Exam 2 postquiz

52) Explain the ATP in muscle contractions.

ATP plays in important role in muscle contraction. To contract, the myofilament myosin has heads that attach to the actin and then bend to pull the actin toward itself. This causes the entire muscle to contract. In order for the muscle to release again, the myosin head must receive a molecule of ATP. When ATP attaches to the myosin, it is converted to ADP and allows the myosin to release the actin, which in turns allows the entire muscle to relax. (incorporate into essay) ADP cleaves to the myosin head to activate "power stroke."

34) Protein that makes up the thin myofilament.

Actin

43) This part of the peripheral nervous system regulates involuntary body functions, heart rate, and breathing rate.

Autonomic nervous system

57) The hormone _ calcium from the blood and causes it to be stored in the bone.

Calcitonin

71) The thin outer layer (1-to 2-mm thick) of each hemisphere of the brain that serves to increase the surface area by being arranged in a folded manner is called the __.

Cerebral Cortex

3) Which bones form a connection between the scapula and the sternum to support the pectoral girdle?

Clavicles

67) Motor neurons that carry information away from the brain or spinal cord are known as _ neurons.

Efferent

37) Synapse in which neurotransmitters allow sodium to enter the postsynaptic cell.

Excitatory synapse

59) The _ joints have no joint cavity and usually do not permit movement. Sutures between skull bones are this kind of joint.

Fibrous

2) Membranous areas in the infant skull that join bones and function to allow for rapid growth of the brain are known as _.

Fontanels

22) The photoreceptors are most tightly packed into a specific part of the retina called the _.

Fovea

78) _ is caused by excessive aqueous humor pressure.

Glaucoma

73) The _ is responsible for converting information from the short-term to the long-term memory.

Hippocampus

*20) Fred has been diagnosed with a disease that causes him to forget that his relatives have been to see him. What parts of his brain are likely affected, given this information?

Hippocampus and amygdala

36) Synapse in which neurotransmitters decrease the chance of an action potential on the postsynaptic cell.

Inhibitory synapse

39) Membrane proteins that allow specific charged molecules to pass through from one side of the membrane to the other.

Ion channels

17) Which of the following can be defined as a collection of structures involved in emotions and memory?

Limbic system

42) This is a group of brain structures that helps us to experience feelings such as joy, fear, and anger.

Limbic system

26) Vertebrae in the lower back region just above the sacral region.

Lumbar

16) Which of the following structures connects the spinal cord to the rest of the brain and influences breathing rhythm and blood pressure?

Medulla oblongata

74) Inflammation of the protective coverings of the brain and spinal cord is known as _.

Meningitis

*25) Mina had a throat infection; in a few days it had spread to her ear. What part of her ear would be affected first?

Middle ear

14) Muscle cells that are not exercised will atrophy or shrink in size. Lou Gehrig's disease affects nervous tissue but also causes muscle atrophy. What type of nerve cell must be affected to cause this muscle-wasting condition?

Motor neurons

62) A(n) __ is a motor neuron and all the muscle cells that it stimulates.

Motor unit

*13) Which of these diseases involves the destruction of the myelin sheath on certain neurons within the brain and spinal cord?

Multiple Sclerosis

35) Protein that makes up the thick myofilament.

Myosin

68) Axons and dendrites, or both, arranged in bundles and covered by connective tissue are _.

Nerves

12) Which of the following is a chemical signal that diffuses across the gap between adjacent neurons to convey a message to the next cell?

Neurotransmitter

79) If light strikes a photopigment, the photoreceptor cell will decrease the amount of _ it is releasing.

Neurotransmitters

24) Sami stepped into a strange, new house but sensed something that brought back a whole flood of memories about his beloved grandmother from long ago. Which sense most likely brought these special memories back?

Olfaction

30) Calcitonin stimulates the activity of these bone cells.

Osteoblasts

29) Bone cells that break down bone tissue.

Osteoclasts

80) The __ is a sheet of tissue that separates the outer ear from the middle ear.

Tympanic membrane

44) This portion of the central nervous system governs bodily activities during restful conditions.

Parasympathetic nervous system

72) The ___ of the cerebral cortex sends messages to the skeletal muscles in order to control voluntary movement.

Primary motor area

75) A circuit of neurons that helps in the automatic response to a stimulus is a(n) __.

Reflex arc

6) Which of the following is not a function of muscle?

Regenerate calcium in the blood

19) You are generally not aware of the texture of the cloth of your shirt as it rests on your shoulders, unless someone or something happens to make you think of it. What part of the brain is responsible for filtering out such stimuli?

Reticular activating center

28) Produced from the fusion of five vertebrae and allows an individual to sit.

Sacrum

23) This portion of the vestibular apparatus is responsible for dynamic equilibrium.

Semicircular canals

69) During an action potential, the _ ions rush into the axon.

Sodium

45) This part of the peripheral nervous system carries sensory information from the skin, skeletal muscles, and joints to the central nervous system and may also direct voluntary movements.

Somatic nervous system

4) Astronauts returning to earth from an extended stay in space have to be extremely careful or they could break a bone. It takes several weeks to restore normal bone strength. Which would be the best regimen to rebuild lost bone tissue?

Start with walking and build up to jogging, with an extra regimen of light weight lifting in the gym.

76) Sensory receptors repond to changes in the environment called _.

Stimuli

41) A loud, unexpected noise will cause this part of the autonomic nervous system to become active.

Sympathetic nervous system

38) The junction between a neuron and another cell.

Synapse

40) Part of the neuron where neurotransmitters are released.

Synaptic knobs

*8) Which of these structures is part of a muscle cell's plasma membrane that delivers signals to the sarcomere?

T-tubules

27) Bones that form on either side of the cranium and are thought of as the temples.

Temporal

61) _ is a sustained powerful contraction of a muscle that results from frequent stimulation with no time between stimuli for relaxation.

Tetanus

54) Describe the path of a reflex.

The path of a reflex utilizes the three above mentioned neurons. External sensory receptors may generate an impulse due to a stimulus such as stepping on a sharp object. This impulse travels up the sensory neuron to the spinal cord where the interneuron decide on a response. This response is then sent down a motor neuron to an effector that can deal with the problem. If the problem was stepping on something a likely response effector would be the muscles of the leg which would raise the leg up. The important part of the reflex is its speed. If the impulse went all the way to the brain and required a conscious decision, it would be too slow and cause harm to the body. Because the impulse only has to travel as far as the spinal cord, it is much faster and allows the body to avoid further harm.

53) Compare and contrast the sensory, motor, and interneurons.

There are three types of neurons: Sensory, motor, and interneurons. Sensory and motor neurons both carry impulses over long distances. Sensory neurons carry the sensory receptors to the spinal cord. In the spinal cord the impulse is passed on to the interneurons housed there. The interneurons investigate the impulse and translate it into a response impulse. This new impulse is sent out via the motor neurons to the muscle or gland that needs to respond to the initial stimulus. Sensory and motor neurons can be found in the Peripheral Nervous System, whereas interneurons are only in the Central Nervous System.

31) Delivers the signals from the motor neuron to every neuron to every sarcomere of the muscle cell.

Tranverse tubules

33) Covers the myosin binding sites on actin.

Tropomyosin

32) Calcium binds to this protein to initiate a contraction.

Troponin

10) A person may have a muscle injury that really affects the tendon and not the muscle tissue itself. Why is it that after a hard workout, muscle pain will go away in a few days at most, but tendinitis lasts much longer?

Unlike a tendon, muscle tissue has an ample blood supply so it's easier to repair.

77) A jelly-like fluid that prevents the eye from collapsing and holds the retina against the wall of the eye is called the __.

Vitreous humor