Skeletal System -Axial System. Chapter 7 Part A

Transcription

1 Skeletal System -Axial System Chapter 7 Part A

2 Skeleton Learn: Names of the s. Identify specific landmarks that allow: Bones to fit into each other, Organs to fit into the cavities, Muscles to attach, Blood vessels and nerves to pass. Practice Practice Practice Practice Practice!! Functions: Skeleton forms the framework of the body. Along with muscles, it helps in movement of the body and body parts. It protect many internal organs.

3 Skeleton - Divisions Divided into two major subdivisions: Axial system.blue Appendicular system.tan Axial system: Composed of s that form the longitudinal axis of the body/ s that make up the head and trunk. 80 s. Appendicular system: Composed of s that form The limbs. The s that attach the limbs to the axial. 126 s. Total number of s in adult human body: 206

4 Axial Skeleton Axial system: 1) Skull 22 s 2) Bones associated with skull: Hyoid 1 Auditory ossicles 6 s 3) Vertebral column: Vertebrae 24 s Sacrum 1 Coccyx 1 4) Thorax: Sternum Ribs 1 24 s 80 s auditory ossicles U-shaped in the neck that supports the tongue

5 Skull

6 Skull Cranial Bones Horizontal section Posterior Roof Floor Anterior Lateral Cranial s form a box cranial cavity to hold the brain: Roof of the cranium Floor of the cranium Anterior, posterior and lateral walls of the cranium

7 Skull Ethmoid Sphenoid

8 Skull Cranial Bones-Frontal Frontal Supraorbital foramen Frontal (1): Form the forehead, part of the roof of cranium and orbital cavity. Two s at birth fuse by age 6-8 years. Lateral view Supraorbital margin- thickened portion that forms the superior margin of the orbital cavity. Frontal Supraorbital foramen Supraorbital margin Supraorbital foramen- a hole in the margin blood vessels and nerves enter the.

9 Skull Cranial Bones-Frontal Frontal Supraorbital foramen Frontal sinus- air filled space in the. Mucus from sinus helps flush the nasal cavity. Makes the skull lighter. Lateral view Frontal sinus Anterior view Sagittal section

10 Skull Cranial Bones-Parietal s Occipital Lateral view Parietal Temporal Frontal Sphenoid Parietal s (2): Form part of the roof, lateral wall and posterior wall of the cranium. Articulations- Parietal s articulate with one another by sagittal suture. Parietal s also articulate with frontal, temporal, sphenoid and occipital. Q. A fracture in the right superior lateral surface of cranium. Which Superior view

11 Skull Cranial Bones-Temporal s Temporal s (2): Form the lateral wall and floor of the cranium. Lateral view Parietal Frontal External auditory/acoustic meatus: a tubelike opening forms the external ear to direct sound into the ear. External acoustic meatus Occipital Temporal Zygomatic process: a projection of the temporal that connects with the cheek (zygomatic ) form zygomatic arch (cheek arch). Zygomatic arch Zygomatic process of temporal Temporal process of zygomatic Zygomatic arch Temporal Temporal Horizontal section Inferior view

12 Skull Cranial Bones-Temporal s Lateral view Mandibular fossa: two depressions to fit lower jaw (mandible). *Pearson-slide 12 Temporal Mastoid process: Site for attachment of muscles that can rotate/extend head Mastoid process Styloid process Styloid process: - Attached to ligaments that support the hyoid. - Attached to tendon of several muscles associated with hyoid, tongue and pharynx Zygomatic arch Mandibular fossa Styloid process Mastoid process U-shaped in the neck that supports the tongue Inferior view

13 Skull Cranial Bones-Occipital Lateral view Occipital Occipital (1): Forms the floor and posterior wall of the cranium. External occipital protuberance: a bump for attachment of ligaments from cervical vertebrae to support head. Superior and inferior nuchal lines: lines extending from protuberance for attachment of muscles and ligaments to support head. Foramen magnum: a big hole for spinal cord to exit. Occipital condyles: curved surfaces lateral to foramen magnum to articulate with 1 st cervical vertebra. *Pearson-slide 11 Occipital condyle Foramen magnum Occipital Superior nuchal line External Occipital protuberance External Occipital protuberance Inferior view Posterior view Inferior nuchal line

14 Skull Cranial Bones-Sphenoid Sella turcica Lesser wing Greater wing Horizontal section Sphenoid (1): Forms the floor of the cranium. Articulates with all other cranial s to hold them together keystone. Sella turcica: a depression to accommodate pituitary gland. Lesser wings: Extend horizontally anteriorly to sella turcica. Greater wings: Extend laterally from body and forms floor of cranium. Sphenoidal sinuses: drains mucus into nasal cavity. *Pearson- Slide 7 Sella turcica Sphenoidal sinus Sagittal section

15 Skull Cranial Bones-Sphenoid a) Foramen ovale-jaws (slide 23) b) Foramen spinosum-cranial cavity membranes (slide 23) c) Foramen rotundum-face (slide 8) d) Superior orbital fissure-orbit (slide 8) e) Optic canal-optic nerve (slide 8) Superior orbital fissure Optic canal

16 Cribriform plate Horizontal section Skull Cranial Bones-Ethmoid Ethmoid (1): Sponge-like vertically placed in the center of the skull. Cribriform plate: forms the roof of the nasal cavity and floor of the cranium. Has perforations-olfactory foramina- to allow olfactory nerves-provides sense of smell. Crista galli-ridge of that projects from the cribriform plate. Allows the attachment of a membrane that stabilizes the position of the brain. Olfactory foramina Cribriform plate Sagittal section

17 Skull Cranial Bones-Ethmoid Middle nasal concha Ethmoid (1): Perpendicular plate: forms part of the nasal septum. Superior and middle nasal conchae: projections in the nasal cavity cause turbulence of the inhaled air filter, moisten and warm the air. Ethmoidal sinuses: drains mucus into nasal cavity.

18 Squamous suture Lambdoid suture Occipital Parietal Lateral view Temporal Frontal Skull Sutures Coronal suture Sutures: - Seam-lines that connect cranial and facial s to each other dense fibrous connective tissue. - Characterized by zigzag appearance Squamous suture: Temporal Parietal. Coronal suture: Frontal Parietals. Sagittal suture: Parietal Parietal. Lambdoid suture: Occipital Parietals. Superior view

19 Review Cranial Bones! Lateral view Anterior view Cranial floor Inferior view Posterior view Superior view Frontal Parietal Occipital Temporal Sphenoid Frontal Parietal Temporal Occipital Frontal Ethmoid Temporal Sphenoid Occipital Parietal Occipital Temporal Frontal Parietal Occipital

20 Lateral view Lamboid suture Squamous suture External auditory meatus Mastoid process Coronal suture Zygomatic process of temporal Styloid process Review Cranial Landmarks! Anterior view Supraorbital foramen Supraorbital margin Inferior view Zygomatic arch Mandibular fossa Occipital condyle Foramen magnum Mastoid process Cranial floor Cribriform plate Greater wing Sella turcica Posterior view Superior view Sagittal suture Foramen magnum External occipital protuberance Superior nuchal line Inferior nuchal line

21 Skull Fontanelles Sphenoidal fontanelle Posterior fontanelle Mastoid fontanelle Anterior fontanelle Lateral view Superior view Fontanelles: - Soft spots - Non-ossified areas between cranial s-made of tough fibrous membrane - Allows the brain and skull to expand - Enable the bony plates of the skull to flex at birth Craniostenosis: premature closure of one or more fontanelles distortion of the skull can affect proper growth of the brain.

22 Skull Facial s form the face.cheeks, jaws, nose, orbital cavity, and protect/support the entrances to the digestive and respiratory tracts. Nasal Lacrimal Vomer Zygomatic Maxilla Mandible Ethmoid Sphenoid Frontal Temporal Cranial s surround and protect the brain. Parietal Occipital

23 Skull Facial Bones-Nasal s Nasal Nasal s (2): - Forms only the superior part of nose bridge.connected to cartilage that forms the distal portion of the. - Articulates with one another, with ethmoid, with frontal and maxilla. Lateral view Nasal Anterior view

24 Zygomatic Lateral view Skull Facial Bones-Zygomatic s Zygomatic s (2): Cheek s. - Temporal process: a projection of the zygomatic that connects with the temporal form zygomatic arch (cheek arch). Zygomatic arch Zygomatic process of temporal Temporal process of zygomatic Zygomatic arch Inferior view

25 Skull Facial Bones-Maxillae Maxillae (2): - Form the upper jaw. - Two s fuse before birth. - Largest facial. Anterior view Infraorbital foramen Maxilla Palatine process of maxilla Maxillary sinuses: spaces that secrete mucus and drain into the nasal cavity. Alveolar processes: projecting ridge on body of maxilla form alveolar sockets to accommodate teeth. Infraorbital foramen: hone for blood vessel and nerve to enter maxilla. Alveolar process Inferior view

26 Skull Facial Bones-Maxillae Palatine process of maxilla Palatine process of maxilla: horizontal part that forms the anterior part of the hard palate (roof of oral cavity). *Slide 11-Rotate Cleft palate: birth defect when maxillae fail to meet along the midline of the hard palate oral and nasal cavities are continuous; lips are split; difficulty feeding. Inferior view

27 Ramus Angle Body Skull Facial Bones-Mandible Anterior view Mandible (1): Lower jaw the strongest facial and the only movable of the skull. Develops as 2 s fuse before birth. Body: horizontal part of the mandible. Ramus: vertical parts of the mandible. Mandibular/condylar process: rounded projection fits into mandibular fossa of temporal forms temporomandibular joint (TMJ). Coronoid process: Insertion point for temporalis muscle. Mandibular notch: Separates the condylar and coronoid processes. Lateral view TMJ Coronoid process Mandibular notch Head Alveolar process Condylar process Ramus Body Mandible Angle

28 Anterior view Skull Facial Bones-Mandible Mandible: TMJ syndrome: malfunction of the joint headache, referred pain in the ear, muscle pain, noise and reduced movement of the joint physical therapy, anti-inflammatory drug therapy. Four holes: Mental foramen: Opening (in the body) for nerves that carry sensory information from lips and chin to the brain. Ramus Angle Mandibular foramen: Opening (in the ramus)-entrance for mandibular canal-serves lower teeth. Body Mental foramen Mandibular foramen Ramus Angle Body Mental foramen

29 Lacrimal Lateral view Skull Facial Bones-Lacrimal s Lacrimal s (2): Smallest facial. Resembles a fingernail. Part of the medial wall of the orbital cavity. Lacrimal fossa: houses lacrimal sac Lacrimal foramen: passage way for lacrimal artery Lacrimal Lacrimal Lacrimal Anterior view Orbital cavity

30 Skull Facial Bones Palatine s Palatine s (2): Form the posterior part of the hard palate next to palatine process of maxilla. Palatine Inferior view Orbital cavity

31 Skull Facial Bones Vomer (1): A triangular, vertical that forms inferior part of the nasal septum. * Pdf file in Learning Web-Position of vomer-incorrect Vomer Inferior view

32 Skull Facial Bones Inferior nasal conchae (2): The largest of the 3 conchae. (* Superior and middle nasal conchae are part of ethmoid). Functions-Create turbulence in air. - Warms and humidifies internal ear Inferior nasal concha Anterior view Superior and middle nasal conchae of ethmoid Inferior nasal concha Sagittal section

33 Review Skull Bones! maxilla maxilla nasal zygomatic sphenoid palatine vomer mandible maxilla temporal mandible occipital temporal mandible

34 Review Skull Landmarks! Supraorbital foramen Supraorbital margin Zygomatic arch Palatine process-maxilla Temporal process of zygomatic Zygomatic process of temporal Ramus Angle Infraorbital foramen Mental foramen Lambdoid suture Occipital condyle Foramen magnum Sagittal suture Coronal suture External occipital protuberance

35 Skull Orbital Cavity Frontal Sphenoid Superior orbital fissure Optic canal Ethmoid Lacrimal Inferior orbital fissure Zygomatic Orbital cavity: space to accommodate eyeball. Formed by a total of 7 cranial and facial s. Cranial s- frontal, sphenoid, ethmoid. Facial s- zygomatic, maxilla, lacrimal, palatine. Maxilla Palatine Optic canal, superior & inferior orbital fissures for passage of optic and other nerves. Q. Which contains optic canal

36 Skull Paranasal Sinuses Paranasal sinus: space in the s around the nose open into the nasal cavities. Examples: Frontal, Ethmoidal, Sphenoidal and Maxillary sinuses. Functions: Make the skull lighter. Have extensive mucous epithelium that secretes mucus into the nasal cavity provides moisture and traps dust and microorganisms. Sinusitis: viral, bacterial or fungal infection of the sinuses mucous membrane swells openings of sinuses (ostia) narrow mucus accumulates in the sinuses pressure builds headache. Antihistamines, vasoconstrictors and painkillers relieve the pressure and pain.

37 Axial Skeleton-Skull

38 Axial Skeleton Axial system: 1) Skull 22 s 2) Bones associated with skull: Hyoid 1 Auditory ossicles 6 s 3) Vertebral column: Vertebrae 24 s Sacrum 1 Coccyx 1 4) Thorax: Sternum 1 Ribs 24 s 80 s

39 Skull Associated Bones Auditory ossicles: Six smallest s 3 in each ear. Malleus, Incus and Stapes Function: amplify sound stimulus. Auditory ossicles Body Greater horn Lesser horn Hyoid: Single, U-shaped. Located between mandible and larynx. Often fractures during strangulation. Does not articulate with any other floats. Body: horizontal part. Greater and lesser horns/cornua: projections for muscle attachment. Function: supports tongue and attach some of the neck and tongue muscles. An anterior view of the hyoid

40 Axial Skeleton Axial system: Skull Hyoid Auditory ossicles Vertebral column Thorax: Sternum Ribs 22 s 1 6 s 26 s 1 24 s 80 s