humanbody

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The Human Body:

An Orientation Part 1

Joselito B. Diaz, MD, FPNA

College of Rehabilitation Sciences

University of Santo Tomas

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Anatomy

Ana- (apart) -tomy (to cut)

The study of internal & external structures

of the body and the physical relationships

between body parts

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Anatomy

Gross Anatomy

study of large and easily observable structures

considers features visible with the unaided eye

surface anatomy

Microscopic anatomy

study of very small structures with the use of microscope or magnifying lens

considers structures that cannot be seen without magnification

e.g. cells, tissues

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Physiology

Derived from physio = nature; ology = the

study of

The study of how living organisms perform

their vital functions

It considers the physical & chemical

processes responsible for the characteristics

of life

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Relationship Between

Anatomy & Physiology

The parts of the body form a well-organized

unit and each of these parts has a job to do

to make the body operate as a whole

Structure determines what functions can

take place

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Levels of Structural Organization

From Atoms to Organisms

Chemical level

Cellular level

Tissue level

Organ level

Organ System

Organismal level

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Chemical level

• Atoms and molecules

Cellular level

• Cells are the smallest units of all living things

• Cells vary according to their function

Tissue level

• Tissues consist of group of similar cells that have a

common function

• Epithelial, connective, muscular and neural

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Organ level

• Organ is a structure composed of 2 or more tissue types that performs a specific function for the body

• Complex functions are possible

Organ System

• Group of organs that operate to accomplish a common purpose

Organismal level

• Highest level of structural organization

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Organ System Overview

Integumentary System

Skeletal System

Muscular System

Nervous System

Endocrine System

Cardiovascular System

Lymphatic System

Respiratory System

Digestive System

Urinary System

Reproductive System

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Integumentary System

forms the waterproof skin or the external body

covering

cushions and protects the deeper tissues from

injury

helps regulate body temperature

excretes salts and urea in perspiration

contains temperature, pressure and pain receptors

synthesizes vitamin D

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Skeletal System

consists of bones, cartilages, ligaments and

joints

supports and protects body organs

provides leverage for locomotion

site of hematopoiesis or blood cells formation

storehouse of minerals

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Muscular System

formed by skeletal muscles

allows manipulation of the environment,

locomotion and facial expression

helps to maintain posture

produces heat

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Nervous System

composed of brain, spinal cord, nerves, sensory

receptors

the body’s fast-acting control system

responds to internal and external changes by

activating appropriate effectors (muscles and

glands)

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Endocrine System

consists of ductless glands that secrete

hormones to regulate bodily processes such as

growth, reproduction and metabolism

includes the pituitary, thyroid, parathyroids,

adrenals, thymus, pancreas, pineal, ovaries and

testes

not connected anatomically

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Cardiovascular System

the heart and blood vessels are the primary

organs

carries oxygen, nutrients, hormones and other

substances to and from the tissues cells where

exchanges are made

protection from foreign invaders

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Lymphatic System

includes lymphatic vessels, lymph nodes and

other lymphoid organs

returns leaked fluids from blood to the blood

vessels so that blood can be kept continuously

circulating through the body

cleanses the body and contains cells involved

in immunity

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Respiratory System

consists of nasal passages, pharynx, larynx,

trachea, bronchi and lungs

keeps blood constantly supplied with oxygen

and removes carbon dioxide

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Digestive System

basically a tube running through the body from

the mouth – esophagus – stomach – intestines –

rectum – anus

also includes the liver and pancreas

breaks down food and delivers the product to

the blood for dispersal

eliminates undigested food as feces

reclaims water in the large intestine

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Urinary System / Excretory System

composed of kidney, ureters, bladder and

urethra

eliminates nitrogenous wastes from the body

regulates water, electrolytes and acid-base

balance of the blood

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Reproductive System

for the production of offspring

Male Reproductive System

• Testes, scrotum, penis, accessory glands and duct

system

Female Reproductive System

• Ovary, uterine tubes, uterus and vagina

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Necessary Life Functions

Maintaining Boundaries

Movement

Responsiveness

Digestion

Metabolism

Excretion

Reproduction

Growth

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Maintaining Boundaries

Membranes

• Keep the inside distinct from the outside

Skin

• Protects internal organs from drying out, from

bacteria and from damaging effects of heat, sunlight

and chemical substances

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Movement

Propelling oneself from one place to another

Manipulating the external environment

Propelling blood, foodstuffs and urine through

the organs

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Responsiveness / Irritability

ability to sense changes in the environment and

then to react to them

Digestion

process of breaking down ingested food into

simpler molecules that can then be absorbed

into the blood for delivery

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Metabolism

Chemical reactions that occur within the body

cells

• Catabolism

Breaking down complex substances into simpler

building blocks

• Anabolism

Making larger structures from smaller ones

Regulated chiefly by hormones secreted by

the glands of the endocrine system

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Excretion

process of removing wastes from the body

get rid of the useless substances produced

during digestion and metabolism

Reproduction

the production of offspring

cellular or organismal level

mitosis/ meiosis

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Growth

increase in size brought about, usually, by an

increase number of cells

cell-constructing activities must occur at a

faster rate than cell-destroying ones

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Maintaining Life

Survival Needs Nutrients

• Carbohydrates, fats, proteins, vitamins and minerals

Oxygen

• Needs for release of energy from food

Water

• 60-80% of body weight

Body temperature (370C or 980F)

Atmospheric pressure

• Force exerted on the surface of the body by weight of air

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Homeostasis

The body’s ability to maintain relatively

stable internal conditions even though the

outside world is continuously changing

Indicates a dynamic state of equilibrium

Imbalances will lead to development of

diseases and illnessess

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Homeostatic Control Mechanism

accomplished chiefly by the nervous and endocrine systems

3 Components

Receptor

• Some type of sensor that monitors and responds to changes in the environment bringing the information via afferent pathway

Control center

• Determines the level at which a variable is to be maintained, analyzes the information it receives and then determines the appropriate response or course of action

Effector

• Information flows via efferent pathway

• Means of response /output to the stimulus

Nervous System

CORRELATION

COORDINATION

MEMORY

SENSORY

STIMULI Afferent Efferent

MUSCLES

GLANDS

Etc.

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Feedback Mechanisms

Negative Feedback Mechanism

the net effect of the response to the stimulus is to shut

off the original stimulus or reduce its intensity

thermostat action of hypothalamus, heart rate, BP, etc.

Positive Feedback Mechanism

rare in the body

causes an increase in the intensity of the original

stimulus

blood clotting and birth of a baby

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The Human Body:

An Orientation Part 1

Joselito B. Diaz, MD, FPNA

College of Rehabilitation Sciences

University of Santo Tomas

humanbody

Documents

organisms organ level

acting control system

external body

body parts

organisms chemical level

body temperature

body organs

function tissue level