Anatomy: Study of structure and shape of the body Physiology: Study of function of body parts Structure is always related to function

Gross Anatomy: structures examined without a microscope – naked eyes eg. Organs Microscopic Anatomy: structures seen with the microscope eg. Cells, tissues

–Neurophysiology: Function of the nervous system –Cardiac physiology: function of the heart

 Six levels of Organization of body  Chemical Level: - atoms - atoms combine & form molecules - eg. Water, sugar, DNA  Cellular Level: Molecules combine – organelles eg. Nucleus, Mitochondria  a cell is a collection of organelles functioning together  smallest unit of life

 Tissue Level: group of similar cells  Organ Level: consists of two or more tissues, function together  Organ System Level: group of organs functioning together  Organism Level: any living thing, eg. Human

Integumentary System –Eg. Skin, glands, hair, nails –Forms the external body covering –Protects deeper tissue from injury –Location of cutaneous nerve receptors – Prevent water loss –regulates temperature

Skeletal System –Bones, ligaments, tendons –Protects and supports body organs: brain, heart, reproductive organs –Provides muscle attachment for movement –Site of blood cell formation –Stores minerals

Muscular System –Skeletal muscles, smooth muscles, cardiac muscles –Allows locomotion and movement of contents through the organs –Maintains posture

Nervous System –Consists of brain, spinal cord, nerves, sensory receptors –Controls body activities –Responds to internal and external change –Activates body effectors (muscles and glands)

Endocrine System –Like nervous system, ES also controls body activities –Endocrine glands: pineal, pituitary, thyroid, thymus, adrenal, pancreas, testis and ovaries –Secretes hormones Growth Reproduction Metabolism Controlled by hormones

Cardiovascular System –Heart, Blood vessels –Transports materials in body via blood pumped by heart Oxygen Carbon dioxide Nutrients Wastes

Lymphatic System Lymphatic vessels, lymphatic glands, lymph nodes and lymph organs such as spleen, tonsils –Returns fluids to blood vessels –Cleanses the blood –Involve in immunity

Respiratory System Nasal cavity, pharynx, larynx, trachea, bronchi, lungs –Keeps blood supplied with oxygen –Removes carbon dioxide –Production of sound

Digestive System Mouth, esophagus, stomach, intestine, anus, liver, pancreas –Breaks down food –Allows for nutrient absorption into blood –Eliminates indigestible material

Urinary System Kidney, ureter, urinary bladder, urethra –Eliminates nitrogenous wastes –Regulates water and electrolytes – Maintains acid – base balance of the blood

Reproductive System Testis, penis, accessory glands, vas deferens Ovary, uterine tube, uterus vagina –Production of sex cells: eggs and sperms –Production of offspring

 Most common feature of Organism is life  Necessary Life Functions:  Organization: Human is an organism in which all the organ system work in unison  Disruption of organized state – result in loss of functions Maintain Boundaries: outside and inside are maintained separately eg. Cell membrane, integumentary system Movement: facilitated by bones, ligaments, tendons, muscles –Locomotion –Movement of substances, eg. Blood, food, urine etc.

 Responsiveness: ability to sense changes and react  Digestion: Break-down and absorption of nutrients  Delivery of nutrients  Metabolism: all chemical reactions of the body Facilitated by digestive, respiratory, cardiovascular, endocrine systems –Production of energy –Making body structures

 Excretion:  Elimination of waste from metabolic reactions  Takes the help of blood, digestive system and excretory system  Reproduction: Formation of new cells or new organisms  Growth: increase in size and/or number of cells

Goal of all body systems is to maintain life Nutrients –Body takes nutrients through food –Food contains chemicals for energy and cell building –Includes carbohydrates, proteins, lipids, vitamins, and minerals Oxygen –Oxygen is required for chemical reactions which release energy from food Water –60–80% of body weight –Provides for metabolic reaction Stable body temperature: 37 0 C Atmospheric pressure: must be appropriate

 Homeostasis: Maintenance of a stable internal environment of the body  Homeostasis must be maintained for normal body functioning and to sustain life, For eg.  Body temperature: regulated close to 37 0 C  Blood pH: kept at 7.4  Arterial blood pressure: maintain around 120/80 mm Hg  Homeostatic Imbalance - Disturbance in homeostasis causes diseases

The body communicates through neural and hormonal control systems Have three components –Receptor Type of sensor that monitors and responds to changes in the environment (stimuli) Sends information to control center

–Control center Determines set point Analyzes information Determines appropriate response –Effector Provides a means for response to the stimulus

Negative feedback –Includes most homeostatic control mechanisms –Shuts off the original stimulus, or reduces its intensity –Works like a household thermostat E.g. Maintenance of body temperature irrespective of out side temperature Maintenance of blood pressure

Not homeostatic, rare in healthy individuals If change occurs in some variable, system responds to the change in the same direction –Eg. after hemorrhage, blood pressure drops and the heart’s ability to pump blood decreases – Which causes blood pressure to drop further – And homeostasis is not maintained –Normal positive feedback: Blood clotting and childbirth

The Language of Anatomy Special terminology is used to prevent misunderstanding Anatomical position: –Body is erect with feet straight and facing in front, arms on the side with palms facing front Exact terms are used for: –Position –Direction –Regions –Structures

Directional Terms – Describe parts of the body relative to each other –Superior (Cephalic) – up, toward the head –Inferior (Caudal) – down, toward the tail –Anterior or Ventral – front –Posterior or Dorsal – back

–Medial – toward midline –Lateral – away from midline –Intermediade – Between medial and lateral –Proximal – nearest to trunk

–Distal – distant to trunk –Superficial - near the outer surface of the organism eg. skin is superficial to the muscle layer –Deep - away from the surface of the organism eg. Muscle layer is deep to the skin

Terminology for different parts of the body: Upper limb is divided into: Arm, forearm, wrist & hand Arm: extends from shoulder – elbow Forearm: extends from elbow – wrist Lower limb is divided into: Thigh, leg, ankle and foot Thigh: extends from hip – knee Leg: extends from knee – ankle

Central region of the body consists of: Head, neck and trunk Trunk can be divided into: Thorax: chest Abdomen: region between thorax and pelvis, inferior to ribs Pelvis: Inferior end of the trunk associated with hip

 In order to look at the internal structure of the body, medical professionals divide the body into different sections or imaginary planes passing through it  Sagittal Plane: Runs vertically through the body, separating into R and L portions  Median or Midsagittal Plane: Is a sagittal plane, passes through midline of body, divide into equal R & L halves  Frontal or Coronal: divides body into anterior and posterior sections  Transverse / Cross: Runs parallel to ground, divides body into superior and inferior sections

Body Cavities: Spaces within the body contain internal organs Two sets of body cavity Dorsal body cavity –Cranial cavity - houses the brain –Spinal cavity - houses the spinal cord

Ventral body Cavity: contains 3 cavities: Thoracic, abdomen, pelvic Thoracic cavity: surrounded by rib cage, contains heart, thymus, trachea, esophagus, lungs Mediastinum : Central region divide thoracic cavity into R and L parts Lungs are located on each side of mediastinum Diaphragm separates thoracic cavity from abdominal cavity

Abdominal cavity: Contains stomach, intestines, liver, spleen, pancreas, kidneys Pelvic cavity: Contains urinary bladder, rectum, reproductive organs Abdominal and pelvic cavity is not physically separated – Abdominopelvic cavity

Abdomen is sometimes divided into quadrants by two imaginary line which intersect at navel Right-upper quadrant Left-upper quadrant Right-lower quadrant Left-lower quadrant

Abdomen is sometimes divided into nine regions by four imaginary lines: Epigastric Right and left hypochondriac Umbilical region Right and left lumbar Hypogastric Right and left iliac Physicians use the quadrants and regions as a reference point to locate underlying organs