Lecture 1 - Human Body

Exam 1 Material

Anatomy

study of the structure of body parts and their relationship to one another

Physiology

study of the function of body parts and how they work to carry out life-sustaining activities

Necessary Life Functions

• maintaining boundaries

• movement

• responsiveness

• digestion

• metabolism

• excretion

• reproduction

• growth

What does maintaining boundaries entail?

Function of the integumentary system (skin): separation between internal and external environments

• plasma membranes separate cells

• skin separates the organism from the outside environment

What does movement entail?

Function of the muscular system

• allows for external movement of body parts by skeletal muscles (closest to bones)

• allows for internal movement of substances via cardiac muscle (in the walls of the heart) and smooth muscle (in the walls of hollow organs like stomach, intestines, and bladder, and in walls of blood vessels and reproductive tracts)

What is contractility?

movement at the cellular level

What does responsiveness entail?

Function of the nervous and endocrine systems

• the ability to sense and respond to stimuli

  • controls breathing rate

  • withdrawal reflex prevents injury

What does digestion entail?

Function of the digestive system

• breaks down ingested food and absorbs simple molecules into the bloodstream

What does metabolism entail?

Function of every system

• all chemical reactions that occur in body cells - sum of catabolic (breakdown) and anabolic (building) reactions

What does excretion entail?

Function of the urinary, respiratory, and digestive systems

• removal of wastes from metabolism and digestion

  • urea from the breakdown of proteins

  • carbon dioxide from metabolic reactions

  • feces from unabsorbed foods

What does reproduction entail?

Function of the reproductive system

• cell division for growth and repair

• production of offspring

What does growth entail?

Function of every system

• cells of every system increase in size as you grow from a baby to adult

What are the requirements for life?

• Nutrients

• Oxygen

• Water

• Appropriate atmospheric pressure

Nutrient Requirements

Chemicals for energy and cell building

• Carbs: energy source

• Protein: cell building

• Fats: long term energy storage

• Vitamins & Minerals: in chemical reactions and structural purposes

Oxygen Requirements

Essential for the release of energy from foods and body cannot survive more than a few minutes without it

Water Requirements

• Needed for the watery environment that allows chemicals to meet and react to from products

• Is the base that keeps blood fluid and able to flow freely

Atmospheric Pressure Requirements

A specific air pressure is needed to breathe and gas exchange to occur in our lungs

• atmospheric pressure is the collective weight of all of the particles in the air that produces a force

Integumentary System Functions

• made up of the hair, skin, and nails

• forms the external body covering

• protects deeper tissues from injury

• synthesizes vitamin D

• contains cutaneous receptors (pain, pressure, etc) and sweat and oil glands

Nervous System Functions

• made up of the brain, nerves, and spinal cord

• is the fast-acting control system of the body that responds to internal and external changes by activating appropriate muscles and glands

Muscular System Functions

• made up of skeletal, cardiac, and smooth muscle

• Skeletal muscles allow for manipulation of the environment, locomotion, facial expression, produces heat and maintains posture

Skeletal Sytem Functions

• made up of bones and joints

• protects and supports body organs

• is the framework for muscles to use to be able to move

• blood cells synthesized by bones

• store minerals like Calcium (Ca2+)

Cardiovascular System Functions

• made up of the heart, arteries, and blood vessels

• heart pumps blood

• blood vessels transport blood carrying oxygen, co2, nutrients, and wastes

Lymphatic System Functions

• made up of the lymph nodes, lymphatic vessels, spleen, thymus, and red bone marrow

• known as the “immune” system

• picks up fluid that leaked out of blood vessels and returns it into the blood

• disposes of debris in the lymphatic stream

• contains white blood cells (lymphocytes) - protect the body from germs, viruses, and other abnormal cells

• is in charge of the immune response that attacks foreign substances in the body

Respiratory System Functions

• made up of the lungs, bronchus, trachea, larynx, pharynx, and nasal cavity

• supplies the blood with oxygen and removes carbon dioxide

• gas exchange occurs through the walls of the air sacs of the lungs

Endocrine System Functions

• made up of the thyroid gland, thymus, adrenal gland, pancreas, pineal gland, pituitary gland, and the ovaries or testis

• glands secrete hormones that regulate body processes

Digestive System Functions

• made up of the stomach, large and small intestines, rectum, anus, liver, esophagus, and oral cavity

• breaks down food into absorbable units that enter the blood for distribution to body cells

• ingestible foods are eliminated as feces

Urinary System Functions

• made up of the kidneys, ureter, urinary bladder, and urethra

• eliminates nitrogenous waste from the body

• regulates water, electrolytes, and acid-base balance of blood

Female Reproductive System Functions

• made up of the mammary glands in the breasts, ovaries, uterus, vagina, and uterine tube

• overall function is to produce offspring

• ovaries produce eggs and female sex hormones (estrogen and progesterone)

• mammary glands produce milk to nourish newborns

• vagina, uterus, and uterine tube serve as sites for fertilization and development of the fetus

Male Reproductive System Functions

• made up of the prostate, ductus deferens, scrotum, penis, and testis

• overall function is to produce offspring

• testes produce sperm and male sex hormone (testosterone)

• male ducts and glands aid in the delivery of sperm to the female reproductive tract

What is Homeostasis?

• the maintenance of stable internal conditions of the body as external conditions change

• is a dynamic state of equilibrium that always adjusts as needed

• maintained by interrelationships between all systems

What are the components of homeostatic control?

Receptors, Control center and Effectors

What is the function of receptors?

Sense stimuli and monitors the environments

What is the function of the control center?

Determines the set point at which a variable is maintained

Receives information from receptors and determines the appropriate response

What is the function of effectors?

The organ that executes the response after receiving output from the control center

What is negative feedback?

Brings things back to “normal” homeostasis by acting in the opposite direction of the initial change

• majority of feedback mechanisms are negative

What is positive feedback?

Body reacts to take us further away from homeostasis by enhancing or exaggerating the original stimulus

Ex:

• enhancement of labor contractions by oxytocin

• blood clotting

What is homeostatic imbalance caused by?

Disease, sickness, injury

• as you age, control systems become less efficient and increases the risk of illness and produces new age-related changes

How does cancer relate to feedback mechanisms?

If negative feedback mechanisms become overwhelmed, the positive feedback mechanism of producing lots of cancer cells repeatedly occurs and is destructive to the body