ABDOMEN & THORAX

• thoracic cavity

• abdominal cavity

• spinal cavity

• dorsal cavity

thoracic cavity

• lungs, esophagus, bronchi, trachea, thymus gland, and the heart are located here

  • pericardial cavity = heart

  • pleural cavity = lungs

• STERNUM

  • split into 2 sides by the sternum

  • top of the sternum is the monubrium notch

  • body of the sternum

  • xiphoid process

• RIBS

  • 12 pairs of ribs divided into 3 groups

    • true ribs = the first 7

    • false ribs = next 3 attach from vertebrae to cartilage to the 7th rib

    • floating ribs = 2 ribs with no connection to the other 10 that allow bending movement & protect kidneys

  • ribs are for protection and muscular attachment

• PHARYNX

  • common passageway for air & food

  • epiglottis is a flap of cartilage that regulates the swallowing of food going to the stomach & the air going to the lungs

• LARYNX

  • aka voice box w/ vocal cords

  • triangular chamber below the pharynx

  • lined w/ a mucous membrane = collects pathogens

  • anterior part of throat & takes in air

  • there is a space btwn the vocal cords known as the glottis

• TRACHEA

  • windpipe

  • extends from the larynx & passes through larynx

  • 2 tubes at the end called bronchii (branches out)

• BRONCHI

  • lower ends of the trachea separates into right & left

• BRONCHIOLES

  • subdivisions from bronchi as they enter the lungs

  • then subdivides into alveolar sacs which contain alveoli

• ALVEOLI

  • abt 500 mil in adult lung (more than 3x needed for life)

  • gas exchange happens here

• LUNGS

  • diaphragm relaxes when exhaling

  • diaphragm contracts down when inhaling

  • inhalation = voluntary vs exhaling = voluntary

  • inspiration = increases space & air rushes in (inhalation)

  • expiration = decreases space & air rushes out (exhalation)

  • air constantly wants to balance w/i body & outside envmnt

  • pressure decreases as space expands

  • pressure increases as space decreases

  • large & cone-shaped pleural cavity

  • right vs left lung

    • r = three lobes & bigger bc heart

    • l = two lobes & smaller

• SITUATIONS THAT CAN AFFECT RESPIRATION

  • coughing = a deep breath is taken followed by a forceful exhalation from the mouth to clear the lower respiratory tract

  • hiccups = caused by a spasm of the diaphragm & a spasmodic closure of the glottis & result of an irritation to the diaphragm or the phrenic nerve

  • sneezing = upper respiratory tract infection (vs lower = coughing)

  • yawning = a deep prolonged breath that fills the lungs w/ more oxygen

• LUNG CAPACITY & VOLUME

  • to measure how much air you can hold (lung capacity), a device called a spirometer measures the volume & flow of air during inspiration & expiration

  • volume = an amount that can fill up a space

  • factors

    • tidal volume = the amount of air that moves in & out of the lungs w/ each breath (normal = 500 mL of air flow)

    • inspiratory reserve volume = the amount of air you can force a person to take in over & above the tidal volume (3,000 mL)

    • expiratory reserve volume = the amount of air you can force a person to exhale over & above the tidal volume (1,000 mL)

    • we can breathe in more air than the air we can breathe out

    • vital lung capacity = the total amount of air involved w/ tidal volume (add the tidal, ex/inspiratory together = 500+3,000+1,000)

    • residual volume = the amount of air that cannot be voluntarily expelled from the lungs bc there will always be air left (1,500 mL)

    • functional residual capacity = the sum of the expiratory reserve volume plus the residual volume (2,500 mL)

    • total lung capacity = includes tidal volume, inspiratory reserve, expiratory reserve, & residual air (6,000 mL)

respiratory system disorders

• WHEEZING

  • a physical sound when breathing in

• ASTHMA

  • muscles around airways tighten & airway lining swells & gets clogged w/ thick mucus

  • exercise-influenced asthma is a condition in which vigorous physical activity triggers airway narrowing

  • can be allergy-induced also (cats, cold, etc)

  • take an albuterol inhaler to prevent or relieve immediate symptoms

• VOCAL CORD DISFUNCTION

  • go to an ENT to determine rare condition

chest (thorax) injuries

• RIB CONTUSIONS

  • caused by a forceful blow to the ribcage that bruises intercostal muscle

  • feels better w/ more movement

• RIB FRACTURES

  • break in bony structure of thorax

  • most often result of a direct blow to the ribcage

  • displaced fractures of three or more consecutive ribs on the same side of the chest can cause conditions known as flail chest

• CHEST CONTUSIONS

  • bruising over central area of chest

  • results from a compressive forceful blow to the body

  • this type of injury usually does not cause pain during breathing or restrict motion of the ribcage

• MYOCARDIAL CONTUSION & AORTIC RUPTURE

  • contusion to the heart

  • occurs if force applied to sternum is great enough to compress the heart against the spine

• SUDDEN DEATH SYNDROME

  • usually caused by some form of heart disease but not always the case

• PNEUMOTHORAX

  • occurs when air enters thoracic cavity btwn the chest wall & lung

  • change in pressure causes lung to collapse w/i itself

  • pneumothorax = air in pleural cavity

• HEMOPNEUMOTHORAX

  • can orrcur w/ both open & closed chest injuries

  • often accompanies a pneumothorax

  • blood accumulates in pleural space btwn chest wall & lung

• PULMONARY CONTUSION

  • bruise on lung

• BLOWS TO THE SOLAR PLEXUS

  • having the wind knocked out

• HYPERVENTILATION

  • breathing at a rate faster than required for proper exchange of oxygen & carbon dioxide

• SIDE STITCHES

  • occur during vigorous exercise usually w/ novice exercise

  • w/ ppl who don’t know how to breathe properly or overworking

  • intercostal muscle goes into spasm