Introduction to Human Anatomy and Physiology What is

Introduction to Human Anatomy and Physiology

What is Anatomy & Physiology? Anatomy – the structure of body parts Physiology – the function of body parts (what they do and how they do it) The structure (anatomy) of a body part fits function (physiology).

Characteristics of Living Things The human body shares the abilities of all living things: 1. Movement - self initiated change in position, motion of internal parts 2. Responsiveness - Ability to sense changes and react to them 3. Growth - increase in body size 4. Reproduction - Parents produce offspring / passing DNA to new individuals 5. Respiration - Obtaining oxygen (O 2), using it to release energy from food substances, and getting rid of wastes

Characteristics of Living Things 6. Digestion - Chemically changing (breaking down) food substances, and getting rid of wastes 7. Absorption - Passage of Digested products (food substances) through membranes and into body fluids 8. Circulation - Movement of substances throughout the body 9. Assimilation - Changing absorbed substances into chemically different substances 10. Excretion - Removal of wastes

Metabolism All of the body’s processes require a variety of chemical reactions. The chemical reactions and changes that occur in the body to maintain life are called metabolism. All of these processes require energy. How do we obtain energy? Where does it come from?

Metabolism In order for metabolism to occur, your body needs: oxygen, water, heat, and food. Carbohydrates (sugar) provide energy for metabolism Proteins building bodily structures Lipids (fat) store energy

Metabolism All metabolic processes have one main goal: achieving balance and comfort in your body. Homeostasis = the state of a stable, balanced, internal environment. Root words! Homeo? Stasis?

How does the body maintain homeostasis? The body constantly checks itself to make sure it stays in homeostasis. If a system is off-balance or unstable, the body begins the necessary metabolic processes to fix it and restore homeostatic balance.

How does the body maintain homeostasis? One way the body checks itself is using feedback loops: Positive feedback loops & Negative feedback loops

Positive Feedback Loops Positive feedback loops amplify or increase the occurrence of events that the body needs more of. Example: • A baby suckles on its mother’s nipple • This action stimulates a nerve response into mom’s spinal cord and up to her brain • Brain tells her body to produce more milk The loop continues until one of the steps is removed or stopped.

Negative Feedback Loops Negative feedback loops reduce or decrease the occurrence of events that the body needs less of. Rely on: Sensors = detect changes in the body that deviated from homeostasis and notify the brain Effectors = respond to the changes to regain homeostasis

Negative Feedback Loops Negative feedback loops reduce or decrease the occurrence of events that the body needs less of. Example: • Body gets too hot…exceeds 37°C (98. 6°F) • Sensors (like nerve endings in skin) send signal to brain • Brain stimulates sweat glands • Body cools to normal, comfortable temperature The loop stops once homeostasis is reached.

Levels of Anatomical Organization Organelles = mini-organs with specific jobs to help cells function Cells = smallest living unit of your body, building blocks Tissues = group of cells that do a similar function

Levels of Anatomical Organization Organ = group of tissues that do a similar function System = group of organs that carry out the same bodily process

Levels of Anatomical Organization Organism = group of systems that work together to keep a living thing alive and in homeostatic balance

Anatomical Terminology Anatomical Position = standing erect, face forward, arms at side, palms facing forward 1. Superior 2. Inferior 3. Anterior 4. Posterior 5. Medial 6. Lateral 7. Proximal 8. Distal 9. Superficial 10. Deep

Planes of the Body

Movements of the Body Flexion = decreasing joint angle Extension = increasing joint angle Abduction = moving away from the midline (when someone is abducted, they are taken away from home) Adduction = moving toward the midline Supination = rotating palms to face anterior Pronation = rotating to palms face the posterior Dorsiflexion = flexion of the ankle so that toes point superiorly (commonly called flexing your foot) Plantarflexion = extension of the ankle so that toes point inferiorly (commonly called pointing your toes) Opposition = bringing thumb and pinkie together Reposition = bringing thumb and pinkie apart

Human Body Organization: Body Cavities Cranial cavity = head (contains brain) Vertebral cavity = contains spinal cord Dorsal cavity = back side Ventral cavity = front side

Human Body Organization: Body Cavities Thoracic cavity = chest - Pleural cavities (left & right) = contain lungs - Pericardial cavity = contains the heart - Mediastinal cavity = contains pericardial cavity and the remaining thoracic organs, like the trachea The diaphragm is a muscle that separates the thoracic and pelvic cavities Abdominal cavity = stomach area (stomach, intestines) Pelvic cavity = lower abdomen, inside hips (bladder, reproductive organs)

Mediastinal cavity the mediastinal cavity