muscle and skeletal systems

week 2

what are the three things somites eventually develop into

1. dermatomes

2. myotomes

3. sclerotomes

dermatomes form the

dermis

myotomes form

individual skeletal muscles

sclerotomes form the

axial skeleton

somitomeres are precursors to somites. what happens in the head region vs the trunk

head- do not become somites but give rise to similar cells

trunk - do become somites

muscle within the iris of the eye is unique in that it is derived from the

mesoderm

which muscle type is the only one that develops from myotomes

skeletal

what describes skeletal muscle

tissue attached to bone

allows skeletal movement

voluntary control

smooth and cardiac muscle are developed from

splanchnic mesoderms

smooth muscle description

• involuntary control

• found in hollow organs and parts

  • bladder and blood vessels

cardiac muscle description

makes up the thick middle layer of the heart

what are the two types of bone formation

endochondral ossification

intramembranous ossification

in intramembranous ossification, bone forms ______ _____ _______ that gradually incorporate each other

centers of mineralization

in intramembranous ossification, what arises from neural crest cells

osteoblasts (cells which build bone)

what are examples of intramembranous ossification

flat bones of the skull and face, clavicle

in endochondral ossification, chondroblasts arise from _______ and form the structure of the bone as ______ first

sclerotomes

cartilage

in endochondral ossification, cartilage is remodeled with

bone marrow cells

blood vessels

osteoblasts/osteoclasts

osteoblasts deposit bone on the

remnants of the cartilage in endochondral ossification

what are examples of bones formed by endochondral ossification

long bones

metacarpals/metatarsals

vertebrae + ribs

what is the presentation of malignant hyperthermia

• sudden rise in body temp

• muscle fasciculation and rigidity

• tachypnea

• tachycardia

• arrhythmia

  • death

what species is affected by malignant hyperthemia

pigs (porcine stress syndrome - most recognized)

dogs

horses

humans

what is happening in malignant hyperthermia

increase of intracellular Ca2+ levels in skeletal muscles

what can induce malignant hyperthermia

stress, exercise, and anesthesia

is malignant hyperthermia always congenital

yes

what kind of defect is responsible for malignant hyperthermia

mutation in calcium channel gene - autosomal dominant inheritance

what diagnostics are used for malignant hyperthermia

in vitro contracture test (IVCT) via muscle biopsy and DNA analysis

is malignant hyperthermia treatable?

dantrolene is the only effective treatmentw

what considerations should be made for individuals with malignant hyperthermia

avoid stress and exercise

avoid inhalant anesthesia

what is the prognosis for malignant hyperthermia

guarded - if individual can live low stress life