Body cavities, etc.
What is a body cavity and how many body cavities are there?
Internal chambers holding/protecting vital organs. Allow organs to change in shape and size.
There are two.
Describe homeostasis and its aspects.
Steady state. regulation of internal environment (temperature, pH, salinity, fluid levels)
Can a person be double-jointed? Explain.
No, double-jointed is a misnomer for a hyperflexible joint.
What is the cause of gigantism and dwarfism?
Hyper or Hypo secretion of GH
Which of the two types of bone growth involve cartilage?
Endochondral
What are the parts of the dorsal cavity?
What are the parts of the ventral cavity?
Dorsal: Cranial and spinal (vertebral canal)
Ventral: thoracic (pleural and pericardial) and abdominopelvic (abdominal and pelvic)
What are the 3 parts of a homeostatic regulatory mechanism
A receptor (senses a stimuli), control center (process info and generate a response), effector (respond to the command of the control center)
What causes double-jointedness?
Cause: abnormal shape of bony joint surface, connective tissue defect, or abnormal joint proprioception
How is spongy bone arranged?
As spicules/trabeculae surrounded by red bone marrow
Which of the two types of bone growth occurs within a fibrous membrane?
intramembranous
What is proprioception and what causes it?
The "sixth sense", a largely unconscious ability to locate body parts/segments in space in relation to one another.
Provided by muscle spindles in skeletal muscles and tendons, fibrous capsules in joints, combined with info from sensory neurons in the inner ear
Describe and give an example of a positive feedback loop.
Increases/accelerates the actions of the body
Produces more instability and chaos in the body
Uncommon and short-lived
ex: blood clotting and childbirth
Name the 3 types of bone cells and their functions.
Osteoblasts: bone builders. they deposit unmineralized bone called osteoid. controls subsequent mineralization into mature bone.
Osteocytes: the bone messengers. started off as osteoblasts but became trapped in the bone matrix.
Osteoclasts: bone destroyers. produce an acidic environment that dissolves hydroxyapatite.
What type of bone needs a central canal and why?
Spongy bone does not because its surrounded by red bone marrow and so already enriched with what it needs
Cortical bone needs it to supply the bone cells with blood and nutrients
True or false, bone growth begins 6 weeks after conception/in utero.
False, it's 8.
What lines the abdominopelvic cavity?
Peritoneum
Describe and give an example of a negative feedback loop.
Prevents sudden and severe changes in the body
Causes the opposite of the bodily disruption to occur
The most common type of feedback loop
ex: Body temp, blood pressure, glucose regulation
Where are osteocytes housed and how do they communicate?
What are the two types of bone growth?
Intramembranous and Endocondral
Skull = intramembranous
Long bones = endochondral
It's a constant process throughout life. Due to calcium needs, loading forces, and micro/major trauma
Explain the arrangement of bone cells in cortical bone.
They are arranged in a Haversian Canal system. the opening/canal permits the exchange of materials and blood between bone cells.
Which hormones promote vs cease bone growth and how?
Promote: growth hormone and thyroxine (increase rate of protein synthesis, increase energy production from food, increase rate of mitosis of osteoblasts)
Cease: Estrogen and Testosterone (promote closure of the epiphysis of long bones, help with maintenance of calcium)
How many bones do humans have?
Anywhere from 270-300 since in non-adults, the epiphyses haven't fused.