The Human Body: An Orientation List as many body systems as you can in 10 seconds.

The Human Body – An Orientation Learning Targets: I will be able to: define anatomy and physiology. explain how anatomy and physiology are related. name the organ systems of the body, and briefly state the major functions of each system. define homeostasis and explain its importance.

The Human Body – An Orientation anatomy: study of the structure and shape of the body and its parts physiology: study of how the body and its parts work or function

Anatomy – Levels of Study Gross (Macroscopic) Anatomy Focuses on anatomical structures that can be seen by the naked eye, such as the external and internal bodily organs.

Anatomy – Levels of Study Microscopic Anatomy Cytology, the study of the structure and function of cells Histology, the study of the organization and details of biological tissues

Levels of Structural Organization

 What is anatomy? What is physiology? What is the difference between gross anatomy and microscopic anatomy? study of the structure and shape of the body and its parts study of how the body and its parts work or function 3. Gross (Macroscopic) Anatomy focuses on anatomical structures that can be seen by the naked eye, microscopic anatomy focuses on anatomical structures that can be seen with a microscope

Organ System Overview Integumentary System Consists of: skin, nails, hair, glands in skin, nerve endings, and receptors in skin Forms the external body covering and protects deeper tissues from injury. Houses cutaneous receptors, sweat glands, oil glands, and synthesizes vitamin D

Skeletal System Consists of: bones, joints, and connective tissues Protects and supports body organs Provides attachment framework for muscle movement Site of blood cell formation Stores minerals

Muscular System Consists of: striated skeletal, cardiac, and smooth muscle tissue. Maintains posture and produces movement (locomotion). Produces heat.

Nervous System Consists of: brain, spinal cord, ganglia, nerves, sensory organs Control system of the body, responds to internal and external changes Activates muscles and glands

Endocrine System Consists of: pituitary gland, pineal gland, thyroid gland, thymus, parathyroid, adrenals glands, endocrine portion of pancreas, ovaries, and testes (all secrete hormones into blood). Glands from the endocrine system secrete hormones that regulate many processes like growth, metabolism, and reproduction.

Cardiovascular System Consists of: heart, blood vessels, blood Blood is pumped by the heart and transported by blood vessels. Blood carries oxygen, carbon dioxide, nutrients, waste and more throughout the body.

 Why does the muscular system need the skeletal system? How does the endocrine system use the cardiovascular system? Muscles cannot move the body without a structure to pull against Hormones produced by the endocrine system are transported by the cardiovascular system

Lymphatic System Consists of: tonsils, spleen, thymus, lymph nodes, lymphatic vessels, lymph fluid, red bone marrow, and thoracic duct. Houses white blood cells (lymphocytes) involved in immunity. Returns leaked fluid from blood vessels to the blood and disposes debris within the lymphatic stream.

Respiratory System Consists of: nose, nasal cavity, pharynx, larynx, trachea, bronchi, and lungs Removes carbon dioxide and continually supplies blood with oxygen. Gaseous exchanges occur in the respiratory system (lungs).

Digestive System Consists of: mouth, esophagus, stomach, small and large intestine, rectum, and anus (all in gastrointestinal tract); Accessory (or associated) organs include salivary glands, pancreas, liver, and gallbladder Breaks down food to be absorbed and eliminates indigestible waste.

Urinary System Consists of: Kidneys, ureters, bladder, and urethra Eliminates nitrogenous wastes from the body. Regulates: acid-base, electrolyte and water balances of blood.

Reproductive System MALE: Consists of: prostate gland, penis, testes, seminal vesicles, urethra, scrotum, ductus deferens, and bulbourethral glands. FEMALE: Consists of: mammary glands, ovaries, uterus, uterine tubes, vagina, and vulva.

Reproductive System The main function of the reproductive system is to produce offspring. Sex hormone and sperm are produced by the male testes. Male ducts and glands help deliver the sperm. Ovaries produce female sex hormones and eggs. Other female reproductive structures serve as sites of fertilization and development. For instance, the mammary glands produce milk for the newborn.

 Which system fights infection? What are the two primary functions of the digestive system? Why does the urinary system regulate the acid-base balance of blood? Name one functional difference between male and female reproductive systems. Lymphatic system controls white blood cells Breaks down food to be absorbed and eliminates indigestible waste. Slight variations in blood pH can negatively effect the functions of vital organs Answers will vary

Homeostasis homeostasis: maintenance of a stable internal environment = a dynamic state of equilibrium Homeostasis must be maintained for normal body functioning and to sustain life. homeostatic imbalance: a disturbance in homeostasis resulting in disease

Maintaining Homeostasis The body communicates through neural and hormonal control systems. The neural control system consists of three systems. Receptor Responds to changes in the environment (stimuli) Sends information to control center

Maintaining Homeostasis Control center Determines set point Analyzes information Determines appropriate response Effector Provides a means for response to the stimulus

Maintaining Homeostasis An animal’s body maintains a relatively constant internal environment. How is this accomplished? It is surprisingly similar to the way a thermostat and heating system maintain a relatively constant temperature inside a room. The diagram shows how a thermostat responds when the temperature becomes too hot or too cold.

Feedback Mechanisms Negative feedback Includes most homeostatic control mechanisms. Shuts off the original stimulus, or reduces its intensity. Works like a household thermostat.

Feedback Mechanisms Positive feedback Increases the original stimulus to push the variable farther. In the body this occurs rarely, as in blood clotting and birth of a baby.

 Why is homeostasis important? What are the three parts of the neural control system? How are negative and positive feedback mechanisms different? Homeostasis must be maintained for normal body functioning and to sustain life. Receptor, control center, effector Negative feedback brings the variable back to a set point, positive feedback pushes the variable further