The Human Body: An Overview Chapter 1

An Overview… Anatomy – the study of the structure and shape of the body and body parts and their relationship with one another Physiology – the study of how the body and its parts work or function

Levels of Structural Organization Atom – the smallest unit of matter Molecule – two or more atoms Macromolecules – two or more molecules Cell – the smallest unit of life Tissue – group of cells that work together and have a common function Organ – group of tissues that work together… Organ system – group of organs… Organism – group of organ systems…

Organ System Overview Integumentary – skin Skeletal – provide framework for the body Muscular – provides movement Nervous – brain, spinal cord, and nerves Endocrine – produces hormones

Organ System Overview (cont.) Cardiovascular – heart and blood vessels Lymphatic – immune system Respiratory – lungs Digestive – esophagus, stomach, and intestines Urinary – elimination of liquid waste Reproductive - sperm, eggs, etc.

Maintaining Life Movement Responsiveness – the ability to sense changes (stimuli) in the environment and then react to them Digestion

Maintaining Life (cont.) Metabolism  breaking down macromolecules into simple building blocks  making larger structures from smaller ones  using nutrients and oxygen to produce ATP molecules Excretion – removing waste from the body Reproduction Growth

Survival Needs Nutrients Oxygen – approximately 20% of the air is consist of this gas Water – 60% to 80% of body weight Body temperature – needs to be around 98°F Atmospheric pressure – aids in gas exchange and blood flow

Homeostasis Homeostasis – the body ability to maintain relatively stable internal conditions even though the outside world is changing  Example Body temperature (very similar to a thermostat)

Homeostasis (cont.) Negative feedback mechanisms – return stimuli back to set point Negative feedback Set point Body temp. increases Homeostatic Balance of Body Temperature External heat increases 98°F 90°F 105°F

Anatomical Position Anatomical position – standing with palms held unnaturally forward with thumbs pointing away from the body

Directional Terms Superior – Toward the head; above Inferior – Away from the head; below Anterior – Toward the front Posterior – Toward the backside Medial – Toward the midline of the body Lateral – Away from the midline; the outer side of the body

Directional Terms (cont.) Intermediate – Between a medial and a lateral structure  Ex. The armpit is intermediate between the breastbone and shoulder. Proximal – Close to Distal – Far from Superficial – Toward the body surface Deep – Away from the body surface; more internal

Directional Terms (cont.) Superior Inferior Anterior Posterior Medial Lateral Superficial Deep Proximal Distal Intermediate

Anterior Body Landmarks Abdominal – stomach Axillary – armpit Brachial – arm Carpal – wrist Digital – fingers, toes Femoral – thigh Nasal – nose Oral – mouth Orbital – eye area Patellar – anterior knee Pubic – genital region Sternal – breastbone Tarsal – ankle Thoracic – chest Umbilical - navel

Posterior Body Landmarks Cephalic – head Deltoid – curve of shoulder Gluteal – buttock Lumbar – lower spine region Occiptal – posterior part of head Popliteal – posterior knee area Scapular – shoulder blade Vertebral – spine area

Body Planes and Sections Plane – an imaginary line separating the body into sections  Sagittal (median or midsagittal) – A cut made dividing the body into left and right equal parts  Frontal – A cut made dividing the body into anterior and posterior parts  Transverse – A cut made dividing the body into superior and inferior parts

SagittalFrontalTransverse

Body Cavities Cavity – an empty space in the body  Dorsal body cavity Cranial Spinal  Ventral body cavity Throracic– chest Abdominal – stomach Pelvic – hip  Abdominopelvic – combination of abdominal and pelvic cavities

Nine Regions of the Body Upper three  Right (R.) and left (L.) hypochondriac hypo = belowchondro = cartilage  Epigastric Epi = abovegastric = stomach Middle three  R. and L. lumbar – lower spine  Umbilical – navel Lower three  R. and L. iliac – superior part of the hip  Hypogastric