University of Chicago
Type of paper: Thesis/Dissertation Chapter
1. (5 pts) Describe the metabolic process providing your energy while you were walking (at an easy pace) before the bee stung you. Include which molecules are being consumed.
The metabolic process providing my energy while I was walking at an easy pace is aerobic metabolism. During aerobic metabolism, mitochondria absorb from the surrounding cytoplasm these molecules: ADP, phosphate ions, O2, and organic substances like pyruvate. These molecules go through the citric acid cycle. The electron transport chain is also involved to create ATP. For each molecule of pyruvate that goes into the citric acid cycle, the cell gains 17 ATP molecules. Glycogen reserves can also be used and converted to glucose. Glycolysis breaks down glucose molecules to create more pyruvate. However, if not enough glycogen is available, the cell can also use amino acids and lipids to do this. This is a very efficient process but also only contributes a fraction of the ATP during aerobic metabolism. At moderate levels of activity, most of the energy during aerobic metabolism comes from work done by the mitochondria. The muscles involved during this process need all of the energy produced as ATP, and there is no extra left over in this particular metabolic process if muscle activity increases (“Muscle Tissue” P. 306-7).
2. (8 pts) Trace the sound of the bee from your outer ear to perception. (Include all focusing, conduction, transduction, transmission and perception processes and structures).
Sound vibrations from the buzzing bee vibrate the air molecules as pressure waves around my ear and enter the auricle which is cone-shaped in order to direct these sound waves into the ear via the external acoustic meatus. The sound waves reach the tympanic membrane through the external acoustic meatus and cause it to vibrate. When the tympanic membrane moves, it causes the auditory ossicles to move. The auditory ossicles are made up of the malleus, incus, and stapes. These ossicles are important because they amplify the sound. The stapes then transfers this movement to the oval window and the pressure waves move through the perilymph of the scala vestibuli. These waves then disturb the basilar membrane as they move toward the round window of the scala tympani. This causes vibrations of hair cells against the tectorial membrane. The information about where the sound originated and about how strong the pressure waves are is interpreted by the central nervous system over the cochlear branch of cranial nerve VIII (“The Special Senses” P. 584-5).
3. (4 pts) Turn your head to the right. (Create a table that describes which muscles move which bones across which joints under the control of which nerves).
Bends head towards shoulder and turns face to opposite sideSternocleidomastoidClavicular head attaches to sternal end of clavicle; sternal head attaches to manubrium. Mastoid region of skull and lateral portion of superior nuchal lineAccessory Nerve XI; Cervical Spinal Nerves (C2-C3) Rotates and laterally flexes neck to that side, Splenius (Splenius capitis, splenius cervicis)Spinous processes and ligaments connecting inferior cervical and superior thoracic vertebrae, Mastoid process, occipital bone of skull, and superior cervical vertebrae, Cervical Spinal Nerves Rotates and laterally flexes neck to that sideLongissimus capitis Transverse process of inferior cervical and superior thoracic vertebrae, Mastoid process of temporal boneCervical and thoracic spinal nerves Rotates and laterally flexes neck to that sideLongissimus cervicis, Transverse process of superior thoracic vertebrae. Transverse processes of middle and superior cervical vertebrae. Cervical and thoracic spinal nerves. Extends vertebral column and rotates toward opposite side. Semispinalis cervicis. Transverse processes of T1-T5 or T6 Spinous processes of C2-C5Cervical spinal nerves Rotates head to that sideLongus capitis. Transverse processes of cervical vertebraeBase of the occipital boneCervical spinal nerves. Flexes or rotates neckLongus colliAnterior surfaces of cervical and superior thoracic vertebraeTransverse processes of superior cervical vertebraeCervical spinal nerves (“The Muscular System” P. 339-341)
4. (6 pts) Move your eyes and look at the bee. (Create a table that describes which nerves control which muscles to cause the needed eye movements).
Eye looks down. Inferior RectusSphenoid around optic canal. Inferior, medial surface of eyeball. Oculomotor Nerve III Eye looks laterally. Lateral Rectus. Sphenoid around optic canalLateral surface of eyeball. Abducens Nerve VI Eye rolls, looks down and laterally. Superior ObliqueSphenoid around optic canal. Superior, lateral surface of eyeball. Trochlear Nerve IV (“The Muscular System” P. 335)
5. (8 pts) Trace the image of the bee to perception. (Include all focusing, transduction, transmission and perception processes and structures).
After a retinal molecule absorbs light, the normally 11-cis form of the bound retinal molecule straightens to become the 11-trans from. This change activated the opsin molecule. Opsin activates transducin which is a G protein. This G protein then activates phosphodiesterase. Phosphodiesterase is an enzyme that breaks down cyclic-GMP. The break-down of cyclic-GMP removes them from the gated sodium channels and makes the gated sodium channels inactive. Because of this, sodium ion entry into the cytoplasm decreases. This sodium ion reduction then reduces the dark current. Active transport continues to remove sodium ions from the cytoplasm even though the gated sodium channels are closed. This causes the transmembrane potential to drop down to -70 mV and hyperpolarize. This hyperpolarization decreases neurotransmitter release. The adjacent cell is then aware that the photoreceptor has absorbed a photon. A specific ganglion cell keeps track of a specific portion of the visual field. Rods are also called M cells and give the brain information about a general location of received photons and light rather than very specific information.
Cones are also called P cells and can be much more specific than rods. The P cells are smaller and more numerous than M cells. This helps them be better at giving information about edges, fine detail and color. The activation of a P cell gives information about a very specific location. The P cells give high resolution information. Axons from the ganglion cells converge on the optic disc, penetrate the eye, and continue toward the diencephalon on the optic nerve.
II. From there the information is split in half and travels to the back of the brain and to the occipital lobe. Together, the diencephalon and the brain stem process the information and control eye reflexes and pupil dilation and/or constriction in order to see clearer and focus in on an object. Depth perception is a phenomenon that takes place when the visual cortex of my occipital lobes reviews the slightly different information obtained by each eyeball. The superior colliculi of the midbrain make motor commands that control unconscious eye, head, and/or neck actions that respond to visual stimuli. My eyes in the bright summer light looking at a bee that is so close (on my right shoulder) are likely to constrict so as to limit the photon stimulation on my retina and so as to focus on just the tiny bee (“The Special Senses” P. 569-74).
6. (11 pts) Move your left hand to swat the bee. (Create a table that describes which muscles move which bones across which joints under the control of which nerves). Limit your discussion to the movement at the shoulder and elbow only (do not include any un-needed muscles nor discuss the movement at any other joints).
Move Left Arm Toward Right Side
Flexion and medial rotation at shoulderDeltoid (anterior part)Clavicle and scapula (acromion and adjacent scapular spine)Deltoid tuberosity of humerus. Axillary nerve (C5-C6) Medial rotation at shoulder. SubscapularisSubscapular fossa of scapula. Lesser tubercle of humerusSubscapular nerves (C5-C6) Adduction and medial rotation at shoulder. Teres MajorInferior angle of scapula. Passes medially to reach the medial lip of intertubercular groove of humerus. Lower subscapular nerve (C5-C6) Adduction and flexion at the shoulder. Coracobrachialis. Coracoid process. Medial margin of shaft of humerusMusculocutaneous nerve (C5-C7 Flexion, Adduction, and medial rotation at shoulder. Pectoralis Major. Cartilages of ribs 2-6, body of sternum, and inferior, medial portion of clavicle. Crest of greater tubercle and lateral lip of intertubercular groove of humerusPectoral nerves (C5-T1) Adduction and medial rotation at shoulderLatissimus DorsiSpinous processes of inferior thoracic and all lumbar vertebrae, ribs 8-12, and thoracolumbar fasciaFloor of intertubercular groove of humerus. Thoracodorsal nerve (C6-C8) Adduction at the shoulderTriceps brachii (long head)Infraglenoid tubercle of scapula Olecranon of ulna. Radial nerve (C6-C8) Bend left forearm towards right shoulder
Flexion at elbow and shoulderBiceps brachiiShort head from the coracoid process; long head from the supraglenoid tubercle; both on the scapulaTuberosity of radiusMusculocutaneous nerve (C5-C6) Flexion at elbow Brachialis Anterior, distal surface of humerus Tuberosity of ulna Musculocutaneous nerve (C5-C6) and radial nerve (C7-C8) Flexion at elbow. Brachioradialis Ridge superior to the lateral epicondyle of humerusLateral aspect of styloid process of radius. Radial nerve (C5-C6) (“The Muscular System” P. 353-355)
7. (2 pts) What molecule provided the energy for the movement of your arm?
ATP (adenosine triphosphate) provided the energy for the movement of my arm.
8. Feel the pain of the stinger in your skin.
a. (3 pts) What layers of the skin are penetrated and what tissue types make them up?
The epidermis is the outermost layer of skin, and it is made of stratified squamous epithelium. The dermis is deep to the epidermis and it is made of dense irregular connective tissue. The hypodermis is deep to the dermis and is made of adipose tissue (“The Tissue Level of Organization” P. 114-126).
b. (5 pts) Trace the pain sensation from the receptors to perception.
There are pain receptors on the shoulder that communicate to the central nervous system. Because a bee sting is a stinging, injection-like pain, it would be considered “fast pain.” Fast pain sensations are carried by myelinated Type A fibers. The myelination helps the information to travel faster down the neuron. The bee sting stimulates the dendrites of nociceptors in the shoulder and causes depolarization. The initial segment of the axon must reach threshold in order to release an action potential. Once an action potential is released, it travels by neurons to the central nervous system. When the action potential reaches the central nervous system, glutamate and/or substance P are released as neurotransmitters. These neurotransmitters make it easier for neurons to travel along pain pathways. This is known as pain perception (“Neural Integration I: Sensory Pathways and the Somatic Nervous System” P. 498).
9. (8 pts) Explain your autonomic response to this event. State which division is taking control and describe exactly how that division will effect breathing rate, heart rate, and pupil size. (Note: don’t just describe the effect, but describe the control pathway that leads to that effect, including any chemical messengers involved.)
The sympathetic division of the autonomic nervous system is taking control. This division increases breathing rate, heart rate, and pupil size. The visceral motor nuclei in the hypothalamus activates autonomic nuclei in the brain stem and spinal cord. The brain stem and spinal cord in turn activate autonomic ganglia that then stimulate visceral effectors such as smooth muscle, glands, cardiac muscle, and adipocytes. Smooth muscle effectors affect blood vessels by constricting them and increasing blood pressure and speeding up blood flow in order to increase oxygen circulation. The smooth muscle also affects the constriction/dilation of the lungs. The sympathetic nervous system wants to dilate the lungs to increase breathing rates and oxygen intake. The glands that are stimulated cause the body to perspire. The cardiac muscle increases heart rate. Adipocytes can be used for energy because they are fatty acids (lipids) and can be used to make ATP during glycolysis very quickly (“Neural Integration II: The Autonomic Nervous System and Higher-Order Functions” P. 518-523).
10. (6 pts) Describe the elements of the homeostatic control system that caused the sweating and the red skin. Include the control pathway involved.
The control pathway of the sympathetic division that caused the sweating and the red skin was the sympathetic chain ganglia. Preganglionic fibers carried motor commands that affect the head, neck, limbs, and thoracic cavity. The unmyelinated postganglionic fibers that control the body wall enter the gray ramus and return to the spinal nerve for further distribution. They then are able to innervate the sweat glands of the skin and the smooth muscles in blood vessels. This innervation causes the sweat glands to sweat and the blood vessels to constrict. Constricting the blood vessels is helpful because it will raise blood pressure and increase oxygen circulation (“Neural Integration II: The Autonomic Nervous System and Higher-Order Functions” P. 521)
11. (1 pts) Describe the metabolic process providing your energy while you were running (as fast as you could) after the bee stung you. Include which molecule(s) is(are) being consumed.
The metabolic process that was providing my energy while I was running as fast as I could was anaerobic metabolism. This metabolic process does not require oxygen and uses glycolysis to generate 2 ATP molecules but also to generate 2 pyruvate molecules. Each pyruvate molecule can be broken down by the mitochondria to generate 17 ATP molecules. This is a total of 34 ATP molecules. This is a lot of energy and is necessary when muscles are at peak activity levels (“Muscle Tissue” P. 306-7).
12. (5 pts) Explain what the “Epi-Pen” contains (what kind of chemical is that) and how that will help in this situation. What effect will that pen have on the breathing rate?
The “Epi-Pen” contains epinephrine which is a neurotransmitter. It will try to improve the situation of an allergic reaction by increasing breathing rate, increasing heart rate, raise dropping blood pressure, reduce inflammation, and reverse hives (“Drugs and Medications – Epipen im”).
“Drugs and Medications – Epipen im.” WebMD. Last Revised: 2013. First
published by WebMD, 2005. Web. Visited: 30 November 2013.
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Martini, F. H., Nath, J. L., and Bartholomew, E. F. “Muscle Tissue.” Anatomy & Physiology. 9th Ed. Boston: Benjamin Cummings, 2012.
Martini, F. H., Nath, J. L., and Bartholomew, E. F. “Neural Integration I: Sensory Pathways and the Somatic Nervous System.” Anatomy & Physiology. 9th Ed. Boston: Benjamin Cummings, 2012. Martini, F. H., Nath, J. L., and Bartholomew, E. F. “Neural Integration II: The Autonomic Nervous System and Higher-Order Functions.” Anatomy & Physiology. 9th Ed. Boston: Benjamin Cummings, 2012.
Martini, F. H., Nath, J. L., and Bartholomew, E. F. “The Special Senses.” Anatomy & Physiology. 9th Ed. Boston: Benjamin Cummings, 2012.
Martini, F. H., Nath, J. L., and Bartholomew, E. F. “The Tissue Level of Organization.” Anatomy & Physiology. 9th Ed. Boston: Benjamin Cummings, 2012.