Term
| what is the triangle of auscultation? |
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Definition
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Term
| where does fertilization usually occur? |
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Definition
| the ampulla of the uterine tube. |
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Term
| cleavage of the zygote first forms a what? |
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Definition
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Term
| the morula forms ahollow ball called a ??? |
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Definition
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Term
| cells of the blastocyst differentiate into a what? |
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Definition
| a bilaminar disc with an outer epiblast and inner hypoblast |
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Term
a primitive streak appears
in the caudal midline of the epiblast. Cells of the
epiblast invaginate into the streak to form a third layer
between the epiblast and hypoblast, the embryonic
mesoderm |
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Definition
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Term
Additional cells of the epiblast displace the hypoblast
and form the embryonic endoderm. As soon as the
mesoderm is formed the remaining cells of the epiblast
are called the embryonic ectoderm. |
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Definition
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Term
| what are the main derivatives of the ectoderm? |
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Definition
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Term
| what are the main derivatives of the endoderm? |
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Definition
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Term
| what are the main derivatives of the mesoderm? |
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Definition
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Term
A primitive node lies on the cranial end of the primitive streak.
Cells arising from the primitive node invaginate between the
ectoderm and endoderm to form a narrow rod of cells. This
primitive rod or notochord forms the axis of the embryo around
which the axial skeleton develops |
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Definition
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Term
Ectoderm is induced by cells within the notochord to form a
thickened plate. This neural plate invaginates to form the neural
tube (precursor to CNS). Neural crest cells pinch off during this
process and migrate laterally to later form: spinal (DRG), cranial
and sympathetic ganglia associated with the PNS |
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Definition
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Term
Mesoderm differentiates into three paired
regions on either side of the neural tube. what are they? |
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Definition
1. Paraxial mesoderm forms somites.
2. Intermediate mesoderm contributes
to the urogenital system.
3. Lateral plate mesoderm |
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Term
| the lateral plate mesoderm further divides into what three things? |
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Definition
a. Parietal (somatic) mesoderm combines with surface ectoderm to form the lateral and
ventral body wall. Parietal mesoderm also forms CT of muscle/viscera.
b. Visceral (splanchnic) mesoderm combines with endoderm to form the walls of the gut,
vessels and heart. Visceral mesoderm also forms most smooth and cardiac muscle.
c. A primitive body cavity (coelom) forms between the parietal and visceral mesoderm. |
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Term
| what are the parietal pleura and peritoneum? What are visceral pleura and peritoneum? |
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Definition
| 1st are innervated by somatic GSA fibers. 2nd are innervated by GVA fibers. |
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Term
| describe somite differentiation. |
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Definition
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Term
| what three structure arise from the somite? |
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Definition
| sclerotome, myotome, and dermatome. |
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Term
| ***** what is the sclerotome? what do these develop into? |
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Definition
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Term
| what is the myotome? what do these develop into? |
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Definition
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Term
| what is the dermatome? what do these develop into? |
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Definition
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Term
| key concept: Each somite forms a close relationship with a single spinal nerve |
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Definition
Sclerotome = portion of bone and joints
supplied by a single spinal segment.
Myotome = group of skeletal muscles
supplied by a single spinal segment.
Dermatome = cutaneous area of skin
supplied by a single spinal segment |
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Term
dermatome maps
T4 is the nipple line.
T10 is the umbilicus. |
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Definition
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Term
| There are 5 steps of limb development. what is the 1st step? |
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Definition
Each primitive limb bud consists of a mass of mesenchyme derived from
the lateral plate of somatic mesoderm covered by a layer of epithelium
derived from ectoderm. These lateral plate mesenchymal cells will
undergo endochondral ossification: mesenchymal cells → chondroblasts →
hyaline cartilage model → bone. (Exception within limbs: clavicle |
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Term
| There are 5 steps of limb development. what is the 2nd step? |
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Definition
Limb buds begin as flat paddles projecting from the body wall. The
paddles have defined ventral and dorsal surfaces as well as cranial
(preaxial) and caudal (postaxial) borders. The thumb/big toe lie on the
cranial border and the pinky/little toe on the caudal border. |
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Term
| There are 5 steps of limb development. what is the 3rd step? |
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Definition
Skeletal muscle cells derived from the somatic hypomere migrate into the
limb buds. Epiblast → mesoderm → paraxial mesoderm → somites →
myotome → hypomere. Somitic dermatome cells which form the dermis
and subcutaneous tissues of the skin similarly migrate |
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Term
| There are 5 steps of limb development. what is the 4th step? |
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Definition
Remember each somite has a close relationship with a single spinal nerve.
Ventral rami migrate into the mesenchyme of the developing limb buds
around week 5 allowing each spinal segment to innervate structures
associated with their corresponding somite. |
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Term
| There are 5 steps of limb development. what is the 5th step? |
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Definition
Deep fascia within the limb buds contain and separate the developing
muscles into well-defined groups or compartments. Each limb muscle will
receive innervation from multiple spinal segments and will retain this
relationship no matter how far it migrates from its original somatic
segment. Muscles that lie on the ventral surface of the embryo become
flexors; those on the dorsal surface of the embryo, extensors. |
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Term
| describe the organization of the upper limbs |
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Definition
The upper limb buds lie opposite the lower five cervical (C4-C8) and upper two thoracic (T1-T2) body
segments of the embryo |
|
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Term
| describe the development of the limbs from weeks 5-8 |
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Definition
1. At week five the limb buds appear as paddles and
extend laterally and caudally (out and down). The
thumbs and big toe both face cranially (up).
2. At week six the limb buds bend inward at the
future site of the elbows and knees resulting in
both areas pointing laterally. Thus, future palms
and soles face the trunk.
3. Prior to joint development, the upper limbs
undergo 90 degrees of torsion along the long axis.
The future elbow now faces caudally (down); the
future knee cranially (up).
4. In the adult anatomical position, the upper limb
ventral and dorsal surfaces correspond exactly with
those of the embryo. Thus, there is a ventral flexor
surface and a dorsal extensor surface which
receives innervation from anterior and posterior
divisions of ventral rami, respectively. This will
not be the case for the lower limb |
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Term
As ventral rami enter the limbs they braid to form
plexuses. The brachial plexus supplies the upper
limb; the lumbosacral, the lower limb. Each of these
plexuses form divisions which supply the developing
embryonic compartments:
• ventral flexor compartment = anterior divisions
• dorsal extensor compartment = posterior divisions
7. All terminal peripheral nerves of the limbs arise
from these plexuses and thus will be associated with
either the ventral or dorsal embryonic
compartment |
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Definition
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Term
| the ventral rami of of which levels combine to form the brachial plexus? |
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Definition
| C5-T1 (sometimes c4 and t2) |
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Term
| the subclavian artery goes between two scalenes. does the subclavian vein go through there? |
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Definition
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Term
| the axilarry artery is the continuation of the subclavian artery and it is the arterial supply for the upper limb. |
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Definition
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Term
C3 – base of neck like a “collar”
C4 – over the shoulder like a “shawl”
C5 – anterolateral arm just lateral to
deltopectoral groove
C6 – lateral side of the thumb
C7 – middle finger
C8 – medial side of little finger
T1 – distal medial arm
T2 – axilla |
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Definition
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Term
there are two exceptions 1. sensory fibers from the c4 ventral rami travel to the shoulder via the cervical plexus
2. sensory fibers from T2, t3 ventral rami travel to the medial arm via a named peripheral nerve. the intercostal brachial cutaneous nerve. |
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Definition
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Term
| shoulder flexion and abduction are innervated by |
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Definition
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Term
| elbow flexion/extension are innervated by |
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Definition
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Term
| finger abduction adduction are innervated by |
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Definition
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