Anatomy and Physiology: Homeostasis, Integument, Neurophysiology, Muscle A&P, CNS

1. Negative Feedback Loops and Blood Glucose Levels

1. Define homeostasis. Describe how negative feedback loops help to maintain a healthy range of glucose levels within the bloodstream. Ensure that you describe the components of a feedback loop and indicate which organs/structures act as these components in the example given above. Be sure to describe how blood glucose levels are both increased and decreased.

 

2. Define homeostasis. Describe how positive feedback loops help to prevent bleeding from minor wounds by helping to form a blood clot. Ensure that you describe the components of a feedback loop and indicate which organs/structures act as these components in the example given above. Be sure to describe how the feedback loop is interrupted (i.e. how a return to homeostasis is achieved).

3. Describe the 6 functions of the skin. In doing so, please describe the anatomical features, specialized cells and / or biological processes that are involved in carrying out these functions.

 

4.Describe the structure and function of skin glands. Please be sure to indicate the body area, layer of integument and location of the gland opening. In addition, describe the overall nature of the secretion produced by each skin gland.

5. Describe how charge separation, leak channels, and ion pumps contribute to generating and maintaining the negative resting membrane potential (RMP) of a neuron. What would happen to the resting membrane potential if the sodium-potassium pumps stopped working?

 

6. List three reasons why the refractory period of an axon is important to its function. What is occurring during the refractory period? (in which direction are ions moving and which ion channels are opening/closing) How do the absolute and relative refractory periods differ? Why is 60Hz alternating current so deadly? (discuss in terms of the refractory period).

 

7.Describe the steps involved in neurotransmission across a cholinergic (acetylcholine),chemical synapse (from presynaptic to postsynaptic cell). How does Botox interfere with this process? How does neostigmine help to increase synaptic function at cholinergic synapses? (e.g. a neuromuscular junction)

8. What is a sarcomere? Discuss the major structural components of a sarcomere. What components contribute to the banding pattern of the sarcomere? (focus on the I band  and A bands) What is meant by the sliding filament mechanism of contraction? Which band decreases in size during contraction of a sarcomere and why? What term describes an arrangement of sarcomeres that have been placed end to end? How do skeletal fibres increase in size? What is this increase in size termed?

2. Positive Feedback Loops and Blood Clotting

 

9. Describe in detail the four steps of the contraction cycle. What two key ingredients must be present for contraction to occur? Explain the importance of ATP in the contraction cycle by discussing why rigor mortis occurs shortly after death. Does rigor mortis eventually dissipate, why or why not?

 

10. Describe the three main factors that determine the amount of force a skeletal muscle can generate. Explain how these factors influence force production.

 

11.Cigarette smokers may absorb copious amounts of nicotine during their recreational activities. What effect does nicotine have on the parasympathetic and sympathetic branches of the autonomic nervous system? What are some of the consequences of this increased autonomic activity? Describe in terms of the three F’s and the three R’s (or SLUDD).

 

12. Describe the effects of the parasympathetic and sympathetic nervous systems on the heart (cardiomyocytes, pacemaker cells, coronary arteries). In doing so, please describe the neurotransmitters and receptors that are involved.

 

13.Describe in detail how the diameter of the pupil of the eye is regulated by the parasympathetic and sympathetic nervous systems. In doing so, please describe the neurotransmitters and receptors that are involved. How does the drug atropine cause pupillary dilation such that an ophthalmologist can conduct a thorough examination of the internal structures of the eye?

14. The CNS is protected by its coverings – the meninges – and a salty fluid known as cerebral spinal fluid (CSF). How and where is CSF produced within the CNS? Trace the route of CSF flow from its origin to its destination in the venous drainage of the cranium. List all structures that CSF flows through along the way. What is the function of CSF and how does it differ from blood plasma?

 

15.The cerebral cortex is organized into functional areas. One specialized area involved in speech is known as Broca’s area. Where is Broca’s area located? What is its role in regulating speech? What cerebral artery arising from the circle of Willis is mainly responsible for supplying blood to Broca’s area? What signs and / or symptoms would accompany a stroke involving Broca’s area? Would this affect one’s ability to understand  speech? Why or why not?

 

16.What are the two major functions of the limbic system? What major components make up the limbic system? Describe in some detail the role of the  hippocampus and amygdala.

17. How would damage to the hippocampus affect the functioning of the limbic system? (list some clinical signs and symptoms)

3. Functions of the Skin

18. You are sleeping in lecture again when your friend kindly pinches your arm. You immediately wake up and yell out some choice words which earn you a quizzical stare from the instructor. In the aftermath, you realize that your friend was only trying to wake you by manipulating your reticular formation. Where is the reticular formation located? What sensory inputs does it receive? What is its function and how does it help you to temporarily block out the pain sensations coming from your arm?

 

18. What major function does the cerebellum perform? What three major inputs does the cerebellum rely on to perform this function? What muscles are mainly regulated by the medial vs lateral cerebellum? The cerebellum operates in an ipsilateral fashion. What does this mean? What is the Romberg test? A person that experiences increased postural sway with their eyes closed, but is still able to touch their finger to their nose with their eyes closed, likely has an issue with what input to the cerebellum? Explain.

 

19. There are six cranial nerves involved either directly or indirectly with vision. List each nerve and describe its role as it relates to vision.

 

20. An increase in intraocular pressure can lead to a condition known as glaucoma. What structure is responsible for the production of aqueous humour? Describe the route of flow of aqueous humour from its origin to its destination in the venous circulation. How does pupillary dilation during sleep affect the drainage of aqueous humour?

 

21. Describe the changes that occur in the eye to allow an individual to focus on a book in their lap after having viewed an object at a distance. Please indicate any important muscles, nerves and/or other structures that are involved in achieving this convergent gaze.

 

22. How is the atmospheric pressure equalized across the tympanic membrane? How do upper respiratory tract infections interfere with this process? Describe three complications that may arise due to a middle ear infection.

 

23. List the structures through which sound waves must travel from the external auditory meatus to the cilia of the hair cells within the organ of corti. Why are high frequencies detected at the base of the cochlea while low frequencies are detected at the tip? Why does chronic exposure to loud noises cause hearing loss in the high frequency range?

 

24. Trace the route that pain & temperature sensations from the integument to the primary sensory cortex. Mention any important synapses and/or CNS structures encountered on the way. How does this route differ from that taken by the 3 other sensory modalities? (i.e. touch, pressure and proprioception) In doing so, please be sure to mention the white matter tracts that are involved and where crossover of information occurs.

25. Using any five of the following seven clinical signs, describe what one would find in a patient with a CNS lesion involving upper motor neurons: muscle weakness, muscle atrophy, somatic reflexes, muscle tone, fasciculations, clonus and Babinski sign. Please indicate why each sign would or would not be present.

 

26. Using any five of the following seven clinical signs, describe what one would find in a patient with a CNS lesion involving lower motor neurons: muscle weakness, muscle atrophy, somatic reflexes, muscle tone, fasciculations, clonus and Babinski sign. Please  indicate why each sign would or would not be present.

 

27. List the major ligaments that help to stabilize the vertebral column (vertebrae). What type of lower back pain is caused by a slipped (herniated) intervertebral disc? What is the most common slipped disc and why? What spinal nerve is affected? What is this condition termed and what signs and symptoms does it give rise to? Describe two tests used to diagnose this type of low back pain.