Unit Three Part Two Flashcards
1
Q
What are the two mechanisms of ossification
A
Intramembranous bone development and endochondral bone development
2
Q
Where does intramembranous bode development occur
A
In flat bones of the body such as skull bones, sternum and ilium
3
Q
The skeleton is derived from
A
Mesoderm
4
Q
Mesenchyme cells is derived from
A
Mesoderm
5
Q
Mesenchyme cells are what type of cells
A
Polypotential cell
6
Q
Mesenchyme cells can develop into
A
Fibroblasts, myoblast, chondroblast and osteoblasts
7
Q
Osteoblast cells form
A
Bone
8
Q
Osteoblasts secrete
A
Osteoid
9
Q
What is osteoid
A
Soft bone similar to wet cement
10
Q
Function of osteoid
A
Allows for diffusion of O2, nutrients, and waste products
11
Q
What eventually happens to osteoid
A
Going to harden due to taking in phosphate and calcium
12
Q
When osteoblasts osteoid hardens what occurs
A
Turns into osteocyte
13
Q
What is the developmental sequence of intramembranous bone development
A
Mesoderm, mesenchyme, osteoblast, osteoid, osteocyte
14
Q
Where does endochondral bone development occur
A
In long bones primarily in the limbs
15
Q
Development line in endochondral bone development
A
Mesoderm, mesenchyme cells, chondroblast, blood vessel brings in osteoblast , osteoid, osteocyte
16
Q
When osteoblast is brought into chondroblast through blood vessel what occurs
A
Chondroblast replaced by osteoblast
17
Q
Advantage of endochondral bone development
A
Allows for growth out of the bone after bone has been established due to growth plates
18
Q
If blood vessel does not get to bone what occurs
A
Bone will stop development at cartilaginous stage
19
Q
Eventually growth plates will close and then what occurs
A
End of growth, fixed height at this point
20
Q
The skull is divided into what two parts
A
Neurocranium and visceral cranium
21
Q
What bones are in the neurocranium
A
Bones that cover brain such as upper skull, parietal, frontal and occipital
22
Q
The visceral cranium contains what bones
A
Facial
23
Q
The neurocranium uses what type of ossification
A
Both of them
24
Q
What is the upper portion of the neurocranium referred as
A
Membranous neurocranium
25
The upper portion of the neurocranium uses what type of ossification
Intramembranous ossification
26
What bones make up the membranous neurocranium
Parietal, squamous portion of temporal and frontal bone
27
The lower portion of the neurocranium is called
Cartilaginous neurocranium
28
What type of ossification does cartilaginous neurocranium uses
Endochondral ossification
29
What bone makes up the cartilaginous neurocranium
Occipital bone
30
In the skull, little islands of bone start to form in the flat bone that eventually
Grows out but don’t fully touch
31
What are fontanelles
Areas of the flat bone in the skull that remain when bones don’t touch
32
Fontanelles AKA
Soft spot
33
Fontanelles represent areas where
The intramembranous ossification has not quite finished
34
Fontanelles serve what two functions
Allow the skull some ability to contract or push together during birth, site at where baby head is going to grow
35
Most of the viscerocranium is the face and develops from
Pharyngeal arch one
36
The vertebral column develops from
Paraxial mesoderm
37
The mesoderm form segmental structures called
Somites
38
Somites divided into
Dermatome, myotome, and sclerotome
39
Dermatome forms
Dermis of skin
40
Myotome forms
Muscles associated with spine
41
Sclerotome forms
Vertebrae
42
When the sclerotome splits what side is the largest
The lowest
43
How does vertebrae form
Sclerotome splits and a lower portion fuses with a top portion and forms vertebrae
44
Why does the vertebrae grow out towards the muscle
Development of spinal nerve
45
Separation of vertebrae forms the
IVF
46
The sternum develops from
Somatic mesoderm
47
When sternum first forms how many segments
4, 2 round bilateral structures on top and 2 bars of somatic mesoderm
48
The two round bilateral structures on top of sternum and fuse together to create
Manubrium
49
How do the 2 bars of sternum form
Basically zip together from top to bottom to form sternum
50
What portion of TVP is true TVP
Posterior
51
Anterior portion of TVP contains
Costal process
52
How does a rib form
Costal portion of TVP elongates
53
Rib is an extension of
TVP
54
Does the extension of TVP occur only in thoracic
Mostly but can occur in lumbar and cervical
55
Origin of the Rib
Paraxial mesoderm
56
What is the primary inducer for limb development
Apical ectodermal ridge (AER)
57
AER is derived from
Ectoderm
58
AER causes
Mesoderm specifically mesenchyme cells to begin their development into fibroblast, myoblast or osteoblast
59
Mitosis of mesenchymal cells occurs where
In mesenchymal mesoderm
60
Where do you see differentiation of mesenchymal cells in limb development
Progress zone
61
How does the upper limb grow
Grows straight out and then comes down, thumbs up and elbows face backwards
62
How does the lower limb grow
As it grows, going to rotate inward 180 degrees and knees face forward
63
Dermatomes are
Innervation of the skin
64
How do dermatomes appear in upper limbs
Start as stack segments and as limb grows, it pulls dermatome with it but stay stacked on each other
65
How do dermatomes look in lower limbs
Dermatomes are stacked on each other in the beginning, as limb elongates dermatomes spiral due to inward rotation of limb
66
Axial musculature develops from
Paraxial mesoderm
67
Axial musculature is associated with
Somites
68
Axial musculature begin as
Paraxial cubes or somatic cubes
69
Each somatic cube contains
Own innervation
70
How do somatic cubes form
They fuse together and create long muscles and bring their innervation with them
71
What forms somites
Paraxial mesoderm
72
Sclerotome forms
Cartilage and bone associated with axial skeleton
73
How many regions of somites
5
74
What is the most cranial region of somites
Occipital somites
75
Occipital somites has how many pairs
4
76
Occipital somites gives us what
The base of the skull
77
How many pairs in cervical somites
8 pairs
78
Cervical somites form where
Area of neck
79
What are the different regions of somites
Occipital, cervical, thoracic, lumbar and sacralcoccygeal somites
80
How many pairs of thoracic somites
12 pairs
81
Thoracic somites develop where
Thorax
82
How many pairs of lumbar somites
5 pairs
83
Number of pairs in sacralcocygeal somites
Vary in number depending on length of your tail
84
As time goes on what happens to the first occipital somite
Lose it with no adult derivative
85
As tail degenerates what happens to sacralcoccygeal somites
Reduce themselves to 8
86
Myotomes form what
Musculature associated with axial skeleton
87
First thing to occur to myotome
Separate and going to form epimere
88
The epimere forms what
Erector spinalis muscles
89
The other part of the myotome once it splits is
The hypomere
90
The hypomere first starts as
Single solid mass of cells
91
What happens to hypomere as development continues
Separate into three layers
92
What are the other layers of the hypomere
Abdominal muscles and intercostal muscles
93
Muscles having dorsal ramus are derived from
Epimere
94
Muscles with ventral ramus are derived from
Hypomere
95
What inducer causes mesenchymal cells will become myoblasts
AER
96
The limb musculature is going to divide themselves into two regions of
Preaxial muscles and postaxial muscles
97
Preaxial muscles are
In front of CT
98
Postaxial muscles are
Muscles behind CT
99
In the upper extremity, the preaxial muscles are going to be
Flexor muscles
100
The postaxial muscles in the upper extremity are going to be
Extensor muscles
101
What separates the preaxial and postaxial muscles in the upper extremity
Interosseus membrane
102
In lower extremity the preaxial muscles are
Extensors (quads)
103
In lower extremity, the postaxial muscles are going to be
Flexors (hamstrings)
104
The nervous system develops from the
Ectoderm
105
What is the primary inducer of nervous system development
The notochord
106
The notochord releases various chemicals that causes
Ectodermal cells in this region to begin their development
107
The ectodermal cells first start as
Squamous cells
108
The squamous ectodermal cells become what
Columnar shaped cells
109
The columnar shaped ectoderm cells form the
Neural plate
110
The neural plate becomes the
Neural groove when begins to fold inward
111
The edges of the neural groove come together and fuse to form
The neural tube
112
The closure of the neural tube occurs where
The 4th somite level
113
Once the neural tube forms what occurs
Becomes double zipper and folds in two different direction
114
At closure at 4th somite, everything above is
Cranial and is brain
115
Everything caudal of 4th somite closure is
Spinal cord
116
Neural tube formation occurs when
Start at third week and end at third week
117
What are the ends of the neural tube called
Neuropores
118
What is the first thing to happen in the nervous system development
Neuropores have to close
119
Once the neuropores close what occurs next
The cranial aspect of the tube is going to start to develop in the three vesicle brain
120
When does the three vesicle brain develop
Fourth week
121
What is the most cranial part of the three vesicle brain
Prosencephalon
122
What is the fastest growing area of the three vesicle brain
Prosencephalon
123
What are the three vesicles in the three vesicle brain
Prosencephalon, mesencephalon, and rhombencephalon
124
Which three vesicle brain part is growing in size but not as fast as prosencephalon
Mesencephalon
125
What three vesicle brain part is increasing in length but not width
Rhombencephalon
126
Everything below the rhombencephalon is the
Spinal cord
127
Is the three ventricle brain solid or hollow
Hollow
128
When does the five vesicle brain occur
Fifth week of development
129
The prosencephalon forms the
Telencephalon and diencephalon
130
The telencephalon contains what
Lateral ventricles
131
Where is the third ventricle of the five ventricle brain
Diencephalon
132
In the five ventricle brain, the mesencephalon contains what ventricle
Cerebral aqueduct
133
The rhombencephalon in the five ventricle brain forms the
Metencephalon and myelecephalon
134
What part of the five ventricle brain shares the fourth ventricle
Metencephalon and myelecephalon
135
What is the adult derivative of telencephalon
Cerebrum
136
Adult derivative of diencephalon
Thalamus
137
Adult derivative of mesencephalon
Midbrain of brain
138
Adult derivative of metencephalon
Cerebellum and pons
139
The adult derivative of myelecephalon
Medulla
140
When brain is growing what happens to it to fit in skull
Begins to fold
141
What are the folds in the five ventricle brain
Cervical flexure, pontine flexure, rhombencephalic isthmus, and cephalic flexure
142
The cervical flexure is the dividing line of the
Brain and spinal cord
143
The cervical flexure is at what level
4th somite level
144
The pontine flexure is the dividing line of
Metencephalon and myelencephalon
145
The rhombencephalic isthmus is the boundary line of
Metencephalon and mesencephalon
146
What flexure is located at the midpoint of mesencephalon
Cephalic flexure
147
The layer of cells on the outside of the lumen form what
The mantle layer
148
The mantle layer forms
The cell bodies of the developing neurons and becomes the gray matter
149
The mantle layer can be divided into two populations of cells known as
Alar plate (dorsal) and basal plate (ventral)
150
Anything that develops from alar plate is going to have what type of function
Sensory
151
Anything that develops from basal plate is going to have what function
Motor function
152
Outside the mantle layer is the
Marginal layer
153
The marginal layer contains
Axons of neurons and form white matter
