Chapter 7 Lecture Guide to Accompany Open Stax Anatomy and Physiology
Overview
This lecture outline accompanies the chapter 7 PowerPoint for Open Stax Anatomy and Physiology 2E.
Chapter
7.1: Divisions of the Skeletal system
- The ____________ consists of the 206 bones of the adult body.
- The skeletal system is the skeleton, cartilage, and ligaments that support and shape the body.
- Functions of the skeletal system
- Provide a rigid internal structure that can support the body's weight against the force of gravity.
- Provide a structure upon which muscles can act to produce body movements
- Protection of internal organs
- Primary sites for storage of minerals
- Stores fat, houses the blood-producing tissues of the body
- The two major divisions of the skeleton:
- ___________
- Forms the vertical, central axis of the body
- Includes the bones of the head, neck, chest, and back
- Protects the brain, spinal cord, heart, and lungs.
- Serves as the attachment site for muscles that move the head, neck, and back.
- Includes the ______, the __________ column, (__________ (24 bones), _________ and ___________) and the ____________ cage (12 pairs of ribs and sternum).
- Other structures included are the ___________ bone, and ear ____________.
- __________________________________
- Bones of the upper and lower limbs, plus the bones that attach each limb to the axial skeleton
7.2 The Skull
- ___________ – protects the brain and supports the face
- _________ bones
- Underly facial structures
- Form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws
- _________ case (cranial vault)
- Surrounds and protects the brain and houses the middle and inner ear structures.
- The skull consists of 22 individual bones
- Twenty-one is immobile and united into a single unit.
- The 22nd bone is the ________________ (lower jaw), which is the only movable bone of the skull.
Anterior View of Skull
- _________ – bony socket that houses the eyeball, and muscles of the eye and upper eyelid.
- _________________ margin – Upper margin of the anterior orbit.
- __________________ foramen – located at the midpoint of the supraorbital margin, provides passage for a sensory nerve to the skin of the forehead.
- __________________ foramen – located below the orbit, the point of emergence for the sensory nerve that supplies the anterior face below the orbit.
- ________ cavity – located inside the nasal area of the skull.
- ________ septum – divides the nasal cavity into halves, formed by the:
- _______________ plate of the ethmoid bone (superior portion)
- ________ bone – forms the inferior portion of the nasal septum.
- ________ nasal ________ - large bony plate projecting from each lateral wall of the nasal cavity (independent bone of the skull)
- ________ nasal concha – located above inferior nasal concha, part of ethmoid bone.
- ________ nasal concha – smaller and out of sight above the middle concha, just lateral to the perpendicular plate in the upper nasal cavity
Lateral View of Skull
- _______________ arch – an arch of bone on the side of the skull from the cheek to above the ear canal.
- Formed by two processes
- Temporal process of the zygomatic bone – a short anterior component that forms the cheekbone
- Zygomatic process of the temporal bone – extends forward from the temporal bone to join the temporal process
Bones of the Brain Case
- Cranial cavity – interior cavity occupied by the brain.
- Calvaria – skullcap,
- The floor of the braincase is referred to as the base of the skull.
- It is subdivided into three large spaces.
- Anterior cranial fossa
- Middle cranial fossa
- Posterior cranial fossa
- The braincase consists of eight bones.
- ________– upper lateral side of the skull, paired bones with right and left sides.
- ________ forms the lower lateral side of the skull
- Landmarks of the temporal bone
- ________ acoustic meatus – ear canal
- ________ acoustic meatus – connects the middle and inner ear cavities.
- ______________ fossa – mandible joins the jaw
- ________ tubercle – located anterior to the mandibular fossa, contributes to the temporomandibular joint with mandibular fossa
- ________ process - attachment site for muscles and a ligament that supports the hyoid bone.
- ________________ foramen – small opening between the styloid and mastoid processes.
- ________ process – considerable prominence which serves as a site for muscle attachment.
- ________ ridge – located in the floor of the cranial cavity, houses the structures of the middle and inner ears
- ________ canal provides passage through the base of the skull for the carotid artery.
- ________ bone forms the forehead
- ________ – slight depression between the eyebrows.
- Forms the supraorbital margin of the orbit
- ________ bone – the single bone that forms the posterior skull and posterior base of the cranial cavity
- External occipital protuberance – serves as an attachment site for a ligament.
- Superior nuchal line – the most superior point of attachment of neck muscles
- Foramen magnum – a large opening that allows the spinal cord passage as it exits the skull.
- Occipital condyles – form joints with the first cervical vertebra and support the skull on top of the vertebral column.
- ________ bone serves as the keystone of the skull and forms much of the base of the central skull.
- Lesser wings – mark the boundary between the anterior and posterior fossa.
- Sella turcica (Turk's saddle)
- Hypophyseal (pituitary) fossa houses the pituitary gland.
- Greater wings
- Medial and lateral pterygoid plates
- Right and left medial pterygoid plates to form the posterior, lateral walls of the nasal cavity.
- The lateral pterygoid plates serve as muscle attachment sites
- ________ bone – single midline bone, forms the roof and lateral walls of the upper nasal cavity, the upper portion of the nasal septum, and the medial wall of the orbit.
- Crista Galli – bony projection serves as the anterior attachment point for the dura mater.
- Cribriform plate – contains olfactory foramina; small nerve branches from the olfactory areas pass through these on the way to the brain.
- Ethmoid air spaces part of the paranasal sinus system
Sutures of the Skull
- ________ – immovable joint between adjacent skull bones.
- The coronal suture runs from left to right across the skull within the coronal section plane, joining the frontal and paired parietal bones.
- The sagittal suture extends posteriorly from the coronal suture, running along the midline at the top of the skull, unites the paired parietal bones
- Lambdoid suture joins the occipital bone to the right and left parietal and temporal bones.
- Squamous suture on the lateral skull unites the squamous portion of the temporal bone with the parietal bone.
- Pterion: a small H-shaped suture that unites the frontal, parietal, temporal, and greater wing of the sphenoid bone.
Facial Bones of the Skull
- ________ bone – (maxilla (plural = maxillae)) forms the upper jaw, most of the hard palate, the medial floor of the orbit, and the lateral base of the nose.
- Alveolar process of the maxilla
- The curved inferior margin that forms the upper jaw and contains the upper teeth.
- Infraorbital foramen – located on the anterior maxilla just below the orbit, the point of exit for a sensory nerve
- Palatine process – located on the inferior skull join at the midline to form the hard anterior palate.
- Hard palate – a bony plate that forms the roof of the mouth and floor of the nasal cavity.
- ________ bone – includes the lateral walls of the nasal cavity and medial wall of each orbit.
- _______________ bone is also known as the cheekbone, forms much of the lateral wall of the orbit and lateral–inferior margins of the anterior orbital opening. The short temporal process projects posteriorly to include the anterior portion of the zygomatic arch
- ________ bone – one of two small bones that form the bridge of the nose
- ________ bone forms the anterior, medial wall of each orbit.
- Nasolacrimal canal – tears of eye drain at the medial corner of the eye into this canal
- ___________ nasal concha – a curved bony plate that projects into the nasal cavity space from the lower lateral wall. The largest of the nasal concha.
- ________ – an unpaired bone forms the posterior-inferior part of the nasal septum.
- ________forms the lower jaw and the only movable bone of the skull
- The ramus of the mandible is the posterior, vertical orientation of the lower jawbone.
- The angle of the mandible – where the body and ramus come together
- Coronoid process – the anterior projection provides attachment for biting muscles
- The condylar process is the posterior projection of the mandible, which is topped by the oval-shaped condyle.
- Alveolar process – the upper border of the mandibular body serves to anchor the lower teeth
- Mental protuberance – the chin
- Mental foramen – exit site for a sensory nerve
The Orbit
- The bony socket that houses the eyeball and contains the muscles to move the eyeball or open the upper eyelid.
- The walls of the orbit are formed from seven bones
- The frontal bone forms the roof
- Zygomatic bone forms the lateral wall and lateral floor.
- Maxilla forms the medial floor
- Palatine helps form the medial floor
- Ethmoid and lacrimal bones make up the medial wall.
- Sphenoid bone forms the posterior orbit
- The ________ canal allows the passage of the optic nerve from the retina to the brain.
- The ________ orbital fissure provides passage for the ophthalmic artery, sensory nerves, and motor nerves for eye movements.
The Nasal Septum and Nasal Concha
- Composed of bone and cartilage
- Formed by the perpendicular plate of the ethmoid and vomer bones
- ________ cartilage fills in the gap between the ethmoid and vomer bones and separates the left and right nostrils.
- ________ conchae (superior, middle, and inferior)
- Bony plates curve downward, swirl incoming air, warm and moisturize incoming air
Cranial Fossae
- Divide the floor of the cranial cavity into three spaces
- ________ cranial fossa – most anterior and the shallowest
- Overlies the orbits and contains the frontal lobes of the brain
- ________ cranial fossa – deeper and posterior to the anterior fossa
- Extends from the lesser wings to the petrous ridges.
- Has the following openings:
- ________ canal provides a passageway for the optic nerve.
- Superior orbital ________ allows passage of nerves
- Foramen ________ – exit point for sensory nerve
- Foramen ________ – passage for sensory nerve
- Foramen ________ – passageway for a vital artery
- ________ canal – a passage for the internal carotid artery
- Foramen lacerum
- Posterior Cranial Fossa
- The deepest portion of the cranial cavity.
- Contains the foramen ________
- Hypoglossal ________ – passageway for cranial nerve XII
- ________ foramen – passageway for several cranial nerves and veins that return blood from the brain.
- Paranasal Sinuses
- Hollow air-filled spaces located within certain bones of the skull
- Communicate with the nasal cavity and are lined with nasal mucosa
- Reduce bone mass, lighten the skull, and add resonance to the voice.
- ________ sinus is located above the eyebrows within the frontal bone.
- ________ sinus – the most prominent sinus, which is paired and located within the left and right maxillary bones
- ________ sinus – single midline sinus located within the sphenoid bone
- ________ air cells – multiple small spaces separated by fragile bony walls. It is located on both sides of the ethmoid bone.
Hyoid bone
- An independent bone that does not articulate with any other bone.
- Located in the upper neck near the level of the inferior mandible
- Serves as the base for the tongue and is attached to the larynx and pharynx.
7.3 The Vertebral Column
Also known as the spinal column or spine
It consists of a sequence of vertebrae, each separated by an intervertebral disc.
It supports the head, neck, and body and allows their movements.
It protects the spinal cord, which passes down the back through openings in the vertebrae.
Regions of the Vertebral Column
- 24 vertebrae, plus sacrum and coccyx
- Five regions
- Neck – 7 cervical vertebrae designated C1 – C7
- Upper back – 12 thoracic vertebrae designated T1 – T12
- Lower back – 5 lumbar vertebrae designated L1 – L5
- Sacrum – the fusion of five sacral vertebrae
- Coccyx – tailbone results from the fusion of three to four coccygeal vertebrae.
Curvatures of the Vertebral Column
- Four curvatures along its length increase the column's strength, flexibility, and ability to absorb shock.
- Primary and Secondary curvatures
- Primary curves are retained from the fetal curvature
- ________ curve involves the thoracic vertebrae
- __________________l curve forms by the sacrum and coccyx
- Secondary curves develop after birth, opposite to the original fetal curvature.
- ________ curve (neck region) develops as the infant begins to hold its head upright when sitting.
- ________ curve (lower back) develops as the child begins to stand and walk. Generally deeper in females
- Disorders in spinal curvatures
- ________ (hunchback) excessive posterior curvature of the thoracic region.
- ________ (swayback), an excessive anterior curvature, happens in pregnant women before childbirth or in obesity.
- ________ – an abnormal lateral curvature accompanied by twisting of the vertebral column.
General Structure of a Vertebra
- ________ – anterior portion that supports the body weight. Increase in size and thickness going down the vertebral column
- _______________ discs separate the bodies of individual vertebrae.
- ________l arch - forms the posterior portion of each vertebra.
- Left and right ________
- Each pedicel forms one of the lateral sides of the vertebral arch
- Left and right ________
- Each lamina forms part of the posterior roof of the vertebral arch.
- ________ foramen – a large opening that contains the spinal cord
- Vertebral foramina align to form the vertebral (spinal) canal
- _______________ foramen – openings through which a spinal nerve exits from the vertebral column.
- __________ process – projects laterally and arises from between the pedicel and lamina
- ________ process – projects posteriorly at the midline of the back
- Superior articular ________ faces upward joins with the i________ articular process of the next higher vertebra
Regional Modifications of Vertebrae
- Cervical vertebrae
- Small body, carry the least amount of weight
- ____________ foramen – found in the transverse processes of cervical vertebrae, carry the vertebral artery up into the brain
- Flatter superior and inferior articular processes
- C1 vertebrae (atlas) do not have a body or spinous process
- Ring-shaped, consisting of an anterior and posterior arch.
- C2 vertebra (axis) is the axis of left-right rotation and contains the dens (odontoid process)
- Thoracic vertebrae
- Larger bodies than cervical vertebrae
- The spinous process is more prolonged and points downward
- Have several additional articulation sites.
- ________ – point of rib attachment
- ________ facets located on the lateral sides of each body of a thoracic vertebra
- Lumbar vertebrae
- Carry the most weight and have extensive and thick vertebral bodies.
- Large, articular processes, superior faces backward and inferior faces forward
Sacrum and Coccyx
- Sacrum
- Triangular-shaped bone, thick and wide, formed by the fusion of five sacral vertebrae
- Features
- Median sacral ________ – a bumpy ridge that is the remnant of fused spinous processes found on the posterior surface on the midline.
- ________ sacral crest – fused transverse processes
- ________ promontory – the anterior lip of the superior base of the sacrum
- Sacral ________l – a bony tunnel passing through the sacrum
- Sacral ________s – inferior tip of the sacrum
- Sacral __________a – series of paired openings (posterior and anterior) allow for the passage of the sacral spinal nerves
- Superior ___________ process articulates with the inferior articular process of the L5 vertebrae
- Coccyx
- The tailbone is derived from the fusion of the four tiny coccygeal vertebrae
- Articulates with the inferior tip of the sacrum
Intervertebral Discs and Ligaments of the Vertebral Column
- Intervertebral Disc
- A fibrocartilaginous pad that fills the gap between adjacent vertebral bodies.
- Anchored to the bodies of its adjacent vertebrae
- Provide padding between vertebrae
- Thinner in the cervical region and thickest in the lumbar region
- Two parts
- ________ fibrosis - is the tough fibrous outer layer
- ________ pulposus - softer, more gel-like material with high water content.
Ligaments of the Vertebral Column
- ________ longitudinal ligament – runs down the anterior side of the vertebral column, resists excess backward bending of the vertebral column
- ___________________ ligament – located on the posterior side of the vertebral column. It interconnects the spinous processes of the thoracic and lumbar vertebrae
- ________ ligament – attached to the cervical spinous processes and extends upward and posteriorly to the midline base of the skull
- __________ longitudinal ligament – attached to the posterior sides of the vertebral bodies
- Ligamentum ________ – Short, paired ligaments that interconnect the lamina regions of adjacent vertebrae.
7.4 The Thoracic Cage
The thoracic cage consists of 12 pairs of ribs with their costal cartilages and the sternum.
It protects the heart and lungs
- Sternum
- Elongated flat bone that anchors the anterior thoracic cage
- Three parts
- ____________ – more comprehensive, superior portion
- __________ (suprasternal) notch – shallow U-shaped border
- __________ notch – a shallow depression located at either side of the superior-lateral margins of the manubrium
- ________ angle joins the manubrium to the body
- ________ – elongated central portion
- __________ process – the inferior tip of the sternum
Parts of a Typical Rib
- ________ - the posterior end of a typical rib
- Articulates with the costal facet of a thoracic vertebrae
- ________ – lateral to the head
- ________ – articulates with the facet located on the transverse process of the vertebrae.
- ________ – the remainder of the rib
- ________ – lateral to the tubercle, the point at which the rib has the most significant degree of curvature, forming the most posterior extent of the thoracic cage
- ________ groove – a shallow passageway for blood vessels and nerves
Rib Classifications
- ________ cartilage – ending of each rib made of hyaline cartilage, attach ribs directly or indirectly to the sternum.
- ________ ribs – are ribs 1 – 7 (vertebrosternal ribs). Attach directly to the sternum by costal cartilage.
- ________ ribs – are ribs 8 – 12 (vertebrochondral ribs). Costal cartilage from these ribs does not attach directly to the sternum.
- For ribs 8 -10, the costal cartilages are attached to the cartilage of the next higher rib.
- __________ ribs – false ribs 10 – 12. These short ribs do not attach to the sternum at all.