6/24/11 1 Bi100 Chapter 1 Introduction to Human Anatomy and Physiology Anatomy and Physiology A. Anatomy deals with the structure (morphology) of the body and its parts; in other words, what are things called? B. Physiology studies the functions of these parts or asks the question, “how do they work?” C. The two disciplines are closely interrelated because the functional role of a part depends on how it is constructed. A & P Anatomy: Anatomy is more about STRUCTURE. Classical anatomy used to rely on dissection but more commonly today it relies on medical imaging. Physiology: • Physiology is more about FUNCTION. Experiments are typically used to determine how things work in the human body at the various levels of organization.
Transcript
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Bi100 Chapter 1
Introduction to Human Anatomy and Physiology
Anatomy and Physiology
A. Anatomy deals with the structure (morphology) of the body and its parts; in other words, what are things called?
B. Physiology studies the functions of these parts or asks the question, “how do they work?”
C. The two disciplines are closely interrelated because the functional role of a part depends on how it is constructed.
A & P
Anatomy: Anatomy is more about STRUCTURE. Classical anatomy used to rely on dissection but more commonly today it relies on medical imaging.
Physiology: • Physiology is more about
FUNCTION. Experiments are typically used to determine how things work in the human body at the various levels of organization.
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Atom
Molecule
Macromolecule
Organelle
Cell Tissue
Organ
Organism
Organ system
Levels of Organization: • The human body is the sum of its parts • these parts can be studied at a variety of levels of
organization.
Levels of Organization: – Atoms are the simplest level. – Two or more atoms comprise a molecule. – Macromolecules are large, biologically important molecules
inside cells. – Organelles are aggregates of macromolecules used to carry
out a specific function in the cell. – Cells are the basic living unit.
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Levels of Organization: – Tissues are groups of cells functioning together. – Groups of tissues form organs. – Groups of organs function together as organ
systems. – Organ systems functioning together make up an
organism.
Characteristics of Life Fundamental characteristics of life are traits shared by all
organisms. 1. Movement (internal or gross) 2. Responsiveness (reaction to internal or
external change) 3. Growth (increase in size without change in
shape) 4. Reproduction (new organisms or new cells) 5. Respiration (use of oxygen; removal of CO2)
Characteristics of Life 6. Digestion (breakdown of food into simpler
forms) 7. Absorption (movement of substances
through membranes and into fluids) 8. Circulation (movement within body fluids) 9. Assimilation (changing nutrients into
chemically different forms) 10. Excretion (removal of metabolic wastes)
Taken together, these 10 characteristics constitute metabolism – the chemical processes that occur in living organisms.
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Homeostasis • 1. Maintenance of a stable internal
environment is called homeostasis • 2. Homeostasis is regulated through
control systems which have receptors, a set point and effectors in common
• the receptors detect a change in the body’s normal set point and cause effectors such as muscles, or glands to do something (a feedback loop)
Homeostasis
Negative feedback – mechanisms oppose the
original stimulus • Most common
– temperature example: if you’re too hot, negative feedback will cool you off (by sweating for example)
positive feedback • mechanisms intensify the
original stimulus • childbirth example:
contractions during labor get more intense during childbirth until the baby is delivered
Homeostasis = normal body temperature (35.8°C–38.2°C)
Activates heat-loss center in hypothalamus
Blood warmer than hypothalamic set point
Sweat glands activated: secrete perspiration, which is vaporized by body heat, helping to cool the body
Skin blood vessels dilate: capillaries become flushed with warm blood; heat radiates from skin surface
Body temper- ature decreases: blood temperature declines and hypo- thalamus heat-loss center “shuts off”
Stimulus: Increased body temperature (e.g., when exercising or the climate is hot)
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Homeostasis = normal body temperature (35.8°C–38.2°C)
Activates Heat-promoting center in hypothalamus
Blood cooler than hypothalamic set point
Skeletal muscles activated when more heat must be generated; shivering begins
Skin blood vessels constrict: blood is diverted from skin capillaries and withdrawn to deeper tissues; minimizes overall heat loss from skin surface
Body temper- ature decreases: blood temperature declines and hypo- thalamus heat-loss center “shuts off”
Stimulus: Decreased body temperature
Organization of the Human Body
• A. Major features of the human body include its cavities, membranes, and organ systems.
• B. Body Cavities: – 1.The body can be
divided into an axial portion (head, neck, and trunk) and an appendicular portion (upper & lower limbs).
•
Thoracic cavity
Abdominopelvic"cavity"
Abdoaminal "cavity"
Diaphragm
Pelvic cavity
Cranial cavity
Vertebral canal
Thoracic cavity
Abdominopelvic"cavity"
Abdominal"cavity"
Pelvic cavity
Right pleural"cavity"
Mediastinum Left pleural cavity
Pericardial"cavity"
Diaphragm
Vertebral canal
Cranial cavity
Thoracic"cavity"
(a)
(b) Fig01.08
Organization of the Human Body
• a. The back portion of the axial portion contains the cranial cavity and the vertebral canal.
• b. The front portion contains the thoracic cavity and the abdominopelvic cavity (abdominal and pelvic cavities combined).
• The
Fig01.08
Thoracic cavity
Abdominopelvic"cavity"
Abdoaminal "cavity"
Diaphragm
Pelvic cavity
Cranial cavity
Vertebral canal
Thoracic cavity
Abdominopelvic"cavity"
Abdominal"cavity"
Pelvic cavity
Right pleural"cavity"
Mediastinum Left pleural cavity
Pericardial"cavity"
Diaphragm
Vertebral canal
Cranial cavity
Thoracic"cavity"
(a)
(b)
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Thoracic & Abdominopelvic Membranes:
• Parietal attaches to wall cavity and Visceral covers the internal organ.
• 1.The thoracic cavity is lined with pleural membranes; the parietal pleural membrane lines the thoracic cavity wall and the visceral pleural membrane covers the lungs. A thin layer of serous fluid separates the two layers.
Thoracic & Abdominopelvic Membranes:
• 2. The heart is surrounded by pericardial membranes. The parietal pericardium makes up an outer sac and the visceral pericardium covers the heart. Serous fluid separates the two layers.
• 3. Peritoneal membranes line the abdominopelvic cavity; a parietal peritoneum lines the wall while visceral peritoneum covers the organs.
Organ Systems Body Coverings
a. The integumentary system, including skin, hair, nails, and various glands, covers the body. It protects underlying tissues, helps regulate body temperature, senses changes, and synthesizes certain products.
Support and Movement b. The skeletal system is made up of bones and ligaments. It
c. The muscular system consists of the muscles that provide body movement, posture, and body heat.
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Organ systems Integration and Coordination
d. The nervous system consists of the brain, spinal cord, nerves, and sense organs. It integrates incoming information from receptors and sends impulses to muscles and glands.
e. The endocrine system, including all of the glands that secrete hormones, helps to integrate metabolic functions.
Organ systems Transport
f. The cardiovascular system, made up of the heart and blood vessels, distributes oxygen and nutrients throughout the body while removing wastes from the cells.
g. The lymphatic system, consisting of lymphatic vessels, lymph nodes, thymus, and spleen, drains excess tissue fluid and includes cells of immunity.
Organ systems Absorption and Excretion
h.The digestive system is made up of the mouth, esophagus, stomach, intestines, and accessory organs. It receives, breaks down, and absorbs nutrients. i.The respiratory system exchanges gases between the blood and air and is made up of the lungs and passageways. j.The urinary system, consisting of the kidneys, ureters, bladder, and urethra, removes wastes from the blood and helps to maintain water and electrolyte balance.
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Organ systems Reproduction
k. 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.
Anatomical Terminology
A. Anatomical position : A. body erect, face forward, upper limbs at
sides with palm forward.
B. Relative Positions: 1. Terms of relative position describe the location of one body part with respect to another.
2. Terms of relative position include: superior, inferior, anterior, posterior, medial, lateral, bilateral, ipsilateral, contralateral, proximal, distal, superficial (peripheral), and deep.
Body Sections: • 1. A sagittal section divides the body into
right and left portions. If it passes along the midline and divides the body into equal parts it is midsagittal. A section lateral to the midline is parasagittal.
• 2. A transverse (horizontal) section divides the body into superior and inferior portions.
• 3. A frontal (or coronal) section divides the body into anterior and posterior sections.
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Body Quadrants 4 quadrants centered
around the belly button 2 upper quadrants (right and
left)
2 lower quadrants (right and left)
*note right and left is always your patient’s right or left
