Introduction to Anatomy & Physiology

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First a Review….Levels of Organization within the Body

• Subatomic particles– Proton, neutron, electron

• Atom– Carbon, nitrogen, hydrogen, oxygen

• Molecule– Water molecule, glucose molecule

• Macromolecule– Protein molecule (enzyme), DNA molecule

• Organelle (“tiny organs” within cells)– Mitochondria, nucleus, Golgi apparatus

Levels of Organization cont…• Cells

– Specialized to perform a certain function– Ex: Cardiac cells are specialized to contract – help

the heart beat

• Tissue– 4 major types: epithelial, connective, muscle, nervous

• Organ– Skin, kidney, heart, femur

• Organ system– Skeletal system, digestive system

• Organism– Human, cat

Anatomy

• Study of the structure of an organism

• Looks at the appearances, location and relationships of body parts– Example: How do the bones of the leg fit

together?

• Anatomy can be studied through dissection

Physiology

• Study of the function of living organisms and its parts– How the body works

Unifying Concept

Structure is always related to Function

(Structure determines Function)

Body structures (anatomy) seemed “designed” to perform their function

(physiology)

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Example within the Body:

• Cilia (an organelle)– Structure: hair-like projection of cells

• Found on the cells that make up the tissue lining of the respiratory tract

– Function: trap and eliminate inhaled contaminants (dust and other allergens)

Review:

• Anatomy is the study of?

• Physiology is the study of?

• ________ determines ________?

Which of the following correctly describes the levels of organization with the body?

A: Subatomic particle atom macromolecule molecule cell organelle tissue organ organism organ system

B: molecule macromolecule subatomic particle atom organelle cell tissue organ organ system organism

C: subatomic particle atom molecule macromolecule organelle cell tissue organ organ system organism

Characteristics of Life

• What is life?

• What does it mean to be alive?

• What differentiates a functioning, living being from a dead body?

• Responsiveness• Conductivity• Growth• Respiration• Digestion

Characteristics of Life

• Absorption• Secretion• Excretion• Circulation• Reproduction

Characteristics of Life

• Responsiveness– Allows an organism to sense, monitor and respond to

changes in the environment– Ex: withdrawing from a painful stimuli (pinprick)

• Conductivity– Cells and tissue transmit a wave of excitement from

one point to another with the body– Ex: heart beat

• Growth– Normal increase in the size or number of cells– Shape remain the same– Ex: bone growth

Characteristics of Life cont…

• Respiration– Exchange of respiratory gases (oxygen &

carbon dioxide) between an organism and the environment

• Digestion– Food products are broken down into simpler

substances that can be used by cells within the body

• Ex: Lactose (the sugar in milk) is broken down by lactase (an enzyme) into glucose and galactose to be used by the body for energy

Characteristics of Life cont…

• Absorption– Digested nutrients are absorbed through the digestive

tract to be used by cells

• Secretion– Production & delivery of specialized substances for

diverse body functions– Ex: Pancreas secretes insulin

• Excretion– Removal of wastes products– Ex: Renal system (kidneys) filter blood, remove

wastes, wastes excreted in urine

Characteristics of Life cont….

• Circulation– Movement of body fluids throughout the body– Ex: blood carries oxygen throughout the body

• Reproduction– Formation of new individuals

• Ex: sexual reproduction

– Formation of new cells via cell division (mitosis)

• Ex: growth, wound repair

Metabolism

Used to describe all the physical and chemical processes taking place within the

body to maintain life.

Homeostasis

• Body strives to maintain a constant internal environment– Ex: Temperature, water balance, blood sugar (fig

1-12)

• Regulatory mechanisms within the body are responsible for maintaining homeostasis

Homeostatic Control Mechanisms

• Groups of processes that maintain or restore the body’s internal homeostasis

• Processes are known as feedback control systems (or loops)

• 3 components:1. Sensor (or receptor)

2. Integrator (Control Center)

3. Effector

Homeostatic Control Mechanisms

Negative Feedback Loop

• Negative feedback systems are inhibitory– Oppose change within the body by creating

an opposite response – Stabilize physiological variables– Help maintain homeostasis – Ex: temperature regulation (previous slide)

Positive Feedback Loops

• Positive feedback loops are stimulatory– Amplify or reinforce changes within the body– Can be (not always) harmful because of the

disruption of homeostasis– Ex: child birth

Positive Feedback Loop – Child Birth

• During the delivery of an infant, the baby is pushed from the uterus (womb) into the birth canal

Baby (stimulus) stretch receptors (receptor/sensor) brain (control center) oxytocin release (effector) uterus contracts increasing the movement of the baby

Review

Negative Feedback = inhibits

Positive Feedback = stimulates

Anatomical Position

•Reference position that gives meaning to the directional terms used to describe body parts and regions

Directional Terms

Label the following on your handout:

• Anterior/Posterior (9/11)

• Ventral/Dorsal (9/11)

• Superior/Inferior (10/6)

• Proximal/Distal (7/12)

• Lateral/Medial (8/4)

Subdivisions of the Body

• Axial– Along the middle or axis– spine, ribs, skull

• Appendicular – Appendages– Arms, legs

Body Cavities & SubdivisionThe body is not a solid structure – contains

two main cavities:1. Dorsal body cavity (8)

–Cranial cavity (1)–Spinal cavity (2)

2. Ventral body cavity (7)–Thoracic cavity (4)

» Mediastinum (9)» Pleural cavities (3)

–Abdominal cavity (5)–Pelvic cavity (6)

Body Planes

Transverse (1)

Frontal or Coronal (3)

Sagittal (5)

4 Abdominal Quadrants

• Right upper quadrant (RUQ)

• Left upper quadrant (LUQ)

• Right lower quadrant (RLQ)

• Left lower quadrant (LLQ)

Mechanisms of Disease

1. Genetic Mechanisms– Altered or mutated genes code for abnormal

proteins• Results in altered/abnormal structure• Abnormal structure = absence of function or

abnormal or disruptive function• Overall result = disruption of body’s homeostasis

Mechanisms of Disease

2. Pathogenic Organisms (pathogenic = disease causing)

– Prions: proteins that convert normal proteins in the nervous system to abnormal proteins• Abnormal protein can be inherited • Ex: mad cow disease

– Viruses: Intracellular parasites that invade human cells and cause them to produce viral components

Mechanisms of Disease

– Bacteria: Primitive cells that lack nuclei. Cause infection by parasitizing tissues and/or disrupting normal function

– Fungi: Cannot make their own food so they parasitize on human tissue

– Protozoa: Protist (unicellular organism), also parasitize human tissue

– Pathogenic animals: Large multicellular organisms such as insects or worms

• Parasitize human tissue via bite or sting• Ex: hook worm

Mechanisms of Disease

3. Tumors and cancer– Cause abnormal tissue growth– Abnormal structure = abnormal function

4. Physical & chemical agents– Toxic or destructive chemicals– Extreme hear or cold– Radiation

**All affect normal homeostasis of the body**

Mechanisms of Disease

5. Malnutrition– Insufficient or imbalanced nutrient intake can

cause various diseases• Ex: Low fiber/high fat diet is a known risk factor

for colorectal cancer

6. Autoimmunity– Immune system attacks one’s own body

• Systemic lupus erythematosus

Mechanisms of Disease7. Inflammation

– Normal response that occurs after an infection/injury

– Damage occurs when inflammation occurs at inappropriate times or is abnormally prolonged

8. Degeneration– Still unknown process– Tissues break apart or degenerate – Results from disease or aging

Body Types

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Endomorph: Apple vs Pear Shape

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