Chapter 6 Flashcards
True or False: The three types of cartilage are hyaline, elastic, and fibroblastic.
A) True
B) False
B) False
Explanation: The three types of cartilage are hyaline, elastic, and fibrocartilage.
True or False: Osteomalacia is a condition where bones are poorly mineralized, leading to soft and weak bones.
A) True
B) False
A) True
Explanation: Osteomalacia is characterized by inadequate mineralization of bones, resulting in soft and weak bone structure.
What type of bone growth increases the length of long bones?
A) Appositional growth
B) Endochondral growth
C) Intramembranous growth
D) Interstitial growth
D) Interstitial growth
Explanation: Interstitial growth is responsible for the increase in the length of long bones, occurring at the epiphyseal plate.
Match the hormone with its function in the skeletal system:
A. Growth hormone
B. Thyroid hormone
C. Testosterone/Estrogen
D. Parathyroid hormone
- Stimulates osteoclasts to degrade bone matrix releasing Ca2+
- Most important hormone in stimulating epiphyseal plate activity in infancy and childhood
- Modulates activity of growth hormone and ensures proper proportions
- Promotes adolescent growth spurts and causes masculinization or feminization of the skeleton; later ends longitudinal bone growth by inducing epiphyseal plate closure
2, 3, 4, 1
Explanation: Growth hormone stimulates epiphyseal plate activity, thyroid hormone modulates growth hormone, testosterone/estrogen promote growth spurts and epiphyseal plate closure, and parathyroid hormone regulates calcium levels by stimulating osteoclast activity.
Which component contributes to the tensile strength and flexibility of bones?
A) Hydroxyapatites
B) Collagen fibers
C) Calcium phosphate
D) Osteocytes
B) Collagen fibers
Explanation: Collagen fibers, part of the organic matrix called osteoid, provide tensile strength and flexibility to bones.
True or False: Cartilage has a flexible matrix that can accommodate mitosis of chondrocytes, making it an excellent scaffolding tissue upon which to build bone.
A) True
B) False
A) True
Explanation: Cartilage’s flexible matrix allows for the mitosis of chondrocytes, which is essential for bone growth and development.
Which of the following is NOT a classification of bones by shape?
A) Long bones
B) Flat bones
C) Regular bones
D) Short bones
C) Regular bones
Explanation: Bones are classified by shape into long, flat, short, and irregular bones. There is no category called “regular bones.”
True or False: Bone lengthening ceases when the epiphyseal plate closes.
A) True
B) False
A) True
Explanation: Bone lengthening stops when the epiphyseal plate closes, which happens near the end of adolescence.
True or False: The periosteum is involved in bone growth and repair.
A) True
B) False
A) True
Explanation: The periosteum contains osteogenic cells that can differentiate into bone-forming cells, thus playing a key role in bone growth and repair.
Fill in the blank: The __________ contains osteogenic cells that can differentiate into osteoblasts and contribute to bone growth and repair.
Periosteum
Explanation: The periosteum is a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints.
Fill in the blank: The two control loops that regulate bone remodeling are __________ and __________.
Ca2+ homeostasis and responses to mechanical/gravitational forces
Explanation: Bone remodeling is regulated by the balance of calcium levels in the blood (Ca2+ homeostasis) and the mechanical and gravitational forces acting on the bones, ensuring that bone strength and integrity are maintained.
True or False: Cartilage is converted into bone during endochondral ossification.
A) True
B) False
B) False
Explanation: During endochondral ossification, cartilage is not converted into bone but is replaced by bone.
True or False: Cartilage is highly vascularized and innervated.
A) True
B) False
B) False
Explanation: Cartilage is avascular and does not contain nerves; it is surrounded by the perichondrium, which provides nutrients.
Fill in the blank: Bone development or ossification begins in the ________ month of embryonic development.
Second
Explanation: Ossification, or the process of bone formation, begins in the second month of embryonic development.
Fill in the blank: In adults, ________ bone is replaced approximately every 3-4 years, while ________ bone is replaced approximately every 10 years.
Spongy, compact
Explanation: Spongy bone is replaced every 3-4 years, and compact bone is replaced every 10 years in adults.
What is the role of red bone marrow in adults?
A) Mineral storage
B) Blood cell formation
C) Fat storage
D) Bone remodeling
B) Blood cell formation (hematopoiesis)
Explanation: In adults, red bone marrow is responsible for hematopoiesis, the process of forming new blood cells. It is typically found within the trabeculae of spongy bone, particularly in flat bones like the sternum and pelvic bones.
Which cells are responsible for bone resorption?
A) Osteoblasts
B) Osteocytes
C) Osteoclasts
D) Chondrocytes
C) Osteoclasts
Explanation: Osteoclasts are the cells that break down bone tissue during bone resorption.
What is the function of osteoblasts in bone tissue?
A) Break down bone
B) Form bone matrix
C) Store fat
D) Provide nutrients
B) Form bone matrix
Explanation: Osteoblasts are bone-forming cells that secrete the bone matrix, which includes collagen and calcium-binding proteins.
True or False: Skeletal cartilage contains blood vessels and nerves.
A) True
B) False
B) False
Explanation: Skeletal cartilage does not contain blood vessels or nerves. It is surrounded by a layer of dense irregular connective tissue called the perichondrium, which contains blood vessels for nutrient delivery.
True or False: The periosteum is involved in bone growth and repair.
A) True
B) False
A) True
Explanation: The periosteum contains osteogenic cells that can differentiate into bone-forming cells, thus playing a key role in bone growth and repair.
Fill in the blank: The most abundant type of cartilage in the human body is __________ cartilage.
Hyaline
Explanation: Hyaline cartilage is the most abundant type of cartilage in the human body.
True or False: The periosteum is a double-layered membrane that covers the external surfaces of bones.
A) True
B) False
A) True
Explanation: The periosteum is a double-layered membrane that covers the outer surfaces of bones except at the joint surfaces, providing protection and serving as an attachment point for tendons and ligaments.
Fill in the blank: Fibrocartilage is found in the __________, __________, and __________.
Intervertebral discs, pubic symphysis, menisci of the knee
Explanation: Fibrocartilage is found in areas that require strong support and the ability to withstand heavy pressure.
Which type of cartilage is found in the intervertebral discs and the meniscus of the knee?
A) Hyaline cartilage
B) Elastic cartilage
C) Fibrocartilage
D) Articular cartilage
C) Fibrocartilage
Explanation: Fibrocartilage is found in the intervertebral discs and the meniscus of the knee, where it provides strong support and the ability to withstand heavy pressure.
True or False: Spongy bone contains osteons.
A) True
B) False
B) False
Explanation: Spongy bone does not contain osteons. Instead, it has trabeculae, which align along lines of stress to help resist it.
True or False: Compact bone is also known as lamellar bone due to its lamellae structure.
A) True
B) False
A) True
Explanation: Compact bone is referred to as lamellar bone because it is composed of lamellae, which are layers of bone matrix arranged in concentric circles.
True or False: Bone remodeling is a life-long process that helps to repair microdamage in bone matrix.
A) True
B) False
A) True
Explanation: Bone remodeling is a continuous process where old bone is replaced by new bone, which helps in maintaining bone strength and integrity.
Fill in the blank: The __________ layer of bone is dense and looks smooth and solid, while the __________ bone inside has a honeycomb structure filled with marrow.
A: Compact, spongy
Explanation: Compact bone is the dense outer layer, and spongy bone is the inner, honeycomb-like structure filled with marrow.
What law states that bones grow or remodel in response to demands placed on them?
A) Wolff’s law
B) Newton’s law
C) Hooke’s law
D) Boyle’s law
A) Wolff’s law
Explanation: Wolff’s law explains that bones adapt based on the mechanical stresses placed upon them.
Fill in the blank: Hyaline cartilage is found in the __________, __________, __________, and __________.
Nose, trachea, larynx, ends of long bones
Explanation: Hyaline cartilage is found in various parts of the body, providing smooth surfaces for joint movement and structural support.
Match the classification of bones by shape with an example:
A. Long bones
B. Short bones
C. Flat bones
D. Irregular bones
- Limbs
- Wrist and ankle bones
- Sternum and skull bones
- Vertebrae and hip bones
1, 2, 3, 4
Explanation: Long bones are found in the limbs, short bones in the wrist and ankle, flat bones in the sternum and skull, and irregular bones in the vertebrae and hip.
During embryonic development, the skeleton is primarily made up of what?
A) Bone
B) Cartilage and fibrous membranes
C) Muscle
D) Tendons
B. Cartilage and fibrous membranes
Explanation: During embryonic development, the skeleton is initially composed of cartilage and fibrous membranes, which are gradually replaced by bone.
Fill in the blank: Cartilage can grow both from within, known as __________ growth, and by laying down new layers on the surface, known as __________ growth.
Interstitial, Appositional
Explanation: Cartilage can grow interstitially (from within) and appositionally (by adding new layers to the surface).
Fill in the blank: Osteocytes, found in __________, serve to monitor and maintain the bone matrix.
Lacunae
Explanation: Osteocytes are mature bone cells located in lacunae, and they are responsible for maintaining the bone matrix and acting as stress or strain sensors.
What are the seven important functions of bones?
A) Support, protection, movement, mineral and growth factor storage, blood cell formation, triglyceride storage, hormone production
B) Flexibility, shock absorption, insulation, movement, protection, blood cell destruction, hormone production
C) Energy production, nutrient absorption, muscle attachment, support, balance, temperature regulation, blood cell formation
D) Storage of water, support, protection, movement, sound transmission, nutrient absorption, hormone production
A) Support, protection, movement, mineral and growth factor storage, blood cell formation, triglyceride storage, hormone production
Explanation: Bones perform these key functions to support and protect the body, facilitate movement, store minerals and growth factors, form blood cells, store fat, and produce hormones.
True or False: The embryonic skeleton is comprised mostly of hyaline cartilage.
A) True
B) False
A) True
Explanation: The embryonic skeleton is mainly made up of hyaline cartilage, which provides a template for bone formation.
True or False: There are 206 bones in the human skeleton.
A) True
B) False
A) True
Explanation: The human skeleton is composed of 206 bones, which are divided into the axial skeleton and the appendicular skeleton.
Fill in the blank: The inorganic part of bone is primarily composed of __________.
Hydroxyapatites (calcium phosphate crystals)
Explanation: These mineral salts give bone its hardness and resistance to compression.
Which of the following is NOT one of the seven functions of the skeletal system?
A) Support
B) Protection
C) Hormone production
D) Temperature regulation
D) Temperature regulation
Explanation: The seven functions of the skeletal system include support, protection, movement, mineral and growth factor storage, blood cell formation (hematopoiesis), triglyceride (fat) storage, and hormone production. Temperature regulation is not one of the functions of the skeletal system.
Fill in the blank: Growth hormone, released by the pituitary gland, is the most important hormone for stimulating ________ plate activity in childhood.
Epiphyseal
Explanation: Growth hormone stimulates the activity of the epiphyseal plate, which is crucial for bone growth during childhood.
True or False: Interstitial growth requires the presence of cartilage at the epiphyseal plate.
A) True
B) False
A) True
Explanation: Interstitial growth occurs by the division of chondrocytes and the secretion of new matrix at the epiphyseal plate, leading to an increase in bone length.
Fill in the blank: Elastic cartilage is found in the __________ and the __________.
External ear, epiglottis
Explanation: Elastic cartilage provides flexibility and support in structures such as the external ear and the epiglottis.
The most abundant type of cartilage in the human body is hyaline cartilage.
Question options:
True
False
True
The structural unit of compact bone (osteon) resembles the growth rings of a tree trunk.
Question options:
True
False
True
An osteon contains osteocytes, lamellae, and a central canal, and is found in compact bone only.
Question options:
True
False
True
The periosteum serves to protect bone, but also to nourish it as it is supplied with nerves and blood vessels.
Question options:
True
False
True
The humerus is an example of long bone.
Question options:
True
False
True
Which of the following statements about cartilage is not true?
Question options:
A) The most abundant type of cartilage in the human body is hyaline cartilage.
B) The three types of cartilage are: hyaline, elastic and cutaneous.
C) The embryonic skeleton is comprised mostly of hyaline cartilage.
D) Cartilage has a flexible matrix that can accommodate mitosis of chondrocytes – this makes it an excellent scaffolding tissue upon which to build bone.
B) The three types of cartilage are: hyaline, elastic and cutaneous.
The functions of the skeletal system include all of the following, except:
Question options:
A) support
B) production of blood cells (hematopoiesis)
C) storage of minerals
D) movement
E) hormone production
F) All are functions of bones
F) All are functions of bones
The mitotically-active bone cells that secrete bone matrix (osteoid) are:
Question options:
A) Osteoclasts
B) Osteoblasts
C) Bone Lining cells
D) Chondroblasts
B) Osteoblasts
Identify the structure labelled ‘A’ below:
A) diaphysis
B) compact bone
C) medullary cavity
D) periosteum
E) epiphysis
E) epiphysis
Identify the structure labelled ‘F’ below:
A) diaphysis
B) compact bone
C) medullary cavity
D) periosteum
E) epiphysis
C) medullary cavity
Identify the structure labelled ‘B’ below:
A) diaphysis
B) compact bone
C) medullary cavity
D) periosteum
E) epiphysis
A) diaphysis
Identify the bone structure labelled ‘E’ below:
A) circumferential lamellae
B) osteon
C) lamellae
D) perforating (Volkman’s) canal
E) central (Herversian) canal
A) circumferential lamellae
Identify the bone structure labelled ‘A’ below:
A) circumferential lamellae
B) osteon
C) lamellae
D) perforating (Volkman’s) canal
E) central (Herversian) canal
E) central (Herversian) canal
Identify the bone structure labelled ‘B’ below:
A) circumferential lamellae
B) osteon
C) lamellae
D) perforating (Volkman’s) canal
E) central (Herversian) canal
D) perforating (Volkman’s) canal
Identify the bone structure labelled ‘C’ below:
A) circumferential lamellae
B) osteon
C) lamellae
D) perforating (Volkman’s) canal
E) central (Herversian) canal
B) osteon
The term osteoid refers to the organic part of the matrix of compact bones.
Question options:
True
False
True
Bones stop interstitial growth at the end of adolescence, but appositional growth can continue throughout our lifetimes.
Question options:
True
False
True
Spongy bone does not contain osteons, though the trabeculae are aligned along stress lines.
Question options:
True
False
True
Parathyroid hormone increases osteoblast activity to release more calcium ions into the bloodstream.
Question options:
True
False
False
The most important hormone in regulating bone growth during youth is thyroid hormone.
Question options:
True
False
False
A deficiency of thyroid hormone during bone formation would cause what kind of defect?
Question options:
A) Uneven proportions in long bones
B) Inadequate calcification of bone
C) Decreased remodeling activity
D) Decreased interstitial growth of long bones at the epiphyseal plate
A) Uneven proportions in long bones
Which of the following statements about bone growth is incorrect?
Question options:
A) Interstitial growth requires the presence of cartilage at the epiphyseal plate.
B) During interstitial growth, the epiphyseal plate maintains a constant thickness as new bone grows on the distal end (i.e. closer to the epiphyses) while new cartilage grows on the proximal end (i.e. closer to the diaphyses) of the bone.
C) Interstitial bone growth ends at the end of adolescence.
D) Appositional growth can occur any time throughout life.
E) All are true statements
E) All are true statements
Which of the following statements about pre-natal ossification is not true?
Question options:
A) Endochondral ossification is responsible for most bone formation during development.
B) Intramembranous ossification produces the flat bones of the skull and clavicles.
C) In endochondral ossification, bone forms by replacing hyaline cartilage “models”
D) In endochondral ossification existing cartilage must first be broken down and then replaced by bone.
E) All are true statements
E) All are true statements
Which of the following statements about bone remodeling is not true?
Question options:
A) Bone resorption occurs first, followed by the laying down of new bone.
B) Bone remodeling occurs throughout our lifetimes.
C) Remodeling is accomplished by the coordinated efforts of osteoblasts and osteoclasts.
D) Mechanical and gravitational forces acting upon bones play a role in remodeling.
E) Remodeling is regulated hormonally/chemically by growth hormone and blood Ca++ levels.
E) Remodeling is regulated hormonally/chemically by growth hormone and blood Ca++ levels.
What hormone is the most important regulator of bone growth during adolescence?
Question options:
A) Growth hormone
B) Thyroid hormone
C) Calcitonin
D) Parathyroid hormone
E) Testosterone and estrogen
A) Growth hormone
