Ch. 7 The Skeleton Flashcards
What percentage of body mass does the skeletal system account for?
20%
What are the main components of the skeletal system?
Bones, cartilages, joints, and ligaments
Which part of the skeleton allows for mobility?
Appendicular skeleton
What is the origin of the word ‘skeleton’?
Greek word meaning ‘dried-up body’ or ‘mummy’
What does the thoracic cage consist of?
Bones of the chest
What bones form the pectoral girdle?
Clavicle and scapula
What are the components of the upper limb?
Arm, forearm, and hand
What bones contribute to the os coxae?
Hip bones
What are the components of the lower limb?
Thigh, leg, and foot
What are the two main parts of the human skeleton?
Axial skeleton and appendicular skeleton
What is the primary function of the appendicular skeleton?
The appendicular skeleton allows mobility.
What are the components of the axial skeleton?
The skull, vertebral column, and thoracic cage.
What are the components of the appendicular skeleton?
The pectoral girdle, upper limb, pelvic girdle, and lower limb.
Skeleton
The framework of bones, cartilages, joints, and ligaments that supports and protects the body.
What percentage of body mass does the skeletal system account for?
About 20% of body mass.
What are ligaments?
Ligaments are connective tissues that connect bones and reinforce joints.
What is the function of joints in the skeletal system?
Joints provide for the remarkable mobility of the skeleton.
Axial Skeleton
The part of the skeleton that includes the skull, vertebral column, and thoracic cage, supporting and protecting the central part of the body.
Appendicular Skeleton
The part of the skeleton that includes the pectoral girdle, upper limbs, pelvic girdle, and lower limbs, allowing for mobility.
How many bones make up the axial skeleton?
80
Which of the following is NOT a region of the axial skeleton?
Pectoral girdle
What is the primary function of the axial skeleton?
Supports the head, neck, and trunk
Which bones form the thoracic cage?
Ribs, sternum, and thoracic vertebrae
What does the axial skeleton protect?
Brain, spinal cord, and organs in the thorax
What are the three major regions of the axial skeleton?
The skull, vertebral column, and thoracic cage
Which part of the skeleton forms the longitudinal axis of the body?
The axial skeleton
Axial Skeleton
The part of the skeleton that forms the longitudinal axis of the body, including the skull, vertebral column, and thoracic cage.
Thoracic Cage
The part of the axial skeleton formed by the ribs, sternum, and thoracic vertebrae.
How many cranial bones are in the skull?
8
Which bone forms the lower jaw and is connected to the skull by freely movable joints?
Mandible
What is the name of the joints that firmly unite the bones of the adult skull?
Sutures
Which suture connects the parietal bones to the frontal bone?
Coronal suture
What is the function of the cranial bones?
Protect the brain and furnish attachment sites for head and neck muscles
What is the cranial vault also known as?
Calvaria
Which bones form the superior and lateral aspects of the skull?
Parietal bones
What is the name of the large hole at the base of the occipital bone?
Foramen magnum
Which bone is known as the keystone of the cranium?
Sphenoid bone
What is the function of the ethmoid bone’s cribriform plates?
Allow filaments of the olfactory nerves to pass to the brain
How many facial bones are in the human skull?
14
Cranium
The part of the skull that encloses and protects the brain.
Sutures
Interlocking joints that connect the bones of the skull.
Name the four major sutures of the skull.
Coronal, sagittal, squamous, and lambdoid sutures.
What are the three fossae of the cranial base?
Anterior, middle, and posterior cranial fossae.
Cranial cavity
The space within the skull that houses the brain.
What bone forms the forehead?
Frontal bone
Which bone forms the posterior aspect and most of the base of the skull?
Occipital bone
Foramen magnum
The large opening in the occipital bone through which the spinal cord connects with the brain.
What is the function of the occipital condyles?
They articulate with the first vertebra of the spinal column, allowing nodding movements of the head.
Sella turcica
A saddle-shaped prominence on the sphenoid bone that houses the pituitary gland.
What is the function of the cribriform plates of the ethmoid bone?
They form the roof of the nasal cavity and allow the passage of olfactory nerves.
Crista galli
A triangular process of the ethmoid bone that serves as an attachment point for the dura mater.
Which bones form the bridge of the nose?
Nasal bones
What is the function of the lacrimal bones?
They form part of the medial walls of the orbits and house the lacrimal sacs for tear drainage.
Maxillae
The bones that form the upper jaw and central portion of the facial skeleton.
What is the main function of the anterior longitudinal ligament?
Preventing hyperextension of the spine
What is the shape of the vertebral foramen in lumbar vertebrae?
Triangular
What is the primary role of the ligamentum flavum?
Connecting adjacent vertebrae and providing elasticity
What is the primary function of the vertebral column?
To transmit the weight of the trunk to the lower limbs, protect the spinal cord, and provide attachment points for ribs and muscles.
Cervical Vertebrae
The seven vertebrae at the top of the vertebral column, numbered C1-C7, with a concave curvature.
How many vertebrae make up the thoracic curvature?
12 vertebrae, numbered T1-T12.
Intervertebral Discs
Cushionlike pads composed of an inner gelatinous nucleus pulposus and a strong collar called the anulus fibrosus, acting as shock absorbers.
What are the four curvatures of the vertebral column?
Cervical, thoracic, lumbar, and sacral curvatures.
Ligamentum Flavum
A strong ligament containing elastic connective tissue that connects adjacent vertebrae and stretches as we bend forward.
Scoliosis
An abnormal lateral curvature of the spine, often occurring in the thoracic region.
What is the main characteristic of lumbar vertebrae?
They are massive and kidney-shaped, designed to support greater weight.
Kyphosis
A dorsally exaggerated thoracic curvature, commonly known as hunchback.
What is the role of the anterior longitudinal ligament?
To prevent hyperextension of the spine and support the vertebral column.
Lordosis
An accentuated lumbar curvature, often referred to as swayback.
Which ribs are known as true ribs?
Ribs 1-7
What is the primary function of the thoracic cage?
Protecting vital organs of the thoracic cavity
Which part of the sternum articulates with the clavicles?
Manubrium
What is the function of the intercostal muscles?
Lifting and depressing the thorax during breathing
Which ribs are called floating ribs?
Ribs 11 and 12
What is the xiphisternal joint?
The point where the sternal body and xiphoid process fuse
Which ribs attach directly to the sternum by individual costal cartilages?
Ribs 1-7
What is the jugular notch?
The central indentation in the superior border of the manubrium
Which ribs are called vertebrochondral ribs?
Ribs 8-10
What is the function of costal cartilages?
They secure the ribs to the sternum.
What are the three parts of the sternum?
Manubrium, body, and xiphoid process
What is the anatomical term for true ribs?
Vertebrosternal ribs
What is the jugular notch?
The central indentation in the superior border of the manubrium.
What is the sternal angle?
A horizontal ridge where the manubrium joins the sternal body.
Manubrium
The superior portion of the sternum, shaped like the knot in a necktie.
Xiphoid process
The inferior end of the sternum, a small process that is usually ossified in adults over 40.
Intercostal space
The space between ribs occupied by intercostal muscles.
True ribs
Ribs 1 through 7 that attach directly to the sternum by individual costal cartilages.
False ribs
Ribs 8 through 12 that either attach indirectly to the sternum or lack a sternal attachment.
Floating ribs
Ribs 11 and 12 that have no anterior attachments.
What is the appendicular skeleton?
Bones of the limbs and their girdles
What is the function of the pectoral girdles?
Attach the upper limbs to the body trunk
What is the primary role of the pelvic girdle?
Secures the lower limbs
How many major segments are each limb composed of?
Three
What connects the segments of the limbs?
Movable joints
What is the appendicular skeleton?
Bones of the limbs and their girdles that are appended to the axial skeleton.
What is the function of the pectoral girdle?
To attach the upper limbs to the body trunk.
What does the pelvic girdle secure?
The lower limbs.
How many major segments does each limb have in the appendicular skeleton?
Three major segments.
What connects the segments of the limbs in the appendicular skeleton?
Movable joints.
Appendicular skeleton
Bones of the limbs and their girdles that are appended to the axial skeleton.
Pectoral girdle
The set of bones that attach the upper limbs to the body trunk.
Pelvic girdle
The set of bones that secure the lower limbs.
What is the function of the clavicles in the pectoral girdle?
They hold the scapulae and arms out laterally
What connects the pectoral girdle to the axial skeleton?
The articulation of the clavicles to the sternum
What is the shape of the scapula?
Triangular
Which part of the scapula articulates with the humerus to form the shoulder joint?
Glenoid cavity
What is found on the anterior surface of the scapula?
Subscapular fossa
What is the function of the curves in the clavicle?
To ensure it fractures anteriorly to avoid damaging the subclavian artery
What is the acromion?
A projection on the scapula that articulates with the clavicle
What is the primary function of the pectoral girdle?
To attach the upper limbs to the axial skeleton and provide attachment points for muscles that move the upper limbs.
Which bone marking on the scapula articulates with the clavicle?
The acromion.
Clavicle
A slender, S-shaped bone that acts as a brace to hold the scapulae and arms out laterally and transmits compression forces from the upper limbs to the axial skeleton.
Scapula
A thin, triangular flat bone that lies on the dorsal surface of the rib cage and forms part of the shoulder girdle.
Acromion
A triangular projection on the scapula that articulates with the clavicle to form the acromioclavicular joint.
Glenoid cavity
A shallow, pit-shaped cavity on the scapula that articulates with the humerus to form the shoulder joint.
What is the sole bone of the arm?
Humerus
Which bone is the medial bone of the forearm?
Ulna
Which bone articulates with the scapula at the shoulder?
Humerus
Which bone is the lateral bone of the forearm?
Radius
What is the name of the bone that forms the palm of the hand?
Metacarpals
Which bone is responsible for forming the elbow joint with the humerus?
Ulna
Which bone has the anatomical neck and surgical neck?
Humerus
Which bone has the radial tuberosity?
Radius
What is the name of the bony part that rests on the table when you lean on your elbows?
Olecranon
Which bones form the wrist?
Carpals
What is the main function of the interosseous membrane between the radius and ulna?
Connecting the radius and ulna along their entire length
What is the anatomical term for the thumb?
Pollex
What is the name of the condition caused by overuse and inflammation of tendons in the wrist?
Carpal tunnel syndrome
Humerus
The sole bone of the arm, articulating with the scapula at the shoulder and with the radius and ulna at the elbow.
Olecranon
The bony prominence of the ulna at the elbow, forming the angle of the elbow.
Interosseous membrane
A flat, flexible ligament connecting the radius and ulna along their entire length.
Carpal bones
Eight marble-sized bones forming the wrist, arranged in two rows of four bones each.
Metacarpals
Five long bones forming the palm of the hand, numbered I to V from thumb to little finger.
Phalanges
Fourteen miniature long bones forming the fingers, with three in each finger except the thumb, which has two.
What are the three bones that make up the hip bone (os coxae)?
Ilium, ischium, and pubis
What is the function of the acetabulum?
Receives the head of the femur
Which part of the ilium is an important anatomical landmark and easily felt through the skin?
Anterior superior iliac spine
Which bone forms the posteroinferior part of the hip bone?
Ischium
What is the primary function of the ischial tuberosity?
Bears weight when sitting
What structure is formed by the bodies of the two pubic bones?
Pubic symphysis
Which of the following correctly describes a difference between the female and male pelvis?
The female pubic arch is rounder
Which of the following forms the pelvis but is not part of the coxal bones?
Sacrum
What are the three bones that make up the hip bone?
The ilium, ischium, and pubis.
Os Coxae
Another term for the hip bone, consisting of the ilium, ischium, and pubis.
What is the main functional difference between the male and female pelvis?
The female pelvis is adapted for childbearing, being wider, shallower, lighter, and rounder.
Iliac Crest
The thickened superior margins of the ilium where many muscles attach.
What is the significance of the pubic symphysis?
It is the joint where the two pubic bones are joined by a fibrocartilage disc.
Pubic Arch
The V-shaped angle formed by the inferior pubic rami, which is broader in females.
What is the role of the sacroiliac joint?
It transmits the weight of the body from the spine to the pelvis.
What is the primary function of the patella?
Protects the knee joint and improves leverage of thigh muscles
Which bone forms the heel of the foot?
Calcaneus
Which bone articulates with the tibia at the ankle joint?
Talus
What is the weakest part of the femur, often fractured in hip injuries?
Neck
What is the function of the medial and lateral condyles of the femur?
Articulate with the tibia to form the knee joint
Which bone is known as the shinbone?
Tibia
Which bone does not bear weight but helps stabilize the ankle joint?
Fibula
How many phalanges are there in each toe except the great toe?
Three
Which bone is known as the largest, longest, and strongest bone in the body?
Femur
Femur
The single bone of the thigh, and the largest, longest, and strongest bone in the body.
What is the function of the patella?
It protects the knee joint anteriorly and improves the leverage of the thigh muscles acting across the knee.
Patella
A triangular sesamoid bone enclosed in the tendon that secures the anterior thigh muscles to the tibia.
What is the primary function of the tibia?
To receive the weight of the body from the femur and transmit it to the foot.
Tibia
The larger and more medial bone of the leg, second only to the femur in size and strength.
What is the role of the fibula in the leg?
It helps stabilize the ankle joint but does not bear weight.
Fibula
A sticklike bone with slightly expanded ends that articulates with the tibia and helps stabilize the ankle joint.
What are the main functions of the foot?
To support body weight and act as a lever to propel the body forward when walking or running.
Tarsals
Seven bones that form the posterior half of the foot, including the talus and calcaneus.
Which bones form the knee joint?
The lateral and medial condyles of both the femur and tibia.
What is the function of the arches of the foot?
To support weight and provide springiness, making walking and running more economical in terms of energy use.
What are the unossified remnants of fibrous membranes connecting the skull bones at birth called?
Fontanelles
Which fontanelle is palpable for 1½ to 2 years after birth?
Anterior fontanelle
What condition involves the failure of the right and left halves of the palate to fuse medially?
Cleft palate
At what age does the cranium almost reach adult proportions?
8 to 9 years
Which spinal curvatures are well developed at birth?
Thoracic and sacral curvatures
What is the term for the condition where the femoral head is partially or completely dislocated in newborns?
Developmental dysplasia of the hip (DDH)
What skeletal changes occur during puberty in females?
The pelvis broadens in preparation for childbearing
What happens to the spine as the discs become thinner and less elastic with age?
The risk of disc herniation increases
What condition is characterized by the loss of bone mass in the jaws, making them look small and childlike in old age?
Osteoporosis
Why are fontanelles important during birth?
They allow the infant’s head to be compressed slightly during birth and accommodate brain growth.
When does the lumbar curvature develop in infants?
When the baby begins to walk, around 12 months.
Fontanelle
Unossified remnants of fibrous membranes connecting the skull bones at birth.
Cleft palate
A congenital condition where the right and left halves of the palate fail to fuse medially.
Developmental dysplasia of the hip (DDH)
A condition involving partial or complete dislocation of the femoral head and poorly developed acetabulum in newborns.
Primary curvatures
The thoracic and sacral curvatures of the spine that are convex posteriorly and present at birth.
Lumbar curvature
A secondary curvature of the spine that develops when a baby begins to walk, around 12 months.
What is a common congenital defect where the soles of the feet face medially and the toes point inferiorly?
Clubfoot
What is the purpose of a laminectomy?
To relieve the symptoms of a ruptured disc
What does an orthopedist specialize in?
Restoring lost skeletal system function or repairing damage to bones and joints
What is pelvimetry used for?
To determine whether the pelvis is of adequate size for normal delivery of a baby
What is spina bifida?
A congenital defect of the vertebral column where one or more vertebral arches are incomplete
What is the goal of spinal fusion?
To immobilize and stabilize a specific region of the vertebral column
Chiropractor
A specialist who treats diseases by manipulating the vertebral column.
Laminectomy
Surgical removal of a vertebral lamina, often to relieve symptoms of a ruptured disc.
Pelvimetry
Measurement of the dimensions of the pelvis to determine if it is adequate for normal delivery of a baby.
Spinal fusion
A surgical procedure involving the insertion of bone chips to stabilize a specific region of the vertebral column.
What are the principal subdivisions of the axial skeleton?
Skull, vertebral column, and thoracic cage
What is the primary function of the appendicular skeleton?
Allows mobility for manipulation and locomotion
Which bone is the only bone of the thigh?
Femur
Which bones form the leg?
Tibia and fibula
Which bones are included in the foot?
Tarsals, metatarsals, and phalanges
Which tarsal bone articulates with the tibia superiorly?
Talus
What are the three arches of the foot?
Lateral longitudinal, medial longitudinal, and transverse
What are fontanelles and their function?
Soft spots on a baby’s skull that allow brain growth and ease birth passage
At what age do the head and torso equal the length of the lower limbs?
By the age of 10
What changes occur in the female pelvis during puberty?
Changes preparatory for childbirth
What happens to the intervertebral discs with old age?
They thin, leading to a gradual loss in height and increased risk of disc herniation
What is the function of the hyoid bone?
Serves as an attachment point for tongue and neck muscles
How many movable vertebrae are in the vertebral column?
24
What are the first seven pairs of ribs called?
True ribs
Femur
The only bone of the thigh, with a ball-shaped head that articulates with the acetabulum.
Fontanelles
Soft spots on a baby’s skull that allow brain growth and ease birth passage.
What are the eight cranial bones?
Paired parietal and temporal bones, and single frontal, occipital, ethmoid, and sphenoid bones.
Hyoid bone
A bone in the neck that serves as an attachment point for tongue and neck muscles.
Pectoral girdle
Consists of the clavicle and scapula, attaching the upper limbs to the axial skeleton.
What bones form the pelvic girdle?
Two hip bones and the sacrum.
What bones make up the arm, forearm, and hand?
The humerus (arm), radius and ulna (forearm), and carpals, metacarpals, and phalanges (hand).
Acetabulum
The socket in the hip bone that articulates with the head of the femur.
After a hip dislocation and reduction, a nurse would watch the patient carefully for signs of which of these problems?
Sciatic nerve injury
When the hip is pushed out of the hip socket, what specific bones and bony structures might have been injured?
Femur and acetabulum
If you were asked to rest your hands on your hips, what structure in the pelvic girdle would your hands be resting on?
Iliac crest
Name the structures on the femur and the pelvic girdle where the large gluteal muscles of the buttocks attach.
Greater trochanter and iliac crest
Closed reduction
A procedure to set a broken bone without surgery by physically manipulating the bone back into place.
Sciatic nerve
A major nerve extending from the lower end of the spinal cord down the back of the thigh, and is susceptible to injury during hip dislocation.
Acetabulum
The socket in the pelvis that holds the head of the femur, forming the hip joint.
Pelvic girdle
Consists of the paired coxal bones and sacrum that attach the lower limbs to the axial skeleton.
Superior
Toward the head or upper body regions.
Mandible
Lower jawbone; U shaped, largest bone of the face.
Skull
Bony protective encasement of the brain and the organs of hearing and equilibrium; includes cranial and facial bones.
Vertebral column
Formed of a number of individual bones called vertebrae and two composite bones (sacrum and coccyx).
Fossa
A depression, often an articular surface.
Lumbar vertebrae
The five vertebrae of the lumbar region of the vertebral column, commonly called the small of the back.
Thorax
That portion of the body trunk above the diaphragm and below the neck.
Achilles Tendon
Tendon that attaches the calf muscles to the heelbone (calcaneus); also called the Achilles tendon.
Thoracic cage
Bones and costal cartilages that form the framework of the thorax; includes sternum, ribs, and thoracic vertebrae.
Acetabulum
Cuplike cavity on lateral surface of the hip bone that receives the femur.
Pelvis
(1) Basin-shaped bony structure composed of the hip bones, sacrum, and coccyx; (2) funnel-shaped tube within the kidney continuous with the ureter.
Axial
Relating to the head, neck, and trunk; one of the two major divisions of the skeleton.
Fontanelles
Fibrous membranes at the angles of cranial bones that accommodate brain growth in the fetus and infant.
Lateral
Away from the midline of the body.
Thoracic vertebrae
The 12 vertebrae that are in the middle part of the vertebral column and articulate with the ribs.
Cranium
Bony protective encasement of the brain and organs of hearing and equilibrium
Medial
Toward the midline of the body.
Sutures
An immovable fibrous joint; with one exception, all bones of the skull are united by sutures.
Cervical vertebrae
The seven vertebrae of the vertebral column that are located in the neck.
Ramus
Branch of a nerve, artery, vein, or bone.
Pectoral girdle
Bones that attach the upper limbs to the axial skeleton; includes the clavicle and scapula.
