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53 Cards in this Set
- Front
- Back
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What embryonic structure is skeletal muscle derived from?
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paraxial mesoderm (myotome portion of somite and somitomeres)
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What embryonic tissue is smooth muscle derived from?
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mesenchymal cells anywhere in body
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What embryonic tissue is cardiac muscle derived from?
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mesenchymal cells in cardiogenic area
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In muscle histonogenesis, when does the neuromuscular junction develop?
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Myotube stage
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Cuboidal myoblasts will become type of muscle?
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skeletal muscle
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Fusiform myoblasts will become type of muscle?
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Smooth muscle
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What shape are the myoblasts that develop from the cardiogenic mesoderm?
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somewhat cuboidal, will become cardiac muscle
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Myotomes split in to what two portions?
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Dorsal-Epimere
Ventral-Hypomere |
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The hypomere gives rise to what muscles
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the hypaxial muscles
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What are some examples of hypaxial muscles
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intercostals
obliques limb muscles |
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The epimere gives rise to what muscles?
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the epaxial muscles
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What are some examples of epaxial muscles?
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erector spinae
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What innervates the epimere
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Dorsal ramus
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what innervates the hypomere
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ventral ramus
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What are the fates of myotomes?
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1. remain segmental
2. fuse 3. Split longitudinally 4. Split tangentially 5. Migrate from level of origin |
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Give examples of a segmental myotome
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intercostals, levators, rotators, deep back
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Give examples of a fused myotome
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Abdominal obliques, erector spinae
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Give examples of a longitudinally split myotome
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Erector spinae muscles
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Give examples of a tangentially split myotome
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Abdominal obliques, intercostals
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Give examples of a migrated myotome
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Serratus anterior and diaphragm
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What does it mean if a muscle is innervated by several spinal levels
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it is derived from several myotomes
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limb buds develop from what cells
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myotomal cells of hypomere that migrate into limb buds
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Where are the upper limb myotomes from
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C5-T1
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Where are the lower limb myotomes from?
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L2-S3
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Limb bud myotomal cells divide into what muscles masses?
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posterior (dorsal) premuscle mass
and anterior (ventral) premuscle mass |
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In the upper limb, what does the posterior premuscle mass develop into?
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extensor and supinator muscles
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In the upper limb, what does the anterior premuscle mass develop into?
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flexor and pronator muscles
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In the lower limb, what does the posterior premuscle mass develop into?
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extensor and abductor muscles
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n the lower limb, what does the anterior premuscle mass develop into?
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flexor and adductor muscles
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At 6th week of development where do the thumb, big toe, elbows, and knees face?
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Thumb and big toe- up
elbows and knees- laterally |
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Upper and lower limb rotate to which direction?
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Upper limb- 90 degrees laterally
Lower limb- 90 degrees medially |
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What limb structures are derived from ectoderm?
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Neural tube cells – motor neurons
Neural crest – sensory neurons, pigment cells Epidermis |
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What limb structures are derived from mesoderm?
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Myotome -- skeletal muscle
Dermatome -- dermis Lateral mesoderm -- bone, cartilage, blood vessels, CT |
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What structures constitute the beginning and ending of the inguinal canal?
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Begins at deep (internal) inguinal ring (transversalis fascia)
and ends at superficial (external) inguinal ring (external oblique) |
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What spinal level is the ilioinguinal nerve?
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L1
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what does the inguinal canal contain:
In males? In females? |
males- spermatic cord and ilioinguinal nerve
females- round ligament and ilioinguinal nerve |
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What innervates the cremaster muscle?
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The genital branch of the genitofemoral nerve (L1-L2)
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What is in the spermatic cord?
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Ductus deferens
Testicular artery Pampiniform plexus (venous) Genital branch of genitofemoral nerve (L1,2) Autonomics Lymphatics |
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What is the significance of the pampiniform venous plexus
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temperature regulation, cooling arterial blood via countercurrent exchange
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Where do the testes develop?
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Posterior abdominal wall, T10-L1
Between transversalis fascia and peritoneum |
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what abdominal layers are involved in the descent of the testes?
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External oblique
internal oblique transversalis fascia peritoneum |
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what is the processus vaginalis?
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a potential space within the elongation of peritoneum
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what is the gubernaculum?
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The "rope" that pulls the testes down. (folds in peritoneum that aid in the descent of testes)
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What is the fate of the processus vaginalis?
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Upper portion of processus vaginalis is obliterated
Persists at level of testes Forms the Parietal and visceral layers of the tunica vaginalis (serous membrane) |
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What are the treatments for cryptorchidism?
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Hormone therapy:
hCG- stimulates ledig cells to produce testosterone Surgery |
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What covers the spermatic cord and where do the layers originate?
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External spermatic fascia = external oblique
Cremasteric muscle and fascia = internal oblique Internal spermatic fascia= transversalis fascia |
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what is the fate of the gubernaculum in females?
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Ovarian ligament -- ovary to junction of uterus and uterine tube
Round ligament -- junction of uterus and uterine tube to labia majora |
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What is a direct inguinal hernia?
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All are acquired
Do not course through inguinal canal Pass through Hesselbach’s or inguinal triangle; medial to inferior epigastric vessels |
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What is an indirect inguinal hernia?
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Most frequent one in both males and females
Can be congenital or acquired Course through inguinal canal; pass lateral to inferior epigastric vessels |
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What defines Hasselbach's triangle?
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Base – inguinal ligament
Lateral border – inferior epigastric vessels Medial border – rectus abdominis muscle |
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What covers the peritoneal sac in an direct inguinal hernia?
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transversalis fascia and external oblique
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What covers the peritoneal sac in an indirect inguinal hernia?
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transversalis fascia, internal oblique and external oblique layers
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Which hernia is due to a persistence of processus vaginalis?
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indirect inguinal hernia
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