LCD 207 Test 3 (copy)

Respiration

• The exchange of gas between an organism and its environment.

• Neuromuscular event governed by involuntary sensory systems.

• Mostly involuntary but can be overridden voluntarily.

Pulmonary apparatus

• The structures involved in gas exchange in the lungs

• Lungs, trachea, diaphragm, alveoli, etc.

Inspiration

• Breathing in to bring oxygen to the cells of the body.

• Inhalation.

• Active - overseen by nerve impulses.

Expiration

• Breathing out to eliminate waste products.

• Exhalation.

• Passive - body goes back to normal position.

Alveoli

• Miniscule air sacs that bring air into the lungs in an active, muscular process.

• Covered in capillaries (blood vessels) that transport oxygen to body cells via the bloodstream through diffusion.

• Air comes through bronchioles and expands ____ to fill them with air.

• Toxins (CO2) are transported from the venous blood supply to the ____ to be expelled.

Air pressure

• Force exerted in the walls of a chamber by air.

• Air molecules tend to keep their distance from each other.

• If the chamber is opened to the atmosphere, the pressure exerted on the inner walls will be the same as that on the outer walls.

• Making the chamber smaller does not change the force keeping air molecules apart.

Boyle’s law

Given a gas of a constant temperature:

• Increasing the size/volume of the chamber causes a decrease in air pressure.

• Decreasing the size/volume of the chamber causes an increase in air pressure.

Ventilation

Movement of air particles

Positive pressure

• Increase in pressure due to a smaller chamber.

• Exceeds atmospheric pressure.

• Molecules move closer.

Negative pressure

• Decrease in pressure due to a larger chamber.

• Less than atmospheric pressure.

• Molecules move further apart.

• Air will flow to equalize it.

Phrenic nerve

• Arises from C4 & C5.

• Innervates diaphragm bilaterally.

• Oversees respiration, signaling the diaphragm to contract and initiate inspiration.

Upper respiratory system

Includes the mouth, nose, and upper pharynx

Lower respiratory system

Begins at the larynx and includes the trachea and lungs

Inspiration airflow passage

Nasal/oral cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli → lungs

Expiration airflow passage

Alveoli → bronchioles → bronchi → trachea → larynx → pharynx → nasal/oral cavity

Thorax

• Area bounded superiorly by the first rib and clavicle, inferiorly by the 12th rib, & laterally/anteriorly by the ribs and sternum.

• Suspended from the vertebral/spinal column - conduit for the spinal cord.

• Divided into the bony and visceral thorax.

• Serves as a protective enclosure for the structures essential to the lower respiratory system.

• Safeguarded by the rib cage as well as the thoracic and lumbar spine.

• Expands in size vertically, anteriorly, laterally, and posteriorly.

Vertebral column

• Made up of vertebrae - individual bones that make up the spine.

• 33 segments of bone with a rich set of fossa and protuberances.

• Houses the spinal cord.

• Stack at the corpus.

• Vertebrae are numbered from top to bottom. 

• 5 divisions: cervical, thoracic, lumbar, sacral, coccygeal.

Cervical division

• Most superior division of the vertebral column.

• C1 - C7.

• Corpus is anterior, posterior spinal process is posterior.

• Where phrenic nerve arises

Atlas

• Name for vertebrae C1.

• Supports skull and allows nodding movement.

• Reduced posterior tubercle.

• Smaller spinous process.

• Larger vertebral foramen.

• Small corpus.

Axis

• Name for vertebrae C2.

• Allows skull to pivot.

• Odontoid/dens - protrudes through vertebral foramen of C1.

Thoracic division

• Division of the vertebral column.

• T1 - T12.

• Posterior point of attachment for ribs.

Intervertebral foramen

• Openings between adjacent vertebrae in the spinal column.

• Formed by the superior and inferior notches of the pedicles of two adjacent vertebrae.

• Ribs 2 - 9 attach to the transverse process and corpus of the same-numbered vertebra AND the body of that above it. 1, 10, 11, 12 are one-to-one.

Lumbar division

• Division of the vertebral column.

• L1 to L5

• Largest in size.

• Stressed during lifting and ambulation (walking).

Sacral division

• Division of the vertebral column.

• S1 to S5

• Fuse to become the sacrum.

Coccygeal division

• Division of the vertebral column.

• Co1 - Co4.

• Fuse to become the coccyx.

Intervertebral discs

• Separate the divisions of the vertebral column.

• Made of fibrocartilage.

• Each has a gelatinous core (nucleus pulposus) and a fibrous ring (annulus fibrosus).

• Cushion the vertebrae, keep them separated, and allow space for spinal nerves.

Nucleus pulposus

Gelatinous core of the intervertebral discs

Annulus fibrosus

Fibrous ring of the intervertebral discs

Vertebral foramen

Foramen allowing for passage & protection of the spinal cord

Lamina

Flat layers of bone that form part of the vertebral arch in the vertebrae

Pedicle

• Thick projections that extend from the back of the vertebral body to connect to the laminae.

• Superior articular facet rests atop it.

Rib cage

• Protective structure for vital organs, specifically the lungs and heart.

• Encircles the thoracic cavity in a 360-degree formation.

• Starts anteriorly at the sternum (cartilaginous attachment) and wraps around posteriorly to the thoracic spine.

• 5 components: head, neck, tubercle, angle, and shaft (straight component).

• Come in pairs.

True ribs

• 7 pairs of ribs.

• Most superior.

• Directly attach to sternum.

False ribs

• 3 pairs of ribs.

• Central.

• Not directly attached to the sternum; connected via a common cartilaginous structure that links to the lower sternum.

Floating ribs

• 2 pairs of ribs.

• Extend halfway forward and then stop; have no attachment to the sternum.

Costal pleura

• Tissue that covers the inside of the ribs.

• Allows lungs to move smoothly.

Pelvic girdle

• Area composed of the ilium, sacrum, pubic bone, and ischium (lower extremities).

• Provides strong structure for attaching the legs to the vertebral column.

Ilium

Wing-like bone that provides bulk of the support for the abdominal musculature and the prominent hip bone.

Pectoral girdle

• Area composed of the scapula and clavicle (upper extremities).

• Innervated by brachial plexus

Clavicle

• Collarbone.

• Attached to superior sternum and runs laterally to join with scapula.

Scapula

• Shoulder blade

• Located posteriorly on upper part of rib cage.

Sternum

• Breastbone.

• Where ribs attach anteriorly via facets.

• 3 components:

  • Manubrium

  • Corpus

  • Xiphoid process

• Directly connects to true ribs via costal cartilage.

• Indirectly connects to the false ribs through a common cartilaginous structure.

• Does not attach to floating ribs.

Trachea

• Flexible breathing tube that conducts air from the larynx to the lungs.

• Made of C-shaped cartilaginous rings connected by fibrous tissue.

• Remains open at all times for passage of air.

• Lined with a mucous membrane containing hair-like cells (cilia) that secrete mucus (phlegm) to trap particles and move them upward from the lungs.

• Attaches superiorly to the larynx and inferiorly to the mainstem bronchi

• Bifurcates (forks) into two mainstem bronchi → secondary bronchi → tertiary bronchi.

• Anterior to the esophagus with a shared wall.

• Flexion and hyperextension of the neck can change the shape and diameter.

Carina

Inner cartilaginous ridge/edge of the trachea bifurcation

Lungs

• Composed of billions of alveoli.

• Wrapped in pleura.

• Divided into:

  • Right lung - 3 lobes (upper, middle, lower).

  • Left lung - 2 lobes (smaller due to heart taking up space).

• Produce secretions that help keep the lobes slippery, allowing them to move smoothly against each other and the chest wall as you move.

Pleura

• Double-layered serous membrane that surrounds the lungs and lines the chest cavity.

• Connects lobes.

• Keeps the system closed.

• Types: visceral, parietal, mediastinal, diaphragmatic, apical, costal.

• Produces secretions that help keep the lobes slippery, allowing them to move smoothly against each other and the chest wall as you move.

Visceral pleura

Inner layer of pleura that covers the surface of the lungs

Parietal pleura

Outer layer of pleura that lines the chest wall and diaphragm

Mediastinal pleura

Pleura that covers the mediastinum

Diaphragmatic pleura

Pleura that covers the diaphragm

Apical pleurae

Pleurae that cover the superior-most region of the rib cage.

Mediastinum

Area between the two lungs where the heart is located

Diaphragm

• Main, dome-shaped muscle of respiration.

• Inferior to the lungs, attached via pleural linings, tendons, & ligaments. Superior to the abdomen.

• Innervated bilaterally by phrenic nerve.

• Contracts to expand the length of the thoracic cavity vertically.

• Diaphragmatic pleura allows for expansion of alveoli when the ____ pulls down on the lungs.

• Xiphoid process marks the beginning.

Central tendon

• Intermediate region of the diaphragm made of aponeurosis.

• Pulled down and forward during muscle contraction.

Hiatuses

Holes in the diaphragm that allow structures to pass between the thoracic cavity and the abdominal cavity

Foramen vena cava

• Type of hiatus in the diaphragm.

• Where inferior vena cava passes through.

Inferior vena cava

The large vein that carries deoxygenated blood from the lower body back to the heart

Esophageal hiatus

• Type of hiatus in the diaphragm.

• Opening for the esophagus.

External intercostals

• Muscles of inspiration.

• Anterior accessory muscles of thorax.

• Elevates rib cage and expands space between ribs.

• Reside between the 12 ribs.

• Origin: inferior surface of ribs 1-11.

• Course: down and obliquely in.

• Insertion: upper surface of the rib immediately below.

• Covered with translucent intercostal membrane that separates them from the internal intercostal muscles.

• Positioned laterally to the sternum.

• Innervated by thoracic nerves.

Intercartilaginous / Interchondral part

The only portion of the internal intercostals involved in inspiration

Levatores costarum (brevis and longis)

• Muscles of inspiration.

• Posterior accessory muscles of thorax.

• Elevates the rib cage.

• Longis is longer, brevis is shorter.

• Origin: thoracic vertebrae.

• Course: obliquely down and out.

• Insertion: tubercle of the rib below.

Serratus posterior superior

• Muscles of inspiration.

• Posterior accessory muscles of thorax.

• Elevate ribs 2 - 5.

• Pulls posterior part of rib cage up to expand thoracic cavity.

• Origin: spinous process of vertebrae C7 and T1 - T3.

• Course: down and laterally.

• Insertion: Beyond angles of ribs 2 - 5.

Sternocleidomastoid

• Muscle of inspiration.

• Accessory muscle of the neck (superficial).

• Elevates the sternum and rib cage.

• Origin: mastoid process of temporal bone.

• Course: down.

• Subdivides into 2 heads:

  • Sternal head (inserts into sternum).

  • Clavicular head (inserts into clavicle).

Scalenes

• Muscles of inspiration.

• Accessory muscle of the neck/back.

• Anterior, middle, posterior.

• Elevate ribs 1 - 2.

• Provide head stability and facilitate rotation.

• Only contribute to respiration when necessary (ex: during heavy exercise).

• Origin: cervical vertebrae.

Trapezius

• Muscle of inspiration.

• Makes up superficial upper back and neck.

• Fibers fan laterally to insert into scapula & clavicle.

• Elongates neck & controls head.

Pectoralis major

• Muscle of inspiration.

• Muscle of the chest & upper arm.

• Elevates sternum.

• Increases transverse dimension of rib cage.

• Origin: humerus (upper arm bone).

• Course: down and medially.

• Insertion: sternum & clavicle.

• Works with pectoralis minor.

Pectoralis minor

• Muscle of inspiration.

• Muscle of the chest & upper arm.

• Increases transverse dimension of rib cage.

• Origin: scapula.

• Course: down and medially.

• Insertion: anterior surface of ribs 2 - 5.

• Works with pectoralis major.

Subclavius

• Muscle of inspiration.

• Muscle of the chest & upper arm.

• Elevates ribs 1 - 9.

• Anterior movement of the arms.

• Wraps from inner vertebral border (posterior) to ribs (anterior).

Levator scapulae

• Muscle of inspiration.

• Muscle of the back.

• Elevates the scapula & rib cage.

• Contributor to neck extension.

• Origin: C1 - C4.

• Insertion: scapula.

Rhomboideus major & minor

• Muscles of inspiration.

• Muscles of the back.

• Stabilizes pectoral/shoulder girdle.

• Small & rhomboidal shaped.

• Pulls up on rib cage.

• Insertion: scapula.

Internal intercostals

• Muscles of expiration.

• Anterior & lateral muscle of the thorax.

• Depress the rib cage.

• Pull ribs closer together.

• Origin: ribs 2 - 12.

• Course: up and medially.

• Insertion: inferior surface of rib above.

Serratus posterior inferior

• Muscle of expiration.

• Posterior muscle of the thorax.

• Pulls rib cage down.

• Course: up and laterally.

• Insertion: ribs 7 - 12.

Latissimus dorsi

• Muscle of expiration.

• Posterior muscle of thorax & upper limb.

• Smushes during contraction to make medial thorax smaller.

• Stabilizes posterior abdominal wall.

• Anchored to the pelvis via aponeurosis sheath.

• Lateral to spine.

• Insertion: vertebrae.

Aponeurosis

• Tendon & sheath-like connective tissue that serves as an attachment point for muscles when they do not directly attach to a tendon.

• Highly mobile.

Linea alba

• Fibrous midline of the abdomen that extends from the xiphoid process of the sternum to the public bone.

• Where left + right rectus abdominis muscles meet.

• Associated with belly button location.

Linea semilunaris

• Curved line lateral to the linea alba.

• Marks lateral border of rectus abdominis.

• Place of muscle attachment.

Rectus abdominis

• Muscles of expiration.

• Anterolateral abdominal muscles.

• “Six-pack.”

• Pulls rib cage down.

• Decrease size of thoracic cavity by compressing abdomen.

• Flexion of vertebral column.

• Hook into aponeurosis.

• Origin: pubic bone.

• Insertion: xiphoid process of sternum & ribs 5 - 7.

• Divided into 3 sections:

  • Upper: above the umbilicus (belly button). Consists of 2 or 3 segments.

  • Middle: located around the level of the umbilicus. Consist of 2 or 3 segments.

  • Lower: below the umbilicus. Consists of 2 segments.

• Generally contracts as a whole.

Transverse abdominis

• Muscles of expiration.

• Anterolateral abdominal muscles.

• Reduces volume of abdomen.

• Decrease size of thoracic cavity by compressing abdomen.

• Wrap laterally around the waist.

Internal oblique abdominis

• Muscles of expiration.

• Anterolateral abdominal muscles.

• Decrease size of thoracic cavity by compressing abdomen.

• Less visible than external obliques.

External oblique abdominis

• Muscles of expiration.

• Anterolateral abdominal muscles.

• Most superficial and largest abdominal muscles.

• Decrease size of thoracic cavity by compressing abdomen.

Quadratus lumborum

• Muscles of expiration.

• Posterior abdominal muscle.

• Decrease size of thoracic cavity by compressing abdomen.

• Attachments to lower rib cage and pelvis.

Transverse foramen

• Foramen that the vertebral artery passes through.

• Only a part of cervical vertebrae.

Vertebral artery

• Major blood vessel that supplies blood to the brain & spinal cord.

• Arise from subclavian arteries (branches of the aorta).

• Ascends through the transverse foramina of the cervical vertebrae.

Volume

The quantity of air inhaled/exhaled

Tidal volume (TV)

• Amount of air breathed in & out during 1 cycle of respiration.

• Direct relationship to increased exercise.

Inspiratory reserve volume (IRV)

Amount of air that can be inhaled after a tidal inspiration

Expiratory reserve volume (ERV)

Amount of air that can be exhaled after a tidal expiration

Residual volume (RV)

Amount of air remaining in lungs/alveoli after maximum exhalation

Dead air space

Amount of air in the trachea that cannot be involved in gas exchange

Capacity

The combination of volumes that express physiological limits

Vital capacity (VC)

• The volume of air that can be inhaled following a maximal exhalation.

• (VC = TV + IRV + ERV)

Flow

The speed of air moving in/out of the lungs

Pressure generalization

Pressure changes in the lungs during breathing

Pulmonary function test (PFP)

Test that assesses the volume, capacity, flow, and pressure of the lungs

Spirometer

Measures respiratory flow, volumes, and capacities of lungs

Manometer

Measures pressure of lungs

Perfusion

Migration of gas though a barrier

Diffusion

The actual gas exchange across the alveolar-capillary membrane