SE Ch.2b – Anatomy and Physiology Pt.2

17. Compare and contrast the three divisions of the nervous system.

  • The central nervous system (CNS) consists of the brain, spinal cord, spinal nerves, and cranial nerves. It controls consciousness and many mental activities, involuntary functions of the five senses (seeing, hearing, feeling, smelling, and tasting), and voluntary muscle actions including all body movements and facial expressions.
  • The peripheral nervous system (PNS) is a system of nerves that connects the peripheral (outer) parts of the body to the central nervous system; it has both sensory and motor nerves. Its function is to carry impulses, or messages, to and from the central nervous system.
  • The autonomic nervous system (ANS) is the part of the nervous system that controls the involuntary muscles; it regulates the action of the smooth muscles, glands, blood vessels, heart, and breathing.

18. What are the functions of the brain, brain stem, and spinal cord?

  • The brain is the largest and most complex mass of nerve tissue in the body. The brain is contained in the cranium and controls sensation, muscles, and glandular activity It sends and receives messages through 12 pairs of cranial nerves that reach various parts of the head, face, and neck
  • The brain stem connects the spinal cord to the brain. The brain stem is involved In regulating such vital functions as breathing, heartbeat, and blood pressure.
  • The spinal cord is a continuation of the brain stem and originates in the brain, extends down to the lower extremity of the trunk, and is protected by the spinal column. Thirty-one pairs of spinal nerves extending from the spinal cord are distributed to the muscles and skin of the trunk and limbs.

19. What are two types of nerves?

  • Sensory nerves carry impulses or messages from the sense organs to the brain, where sensations such as touch, cold, heat, sight, hearing, taste, smell, pain, and pressure are experienced.
  • Motor nerves carry impulses from the brain to the muscles or glands. These transmitted impulses produce movement.

20. Describe the nerves that affect the head, face, and neck.

There are 12 pairs of cranial nerves arising at the base of the brain and the brain stem. The cranial nerves activate the muscles and sensory structure of the head and neck including skin, membranes, eyes, and ears. Estheticians are primarily concerned with nerves V, VII, and XI, and each one has several branches. The largest of the cranial nerves is the fifth cranial nerve, also known as the trifacial or trigeminal nerve. It is the chief sensory nerve of the face, and it serves as the motor nerve of the muscles that control chewing.

The seventh cranial nerve, also known as the facial nerve, is the chief motor nerve of the face. It emerges near the lower part of the ear and extends to the muscles of the neck. Its divisions and their branches supply and control all the muscles of facial expression and the secretions of saliva.

The eleventh cranial nerve, also known as the accessory nerve, is a type of motor nerve that controls the motion of the neck and shoulder muscles.

22. What two forms of circulation keep blood flowing to all parts of the body and how do they work?

Pulmonary circulation carries the blood from the heart to the lungs to be oxygenated. Systemic or general circulation carries the oxygenated blood from the heart throughout the body and back to the heart again.

23. List the types of blood vessels and their functions.

  • Arteries: Thick-walled, muscular, flexible tubes that carry oxygenated blood away from the heart to the arterioles. The largest artery in the body is the aorta.
  • Arterioles: Small arteries that deliver blood to capillaries.
  • Capillaries: Tiny, thin-walled blood vessels that connect the smaller arteries to venules. Capillaries bring nutrients to the cells and carry away waste materials.
  • Venules: Small vessels that connect the capillaries to the veins. They collect blood from the capillaries and drain it into the veins.
  • Veins: Thin-walled blood vessels that are less elastic than arteries. They contain cuplike valves that keep blood flowing in one direction to the heart and prevent the blood from flowing backward. Veins carry blood containing waste products back to the heart and lungs for cleaning and to pick up oxygen. Veins are located closer to the outer skin surface of the body than arteries.

24. List the components in blood and their functions.

  • Red blood cells carry oxygen to the body’s cells.
  • White blood cells perform the function of destroying disease-causing microorganisms.
  • Platelets contribute to the blood-clotting process, which stops bleeding.
  • Plasma is the fluid part of the blood. It is about 90 percent water and contains proteins, sugars, and minerals. The main function of plasma is to act as a delivery system, carrying vital components including nutrients, hormones, and minerals, to the cells and to take waste away from the cells.

25. Describe the location of the arteries and veins that supply blood to the head, face, and neck and their functions.

The common carotid arteries are the main source of blood supply to the head, face, and neck. They are located on either side of the neck, and each one is divided into an internal and external branch. The blood returning to the heart from the head, face, and neck flows on each side of the neck in two principal veins: the internal jugular vein and external jugular vein. These veins run parallel to the carotid arteries.

26. Describe the functions of the lymphatic/immune system.

  • Act as a defense against disease and invading bacteria and toxins by developing resistance
  • Drain tissue spaces of excess interstitial fluid (blood plasma found in the spaces between tissue cells) in the blood
  • Carry the excess fluid, waste, and impurities away from the cells
  • Aid in reducing swelling, inflammation, and accumulation in the blood vessels

27. What are seven endocrine glands and their functions?

  • The pineal gland plays a major role in sexual development, sleep, and metabolism.
  • The pituitary gland is the most complex organ of the endocrine system. It affects almost every physiologic process of the body: growth, blood pressure, contractions during childbirth, breast-milk production, sexual organ functions in both women and men, thyroid gland function, and the conversion of food into energy (metabolism).
  • The thyroid gland secretes hormones that regulate the body’s metabolism, heart and digestive functions, muscle control, brain development, and maintenance of bone mass.
  • The parathyroid glands regulate blood calcium and phosphorus levels so that the nervous and muscular systems can function properly.
  • The pancreas secretes enzyme-producing cells that are responsible for digesting carbohydrates, proteins, and fats. The islet of Langerhans cells within the pancreas control insulin and glucagon production.
  • The adrenal glands secrete about 30 steroid hormones and control metabolic processes of the body, including the fight-or-flight response. Adrenal gland function affects skin melanization.
  • The ovaries and testes function in sexual reproduction as well as determining male and female sexual characteristics. 

28. What is the function of the reproductive system?

Producing children and passing on our genetics from one generation to another.

29. What are the reproductive hormones?

Estrogen and progesterone are dominant in females and testosterone is dominant in males.

30. What happens with each breath?

With each breathing cycle, an exchange of gases takes place. During inhalation, or breathing in, oxygen is absorbed into the blood. During exhalation, or breathing outward, carbon dioxide is expelled from the lungs.

31. Based on the response to the previous question, why is respiration important to the esthetician?

Healthy skin needs oxygen. A strong respiratory system will help keep the skin oxygenated for maximum benefits. Skin that is poorly oxygenated will be sallow and gray. It will take longer to respond to treatments or may not respond at all.

32. What are digestive enzymes?

Chemicals that break down food into a form that can be used by the body.

33. Describe the steps in digestion.

  • Eating or ingestion: taking food into the body. Moving food along the digestive tract, known as peristalsis.
  • Breakdown of food by mechanical and chemical means, with the use of enzymes, known as digestion.
  • Absorption of the digested food into the circulatory systems for transportation to the tissues and cells.
  • Elimination of solid waste from the body, known as defecation.

34. What body organs work to contribute to the excretory system? What do they do?

  • The kidneys excrete urine.
  • The liver discharges bile, which breaks down digestive fat.
  • The skin eliminates salts and minerals through perspiration.
  • The large intestine eliminates decomposed and undigested food.
  • The lungs exhale carbon dioxide.