Introduction to Human Anatomy & Physiology

Why is it difficult to separate the topics of anatomy and physiology? Structure is always related to function!

Characteristics of Life 10 Characteristics of Life Movement – change in position; motion Responsiveness – reaction to a change Growth – increase in size Respiration – obtain oxygen & remove carbon dioxide; releasing energy from foods Reproduction – production of new organisms and new cells 1-39

10 Characteristics of Life Absorption – passage of substances through membranes and into body fluids Circulation – movement of substances in body fluids Assimilation – changing of absorbed substances into different substances Excretion – removal of wastes Digestion – breakdown of food substances

5 Requirements for Life Water - most abundant substance in body - required for metabolic processes - required for transport - regulates body temperature Food - supply energy - supply raw materials

5 Requirements for Life Oxygen - one-fifth of air - used to release energy from nutrients Heat - form of energy - partly controls rate of metabolic reactions Pressure - atmospheric pressure – important for breathing - hydrostatic pressure – keeps blood flowing

Homeostasis Body’s maintenance of a stable internal environment Homeostatic Mechanisms – monitor aspects of the internal environment and corrects any changes Control Center (set point) (change)(correction) Effectors Response Stimulus (muscles or glands) Receptors (provide info)

Negative feedback- maintains homeostatic  receptors receive info that is close to set point so effectors shut down  most feedback mechanisms in body use this  examples: thirst, respiration, body temperature Positive feedback- continues the production of… - receptors receive info and cause effectors to produce - examples: blood clot stimulates more clotting, baby suckles stimulates more milk Homeostasis Positive and Negative Feedback

Homeostatic Mechanisms Homeostasis

Levels of Organization 7. two or more different kinds of tissues joined together to perform a specific function a group of organs act together to perform a highly complex and specialized function

Levels of Organization

Body Cavities Human body can be divided into two portions:  Axial portion- includes the head, neck, and trunk Dorsal cavity Ventral cavity  Appendicular portion- includes the upper and lower limbs

Body Cavities

Dorsal posterior Ventral anterior Cranial brain Spinal spinal cord Thoracic Mediastinum major blood vessels, esophagus, trachea Pleural lungs Pericardial heart Abdominal liver, spleen, stomach, kidneys, lg/sm intestines Pelvic bladder, rectum, internal reproductive organs Abdominopelvic Diaphragm dome shaped muscle

Body Cavities

Smaller cavities within the head include:  Oral cavity – teeth and tongue  Nasal cavity – within the nose Divided by the nasal septum Includes several sinuses  Orbital cavities – eyes, muscles, nerves  Middle ear cavities – small ear bones

Body Cavities

Whiteboard Review!

Serous Membranes Thoracic Membranes Visceral pleura Parietal pleura Visceral pericardium Parietal pericardium Line walls of thoracic and abdominal cavities and organs Visceral layer – covers an organ Parietal layer – lines a cavity or body wall Abdominopelvic Membranes Visceral peritoneum Parietal peritoneum

Anatomical Reference Systems Anatomical Position – body standing erect, facing forward, upper limbs at the sides, palms facing forward define & describe location, position and relationship of one part to another in the body

Planes of Sections Transverse / Cross - divides the body into superior (upper) & inferior (lower portions

Planes of Sections Coronal or Frontal - divides the body into ventral (anterior) and dorsal (posterior) portions

Planes of Sections Sagittal / Midsagittal or Median - runs vertically and divides right & left

Terms of Direction ventral – anterior: toward the front dorsal – posterior: toward the back cranial – superior: uppermost part (head) caudal – inferior: lowermost part (feet) medial: toward the midline lateral: away from the midline proximal: nearest the point of attachment distal: away from the point of attachment

Terms of Direction superficial - peripheral: toward the surface deep: away from the surface parietal: pertains to the outer layer or wall visceral: pertains to the covering of an organ ipslateral: on the same side contralateral: positioned on the opposite side of something else

Body Cavities

Organ Systems - composed of bones, cartilage, & joints - provides support & framework for vital organs - serves as a place for muscle attachment - consists of striated, smooth & cardiac muscle - striated (skeletal) muscle is responsible for movement - smooth muscle is found in hollow organs - cardiac muscle is found in the heart

Organ Systems - consists of the largest organ in the body; skin and accessory organs - protects underlying tissues - helps regulate body temperature

Organ Systems - consists of the brain, spinal cord, nerves, & special sense organs - highly integrated - senses environmental changes (stimuli) - enables reaction to changes, the ability to think, & coordinates the activities of the other systems - regulates the body’s responses to changes in the external environment -*all this adds up to homeostasis - consists of ductless glands; pituitary, pineal, thyroid, parathyroid, adrenals & portions of the pancreas, ovaries, & testes - secretes hormones directly into the blood stream to target organs throughout the body -coordinates many of the body’s physiological activities -regulates the body’s internal processes

Organ Systems Circulatory - distribute blood throughout the body - consists of heart, blood vessels and blood - transports O 2, absorbed nutrients and hormones - consists of lymph vessels, lymph nodes and lymph - function includes immunity

Organ Systems Digestive System - consists of a long tubular passage - ingests and digests food through physical & chemical processes - small intestines absorbs most of the nutrients - large intestine absorbs water & eliminates undigested materials - accessory organs include: salivary glands, pancreas, liver & gallbladder Respiratory System - consists of nose, pharynx, larynx, trachea, bronchi, and lungs - provides the body with a continuous supply of O 2 - rids body of CO 2

Organ Systems Respiratory System - consists of nose, pharynx, larynx, trachea, bronchi, and lungs - provides the body with a continuous supply of O 2 - rids body of CO 2 Urinary System - comprised of kidneys, ureters, urinary bladder, urethra - eliminates excess water, various salts, foreign substances & cellular waste products - maintains constant internal conditions

Organ Systems male organs: testes, epididymis (sperm storing tubules), vas deferens (sperm ducts), seminal vesicles, prostate, penis and urethra female organs: ovaries, oviducts (fallopian tubes), vagina, external genitalia - designed to perpetuate the species - influences maturation and development