Physiology and Human Anatomy

1. Explain the physiological processes that occur during sleep and the sleep-wake cycle.
The recovery phase of sleep typically prepares an organism for the next step of awakening. Because of the increased protein synthesis, cell division is rapid during this phase.
Two biological mechanisms control the sleep-wake cycle. They interact with one another and provide each other with a sense of balance. Circadian rhythm, which regulates internal body processes, and sleep-wake homeostasis, which induces homeostatic sleep drive, are the two mechanisms.
2. Describe the physiological mechanisms of afferent and efferent nerve pathways, as well as the spinal reflexes. The afferent neurons are the ones that carry the sensory stimulus to the brain, while the efferent neurons are the ones that carry the sensory stimulation away from the brain. The afferent neurons are the ones that convey stimulus from the sensory stimulus to the brain while the efferent is the neurons that convey the motor stimulus to the muscles.

Afferent = Receive and Efferent = Act.

Spinal reflex maintains balance and posture which control trunk and limb muscles.

3.Discuss pain, the type of pain receptors, fast and slow pain fibres and higher-levels of pain input.

Pain is a sensation that is either physical or emotional that causes discomfort.

Nociceptors are the pain receptors that detect pain from the damaged part. There are four types of nociceptors; skin nociceptors, joint, visceral and silent nociceptors. Fast and slow pain fibers include A-delta and C, they control the speed at which nociceptive conduct nerve impulses.



4.Describe the anatomy and physiology of the eye together with the factors that control the amount of light entering the eye (controlled by the sympathetic and parasympathetic nervous system).

Light from the object has reflected the eye through the cornea. The light then progresses to the pupil which is the circular opening in the colored iris. Due to the light fluctuation, the eye pupil changes the size. When the light intensity is high the pupil gets smaller due to pupillary response. As the light gets dimmer the light the pupil gets large.

5. Outline the differences between normal vision, myopia, and hyperopia.

Normal vision is when the eye can focuses objects both at a shorter distance and a long distance clearly. Myopia is the defect where objects at a long distance cannot be focused properly. Hyperopia is a defect of the eye where objects at a long distance cannot be focused clearly.

6. Describe the intricate processes of the retina, rods, and cons in terms of light stimulation together with the function of the thalamus and visual cortex.

The retina is a complex tissue which contains important elements which are many sensitive nerves cells called cones and rods the cones secrete iodopsin pigment which is most effective in the bright light, they provide color vision. The rods secretes visual purple or rhodopsin substance which provides vision in dim light.

Thalamus is located in the forebrain with nerve fibers projecting out cerebral cortex in all directions.



7.Describe the anatomy and physiology of the ear (external, middle and inner ear), how sound waves are converted into graded potential and its effect on the auditory/vestibular nerves and sound perception and balance.

The external part contains Pinna which is the outside part of the ear, external auditory tube this tube connects the outer ear. The tympanic membrane between external and middle ear. The middle ear consists of; ossicles, Malleus, Incus, Stapes. The inner ear contains cochlea, Vestibule, Semicircle canals. When sound is made, it travels to the external auditory tube to middle ear through membrane then inner ear where they are converted into electrical impulses.

8. Describe the processes involved in taste and smell, the physiological events that result in taste and smell deception – from stimulation of the receptor on the tongue and nose and how that translates to a perception of these two events.

Chemical recognition on the tongue sends a signal to the brain, the processes give us an idea on which food we are dealing with which allows us to take certain decisions of modifying behavior accordingly.

Smell like the taste a chemical sense called chemoreceptors detected by sensory cells then sends impulses to the brain, the brain interprets pattern in electrical activity which allows us to recognize the smell.

9.Outline the process involved in the control of motor movement.

Movement is controlled by the primary motor cortex which does not control individual muscle directly but controls the movement of an individual. Alpha motor neurons in the spinal cord which encode the force of contraction of muscles using rate code and size principle.

10.Define smooth and cardiac muscle and describe the processes involved in contraction and relaxation.

Smooth muscles are the involuntary non-striated muscle which is divided into a single unit and multiunit. Its contraction and relaxation are caused by the sliding of actin filaments and myosin filaments over each other. The filaments movement form cross bridges.

Cardiac muscles are involuntary, striated muscles that are usually located in the walls of the earth, in the myocardium. The sliding of myosin and actin filaments causes contraction and relaxation.

11.Describe the processes involved in modification of smooth muscle by the autonomic nervous system.

Smooth muscle needs some signal before starting a contraction. The signals that lead to contraction of smooth muscles are many. These places like teachers and Gal tract have the amount of independent nervous system capable of controlling the smooth muscles in these areas. Smooth muscles receive input from the central nervous system known as extrinsic innervation. The input always comes from the autonomic nervous system.

12.Outline the mechanical events that contribute to cardiac function and describe the pressure changes that occur between right and left heart.

The hearts pump blood through contraction and relaxation of the cardiac muscles in the process known as a cardiac cycle. Blood flows from the left atrium and right atrium to left ventricle and right ventricle through atrioventricular valves. The RA receives blood from the body through vena cava LA receives oxygenated blood from the earth through pulmonary veins. Both atria contact and propel blood to the ventricles.



13.Describe the relationships between heart sound, valve closure and the events that contribute to turbulent blood flow in the heart

The first heart sound is usually produced by closing of mitral and tricuspid valve leaflets. The second heart sound is produced by the closing of the aortic and pulmonic valve leaflets. The second heart sound is unsplit when the subject is holding his or her breath at peak expiration. Normally blood flow is laminar. However, under conditions of high flow, in aorta, laminar flow can be disrupted and become turbulent

14.Outline the process of cardiac output and its control.

Cardiac output is the amount of blood pumped by the heart by unit time. When heart rate increases diastolic filing decreases proportionately hence lowering volume of blood ejected. Elevated heart rate can increase contractility independent of sympathetic effect. Exercise-induced hypertrophy causes an increase in the hearts capacity to generate large stroke volume.

15.Describe the impact of the autonomic nervous system (parasympathetic and sympathetic) on cardiovascular function and their effects on stroke volume, end-diastolic, end-systolic volume and heart rate.

The sympathetic nervous system can exert its influence on the heart by way of the catecholamines, adrenaline, and noradrenaline, circulating in the blood. It increases heart rate and pumps a larger volume of blood. Parasympathetic is the important circulatory effect is the control of heart rate by way of parasympathetic fibers. It decreases heart rate.





16.Discuss how high blood pressure increases the workload of the heart, how heart failure decreases contractility of the heart and what physiological factors improve the tolerance of heart failure.

Heart failure is a disorder where heart pumps blood inadequately. This usually occurs because the heart cannot contract normally. The heart is filled with blood but cannot pump because of the weaker muscles. Decreased Cardiac Output also can lead to decreased blood pressure (BP). Although the systolic function is reduced or not, most of the current evidence on drug treatment is for HF due to left ventricular systolic dysfunction

17. Describe how the heart is nourished and the underlying pathology of atherosclerosis and thromboembolism.

Heart walls are too thick to allow this to soak in sufficient abundance all through them, of the blood flowing through its cavities; accordingly, they are permeated by a very close network of capillary blood vessels which allow for nourishment

Atherosclerosis is fatty deposits that can clog arteries Sometimes deposits in arteries are compared to a plumbing problem. Thrombosis is the formation of a blood clot inside a blood vessel affecting circulatory flow of the blood

18.Outline how blood pressure is controlled (through cardiac output, total peripheral resistance and blood volume).

When the cardiac output is decreased blood pressure also decreases because there is less pressure on the pressure in the vessel walls decrease. When the cardiac output increases the blood pressure also increases because of the increase in the pressure of the vessel walls. When blood volume is reduced blood pressure also is reduced and pressure increases when the volume increases. When peripheral resistance increases, blood pressure increases.

19.Describe the determinants of mean arterial pressure, baroreceptor reflex and the impact of autonomic tone on the circulatory system.

Combined forces form the arterial blood pressure, complex interactions of the cardiac output, resistance produced by arterioles and viscosity of blood. In baroreceptor, the size and force of the vessels. Feedback mechanism alters heart rate and blood pressure. The autonomic nervous system specifically efferent sympathetic modulation creates the smooth muscles to contract and through this skeletal muscle pump is activated which guides in the control of the vascular compliance

20.Discuss the different classifications of hypertension and what happens to the system circulation when either of these conditions occurs.

Hypertension can be classified into primary high blood pressure and secondary high blood pressure.

Primary high blood pressure is the one that is caused by the nonspecific lifestyle for instance too much salt while secondary high blood pressure is high blood pressure due to an identifiable cause, for instance, chronic kidney disease.

21.Describe, in detail the physiological processes of haemostasis and the importance of platelets together with the role of thrombin, the clotting cascade and the intrinsic and extrinsic factors.

Homeostasis is a natural process that stops blood loss when an injury occurs. It involves vasoconstriction which is reflex in which blood vessels narrow to increase the pressure of blood, platelets become activated by thrombin and aggregate at the site of injury, forming a temporary, loose platelet plug which forms the clotting. Intrinsic and extrinsic are the two factors that lead to a fibrin clot.

22.Evaluate B-lymphocyte antibody-mediated response covering the antibody subclasses and the structural component of an antibody and outline this process.

An antibody is also referred to us the immunoglobin (Ig) which is produced by B-lymphocyte that is used in the immune system. The antigen is the foreign target is recognized by the antibody. Each tip of “Y” of an antibody contains a paratope that is particular epitope on an antigen allowing this two structures to bind together with a precision.

23.Describe primary and secondary responses and active versus passive immunity.

The primary response is when Immunoglobin appears in plasma first which is not potent enough to prevent illness while secondary response memory B cells amount rapid response to an antigen which leads to release of many Ig antibodies thereby eliminating pathogen before any symptoms.

Active immunity indicates of antibodies formed through a direct antigen exposure while passive immunity means antibodies are passed down to the recipient even without exposure to an antigen

24.Discuss T-lymphocyte cell mediated immunity, the major types of T-cells (cytotoxic, helper T-cells and regularly T-cells) and the processes involved in cellular destruction.

T-cells accounts 80% of the total lymphocytes. They are called T cells because they mature in the thymus. There are three types of T cell lymphocytes, Cytotoxic, Suppressor, and Helper. The first process of destruction is germ cells which eliminate around 25% pre-meiotic germ. The second process the bulk cytoplasmic contents differentiating spermatids are removed in a process involving active apoptotic caspases. The third process removes sperm mitochondria.

25.Evaluate the physiological importance of the major histocompatibility complex (both class I and II) and its role in immune system function and outline the process.

Major histocompatibility complex is a set of cell surface necessary for the acquired immune system. The main function is bind antigens derived from pathogens and displays them on cell surface for recognition by T cells which are appropriate. This helps other aspects of immune response to occur.































References

Saladin, K. S., & Miller, L. (1998). Anatomy & physiology. New York (NY): WCB/McGraw-Hill.

Tortora, G. J., & Derrickson, B. H. (2008). Principles of anatomy and physiology. John Wiley & Sons.

Robb, J. S., & Robb, R. C. (1942). The normal heart: anatomy and physiology of the structural units. American Heart Journal, 23(4), 455-467.

Edwards, D., Taylor, L., & Vorster, K. (1997). Anatomy and physiology ofthe cardiovascular system. Journal of PeriAnesthesia Nursing, 12(2), 134-137.

DelMonte, D. W., & Kim, T. (2011). Anatomy and physiology of the cornea. Journal of Cataract & Refractive Surgery, 37(3), 588-598.

Chap 6 Reflexes.pdf, retrieved from;

http://www.lamission.edu/lifesciences/lecturenote/AliPhysio1/Chap%206%20Reflexes.pdf