Introduction to the Human Body Chapter 1: Introduction to the Human Body

Anatomy or physiology The skull and vertebral column is part of the axial skeleton. The cerebral cortex consists of 4 lobes: frontal , parietal, temporal, occipital Skeletal muscles pull on bones, creating forces that produce body motion The stomach, small intestine, and large intestine are chambers of the digestive tract.

Anatomy or physiology? Receptors of the eye and ear detect environmental changes for the respective senses of vision and hearing. Antidiuretic hormone, secreted from the posterior lobe of the pituitary gland, stimulates water reabsorbtion in the kidney.

Anatomy and Physiology Study of structure or morphology of the body. Physiology The study of how the body works or functions Pathophysiology – how a body part functions when a person has a disease

II. Levels of Organization From simple to complex Atom molecule Large molecules Cells – basic unit of life Tissues – groups of specialized cells Organs – has a specific function Organ systems – groups of organs Human organism

III. Organs and Organ systems Major organ systems

Integument System Skin, hair and nails Protection Regulate body temperature Sense of touch

Skeletal System Bones, joints, cartilage Protects and supports body organs

Muscular System Responsible for movement of skeleton posture

Nervous System Brain, spinal cord, nerves, sense organs Integration and coordination Regulation and response

Endocrine System Glands                                                                                             Glands Secrete hormones and chemicals to regulate body activities

Circulatory System Heart and blood vessels Transports blood

Lymphatic System Lymph nodes Defend the body immunity

                                                     Respiratory System Lungs Exchange of gases with the environment

Digestive System Convert food to nutrients Absorb nutrients Eliminate waste

Urinary System Kidneys Excrete waste Formation of urine

Reproductive System Enable the human to reproduce

Homeostasis: Maintenance of a constant condition in the internal environment Internal environment: extra cellular fluid surrounding our cells Homois = same, stasis= standing Examples: body temperature, water balance, ion balance, glucose levels, pH

Maintaining Homeostasis Nervous System and the endocrine system Negative Feedback Response – a stimulus is met by a response that reverses the trend of the stimulus

Component of internal environment Receptors: Detect stimuli, deviation from normal Regulatory mechanisms

Negative Feedback Response

Directional Terminology Anatomical Terms Directional Terminology

Anatomical Position Face Forward Arms at side Palms forward Feet forward

1. Prone and Supine Supine: lying face up Prone: lying face down Referring to hand – palms forward Prone: lying face down Referring to hand – palms are back

2. Anterior (ventral) vs. Posterior (dorsal) Anterior - Referring to front of body Posterior – back side of body

Superior vs. inferior Superior – refers to structures above another Inferior – refers to a structure below another

Medial vs. Lateral Medial – located closer to midline Lateral – located away from midline

Proximal vs. distal Proximal – located closer to the point of origin Distal – located away or “distant” from the point of origin.

Body Planes: Sagittal: Vertically through the body Divides body into left and right portions

Frontal or Coronal Plane Extends vertically Perpendicular to sagittal plane Divides body into anterior and posterior halves

Transverse Plane or Horizontal plane Divides the body into superior and inferior portions

Body Cavities Dorsal body cavity Cranial cavity – superior, hollow portion of skull, brain located Spinal cavity – contains the spinal cord, vertebrae make up cavity

Ventral Body Cavity Ventral body cavity Thoracic cavity Superior to diaphragm Contents: Plural cavity (lungs) Mediastinum – chest cavity space Contents: pericardial cavity (heart), upper respiratory tract, esophagus, major blood vessels, thymus gland

Ventral Body Cavity Abdominopelvic cavity Inferior to diaphragm Abdominal cavity: stomach, liver, gallbladder, spleen. Pancreas, small intestine, part of large intestine

Ventral Body Cavity Abdominopelvic cavity Pelvic cavity: rest of large intestine, bladder, rectum, reproductive organs