Anatomy and Physiology NotesTeacher/Classroom Copy
Organization of the Human Body *Chapter 1*
A. Anatomy = Study of the structure and shape of the body and its parts
B. Physiology = Study of how the body and its parts work or function
C. Anatomy—Levels of Study
1. Gross anatomy
a. Large structures b. Easily observable
2. Microscopic Anatomy
a. Very small structures b. Can only be viewed with a microscope
D. Major features of the human body include its cavities, membranes, and organ systems.
A. Body Cavities:
1. The body can be divided into two main cavities, dorsal and ventral. Organs within these cavities are called viscera.
a. The dorsal cavity can be divided into the cranial cavity (brain) and vertebral cavity (spinal cord).
b. The ventral cavity is made up of the thoracic cavity and abdominopelvic cavity, separated by the diaphragm (the muscle that helps you breathe).
i. The abdominopelvic cavity can be divided into the abdominal cavity (digestive organs) and the pelvic cavity (lower digestive organs and reproductive organs).
ii. The thoracic cavity is commonly known as the chest cavity, and contains the heart and lungs.
c. Smaller cavities within the head include the oral cavity, nasal cavity, orbital cavities, and middle ear cavities.
B. Organ Systems:
1. Body Covering
a. The integumentary system, including skin, hair, nails, and various glands, covers the body, senses changes outside the body, and helps regulate body temperature.
2. Support and Movement
a. The skeletal system, made up of bones and ligaments, supports, protects, provides frameworks, stores inorganic salts, and houses blood-forming tissues.
b. The muscular system consists of the muscles that provide body movement, posture, and body heat.
3. Integration and Coordination
a. The nervous system consists of the brain, spinal cord, nerves, and sense organs. It integrates information incoming from receptors and sends impulses to muscles and glands.
b. The endocrine system, including all of the glands that secrete hormones. Hormones circulate in the body fluids and act on specific target cells to help to integrate and control metabolic functions.
a. The cardiovascular system, made up of the heart and blood vessels, distributes oxygen and nutrients throughout the body while removing wastes from the cells.
b.The lymphatic system, consisting of lymphatic vessels, lymph nodes, thymus, and spleen, drains excess tissue fluid and includes cells of immunity.
5.Absorption and Excretion
a.The digestive system, made up of the mouth, esophagus, stomach, intestines and accessory organs, receives, breaks down, and absorbs nutrients.
b.The respiratory system exchanges gases between the blood and air and is made up of the lungs and passageways for air.
c.The urinary system, consisting of the kidneys, ureters, bladder, and urethra, removes wastes from the blood and helps to maintain water and electrolyte balance.
a.The reproductive system produces new organisms.
i.The male reproductive system consists of the testes, accessory organs, and vessels that conduct sperm to the penis.
ii.The female reproductive system consists of ovaries, uterine tubes, uterus, vagina, and external genitalia. The female reproductive system also houses the developing offspring.
C. Anatomical Terminology:
A. Relative Directions
1.Terms of relative position are used to describe the location of a part relative to another part.
2.Terms of relative position include: superior, inferior, anterior, posterior, medial, lateral, proximal, distal, superficial (peripheral), and deep.
1.A sagittal section divides the body into right and left portions.
2.A transverse section divides the body into superior and inferior portions.
- A coronal section divides the body into anterior and posterior sections.
1.The ventral cavity can be divided into three regions (abdominal, thoracic, pelvic).
2.The dorsal cavity is comprised of two divisions (cranial, vertebral).
Chapter 1 notes (Part 2)
A. Necessary Life Functions
1. Maintain boundaries
a. Living organisms “insides” must remain distinct from its “outsides”.
b. Cell membranes and walls – allows needed substances in while keeping damaging or unnecessary substances out.
c. The integumentary system protects internal organs from drying out, from bacteria, heat, sunlight, and chemical substances.
a. Includes all modes of locomotion by the muscular system (walking, swimming, etc...)
b. The muscular system is aided by the skeletal system.
c. Includes movement of substances such as blood, food, and urine are propelled through internal organs.
3. Responsiveness or Irritability
a. Is the ability to sense changes (stimuli) in the environment and react to them.
b. Can be involuntary (hand on hot stove)
c. The nervous system bears the major responsibility for responsiveness.
d. All body cells exhibit responsiveness to some extent.
a. Is the process of breaking down ingested food into simple molecules that can be absorbed into the blood for delivery to all body cells by the cardiovascular system.
5. Metabolism— is all the chemical reactions within the body that occur within cells.
a. Includes breaking down complex substances into simpler building blocks, making larger structures from smaller ones, and using nutrients and oxygen to produce ATP molecules that power cellular activities.
b. Produces energy
c. Makes body structures
d. regulated by hormones secreted by the endocrine system
6. Excretion = process of removing excreta or waste from the body.
a. Eliminates waste from metabolic reactions
b. Digestive system removes indigestible food
c. Urinary system disposes of nitrogen-containing metabolic wastes in urine.
a. Produces future generations or offspring
b. Can be at cellular or organismal level
c. Is regulated by hormones of endocrine system
a. Increases cell size and number of cells
B. Survival Needs
1. The goal of all body systems is to maintain life.
2. This requires survival needs that include:
(1) Chemicals for energy and cell building
(2) Includes carbohydrates, proteins, lipids, vitamins, and minerals
(1) Required for chemical reactions
(2) ~20% of air is oxygen
(1) 60–80% of body weight
(2) Is single most abundant chemical substance in the body and provides the fluid base for body secretions and excretions.
(3)Provides for metabolic reaction
d. Stable body temperature of 37 C (98.6 F)
e. Atmospheric pressure = force by weight of air
(1) Must be appropriate due to breathing and the exchange of oxygen and CO2 in the lungs dependent upon equal atmospheric pressure
1. Homeostasis—maintenance of a stable internal environment even when outside is changing.
a. A dynamic state of equilibrium, or balance
b. Is maintained when its needs are met
2. Homeostasis is necessary for normal body functioning and to sustain life.
3. Homeostatic imbalance
a. A disturbance in homeostasis resulting in disease
D. Maintaining Homeostasis
1. The body communicates through neural & hormonal control systems
a. 1st component: Receptor
(1) Responds to changes in the environment (stimuli)
(2) Sends information to 2nd component: Control Center along the afferent pathway
b. Control center (2nd component)
(1) Determines set point
(2) Analyzes information
(3) Determines appropriate response
c. Effector (3rd component)
(1) Provides a means for response to the stimulus.
(2) Info flows from control center to effector along the efferent pathway.
(3) The results are positive or negative.
E. Feedback Mechanisms
1. Negative feedback
a. Includes most homeostatic control mechanisms
b. Shuts off the original stimulus, or reduces its intensity
c. Works like a household thermostat (hypothalamus)
d. Other mechanisms: regulate heart rate, blood pressure, breathing rate, and blood levels of glucose, oxygen, carbon dioxide, and minerals.
2. Positive feedback
a. Increases the original stimulus to push the variable farther
b. These control infrequent events and do not require continuous adjustments.
c. In the body this only occurs in blood clotting and during the birth of a baby