Ch.7 Vertebral Column & Rib Cage Flashcards Preview

Human Anatomy > Ch.7 Vertebral Column & Rib Cage > Flashcards

Flashcards in Ch.7 Vertebral Column & Rib Cage Deck (20)

Functions of Vertebral Column

- provides vertical support
- supports weight of the head
- helps to maintain upright body position
- transfer axial skeleton weight to the appendicular skeleton of the lower limbs
- houses and protects the delicate spinal cord and providing passageway for spinal nerves connecting to the spinal cord


Parts of a Typical Vertebra

- body: large and block-like; separated by intervertebral discs; is a weight-bearing structure
- vertebral arch: together with the body, the arch surrounds and protects the spinal cord; pedicles form the lateral walls, and laminae the posterior walls
- processes: transverse process extends laterally where a lamina and pedicle join; spinous process projects posteriorly at the junction of the laminae; paired articular processes articulate with an adjacent superior, and an adjacent inferior, vertebrae


Cervical Vertebrae

- have a transverse foramen within the transverse process
- atlas, or C1, is a bony ring with no body; its articulations with the head permit the movement we associate a head-nod (yes)
- axis, or C2, has a peg-like process that articulates with C1 permitting the movement we associate with a head-shake (no)
- C3-C7 have the most features in common of the cervical vertebrae


Thoracic Vertebrae

- larger and stronger than cervical and are easily identified by their costal facets which articulate with the tubercles of ribs
- bodies of thoracic vertebrae articulate with the heads of ribs, except for T11 and T12


Lumbar Vertebrae

- largest and strongest of the unfused vertebrae in the vertebral column
- readily identified by their large size and an absence of costal articular facets



- fusion of the 5 sacral vertebrae result in the formation of the sacrum, process that can last from the age of 16-30 years; transverse lines mark the sites of fusion



- triangular bone that forms from the fusion of three to five vertebral bones
- fusion of coccygeal vertebrae also lasts a number of years, usually from 20-30 years of age


Muscles of Neck that move the head

anterior triangle: angle is bordered: superiorly by the mandible, medially by the cervical midline, and laterally by the anterior borde of sternocleidomastoid muscle
posterior triangle: bordered interiorly by the clavicle, anteriorly by the posterior border of the sternocleidomastoid muscle, posteriorly by anterior border of the trapezious muscle


Anterior Group of Muscles

Sternocleidomastoid: flexes cervical portion, flexes the head at atlanto-axial joint, laterally rotate and flex the head
- manubrium of sternum and the clavicle
- mastoid process and nuchal line of temporal bone
Scalene Muscles: elevates the ribs
- transverse process of ribs 2-7
- first and second ribs


Posterior Group of Muscles

splenious cervici: extend, flexes and rotte the head
splenius capitis: extend head, laterally flex and rotate head
erector spinae: largest muscle of back, forming bulge on either side of the vertebral column
- extensor of the vertebral


Arterial Blood Flow Through the Head and Neck

heart- brachiocephalic trunk- common carotid artery
- external carotid artery- superior thyroid, occipital, temporal, lingual, maxillary and facial arteries
- internal carotid artery, head and neck region
** external also goes to head and neck aswell


Circle of Willis

- important anastomosis of arteries around the sella turcica
- formed from posterior cerebral arteries and posterior communicating arteries (posterior cerebral arteries), internal carotid arteries, anterior cerebral arteries, and anterior communicating arteries (which connect the two anterior cerebral arteries)
- equalizes blood pressure in the brain and can provide collateral channels should one vessel become blocked


Blood Flow Through the Cranium

vertebral artery- basilar arteries- anterior, middle and posterior cerebral arteries- anterior and posterior communicating arteries (circle of Willis)- forms the cerebral arterial circle around the pituitary


Blood Flow- Veins

heart- brachiocephalic vein- subclavian vein- external jugular vein and internal jugular vein- head and neck region


Venous Return from the Cranium

- blood draining from the head passes into three pairs of veins: internal jugular, external jugular, and vertebral veins
- all veins drain into dural venous sinuses and then into the internal jugular veins
- dural venous sinuses are endothelial-lined venous channels between layers of the cranial


Venous Blood Flow (circle of Willis)

- anterior and posterior communicating veins (circle of Willis)- anterior, middle and posterior cerebral veins- basilar veins- vertebral vein- brachiocephalic vein- super vena cava- heart


Muscles of the Thorax that Assist in Breathing

- resp. muscles alter the size of the thoracic cavity which affects pressure in the lungs, and determines whether we inhale or exhale
- diaphragm is most important respiratory muscle
- external and internal intercostal muscles


Nervoud Supply to Thorax

Ansa Cervicalis: 1. Anterior roots= infrahyoid and genihyoid
2. posterior roots= infrahyoid
Phrenic nerve: diaphragm
Segmental branch: deep muscle of neck, levator scapulae and scalene muscles


Blood Supply to Thorax- Thoracic Arota

- begins at the level of intervertebral disc between fourth and fifth thoracic vertbrae
- extends through the arotic hiatus
- sends off numerous small arteries, visceral branches to viscera, and parietal branched to body wall structures


Veins of the Thorax

- braciocephalic veins drain most thoracic structures by a network of veins, called the azygos system, that runs on either side of the vertebral column
- system consists of three veins- the azygos, hemiazygos, and accessory hemiazygos veins
- ultimately they empty into the superior vena cave