Introduction to A&PIntroduction to A&P

Levels of Organization, Levels of Organization, Homeostasis, Body CavitiesHomeostasis, Body Cavities

TerminologyTerminology

Anatomy – the study of internal and Anatomy – the study of internal and external structures of the body, and the external structures of the body, and the physical relationships among body parts. physical relationships among body parts. Ex. Studying the parts of the kidney.Ex. Studying the parts of the kidney.

Physiology – the study of how living Physiology – the study of how living organisms perform their vital functions. organisms perform their vital functions. Ex. Studying the mechanisms by which Ex. Studying the mechanisms by which the kidneys produce urine.the kidneys produce urine.

Levels of OrganizationLevels of Organization

Levels of OrganizationLevels of Organization

chemical level – lowest – chemicals chemical level – lowest – chemicals essential for maintaining life- essential for maintaining life- atomsatoms to to molecules molecules to to macromolecules macromolecules to to organellesorganelles

cellular- basic structural and functional cellular- basic structural and functional unit; ex. Muscle and nerve cellsunit; ex. Muscle and nerve cells

tissue- similar cells with same function; tissue- similar cells with same function; ex. Connective tissue, epithelial tissueex. Connective tissue, epithelial tissue

Levels of OrganizationLevels of Organization

organorgan- structures of definite form and - structures of definite form and function composed of 2 or more tissues; function composed of 2 or more tissues; ex. Heart, liverex. Heart, liver

systemsystem- association of organs with - association of organs with common function ex. Digestive, nervouscommon function ex. Digestive, nervous

organismorganism – all parts of the body – all parts of the body functioning with one anotherfunctioning with one another

MetabolismMetabolism

Definition: sum total of all chemical processes Definition: sum total of all chemical processes occurring in the bodyoccurring in the body

– catabolismcatabolism – breakdown of organic matter, usually – breakdown of organic matter, usually with the release of energywith the release of energy

– anabolismanabolism – buildup of organic matter, usually – buildup of organic matter, usually requiring the input of energyrequiring the input of energy

– Example: A catabolic process would be the Example: A catabolic process would be the breakdown of a Carbohydrate for a release of breakdown of a Carbohydrate for a release of energy to the body. An anabolic reaction would energy to the body. An anabolic reaction would occur when that energy is captured and then used occur when that energy is captured and then used (or required) for something else. (or required) for something else.

HomeostasisHomeostasis

DefinitionDefinition: state of balance in which the : state of balance in which the body’s internal environment remains in the body’s internal environment remains in the normal range. Our body is said to be in normal range. Our body is said to be in homeostasis when the needs of its cells homeostasis when the needs of its cells are met and its activities are occurring are met and its activities are occurring smoothly.smoothly.

Occurs with a balance of positive and Occurs with a balance of positive and negative feedback.negative feedback.

+/- Feedback+/- Feedback

negative feedbacknegative feedback – when the information – when the information decreases the system’s output to bring the decreases the system’s output to bring the system back to its set pointsystem back to its set point– Example: The level of glucose rises after a Example: The level of glucose rises after a

meal, glucose stimulates the release of meal, glucose stimulates the release of insulin, and insulin encourages the passage insulin, and insulin encourages the passage of glucose in the cells and therefore reduces of glucose in the cells and therefore reduces the glucose level. the glucose level.

+/- Feedback+/- Feedback

positive feedbackpositive feedback – the information – the information returned to the system increase the returned to the system increase the deviation from the set point deviation from the set point

– Example: Stimulating a nerve cell causes Example: Stimulating a nerve cell causes sodium ions to flow across the membrane sodium ions to flow across the membrane into the cell; the sodium flow increases the into the cell; the sodium flow increases the membrane’s passageways to encourage membrane’s passageways to encourage more sodium ions to flow inward. The result more sodium ions to flow inward. The result is a nerve impulse.is a nerve impulse.

Body PlanesBody Planes

Planes of the BodyPlanes of the Body

sagittal sagittal – lengthwise plane running from front – lengthwise plane running from front to back, it divides the body into right and left to back, it divides the body into right and left sidessides

transversetransverse – refers to a cut that divides the – refers to a cut that divides the body into superior and inferior portionsbody into superior and inferior portions

Coronal (frontalCoronal (frontal) – lengthwise plane running ) – lengthwise plane running from side to side, it divides the body into front from side to side, it divides the body into front (anterior) and back (posterior) portions(anterior) and back (posterior) portions

Body CavitiesBody Cavities

Body CavitiesBody Cavities

The human is divided into an The human is divided into an axialaxial portion (head, neck and trunk) and an portion (head, neck and trunk) and an appendicularappendicular portion (upper and lower portion (upper and lower limbs)limbs)

The The axial axial portion has 2 major cavities: a portion has 2 major cavities: a dorsal dorsal and a and a ventraventral cavityl cavity

Body CavitiesBody Cavities

– dorsaldorsal – subdivided into the – subdivided into the cranialcranial (brain) (brain) and and spinal spinal (vertebrae and spinal cord) (vertebrae and spinal cord) cavitiescavities

– ventralventral (divided by the diaphragm) – (divided by the diaphragm) – subdivided into the subdivided into the thoracicthoracic (heart, lungs, (heart, lungs, esophagus) and esophagus) and abdominopelvicabdominopelvic ( stomach, ( stomach, intestines, spleen, liver, etc) cavitiesintestines, spleen, liver, etc) cavities

Body CavitiesBody Cavities

thoracicthoracic – the – the mediastinummediastinum separates separates the thoracic cavity into 2 the thoracic cavity into 2 compartments, the left compartments, the left and right lungs. The and right lungs. The mediastinum includes the mediastinum includes the heart, esophagus, heart, esophagus, trachea, and thymus trachea, and thymus glandglandabdominopelvicabdominopelvic cavity cavity includes the includes the upper upper abdomenabdomen and the and the lower lower pelvicpelvic areas. The areas. The abdominal region is abdominal region is subdivided into nine subdivided into nine regionsregions

right right hypochondriachypochondriacepigastricepigastricleft hypochondriacleft hypochondriacright lumbarright lumbarumbilical umbilical left lumbarleft lumbarright iliacright iliachypogastrichypogastricleft iliac regionleft iliac region