In the event you cough, your body relies on a team of muscles working together to clear irritants from your airways. Your diaphragm kicks things off by pulling air deep into your lungs, while the intercostal muscles between your ribs help expand your chest. As you exhale sharply, your abs tighten to build pressure, and your throat muscles snap shut before suddenly releasing air at high speed—like a biological pressure washer. Comprehending these muscles helps explain why coughing feels so forceful, and there’s more to how they coordinate this sudden burst.
Diaphragm: The Primary Muscle for Inhalation During Cough
Your diaphragm plays the biggest role at the moment you take a deep breath before coughing—it’s responsible for about 75% of the air you pull in.
At the time you inhale deeply, your diaphragm contracts and flattens, increasing your thoracic volume. This action lowers intrathoracic pressure, letting air rush into your lungs. The phrenic nerve controls this movement, sending signals from your brain to your diaphragm.
As you prepare to cough, your abdominal muscles tighten, working with your diaphragm to build pressure. Once you finally cough, that stored air explodes out, clearing irritants.
Even in quiet breathing, your diaphragm moves about 1.5 cm, but during a forceful cough, it can drop up to 7 cm.
It’s your body’s powerhouse for strong, effective coughs—no surprise it’s called the primary breathing muscle!
External Intercostal Muscles: Rib Cage Expansion Support
Upon coughing, your external intercostal muscles help lift your rib cage, making it easier to take in the air you need.
They work with your diaphragm to create the strong inhale necessary before a forceful cough.
Without them, your body wouldn’t efficiently expand your chest and build the pressure to clear your airways.
Role in Inspiratory Phase
Because coughing starts with a deep breath, your external intercostal muscles kick into action right away.
These muscles, nestled between your ribs, lift your rib cage during the inspiratory phase, expanding your thoracic cavity to draw in more air. As they contract, they work alongside your diaphragm to create space for your lungs to fill, setting the stage for a powerful cough.
This rib cage expansion is essential—it boosts airflow and primes your airway defensive system to clear irritants. Without strong external intercostals, your cough mechanics would weaken, making it harder to expel mucus or particles.
Consider them as the unsung heroes of that initial deep inhale, ensuring you’ve got the force needed for an effective cough.
Coordination With Diaphragm
Though coughing might feel like a sudden reflex, it’s actually a carefully coordinated effort between your diaphragm and external intercostal muscles. At the moment you cough, your diaphragm contracts downward, while the external intercostals lift your ribs, expanding your thoracic cavity.
This teamwork increases the volume inside your chest, creating the pressure needed for a strong cough. Your diaphragm does most of the heavy lifting—about 75% of the work—but the external intercostals provide crucial support by widening your rib cage.
Without this smooth coordination, your respiratory system wouldn’t generate enough force to clear your airways effectively. Consider it like a well-rehearsed dance: both muscles move in sync to make your cough powerful and efficient, keeping your lungs clear and healthy.
Internal Intercostal Muscles: Assisting Forceful Exhalation
The internal intercostal muscles couldn’t be something you consider about often, but they’re working hard every time you cough. Nestled between your ribs, these muscles are key players in forceful expiration, helping you push air out fast to clear irritants. Here’s how they do it:
- Rib Movement: They pull your ribs downward and inward, shrinking your thoracic cavity to ramp up pressure for a strong cough.
- Teamwork: They partner with your abdominal muscles to boost expiratory force, making cough maneuvers more effective.
- Airway Clearance: By contracting sharply, they help blast air at high speeds, dislodging mucus or debris for better breathing.
Next time you cough, recall these unsung heroes—always on duty to keep your airways clear.
Rectus Abdominis: Generating Intra-Abdominal Pressure
Whenever you cough, your rectus abdominis kicks in hard, tightening to create pressure in your abdomen that helps push air out fast.
It’s like squeezing a balloon—the more force you apply, the stronger the cough gets. This muscle doesn’t work alone, though; it teams up with others to keep your airways clear.
Core Muscle Activation
Coughing isn’t just about your throat—it’s a full-body effort, and your rectus abdominis plays a starring role.
This abdominal muscle tightens to create intra-abdominal pressure, helping you force air out during the cough reflex. Here’s how it works:
- Compression: Your rectus abdominis contracts, squeezing your thoracic cavity like a bellows to push air up and out.
- Timing: It activates just before the cough, building pressure so the elastic recoil of your lungs adds extra force.
- Teamwork: It works with accessory muscles to stabilize your core, ensuring a strong, effective cough.
Without this muscle, coughing wouldn’t be as powerful.
Pressure Regulation Mechanism
Because coughing relies on pressure, your rectus abdominis steps in like a built-in air compressor, squeezing your core to push air out fast.
Once you cough, this muscle tightens hard, ramping up intra-abdominal pressure to blast air past your vocal cords. It works alongside your diaphragm and other expiratory muscles, creating a sudden surge that clears irritants from your respiratory system.
Studies show it can generate forces up to 100 mmHg—enough to make a cough powerful. Your abdominal muscles, especially the rectus abdominis, fire just before peak pressure hits, proving how quickly they respond.
Consider it as your body’s natural pressure valve, ensuring every cough packs a punch. Without it, you’d struggle to clear mucus or debris effectively.
Oblique Muscles: Enhancing Expiratory Force
Several key muscles team up to power your cough, and your obliques are among the most vital. These muscles—the internal oblique and external oblique—work like a natural corset to boost expiratory force.
Here’s how they help:
- Compress the abdomen: Your internal obliques tighten to increase intra-abdominal pressure, pushing air out forcefully during coughing.
- Depress the ribs: The external obliques pull your rib cage down, shrinking your thoracic cavity and amplifying the cough’s power.
- Team up with respiratory muscles: They coordinate with other muscles to clear your airway efficiently.
When you cough, these obliques can create pressure eight times stronger than normal breathing. Their role is vital—without them, your cough wouldn’t pack the punch it needs to protect your lungs.
Scalenes and Sternocleidomastoid: Accessory Inspiration in Cough
Your obliques aren’t the only muscles putting in work as you cough—your neck muscles step in too.
The scalenes and sternocleidomastoid act as accessory muscles, helping your primary inspiratory muscles when you need extra power. The scalenes lift your initial two ribs, while the sternocleidomastoid pulls your rib cage up, boosting thoracic volume for deeper breaths.
This teamwork increases intrathoracic pressure, giving your cough the force it needs to clear irritants. Consider them as backup singers stepping into the spotlight during a tough performance.
Without these muscles, your cough wouldn’t pack the same punch, especially at the times you’re sick or straining. So next moment you hack away, thank your neck for the unsung effort—it’s working overtime to keep your airways clear.
Laryngeal Muscles: Controlling Airflow and Glottis Closure
Here’s how they do it:
- Quick coordination: The recurrent laryngeal nerve signals your muscles to snap shut, then open fast to release the cough.
- Pressure buildup: Closed vocal folds let your lungs pressurize air, like a soda can before it pops.
- Protection mode: Should weakened by neuro-muscular diseases, the seal fails, risking choking or weak coughs.
Your larynx isn’t just for talking—it’s a security system for your lungs.