Anatomy and PhysiologyChapter #1

1.1 Introduction

• Early interest in the human body probably developed as people became concerned about injuries and illness.

• Primitive doctors began to learn how certain herbs and potions affected body functions.

• The belief that humans could understand forces that caused natural events led to the development of modern science.

• A set of terms originating from Greek and Latin words in the basis for the language of anatomy and physiology.

1.2 Anatomy and Physiology

• Anatomy describes the form and organization of body parts.

• Physiology considers the functions of anatomical parts.

• The function of an anatomical part depends on the way it is constructed.

Anatomists continue to discover new anatomical features of the body.

• Anatomy deals with the FORM or STRUCTURE (morphology) of the body and its ORGANIZATION.

• Physiology studies the FUNCTION of these parts.

• The topics of anatomy and physiology are difficult to separate because the structures of body parts are so closely associated with the functions. Ex. The chambers of the heart are adapted to pump blood through blood vessels.

1.3 Characteristics of Life

• Fundamental characteristics of life are traits shared by all organisms.

• Characteristics of life include: - 10 characteristics

Movement, responsiveness, growth, reproduction, respiration, digestion, absorption, circulation, assimilation, excretion

Characteristics

1. Movement- change in position of the body or of a body part; motion of an internal organ. Ex. Migration movement from place to place.

2. Responsiveness-Reaction to a change taking place inside or outside the body.

3. Growth- increase in body size without change in shape. When an organism produces new body materials faster than old ones are worn out.

4. Reproduction- production of new organisms and new cells.

Reproduction and growth are NOT synonymous.

Characteristics continued…

5. Respiration- Obtaining oxygen, removing carbon dioxide, and releasing energy from foods. 6O2 + C6H12O6 = 6CO2 + 6H2O

6. Digestion- breakdown or food substances into simpler forms that can be absorbed and used

7. Absorption- is the passage of substances through various body membranes and into body fluids.

Characteristics continued again..

8. Circulation- movement of substances from place to place in body fluids.

9. Assimilation- changing of absorbed substances into chemically different forms.

10. Excretion- removal of wastes produced by metabolic reactions.

Metabolism- acquisition and use of energy.

1.4 Maintenance of LifeRequirements of Organisms

1. Water- The most abundant chemical in the body. It is used in many metabolic processes, provides the environment for metabolic reactions, and transports substances.

2. Food-are substances that supply the body with chemicals and water necessary in vital reactions.

Requirements of Organisms continued…

3. Oxygen- releases energy from food materials.

4. Heat- is a product of metabolic reactions and it controls the rate at which chemical reactions take place in the body.

5. Pressure- is a force on something. Atmospheric pressure help breathing. Hydrostatic pressure help blood movements.

Homeostasis

• Is a condition of a stable internal environment.

• Body parts function only when the concentrations of water, nutrients, and oxygen and the conditions of heat and pressure remain within certain narrow limits.

Homeostatic Mechanisms

• Homeostatic mechanisms are self regulating control systems. Negative feedback.

1. Receptors- which provide info. about specific conditions (stimuli) in the internal environment.

2. Set point- which tells what a particular value should be. Ex. body temperature 98.6*F. Homeostasis in a healthy person changes around the set point.

3. Effectors- which cause responses that alter conditions in the internal environment.

• Perspiring is a cooling process.• Shivering is a heating process. When the body

needs to conserve heat, blood vessels in the skin surface constrict.

• When a person’s body heat rises, the brain’s temperature control center increases the loss of body heat.

• In maintaining homeostasis, the feedback to the control center is triggered by changes away from the set point.

1.5 Levels of Organization

• Atoms• Molecules• Macromolecules• Organelle• Cell• Tissue• Organ• Organ system• Organism

• Chemicals are made up of smaller structures called atoms and atoms can combine to form molecules.

• Organelles are structures within cells that perform specific functions.

• In the human body, the most complex level of organization is the organ system.

• Tissues are layers or masses that have common functions.

1.6 Organization of the Human Body

• Axial portion- which includes the head, neck, and trunk. (Dorsal and Ventral)

• Appendicular portion- which includes the upper and lower limbs.

• Viscera or visceral organs- vital organs.

Dorsal Cavity

• Dorsal cavity: cavity in the back of the body. Axial portion.

• Divided into the following:

1. cranial cavity: - skull & contains the brain

2. spinal cavity: Vertebral canal contains the spinal cord and backbone

Ventral Cavity

• Ventral cavity: located in the front of the body. • Divided into the following thoracic and

abdominopelvic cavities. Divided by diaphragm

1. Thoracic cavity: - contains the heart & lungsMediastinum separates the cavity into 2

compartments. Left and right• pleural cavities: - contain the lungs• pleural membrane: lines the pleural cavity• pericardial cavity: - contains the heart• pericardium: lines the pericardial cavity

Ventral Cavity Continued

2. Abdominoplevic cavity: abdominal cavity + pelvic cavity

• abdominal cavity: contains stomach, liver, spleen, gallbladder, kidneys, and most of the small and large intestines

• peritoneum: lines the abdominal cavity• mesentery: holds the organs/viscera in place.• pelvic cavity: contains bladder, reproductive

organs, end of large intestines

Organ Systems

1. Integumentary2. Skeletal3. Muscular4. Nervous5. Endocrine6. Cardiovascular7. Lymphatic8. Digestive9. Respiratory10. Urinary11. Reproductive

Body Covering

1. The integumentary system includes the skin, hair, nails, sweat glands, and sebaceous glands (hair follicles).

• Protects underlying tissues, regulates body temperature, houses sensory receptors, and synthesizes various substances.

Support and movement

2. Skeletal system is composed of bones, cartilages and ligaments.

• Provides a framework, protective shields, and attachments for muscles. Produces blood cells and stores inorganic salts.

3. Muscular system includes the muscles of the body.

• Moves body parts, maintains posture, and produces body heat.

Integration and coordination

4. Nervous system consists of the brain, spinal cord, nerves, and sense organs.

• Receives impulses from sensory parts, interprets these impulses, and acts on them by stimulating muscles or glands.

5. Endocrine system consists of glands that secrete hormones, which regulate metabolism.

• Includes pituitary, thyroid, adrenal gland and pancreas, ovaries, testes, pineal gland, and thymus gland.

Transport

6. Cardiovascular system includes the heart and blood vessels.

• Blood transports oxygen, nutrients, hormones, and wastes.

7. Lymphatic system is composed of lymphatic vessels, lymph fluid, lymph nodes, thymus gland, and spleen.

• Defends body against disease-causing agents.

Absorption and excretion

8. Digestive system receives foods, breakdown food into usable molecules, and eliminates waste.

• Includes mouth, tongue, teeth, salivary glands, pharynx, esophagus, stomach, liver, gallbladder, pancreas, small and large intestine.

9. Respiratory system exchanges gases between the air and blood.

• Includes nasal cavity, pharynx, larynx, trachea, bronchi, and lungs.

10. Urinary system filters waste from the blood and helps maintain water, acid-base, and electrolyte balance.

• Includes kidneys, ureters, urinary bladder, and urethra.

Reproduction

11. Reproductive system produce new organisms.

• Male reproductive transports sperm cells

• Female reproductive transports egg cells

1.7 Anatomical Terminology

• Anatomical position: Terms of relative position are used to describe the location of a part relative to another part.

1. Superior: Needs to be in reference to another part. What does it mean? Above

2. Inferior: Opposite of superior, what does it mean? Below

Anatomical Terms continued…

3. Anterior: Means the same as ventral in humans. Where does it refer to? Front

4. Posterior Means the same as dorsal in humans. What is it referring to? Back

Ex. the spinal cord is posterior to the heart

5. Medial means towards the midline.

6. Lateral means towards the side.

Ex. the ears are lateral to the nose.

Anatomical Terms continued again…

7. Proximal also is in reference to another part. It means closer to the point of origin.

8. Distal is the opposite of proximal. It means farther from the point of origin.

9. Superficial is close to the surface.

10. Deep is far from the surface.

Body Sections

• Sagittal: A sagittal section divides the body into right and left portions. Mid-sagittal if it passes the midline.

• Transverse (horizontal, cross-sectional) A transverse section divides the body into superior and inferior portions

• Frontal (coronal): A coronal section divides the body into anterior and posterior sections.

Work Cited

• Human Body picture www.materials.qmul.ac.uk/casestud/implants/

• The Human Body picture www.msichicago.org/omax/human-body/