CHAPTER ONE THE HUMAN BODY An Orientation I

CHAPTER ONE: THE HUMAN BODY: An Orientation

I. WHAT IS ANATOMY? Anatomy = study of the structure and shape of body parts and how they relate to each other Ana = apart Tomy = to cut What does anatomy literally mean? To cut apart

THREE MAIN TYPES OF ANATOMY 1. Gross 2. Microscopic 3. Developmental

GROSS ANATOMY 1. Gross anatomy (macroscopic) = the study of large body structures visible to the naked eye, such as the: - heart - kidney - lung A. Regional Anatomy = All of the structures in one particular region of the body, such as the abdomen or leg. B. Systemic Anatomy = the gross anatomy of the body is studied system by system. C. Surface Anatomy = the study of body structures as they relate to the overlying skin

MICROSCOPIC ANATOMY 2. Microscopic Anatomy = Concerns structures too small to be seen with the naked eye. A. Cytology = the study of cells cyto = cell B. Histology = the study of tissues histo = tissue

DEVELOPMENTAL ANATOMY 3. Developmental anatomy = traces structural changes that occur in the body throughout the life span A. Embryology = concerns environmental changes in the embryo prior to birth

SPECIALIZED BRANCHES OF ANATOMY Used primarily for medical diagnosis and scientific research. Anatomic Pathology = the study of structural changes caused by disease Radiographic Anatomy = studies internal structures through x-ray Molecular Biology = the structure of biological molecules is investigated.

TOOLS FOR STUDYING ANATOMY 1. Anatomic terminology 2. Observation 3. Manipulation 4. Palpation = feeling organs with your hands 5. Auscultation = listening to organ sounds with a stethoscope

II. WHAT IS PHYSIOLOGY? Physiology = study of how the body and its part work or function Physio = nature Ology = the study of What does physiology literally mean? The study of nature

TYPES OF PHYSIOLOGY 1. Renal Physiology = considers kidney function and urine production 2. Neurophysiology = Explains the functioning of the nervous system 3. Cardiovascular Physiology = Studies the functioning of the heart and blood vessels

III. ANATOMY AND PHYSIOLOGY Anatomy and physiology are always related Each part of your body has a job (function) Structure determines the function Principle of complementarity of structure and function: what a structure can do depends on its specific form Examples? ? Bones Heart

IV. LEVELS OF STRUCTURAL ORGANIZATION 1. Chemical 2. Cellular 3. Tissue 4. Organ 5. Organ system 6. Organism

Organ Systems 1. Integumentary 10. Urinary 2. Skeletal 11. Reproductive 3. Muscular 4. Nervous 5. Endocrine 6. Cardiovascular 7. Lymphatic/Immunity 8. Respiratory 9. Digestive

V. MAINTAINING LIFE Necessary Life Functions 1. Maintaining boundaries – separating internal vs. external environments 2. Movement 3. Responsiveness – reaction to stimuli 4. Digestion – breaking down food/chemicals 5. Metabolism – all chemical reactions in a body 6. Excretion – getting rid of wastes 7. Reproduction – producing new cells for growth 8. Growth – occurs when building activities are faster than destroying activities

V. MAINTAINING LIFE Survival Needs 1. Nutrients – carbohydrates, proteins, fats, and minerals 2. Oxygen – necessary for cellular respiration 3. Water – basis of body fluids, 60% of body weight 4. Normal body temperature 5. Atmospheric pressure – needed for proper breathing Just having these needs are not enough You need to have them at the correct amounts

VI. HOMEOSTASIS • Homeostasis = ability of the body to maintain relatively stable internal conditions even though the outside world changes continuously

NEGATIVE FEEDBACK Negative feedback mechanisms = causes the variable to change in the opposite direction, returning to its ideal level. Examples: 1. Regulation of body temperature 2. Blood Sugar 3. Heart Rate Others? ?

EXAMPLES OF HOMEOSTASIS CONTROLLED BY NEGATIVE FEEDBACK

POSITIVE FEEDBACK Positive feedback mechanisms: the response enhances the original stimulus so the original activity is accelerated Less common than negative feedback Examples 1. Blood Clotting 2. Enhancement of labor contractions during childbirth

EXAMPLE OF POSITIVE FEEDBACK

Why would you have a hard time learning and understanding physiology if you did not also understand anatomy?

The Language of Anatomy

I. THE LANGUAGE OF ANATOMY Why use a special kind of language? Why can’t we just say things like, above or below? The human body has so many different shapes and areas to it that saying “above” or “below” is not specific enough We need a special language in order to know exactly which location someone is talking about

II. ANATOMICAL POSITION Most body terminology refers to the body when it is in anatomical position Anatomical position = body is upright, feet parallel, and arms hang at the side with palms facing forward (thumbs pointing away from the body)

Anatomical Position

III. DIRECTIONAL TERMS Directional terms = allow anatomists and medical personnel to explain where one body structure is in relation to another How would YOU describe where your ears are in relation to your nose? Anatomists would say the ears are lateral to the nose

Directional Terms Superior (cranial or cephalad) = above, toward the head Inferior (caudal) = below, towards lower part of body Ventral (anterior) = in front of, on the front side of the body Dorsal (posterior) = behind, on the backside of the body

Directional Terms Medial = towards the midline of the body Lateral = away from the midline of the body Intermediate = between a more medial and a more lateral structure

Directional Terms Proximal = close to the trunk of the body Distal = away from the truck of the body Superficial = towards or at the surface of the body Deep = away from the surface, internal

Directional Terms

Practicing Directional Terms Using the definitions above or Table 1. 1 on pg. 15 of your text, use the correct direction term to complete the sentence. The breastbone is ________ to the spine. The brain is __________ to the spinal cord. The ankle is _________ to the foot. The skin is _________ to the muscles.

IV. REGIONAL TERMS Regional terms are used point to specific parts on the surface of the body To make it slightly easier, we will split the regional terms up into two groups: anterior and posterior

Anterior Body Landmarks Abdominal = anterior body trunk, inferior to ribs Acromial = shoulder Antebrachial = forearm Antecubital = anterior surface of elbow Axillary = armpit

Anterior Body Landmarks Brachial = arm Buccal = cheek Carpal = wrist Cervical = neck Coxal = hip Crural = leg

Anterior Body Landmarks Deltoid = curve of shoulder made by the deltoid muscle Digital = fingers and toes Femoral = thigh Fibular = lateral part of leg Frontal = forehead

Anterior Body Landmarks Inguinal = area where thigh meets body trunk, groin Mental = chin Nasal = nose area Oral = mouth Orbital = eye area Patellar = anterior knee

Anterior Body Landmarks Pelvic = area overlying the pelvis Pubic = genital region Sternal = breastbone area Tarsal = ankle region Thoracic = chest Umbilical = navel

Posterior Body Landmarks Calcaneal = heel of foot Cephalic = head Femoral = thigh Gluteal = buttock Lumbar = area of back between ribs and hips Occipital = posterior surface of head, base of skull

Posterior Body Landmarks Olecranal = posterior surface of elbow Plantar = sole of foot Popliteal = posterior knee area Sacral = area between hips Scapular = shoulder blade region Sural = posterior surface of leg, the calf Vertebral = area of spinal column

V. BODY PLANES AND SECTIONS Section = cut Plane = imaginary line in which a section is made through the body wall or organ Three main types of sections: 1. Sagittal 2. Frontal 3. Transverse

Sagittal Section Sagittal section = cuts along the lengthwise plane of the body Divides the body into right and left parts Median (midsagittal) section = sagittal cut directly down the midline of the body, making equal right and left halves Any sagittal section that is not median, is parasagittal Para = near

Sagittal Section

Frontal Section Frontal section = lengthwise cut that divides the body (or organ) into anterior and posterior parts Can also be called a coronal section

Frontal Section

Transverse Section Transverse section = a cut along a horizontal plane that divides the body or organ into superior and inferior parts Can also be called a cross section

Transverse Section

VI. BODY CAVITIES Two main body cavities: 1. Dorsal 2. Ventral Each cavity (dorsal and ventral) also contains smaller cavities and regions

Dorsal Cavity Has two subdivisions: 1. Cranial cavity = space inside the bony skull Brain is protected in this cavity 2. Spinal cavity = extends from the cranial cavity to the end of the vertebral column Spinal cord is protected in this cavity by the vertebrae

Dorsal Cavity

Ventral Cavity Much larger than the dorsal cavity Contains all structures within chest and abdomen

Ventral Cavity Three subdivisions: 1. Thoracic cavity = contains lungs, heart, trachea Separated from the other two cavities by the diaphragm 2. Abdominal cavity = contains stomach, liver, intestines, pancreas, gallbladder, spleen 3. Pelvic cavity = contains reproductive organs, bladder, and rectum Abdominal and pelvic cavities aren’t actually separated by anything, so they are usually referred to as the abdomoinopelvic cavity

Abdominopelvic Regions Abdominopelivic region can be separated into four quadrants or nine regions The nine regions are: 1. Umbilical region = center region, around navel 2. Epigastric region = superior to umbilical region 3. Hypogastric region = inferior to the umbilical region 4. Right and left iliac regions = lateral to hypogastric region 5. Right and left lumbar regions = lateral to the umbilical region 6. Right and left hypochondriac regions = lateral to the epigastric region

Abdominopelvic Regions

Other Body Cavities 1. Oral and digestive cavities = mouth and digestive organs leading to the anus, which opens to the exterior 2. Nasal cavity = within and posterior to the nose, part of the respiratory system 3. Orbital cavities = contain the eyes 4. Middle ear cavities = medial to the ear drums, contain our body’s three smallest bones