Midterm 2 Flashcards
What do the alveolar macrophages do?
they ingest debris in alveoli and become trapped in the mucus sheets
What do the type II alveolar cells do?
they secrete surfactant which lowers the surface tension of alveolar fluid to inflate the alveoli and prevent alveolar walls from sticking together and collapsing
What are type II alveolar cells?
they are a kind of stem cell that is able to regenerate more of itself and type I
Where is the respiratory epithelium found?
nasal cavity, nasopharynx, and the large airways
What is the respiratory epithelium?
a pseudostratified epithelium that has a mucus layer that floats on a serious (watery) layer
What are the causes for emphysema?
smoking and other irritants like pollution or dust
What is emphysema?
the breakdown of alveolar walls producing abnormally large air spaces and lowering the surface area for gas exchange ( reduced respiratory efficiency) and reducing the elastic recoil ( due to loss of elastic fibers)
What happens during an asthma attack?
the bronchioles are affected and inflamed and become susceptible to contraction by mediator histamine which causes the contraction of smooth muscle
What is the function of the elastic fibers in the airway wall?
they predominate in smaller airways and the respiratory portion. Their elastic recoil provides force for expiration
What is the function of the smooth muscle in the airway wall?
it predominates in smaller airways and controls the diameter of the airway. The constriction of it reduces airflow
What is the function of cartilage in the airway wall?
it is found in larger airways and helps keep them open
What is the funciton of the respiratory airway?
both to conduct air and respire
What structures are apart of the respiratory airway?
located entirely within the lung and are represented by respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli
What is the function of the conducting airway?
to warm, moisten and conduct air
What structures are included in the conducting airway?
the nose, pharynx, larynx, trachea, bronchi, and bronchioles
What are the 2 types of airways?
conducting and respiratory
What is the function of the alveoli?
to minimize amount of tissues but maximize air space
What is the respiratory bronchioles?
they are the start of the respiratory airway, and they terminate on alveolar ducts
What is the function of the terminal bronchiole?
to move air in and out, it is the last conducting airway
Cartilage ring shape of the trachea?
C-shaped not O-ring shaped
The amount of cartilage in bronchioles and bronchi ?
bronchi- little cartilage
bronchioles- no cartilage but supported by smooth muscle
What is the root (Hilum) of the lung?
the site where blood vessels, lymphatics, nerves, and airways enter and leave lungs
What happens when you swallow?
when passing food any connection between the breathing and GI tract must be cut off so the tongue will push the soft palate up and back closing the nasopharynx. The epiglottis is also closed by bringing the larynx up
What are turbinates? (nasal conchae)
bony shelves covered in a mucous membrane that force air close to the warm wall (narrow channels)
What is the epiglottis composed of?
cartilage
What does the eustachian tube do?
it connects the middle ear to the nasopharynx to equalize pressure
What is the nasopharynx composed of?
lots of lymphoid tissue
What is the respiratory portion of the respiratory system?
where gas exchange happens (alveoli)
What is the conduction portion of the respiratory system?
the portion that takes in air
What are the functions of the respiratory system?
exchange of gas between the atmosphere and the blood. Filtration, temperature regulation, and humidification of inspired air (the air we breathe in)e
What happens if the CN XII is damaged?
inability to protrude tongue symmetrically (stick out tongue)
What is the CN XII-hypoglossal nerve attached to?
the medulla
What is the function of the CN XII- Hypoglossal nerve?
it is a pure motor nerve that supplies muscles of tongue and enables tongue movement
What happens if the CN XI is damaged?
weakness when shrugging (elevating) shoulders, turning head to one side against resistance
What is the function of the CN XI- Spinal accessory nerve?
it only has a motor function that supplies trapezius and sternocleidomastoid muscles in the neck
What is the function of the vagus nerve- CN X?
it is a mixed nerve responsible for the regulation of internal organ functions, such as digestion, heart rate, and respiratory rate, as well as vasomotor activity, and certain reflex actions, such as coughing, sneezing, swallowing, and vomiting
What happens if there is damage or disease to the CN IX- Glossopharyngeal nerve?
difficulty in swallowing, loss of gag reflex
What is the CN IX- Glossopharyngeal nerve attached to?
the medulla
What is the primary function of the CN IX- Glossopharyngeal nerve?
mixed (sensory and motor), it is located at the back of the tongue so it controls gag reflex
What happens if there is damage/disease to the cochlear part of the CN VIII?
difficulty in localizing sound
What happens if there is a disease in the vestibular apparatus of the CN VIII?
Meniere’s syndrome (vertigo, nausea, vomiting)
What are the primary functions of CN VIII- vestibulocochlear nerves?
special sensory: balance and equilibrium (vestibular division) and hearing (cochlear division)
What are the parasympathetic functions of CN VII?
controlling the lacrimal gland for tearing (lacrimation) via pterygopalatine ganglion (V2) and submandibular salivary glands via submandibular ganglion (V3)
What are the sensory functions of the CN VII?
control taste to anterior 2/3 of tongue (via chorda tympani) and some sensory goes to skin around ear
What are the motor functions of the CN VII?
control the muscles of facial expression (5 sets of branches)
What happens if the CN VII- facial nerve is damaged?
patient may lose taste (partly), salivation (partly) or lacrimation in one eye, or also get Bell’s Palsy where half of the face is paralyzed
What are the functions of CN VII- Facial nerve?
both sensory and motor (mixed): controls taste, not chewing however, cheeks and lips, muscle to neck, and lacrimation (keeping eyes moist)
What happens if the CN VI- Abducent nerve is damaged?
it leads to paralysis of lateral rectus which ultimately leads to double vision (diplopia), the abducent nerve in general is vulnerable to injury in head trauma or raised intracranial pressure
Where is the CN VI- Abducent nerve located?
at ponto-medullary (between pons and medulla) junction
What is the one muscle that the CN VI- Abducent Nerve supply?
lateral rectus (abducts the eye–> ABducent nerve)
What are the sensory functions of the CN V3- Mandibular nerve?
sensation of lower lip and lower teeth, chin and tongue
What are the motor functions of the CN V3 Mandibular nerve?
supplies muscles of mastication (controlling force of bite)
What is the function of the CN V2- Maxilary Nerve?
it is a pure sensory that supplies sensation to the maxillary air sinus, nasal cavity, lower eyelid, skin of the cheek, maxillary (upper) teeth, and gums
What is the function of the CN V1- Ophthalmic nerve?
it is a pure sensory that supplies sensation to the frontal and ethmoidal paranasal air sinuses, the upper eyelid, side of the nose, forehead, and scalp
What are the largest cranial nerves?
trigeminal nerves (V)
What happens if there is a disease in the CN V- trigeminal nerve?
Tic Douloureux (mainly in V2 and V3), “suicide disease” because of the chronic pain by sensory axons firing inappropriately
What are the 3 divisions (branches) arising from trigeminal ganglion in CN V?
V1- Ophthalmic nerve: sensation of forehead and eye e.g. putting on contacts (pure sensory)
V2- Maxillary nerve: cheek (pure sensory)
V3- Mandibular nerve: mandible (motor and sensory- because it can deal with physically chewing and pain of the lower teeth)
What is the only cranial nerve to emerge from back of brainstem?
trochlear nerve - CN IV
What is the one muscle that the trochlear nerve CN IV supply?
superior oblique
What is the smallest cranial nerve?
CN IV- Trochelar Nerve
What are the primary functions of the CN III- Oculomotor nerve?
motor and eye movements
What happens if the CN III- Oculomotor Nerve is damaged/ disease?
pupillary dilation (will not be able to constrict pupil) and ophthalmoplegia (eye movements are weakened or paralysed)
What does the levator palpebrae superioris do?
elevate the upper eyelid
What are the 2 extra-ocular muscles that CN III- Oculomotor nerve does NOT innervate?
LR6 SO4
the lateral rectus (responsibility of CN VI) and superior oblique (responsibility of CN IV)
Where in the eye does the oculomotor nerve (CN III) supply?
the superior rectus, medial rectus, inferior oblique, inferior rectus and levator palpebrae superioris
What is the path that the optic nerve travels down starting at the retina?
1) Pass through the optic canals of the sphenoid before forming the optic chiasm (chiasma= crossing– because it looks like a X)
2) Axons continue to lateral geniculate nucleus (LGN) of the thalamus as the optic tracts
3) they synapse at the thalamus (LGN) where projection fibers will then end in the occipital lobe
Where does the optic nerve (CN II) originate?
retina
What is the primary function of CN II- Optic nerves?
special sensory (vision)
What happens if the CNII - Optic Nerve is damaged or disease?
there will be visual field defects
What is the optic nerve comprised of?
several axons
The path that olfactory nerves (CN I) travels, starting at the specialized neurons in the epithelium covering the roof of the nasal cavity
1) sensory neurons collect to form bundles
2) these bundles enter the olfactory bulbs
3) the axons along the olfactory tracts carry signal to cerebrum
What is the primary function of olfactory nerves (I)?
special sensory (smell)
What happens when the CN I - Olfactory nerve is damaged/ disease?
hyposmia (low smelling) and/or anosmia (no smelling)