Anatomy & Physiology 2

  1. what causes muscle contractions
    nervous stimulation causes actin and myosin filaments to slide past each other in the muscle cell or fiber.
  2. what are muscle cells made up of?
    myofibrils that consist of sarcomeres
  3. what must be present for a cell to contract?
    calcium and ATP (adenosine triphosphate)
  4. explain the process of muscle contraction (cross-bridge cycle) from motor neuron
    the motor neuron releases calcium from the sarcoplasmic reticulum. when the calcium binds to troponin on actin, tropomyosin moves out of the way so that actin and myosin can make a bridge formation. The bridge is strong when myosin contains ADP and Phosphate. When phosphate is released the myosin head pivots (contraction). When ATP comes, the cross bridge detaches. When ATP hydrolyzes, the energy to create ADP and phosphate puts the head back in its cocked position.
  5. explain how muscles work in pairs-prime movers and antagonist

    what is the synergist
    prime movers execute the movement, while the muscle that produces the opposite movement is the antagonist 

    the synergist helps by assisting the prime mover. works with it.
  6. what is the overall purpose of the nervous system
    it makes all of our senses possible, helps us to think, makes movement possible by causing contraction, helps body functions operate
  7. what do all actions in the nervous system depend on
    transmission of nerve impulses between neurons/nerve cells
  8. what are the function units of the nervous system?
    neurons/nerve cells
  9. what are the 3 main parts of the nerve cell?
    cell body, axon, dendrites
  10. what do axons do?
    they transmit the impulse away from the cell body
  11. what do dendrites do?
    they transmit the impulse toward the cell body
  12. what are the parts of the nervous system
    • CNS-brain and spinal cord 
    • PNS-all the other neurons in the body
  13. what kind of neurons are sensory? what do they do?
    afferent- send signals toward the CNS
  14. what kind of neurons are motor? what do they do?
    efferent-send signals away from the CNS to muscles, glands, and organs
  15. what are 3 major parts of the brain
    the cerebrum, cerebellum, and medulla oblongata
  16. what does the cerebum do?
    associated with movement and sensory input
  17. what does the cerebellum do?
    responsible for muscular coordination
  18. what does the medulla oblongata do?
    controls many vital functions such as respiration and heart rate
  19. how long is the spinal cord?
    18 inches long, stretching from the base of the skull (foramen magnum) to L1/L2
  20. how many spinal nerves exit the spinal cord?
    62 or 31 pairs
  21. what are simple spinal reflexes
    reflexes where nerve impulses travel through the spinal cord, but don't reach the brain
  22. how do most spinal reflexes work?
    they work in ascending and descending pathways. sensory impulses enter the spinal cord through the dorsal horns, while motor impulses exit the spinal cord through the ventral horns.
  23. what is the purpose of the endocrine system?
    it assists the nervous system in homeostasis and plays an important role in growth and sexual maturation
  24. where do the nervous and endocrine systems meet? explain their relationship.
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    they meet at the hypothalamus and the pituitary gland. the hypothalamus governs the pituitary gland, but is controlled by the feedback of hormones in the blood, coming from the pituitary. 

    the nervous and endocrine systems coordinate and control the body, but the endocrine system has more widespread and longer lasting effects
  25. what structure connects the hypothalamus and pituitary gland?
    the infundibulum
  26. what are the 2 major portions of the pituitary gland? which is which?
    the anterior lobe (adenohypophysis) 

    the posterior lobe (neurohypophysis)
  27. does the nervous or endrocrine system effect the body more?
    the nervous and endocrine systems coordinate and control the body, but the endocrine system has more widespread and longer lasting effects
  28. what are 7 major endocrine glands?
    hypothalamus, pituitary gland, thyroid, pancreas, adrenal glands, and gonads (testes & ovaries)
  29. what are hormones?
    chemical messengers that control the growth, differentiation, and metabolism of specific target cells
  30. what are the 2 major groups of hormones? explain..
    steroid- enter the target cells and have a direct effect on the DNA of the nucleus. their receptors are inside of the cell. 

    non steroid- their receptors are outside of the cell and they require a secondary messenger to effect the nucleus. they are usually amines or proteins, but can be fatty acids
  31. what is the most common second messenger?
    AMP- adenosine monophosphate
  32. how do most hormones effect the cell
    by effecting the rate of protein synthesis
  33. what is the function of the endocrine glands 

    name other organs that arent endocrine glands that produce hormones
    to produce hormones 

    the stomach, small intestines, and kidneys
  34. what glands release cortisol and other hormones during stress
    adrenal cortex, anterior and posterior pituitary, and the hypothalamus
  35. what effect does cortisol released from the adrenal cortex have on the body
    reduces inflammation, raises blood sugar level, and inhibits the release of histamine
  36. what gland is called "the master gland"
    the pituitary
  37. what are hormones of the adenophypophysis called? why?
    trophic hormones

    because they act mainly on other endocrine glands
  38. list major adendohyophysis tropic hormones 

    • -somatotropin hormone (STH), or growth hormone (GH)
    • -adrenocorticotropic hormone (ACTH)
    • -thyroid-stimulating hormone (TSH) 
    • -follicle-stimulating hormone (FSH)
    • -luteinizing hormone (LH)
  39. list 2 hormones released from the neurohypophysis
    • oxytocin (the labor hormone) 
    • antidiuretic hormone (ADH)
  40. what is whole blood made up of?
    • 55% blood plasma 
    • 45% erythrocytes (red blood cells), leukocytes (white blood cells), and platelets
  41. where are the erythrocytes, leukocytes, and platelets formed?
    from stem cells in bone marrow
  42. function of erythrocytes
    transport oxygen that is bound to  protein hemoglobin
  43. how many types of leukocytes are there
  44. what percentage of blood plasma contains ions, waste, nutrients, and hormones? where do they go?

    they dissolve into the water
  45. the heart is a double pump system? explain purpose
    the pulmonary circuit-sends blood to the lung for oxygenation

    the systemic circuit-pumps blood to the rest of the body
  46. describe the pulmonary and systemic circuits PATHWAYS (i.e. how the heart works)
    deoxygenated blood enters the superior and inferior vena cava into the rt atria, rt ventricle, and out of the rt and lt pulmonary arteries to the lungs where they get oxygenated (pulmonary) 

    • then the newly oxygenated blood goes through the rt and lt pulmonary veins, to the lt atria, lt ventricle, and out of the aorta to the body (systemic) 
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  47. what are the 4 valves in the heart and where?
    • tricuspid valve-between the rt atria and rt venticle
    • pulmonary valve-between the rt ventricle and pulmonary arteries 
    • bicuspid (mitral) valve-between the lt atrium and lt ventricle (diastole)
    • aortic valve-between the lt ventricle and the aorta
  48. which valves are the semilunar valves?
    the pulmonary and aortic valves
  49. what is the name of the actual heart MUSCLE
  50. what initiates the intrinsic beat of the heart
    the SA, or sinoatrial node in the rt atrium
  51. what defines a cardiac cycle?
    the period of one ventricular contraction to the end of the next ventricular contraction
  52. what happens during the systole phase?
    contraction of the left ventricle
  53. what happens during the diastole phase?
    relaxation in the left ventricle
  54. what does the vascular system consist of?
    the arteries that carry oxygenated blood awat from the heart, veins that carry deoxygenated blood to the heart, and capillaries
  55. what is the function of capillaries in the vascular system? how big are they compared to other vessels?
    they exchange water, nutrients, and waste products between the blood and the surrounding tissues. 

    they are the smallest vessels
  56. which arteries are considered systemic?
    the vessels beginning with the aorta through the branches of the rest of the body
  57. what happens when arteries move further away from the heart? what are these called?
    they become thinner

    arterioles (the veins that run parallel usually have the same name)
  58. characteristics of the walls and pressure of arteries
    the walls are thick and elastic; they operate under high blood pressure
  59. what is vasodilation and vasoconstriction? what are the effects?
    relaxation and contraction of the arterial walls (smooth muscle)

    this influences the blood pressure and blood distribution to the tissues
  60. characteristics of the walls and pressure of veins
    the walls are thinner and less elastic, and they carry blood under low pressure
  61. do deflections of an ECG reflect the systole and diastole of the heart? why?
    • no. 
    • they reflect the electric activity that happens right before (the initiation) the relaxation and contraction happens
Card Set
Anatomy & Physiology 2
Muscular system, nervous system, endocrine system, and circulatory system