W9: Invertebrate Physiology (Physiology Overview 1) [Dr. Blair] Flashcards
What do you think underpins physiology in insects? (5)
- Body plan.
- Brain.
- Nervous system.
- Circulatory system.
- Extras.
Cross-section through the body segment of an insect: What components are there? (7)
- Exoskeleton (chitin).
- Jointed limbs.
- Coelom.
- Gastrointestinal tract.
- Sternum.
- Heart (on dorsal side).
- Nerve chord (on ventral side).
Cross-section through an APES student: What components are there? (5)
- “Coelom”.
- Gastrointestinal tract.
- Sternum.
- Nerve chord (on dorsal side).
- Heart (on ventral side).
Differences between Cross-section through the body of an insect VS an APES student? (2)
- Heart of an insect is on the dorsal side, while the heart of an APES student is on the ventral side.
- Nerve chord of an insect is on the ventral side, while the nerve chord of an APES student is on the dorsal side.
Do insects have more than 1 brain?
No, not exactly as they don’t have the same centralised system as vertebrates.
The “Main brain” of an insect is AKA?
Cerebral ganglia.
What are the parts of the Cerebral ganglia/ “Main brain”? (3)
- Protocerebrum.
- Deutocerebrum.
- Tritocerebrum.
Protocerebrum location?
Anterior part of the insect brain.
Protocerebrum function?
To process visual inputs from the compound eyes & simple eyes (ocelli).
Deutocerebrum location?
Posterior to the protocerebrum.
Deutocerebrum function?
Process sensory information from the antennae, which are important for chemical signals (smell) & mechanical stimuli (touch).
Tritocerebrum location?
Posterior region of the insect brain that connects to the head ganglia.
Tritocerebrum function?
Coordinates and controls feeding behaviour by integrating sensory information from the mouthparts & regulating associated motor functions.
Nervous system attributes? (3)
- Ganglia control different functions (“main brain” controlling different tasks).
- Unlike humans, ganglia are decentralised (literally).
- Ganglia control different parts of the body.
Nervous system components from top to bottom? (7)
- “Main brain”/Cerebral ganglia.
- SOG (Subesophageal ganglion).
- Segmental ganglia (thorax).
- Ventral nerve cord.
- Nerves.
- Segmental ganglia (abdomen).
- Caudal ganglia (abdomen).
SOG stands for?
Subesophageal Ganglion.
Caudal ganglia function?
Control reproduction & excretion.
Insect nervous systems summary? (3)
- CNS.
- PNS.
- SNS.
Central Nervous System attributes? (3)
- Control center.
- Processes information.
- Information moves from the main brain, nerve cord to ganglia.
Peripheral Nervous System attributes? (3)
- Connects the CNS to the body, limbs & organs.
- From the SOG, ganglia to nerves.
- Contains the SGNS.
SGNS stands for?
Stomatogastric Nervous System.
SGNS function?
Controls gut & digestion.
Sympathetic Nervous System (SNS) attributes? (4)
- Controls internal organs.
- Involuntary actions.
- Deals with the heart, tracheae & circulation.
- Visceral Nervous System.
Why would insects want a “decentralised brain” system? (3)
- Makes it efficient at processing sensory information & rapid control of movement.
- Enables insects to perform complex behaviours such as flying, reproduction & feeding.
- Allows functionality, even if parts of the nervous system are damaged such as in the case of lost limbs.
Loss of limbs attributes? (3)
- Segmental ganglia allows for “autonomous” control.
- Other limbs operate as “normal’.
- No incapacitation.
Do insects feel pain?
It’s complicated, but read Crump et al. (2023) paper to come to an informed conclusion.
Based on the Crump et al. (2023) paper, Do insects feel pain?
Yes, as some insects felt pain such as flies, cockroaches and bees. Therefore, whether an insect feels pain is species-dependent.
Circulatory system of insects attributes? (2)
- Made up of the heart & haemocoel.
- Haemocoel contains the haemolymph.
Heart of insects attributes? (3)
- Elongated heart.
- Is a dorsal “vessel”.
- Circulates haemolymph.
Haemocoel attributes? (20
- Open cavity.
- Contains haemolymph.
Haemolymph attributes? (4)
- Equivalent to “blood” in mammals.
- 90% Water: Plasma.
- Transports nutrients to cells, removes waste & distributes hormones throughout an insect’s body.
- Moves from the butt (bottom) to the head of an insect.
Super summary? (3)
- The Brain (cerebral ganglia, decentralised sections).
- Nervous system (CNS/PNS/SNS, perform complex behaviours).
- Circulation (heart, hemolymph, haemocoel, no O2 delivery).
