Week 30 / Muscle, Joints & Bones -2 Flashcards
What are the three parts of the axial skeleton?
The axial skeleton consists of:
Skull
Vertebral column
Bony thorax
What are the functions of the axial skeleton? [5]
Answer:
-Supports and protects organs in the cranial, spinal, and ventral body cavities.
Provides muscle attachment for:
-Adjusting head, neck, and trunk positions.
-Performing respiratory movements.
-Stabilizing or positioning the appendicular skeleton.
-Strong joints with limited movement, reinforced by ligaments.
Question: What are the two sets of bones in the skull?
Answer: The skull consists of:
Cranium
Facial bones
Question: How are the bones of the skull connected?
Answer: The bones are joined by sutures, except for the mandible, which is attached by a freely movable joint.
Question: What is the function of the skull?
Answer: The skull protects the brain and guards the entrances to the digestive and respiratory systems.
Question: How many bones are in the skull, and how are they categorized?
Answer: The skull contains 22 bones:
8 cranial bones (form the braincase)
14 facial bones
Question: What additional bones are associated with the skull?
Answer: 7 additional bones:
6 auditory ossicles (located in the temporal bones)
1 hyoid bone (connected to the temporal bones by ligaments)
Question: What are the bones of the cranium and their locations? [5]
Question: What are the smallest bones in the body, and where are they located?
Answer:
Occipital – Back of the skull
Parietal – Top and most of the sides
Frontal – Anterior (forehead)
Temporal – Lower sides of the skull
Sphenoid & Ethmoid – Form the floor of the cranium
Answer: The ear ossicles (in the middle ear) are the smallest bones:
Malleus
Incus
Stapes
Question: What are the main bones of the face and their functions? [8]
Answer:
Maxillary bone – Forms the upper jawbone
Mandible – Forms the lower jawbone, the only freely movable skull bone
Nasal bones – Fuse to form the bridge of the nose
Inferior nasal conchae – Articulates with multiple bones and creates turbulence in airflow through the nasal cavity
Palatine bone – Forms the anterior portion of the palate
Lacrimal bone – Smallest facial bone, articulates with the frontal, maxillary, and ethmoid bones
Vomer – Thin bone that divides the nasal cavity
Zygomatic bone – Forms the prominence of the cheeks
Question: What are the unique features of the skull?
Answer:
Sutures – Immovable joints between skull bones:
Coronal, Sagittal, Lambdoid, Squamous
Paranasal sinuses – Air-filled cavities located in bones near the nasal cavity
Fontanels – Soft spots in the fetal skull that:
Allow deformation during birth
Calcify over time to form sutures
Question: What are the paranasal sinuses, and where are they located?
Answer: Paranasal sinuses are hollow portions of bones surrounding the nasal cavity.
Question: What are the functions of the paranasal sinuses? [3]
Answer:
Lighten the skull
Produce mucus to moisten and clean the air
Enhance voice resonance and amplification
Question: What are fontanelles in the fetal skull? what is their function?
Answer: Fontanelles are fibrous membranes connecting cranial bones in the fetal skull.
Question: What are the functions of fontanelles?
[2]
Answer:
Allow brain growth
Convert to bone within 24 months after birth
Question: What is the function of the hyoid bone?
Answer: The hyoid bone supports the larynx and serves as an attachment site for muscles of the larynx, pharynx, and tongue.
Question: What are the orbits, and what is their function? [3]
Answer: The orbits are bony cavities that:
Firmly encase the eyes
Cushion the eyes with fatty tissue
House the muscles that move the eyes and the lacrimal glands that produce tears
Question: What are the specific functions of the parts of the hyoid bone?
Answer:
Body of the hyoid – Attachment site for muscles of the larynx, tongue, and pharynx.
Greater horns – Support the larynx and attach to muscles that move the tongue.
Lesser horns – Attach to the stylohyoid ligaments, supporting the larynx.
Question: How many bones form the walls of the orbit?
✅ Answer: The walls of the orbit are formed by seven bones.
Question: What are the functions of the vertebral column? [3]
Answer:
Encloses the spinal cord
Supports the head
Serves as a point of attachment for muscles of the back, ribs, and pelvic girdle
Question: What are the regions of the vertebral column, listed from superior to inferior?
Answer:
7 cervical
12 thoracic
5 lumbar
1 sacrum
1 coccyx
Question: What are the four normal curves in the vertebral column?
Answer:
Cervical and lumbar curves – Convex (bulge anteriorly)
Thoracic and sacral curves – Concave (bulge posteriorly)
🧠 Question: What are the functions of the curves in the vertebral column?
✅ Answer: The curves:
Increase strength
Help with balance
Absorb shocks
🧠 Question: What is the structure of a vertebra?
✅ Answer:
Body – Disc-shaped anterior portion
Vertebral arch – Located posteriorly from the body, forms a hole called the vertebral foramen
🧠 Question: What are the seven processes that extend from the vertebral arch?
✅ Answer:
Transverse process – Extends laterally on each side
Spinous process – Extends dorsally
Superior and inferior articular processes (two of each) – Form joints with adjacent vertebrae
✅ Answer:
Transverse process – Extends laterally on each side
Spinous process – Extends dorsally
Superior and inferior articular processes (two of each) – Form joints with adjacent vertebrae
🧠 Question: What is the structure of the cervical vertebrae?
✅ Answer:
Cervical vertebrae (C1-C7):
Spinous process is often bifid
Transverse foramina on the transverse processes
🧠 Question: What is special about C1 (Atlas)?
✅ Answer:
C1 (Atlas):
Articulates with the head
Specialized to support the head
Lacks a body and spinous process
🧠 Question: What is special about C2 (Axis)?
✅ Answer:
C2 (Axis):
Has a body and spinous process
Contains the dens (tooth-like projection) that creates a pivot for head rotation
🧠 Question: What is the structure of the thoracic vertebrae?
✅ Answer:
Thoracic vertebrae (T1-T12):
Larger than cervical vertebrae
Have facets for articulating with the ribs
🧠 Question: What is the structure of the lumbar vertebrae?
✅ Answer:
Lumbar vertebrae (L1-L5):
Largest and strongest vertebrae
Short and thick spinous processes
🧠 Question: What is the structure and function of the sacrum?
✅ Answer:
Sacrum (S1-S5):
Fused into one unit
Forms the foundation for the pelvic girdle
Contains sacral foramina for nerves and blood vessels
🧠 Question: What is the structure of the coccyx?
✅ Answer:
Coccyx:
4 coccygeal vertebrae fused into 1
🧠 Question 1: What is the average length of the adult vertebral column?
🧠 Question 2: How much of the vertebral column’s length is accounted for by intervertebral discs?
🧠 Question 3: How does a person’s height change when in bed?
🧠 Question 4: What happens to the intervertebral discs during the day and at night?
✅ Answer: The adult vertebral column averages 71 cm (28 inches) in length.
✅ Answer: Intervertebral discs account for about one-quarter of the vertebral column’s length.
✅ Answer: A person is about 1% shorter when in bed due to the compression of the vertebral column during the day.
✅ Answer:
During the day, compression squeezes water out of the discs.
At night, when compression is removed, the discs absorb water.
🧠 Question: What are the functions of the vertebral column?
✅ Answer:
Provides bony protection for the spinal cord
Allows access to the spinal cord for spinal nerves, blood vessels, and lymph vessels
Enables movement through individual vertebrae and intervertebral discs
Provides support for the skull
Acts as a shock absorber protecting the brain
Serves as an attachment for the ribs, shoulder girdle, upper limbs, pelvic girdle, and lower limbs.
🧠 Question: What are the causes of abnormal spinal curvatures?
✅ Answer: Abnormal spinal curvatures can result from:
Disease,
Paralysis of trunk muscles,
Poor posture,
Pregnancy,
Congenital defects
🧠 Question: What is scoliosis, and how does it occur?
✅ Answer:
Scoliosis is an abnormal lateral curvature of the spine, most commonly in the thoracic region.
It is often a developmental abnormality in which the body and arch fail to develop on one side of the vertebrae.
It is more common in adolescent girls.
🧠 Question: What is kyphosis, and what causes it?
✅ Answer:
Kyphosis (hunchback) is an exaggerated thoracic curvature.
It is usually caused by osteoporosis, but can also result from osteomalacia, spinal tuberculosis, or physical activities like wrestling or weightlifting in young boys.
🧠 Question: What is lordosis, and what causes it?
✅ Answer:
Lordosis (swayback) is an exaggerated lumbar curvature.
It is commonly caused by pregnancy or obesity.
🧠 Question: What makes up the thoracic cage?
✅ Answer: The thoracic cage consists of:
Sternum
Costal cartilages
Ribs
Bodies of vertebrae T1-T12
🧠 Question: How are the ribs categorized, and how do they articulate with the sternum?
✅ Answer:
True ribs (1-7): Directly articulate with the sternum via costal cartilages.
False ribs (8-12): Do not articulate directly with the sternum but connect through costal cartilages.
🧠 Question: What are the three portions of the sternum?
✅ Answer: The sternum is formed by three portions, which fuse by around age 25:
Manubrium
Body
Xiphoid process
🧠 Question: How are joints formed between the ribs and vertebrae?
✅ Answer:
Two joints are formed between the facets on the head of the rib and the facets on the bodies of two vertebrae.
Ten ribs form joints between the tubercle of the rib and the transverse process of the lower vertebra.
🧠 Question: What feature does the inferior surface of the rib have, and what does it contain?
✅ Answer: The inferior surface of the rib is deeply grooved, providing a channel for the intercostal nerves and blood vessels.
