagrams.
Prerequisites
Basic knowledge of animal kingdom classification (Phylum Arthropoda, Class Insecta).
Understanding of general insect characteristics.
Familiarity with basic organ system functions (e.g., digestion, circulation, respiration).
Common mistakes
Confusing anal styles (male only) with anal cerci (both sexes).
Incorrectly identifying the type of circulatory system (it is open, not closed).
Misunderstanding the function of hepatic caeca (digestive gland, not excretory).
Forgetting the number of heart chambers or pairs of spiracles.
Incorrectly stating the excretory product (it's uric acid, making them uricotelic).
Keywords
Periplaneta americana
Exoskeleton
Chitin
Head
Thorax
Abdomen
Mouthparts
Tegmina
Anal styles
Anal cerci
Digestive system
Crop
Gizzard
Hepatic caeca
Open circulatory system
Hemolymph
Tracheal system
Spiracles
Malpighian tubules
Uricotelic
Nervous system
Ganglia
Reproductive system
Ootheca
Sexual dimorphism
Practice preview
Identify the accessory reproductive gland in male cockroaches that contributes to the formation of the inner layer of the spermatophore.…
medium
Malpighian tubules, the primary excretory organs in cockroaches, are specifically located at which junction of the alimentary canal?…
hard
Which of the following mouthparts of a cockroach is a median, flexible lobe that functions like a 'tongue' for tasting and manipulating food?…
hard