the neck Flashcards
what is the neck the junction between?
the junction between head and thorax
what is the superior limit of the neck?
mandible and base of skull
what is the inferior limit of the skull?
thoracic inlet
where does the thoracic inlet lie?
through first rib and is higher posteriorly then anterior
what is the thoracic inlet bound by?
first thoracic vertebra posteriorly, first ribs laterally and the manubrium anteriorly
what is the thoracic inlet also known as?
superior thoracic aperture
what divides the lung into anterior and posterior ?
sternocleidomastoid
what are the 2 heads to the sternocleidomastoid?
sterno: attaches to the manubrium of the sternum
cleido: greek origins for bar/bolt
mastoid: mastoid process - air cells present here
this process is absent at birth (risk of damage to facial nerve - stylomastoid foramen) and starts to grow about the age of 1, prominent at about the age of 2 and continues until the first permanent teeth about 6
what are the 2 heads to the sternocleidomastoid?
sterno: attaches to the manubrium of the sternum
cleido: greek origins for bar/bolt
mastoid: mastoid process - air cells present here
this process is absent at birth (risk of damage to facial nerve - stylomastoid foramen) and starts to grow about the age of 1, prominent at about the age of 2 and continues until the first permanent teeth about 6
what are the boundaries of the anterior triangle?
- sternocleidomastoid muscle
- the midline
- lower border of the mandible
what are the boundaries of the posterior triangle?
- sternocleidomastoid
- trapezius muscle
- middle third of the clavicle
what 5 categories can the anterior triangle contents be divided into?
muscles, skeletal elements and viscera, glands, nerves, vessels
what is the mylohoid?
forms the floor of the mouth like a hammock. Arises from the mandible and attaches onto the hyoid bone. It raises the hyoid bone and floor of mouth
what is the anterior belly of the digastric?
One of two muscles (posterior one also). Arises from mandible and passes to the mastoid process. It pulls down the mandible and raises the hyoid bone
what is the strap muscles?
named after where they attach. These depress the hyoid bone and also the larynx, or pull it down, during swallowing (deglutition) and speaking
what is the largest laryngeal cartilage?
thyroid cartilage
where is the cricoid cartilage found?
below the thyroid cartilage, just above trachea
what are the 4 skeletal elements of the anterior triangle?
thyroid cartilage
cricoid cartilage
hyoid bone
trachea
how many laryngeal cartilages are there?
9
what are the single laryngeal cartilages?
3:
thyroid
cricoid
epiglottis
what cartilage forms a complete ring around the trachea?
cricoid
what type of cartilage is the epiglottis?
elastic
what are the paired laryngeal cartilages?
arytenoid
corniculate
cuneiform
what is the order of skeletal elements and cartilage in the anterior triangle?
1 . hyoid bone
2. thyroid cartilage
3. cricoid cartilage
4. first tracheal ring (of cartilage)
5. thyroid gland
what glands are part of the anterior triangle?
thyroid gland
parathyroid
submandibular
what does the endocrine gland do?
secretes hormones into the bloodstream
where does the thyrocervial trunk arise from?
subclavian artery
what encloses the thyroid (endocrine) gland?
pre-tracheal fascia
how do we examine if the thyroid cartilage is enlarged?
ask the patient to swallow, when lightly pressing on the neck from behind the patient, will allow you to see if it is enlarged.
what supplies the thyroid (endocrine) gland?
superior (external carotid artery) and inferior thyroid (thyrocervical trunk) arteries
what hormones does the thyroid gland secrete?
thyroid gland (T3 and T4)
where is the thyroid gland found?
anterior neck between C5-T1 (cervical/thoracic)
what does the thyroid hormone do?
raise the basal metabolic rate, influences synthesis of proteins, and are responsible for nerve growth/development
what are thyroid hormones important for?
development of cells in the body
how many lobes does the thyroid gland have?
what are they linked by?
2 lobes - left and right
linked by isthmus
what is the isthmus in the thyroid gland?
narrow piece of tissue between 2 larger parts of a structure
what is the pyramidal lobe?
where does it come from?
embryological remnant of where the thyroid gland developed from in the floor of the mouth – at the foramen caecum of the tongue.
what is the elevator glandular thyroidae?
a remnant of where the pyramidal lobe formed
where is the elevator glandulae thyroidae?
can extend from foramen caecum of tongue
what is the biggest vein of the neck?
internal jugular vein
what gland and hormone function to raise the level of blood calcium?
endocrine glands and parathyroid hormone
where are the parathyroid glands located?
on the posterior surface of the thyroid gland and appear flat and oval in shape
how many superior parathyroid glands are there and where are they found?
2 – found roughly in the middle of the posterior border of the thyroid lobes
how many inferior parathyroid glands are there and where are they found?
2 – at inferior poles of thyroid gland, although can be a little variable
how does the parathyroid hormone increase blood calcium?
- increasing absorption from the gut
- increasing absorption from the kidney
- increased activity of osteoblasts - breakdown bone and release calcium
how much of the population have more than 4 parathyroid glands?
5%
what does the vagus nerve do?
slows heart rate and breathing
- rest and digest
increasing gut motility
what does the phrenic nerve do?
innervates diaphragm
what does the motor part of the vagus nerve do?
innervates the muscles of the larynx, pharynx and soft palate
what does the parasympathetic part of the vagus nerve do?
smooth muscle of the trachea, bronchi (slows breathing), slows heart rate and increases gut motility
what do the special sensory fibres of the vagus nerve do?
innervation for taste sensation in the epiglottis and root of the tongue
what do the general sensory fibres of the vagus nerve do?
internal aspect of larynx and the ear canal. Also provides visceral sensory innervation to the heart and abdominal structures.
what anchors the heart to the diaphragm?
phrenic nerve
what does the motor phrenic nerve do?
innervate the skeletal muscle of the diaphragm
what does the sensory phrenic nerve do?
innervation to the diaphragm also, specifically the central tendon, as well as the layer around the heart called the pericardium. This structure anchors the heart to the diaphragm
what does the hypoglossal nerve do?
innervates the majority of the muscles of the tongue
minus 1
what drains all of the head and neck?
……
anterior triangle red vessels
….
what can the posterior triangle be divided into?
what does the accessory nerve innervate?
sternocleidomastoid and trapezius
what does the Sternocleidomastoid muscle do?
lateral flexion of neck when acting on its own and flexion of neck when acting both left and right sides.
Where is the trapezius and what does it do?
base of skull and C7-T12 vertebrae spinous processes to lateral third of clavicle and scapula (acromion of)
what are the 3 parts of the accessory nerve (fibres)?
The upper fibres elevate the scapula, and also rotate during abduction of the arm. Middle fibres pull back the scapula (retraction) and lower fibres go inferiorly.
what does the brachial plexus innervate?
motor and sensory innervation to the upper limbs
where is the brachial plexus?
cervical 5 - thoracic 1
what do lymph nodes do?
filter lymph
defend against infection
return to larger veins
what are the superficial lymph nodes?
drain face, neck and scalp and pass to the superficial ring of lymph nodes at the junction of head and neck
what are the deep lymph nodes?
deep cervical lymph nodes. Left jugular lymphatic trunk passes to the thoracic duct ->left subclavian vein
where does the right jugular lymphatic trunk pass to?
right subclavian vein
