Anatomy: Study of body structureAnatomy: Study of body structure Physiology: Study of function of...

• Anatomy: Study of body structure

• Physiology: Study of function of body parts

Structure is always related to function

• Developmental Anatomy: Study of structural changes between conception and adulthood

• Embryology: Study of the changes in fetus, Changes from conception to the eighth week

• Gross or macroscopic: structures examined without a microscope – naked eyes

– Systemic: body is studied system by system

– Regional: body is studied area by area– Surface: study of external form of body and

relation to deeper structures

• Microscopic: structures seen with the microscope

– Cytology: study structural feature of cells– Histology: study of tissues

Physiology: Study of function of body parts or living things

Goal of physiology is to understand how stuff works

How do muscles contract? How do we run? How does our heart beat?

– Cell physiology: examines functioning of cells

– Systemic physiology: studies functions of organ systems

– Neurophysiology: focuses on the nervous system

– Cardiovascular physiology: the heart and blood vessels

Subjects That Encompass Both Anatomy and Physiology

• Pathology: structural and functional changes caused by disease

• Exercise Physiology: changes in structure and function caused by exercise

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• Cell - Smallest unit of life• Cell is the basic structural and

functional unit of plants and animals

Tissue Level: group of similar cells and the materials surrounding them

Organ Level: one or more tissues functioning 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 Synthesizes vitamin D Location of cutaneous

nerve receptors regulates temperature

Skeletal SystemBones, ligaments, tendonsProtects and supports

body organs: brain, heart, reproductive organs

Provides muscleattachment for movement

Site of blood cellformation

Stores minerals

Muscular SystemSkeletal muscles, smooth muscles,

cardiac musclesAllows locomotion and movement of contents through the

organsMaintains postureProduces heat

Nervous SystemConsists of brain, spinal cord,

nerves, sensory receptorsFast-acting control

systemResponds to internal and external

changeActivates body effectors (muscles

andglands)

Endocrine System Endocrine glands: pineal, pituitary, thyroid,

thymus, adrenal, pancreas, testis and ovaries Secretes regulatory

hormones Growth Reproduction Metabolism

Cardiovascular System Heart, Blood vessels Transports materials in body via blood pumped by

heart Oxygen Carbon dioxide Nutrients Wastes

Lymphatic SystemLymphatic vessels, lymphatic glands,

lymph nodes and lymph organs such as spleen, tonsils Returns fluids to blood vessels Cleanses the blood Involve in immunity

Respiratory SystemNasal cavity, pharynx, larynx, trachea, bronchi, lungsKeeps blood supplied with

oxygenRemoves carbon dioxideProduction of sound

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

Urinary SystemKidney, ureter, urinary bladder, urethraEliminates nitrogenous wastesRegulates water and electrolytes Maintains acid – base balance

Reproductive SystemTestis, penis, accessory glands,

vas deferensOvary, uterine tube, uterus

vaginaProduction of sex cells: eggs

and spermsProduction of offspring

Most common feature of Organism is life Characteristics of life: Organization: Specific relationships between the parts

of organism and their functions Disruption of organized state – result in loss of functions Metabolism: all chemical reactions of the body• Facilitated by digestive, respiratory, cardiovascular ,

endocrine systems– Production of energy– Making body structures– Metabolism is necessary for growth, development,

reproduction Responsiveness: ability to sense changes and adjust

Growth: increase in size and/or number of cells

Development: changes in an organism over time From fertilization to death

Reproduction: Formation of new cells or new organisms

• Homeostasis: Maintenance of a stable internal environment of the body

• Internal environment is the interstitial fluid surrounding the cells

• Some of the body parameters kept in a steady state:

• Body temperature: regulated close to 370C

• Blood pH: kept at 7.4

• Arterial blood pressure: maintain around 120/80 mm Hg

• Failure of homeostasis causes diseases and sometimes death

• Homeostatic Mechanisms – monitor aspects of the internal environment and corrects any changes

• Eg. Sweating, shivering maintain body temperature near set point (ideal normal value)

• Fluctuate around the set point to establish a normal range of values

• Two types: negative and positive Feedback• Negative Feedback : maintains homeostasis• Three components:

– Receptor: monitors the value of some variable– Control center: Receives information about variable

from receptor & establishes the set point and controls the effector

– Effector: can change the value of the variable

• 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: childbirth

• Anatomical Position– Person standing erect, face

forward, feet together, palms face forward

• Other Body Positions– Supine: lying face upward– Prone: lying face downward

• Directional Terms – Describe parts of the body relative to each other– Superior (Cephalic) – up, toward the

head

– Inferior (Caudal) – down, toward the tail

– Medial – toward midline

– Lateral – away from midline

– Proximal – nearest to trunk

– Distal – distant to trunk– Proximal and distal terms are used when

referring to limb

• 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

• Anterior or Ventral – front

• Posterior or Dorsal – back

• Terminology for different parts of the body:

• Upper limb is divided into:• Arm, forearm, wrist and 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

• 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

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

Planes of Section Through an Organ

• To observe the internal

structure, organs are sectioned:

• Longitudinal: cut along the length of an organ

• Cross/Transverse: cut at right angle to length of the organ

• Oblique: cut at any but a right angle

• 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• Surrounded by abdominal muscles

• Pelvic cavity: Contains urinary bladder, part of large intestine, internal reproductive organs• Surrounded by pelvic bones

• Abdominal and pelvic cavity is not physically separated – Abdominopelvic cavity

• Serous membrane: Walls of the body cavity and outer surface of the organs are covered by thin tissue membrane known as serous membrane

• Serous membranes occur in pairs separated by serous fluid

– Visceral layer covers the outside of the organ

– Parietal layer lines a portion of the wall of ventral body cavity

• Thoracic cavity contains 3 serous membranes:

• Serous membrane in the pleural (lung) cavity is called PLEURA

• Visceral Pleura: Membrane surrounds the surface of lungs

• Parietal Pleura: Lines the inner surface of thoracic wall

• Serous membrane in the pericardial (heart) cavity is called PERICARDIUM

• Serous membrane in the abdominopelvic cavity is called PERITONEUM