Organs of the human body

              Fig 1: Organs of the human body.

Divisions of physiology

As you learnt earlier, physiology is the study of the function of
anatomical structures. Human physiology is the study of the functions of
the human body. These functions are complex and much more difficult
to examine than most anatomical structures. As a result, there are even
more specialties in physiology than in anatomy, which includes:

i. Cell physiology: This is the cornerstone of human physiology; it
is the study of the functions of cells. It deals with events at the
chemical and molecular levels.

ii. Special physiology: this is the study of the physiology of special
organs. For example, renal physiology is the study of kidney
function.

iii. Systemic physiology: includes all aspects of the function of
specific organ systems; cardiovascular physiology, respiratory
physiology and reproductive physiology are examples of
systemic physiology.

iv. Patho-physiology is the study of the effects of diseases on organ
or system functions (pathos is the Greek word for “disease”).
Modern medicine depends on an understanding of both normal
physiology and patho-physiology

THE STUDY OF DISEASE

Acute: characterized by sudden onset
Aerobe: an organism that lives in an oxygen environment
Ambulatory: able to walk
Anaerobe: an organism that lives in an oxygen-free environment

Anaplasia: the irregular structural characteristics of a cell that identify it as a malig-
nant cancer cell

Anomaly: an abnormal occurrence, especially in reference to birth defects
Antibiotic: a chemical substance derivable from a mold or bacterium that kills
microorganisms and cures infections
Antibody: a protein produced by the body as part of its defense against foreign
bacteria or blood cells
Antisepsis: the prevention of sepsis by excluding or destroying microorganisms
Antiseptic: a substance that kills or prohibits the growth of microorganisms
Asepsis: free from germs
Atrophy: a wasting away or decrease in size of a cell, tissue, organ, or part of the
body caused by lack of nourishment, inactivity, or loss of nerve supply
Autoimmunity: a situation in which the body produces an immune response against
its own organs or tissues, causing severe inflammation and chronic conditions
Bacteria: microorganisms capable of reproduction; some strains cause infection
(and some are beneficial)

Benign: referring to a tumor, or abnormal growth, that is not cancerous and does not
invade nearby tissues or spread to other parts of the body
Chronic: slow developing, recurring
Degenerative: characterized by diminishing capabilities
Diagnosis: the identification of disease or trauma
Disease: an impairment of health that interferes with the body’s ability to function
normally
Disinfect: the prevention of sepsis by excluding or destroying microorganisms
Endemic: characterizing a disease that exists in a location or group of people all the
time
Epidemic: a sudden outbreak of disease in numbers much higher than normal
Etiology: the study of the cause and origin of disease
Exacerbation: a marked increase in symptoms or severity of disease

Fungus: a mold, yeast, or mushroom; some fungi are beneficial; some, such as ring-
worm and athlete’s foot, are not.

Hereditary: genetically passed from parent to child
Hyperplasia: an increase in the number of cells in an organ or tissue
Idiopathic: of unknown origin
Infection: the invasion and growth of microorganisms that may cause cellular injury
in tissue
Inflammation: a protective response from the body in response to infection or injury,
characterized by swelling, heat, redness, and pain
Local: affecting only one part
Malignant: cancerous; a growth with a tendency to invade and destroy nearby tissue
and spread to other parts of the body
Morbid: diseased or sick
Morbidity: any departure, subjective or objective, from a state of physiological or
psychological well-being
Neoplasm: an abnormal growth of tissue that may be benign or malignant
Pandemic: an epidemic that affects an expanded demographic area
Pathogenesis: the origin and development of disease
Pathology: the study of disease

Pathophysiology: the study of how disease and/or trauma alters the normal func-
tioning of the body

Signs: the evidence of disease as perceived by the doctor
Sterilize: to destroy bacteria and other microorganisms
Symptoms: the subjective evidence of disease as perceived by the patient
Syndrome: a group of signs or symptoms characteristic of a particular disease or
abnormal condition
Systemic: affecting the whole body
Trauma: a physical injury or wound caused by an external force of violence, which
may cause death or permanent disability. Trauma is also used to describe severe
emotional or psychological shock or distress.
Virulence: the ability of an organism to cause disease
Virus: an intracellular parasite that causes disease

PATHOLOGY: THE STUDY OF DISEASE

Disease can be defined as an impairment of health that interferes with the body’s abil-
ity to function normally. Injuries, poisonings, the introduction of foreign substances,

and environmental problems do not strictly fall into the category of disease but they
cause their own pathologies nonetheless.
As mentioned, each body system chapter contains its own section on pathology.
But here we will review some general terminology associated with disease and injury.
Let us start by looking at the roots of the word pathology. The suffix –ology means the

study of, and the prefix path– means feeling or suffering, from the Greek pathos, mean-
ing disease. There are two main types of pathology. Anatomical pathology focuses on

the study of tissues removed from a dead or living person to diagnose disease or cause
of death. Clinical pathology is actually a number of subdisciplines that are often

referred to as laboratory medicine: chemistry, histology, microbiology, and other spe-
cialties. To go even further, pathophysiology is the study of how disease and trauma

alter the normal functioning of the body.

To know what is abnormal, you must first know what is normal—not just regard-
ing disease but also regarding simple body function. You may encounter questions on

the test pertaining to normal blood pressure, normal body temperature, normal blood
pH, and so on.

Directional Terminology

While studying the human body, it is vital to know directional terminology. The body
can be described by planes of division (Fig. 3.1). The frontal plane divides the body
into anterior and posterior positions. The frontal plane is also called the coronal plane.
The sagittal plane divides the body into left and right sections; the midsagittal plane
divides the body into equal left and right sections. The transverse plane, which divides
the body into upper and lower sections, is also called the horizontal plane. The body
is also described using anatomical directions as points of reference, as listed.
Anatomical position: standing erect, facing forward, arms at side, palms facing
forward
Anterior (ventral): toward the front; in front of
Caudal (inferior): toward the tail; lower
Cephalad: toward the head; upper
Cranial (superior): toward the head
Deep: far from the surface
Distal: away from a point of reference; farthest from the trunk
Dorsal (posterior): toward the back; in back of
Inferior (caudal): toward the tail; lower
Lateral: away from the midline of the body
Medial: toward the midline of the body
Posterior (dorsal): toward the back; in back of
Proximal: toward or nearest the trunk or point of reference
Superficial: near the surface

Xiaomi says MIUI 9 will be more frugal to run on your phone

It is often the hardware that gets most of the attention when a new Xiaomi smartphone is launched. But the success of Xiaomi can’t be attributed to its hardware prowess alone. Its custom interface, called the MIUI, is quite popular with mainstream users as it offers some unique features which are usually not found in stock Android devices. More importantly it allows user to change the look and feel of the interface by applying unqiue-looking themes.

The MIUI is often criticised for being too resource intensive. Xiaomi has tried to address those issues by optimising it better with its latest version, the MIUI 9.

It was announced in July and available in Beta since August. Its stable version is finally rolling out in phases and devices as old as the Mi3, launched in 2013, are eligible for the update. From the more recent crop of smartphones, available in India, the Redmi Y1, Mi MIX 2, Mi Max 2, Mi Max Prime, Mi5, Redmi Note 4, Redmi 4A, Redmi 3s and Redmi Note 3 are likely to get the update.

The Redmi Note 4, Mi Max 2, and Mi MIX 2, which will be updated on 3 November, will be the first to receive MIUI 9.

Xiaomi has also made subtle changes in the design of the new MIUI. The dock which carries the primary apps, doesn’t show text anymore, just like the dock in plain Android. More pre-loaded themes have been added providing users with more options to choose from. The official themes are developed by the phonemaker itself and look more polished and organised than user generated themes that one has to download from the online store.

The lock screen offers more shortcuts. But instead of cluttering the main lockscreen, Xiaomi has added a second screen to it. It shows up when you swipe left to right on lockscreen and duisplays up to five shortcuts chosen by user. User can get to the apps through the shortcuts the moment the phone unlocks.

There is a new section called App vault on the homepage on the lines of Shelf page in OnePlus’ Oxygen OS. You can access it by swiping left to right on home screen

It provides quick access to scores, calendar events, your favourite apps, and allows users to take quick notes and even book a cab.

Xiaomi claims the new MIUI is faster than its predecessor. The interface uses up less RAM as the software can now prioritise resources in a better manner. So even if there are multiple apps open in the background, the system resources will be allocated to apps that are running in the foreground. The apps will open a lot quicker now.

Xiaomi has also made improvements to a number of pre-loaded apps. The gallery app now offers more features such as the option to remove objects from an image, apply stickers and new filters. The Mi Video app can now club similar type of videos in different groups. It also supports file formats such as mkv.

Also, MIUI 9 offers features of Android 7, such as the split screen mode, in devices running on older version of Android.

Introduction to Anatomy Module 4: Functions of Human Life

By the end of this section, you will be able to:
• Explain the importance of organization to the function of the human organism
• Distinguish between metabolism, anabolism, and catabolism
• Provide at least two examples of human responsiveness and human movement
• Compare and contrast growth, differentiation, and reproduction
The different organ systems each have different functions and therefore unique roles to perform in physiology. These many
functions can be summarized in terms of a few that we might consider definitive of human life: organization, metabolism,
responsiveness, movement, development, and reproduction.
Organization
A human body consists of trillions of cells organized in a way that maintains distinct internal compartments. These
compartments keep body cells separated from external environmental threats and keep the cells moist and nourished. They
also separate internal body fluids from the countless microorganisms that grow on body surfaces, including the lining of
certain tracts, or passageways. The intestinal tract, for example, is home to even more bacteria cells than the total of all
human cells in the body, yet these bacteria are outside the body and cannot be allowed to circulate freely inside the body.
Cells, for example, have a cell membrane (also referred to as the plasma membrane) that keeps the intracellular
environment—the fluids and organelles—separate from the extracellular environment. Blood vessels keep blood inside
a closed circulatory system, and nerves and muscles are wrapped in connective tissue sheaths that separate them from
surrounding structures. In the chest and abdomen, a variety of internal membranes keep major organs such as the lungs,
heart, and kidneys separate from others.
The body’s largest organ system is the integumentary system, which includes the skin and its associated structures, such
as hair and nails. The surface tissue of skin is a barrier that protects internal structures and fluids from potentially harmful
microorganisms and other toxins.
Metabolism
The first law of thermodynamics holds that energy can neither be created nor destroyed—it can only change form. Your
basic function as an organism is to consume (ingest) energy and molecules in the foods you eat, convert some of it into fuel
for movement, sustain your body functions, and build and maintain your body structures. There are two types of reactions
that accomplish this: anabolism and catabolism.
• Anabolism is the process whereby smaller, simpler molecules are combined into larger, more complex substances.
Your body can assemble, by utilizing energy, the complex chemicals it needs by combining small molecules derived
from the foods you eat
• Catabolism is the process by which larger more complex substances are broken down into smaller simpler molecules.
Catabolism releases energy. The complex molecules found in foods are broken down so the body can use their parts to
assemble the structures and substances needed for life.
Taken together, these two processes are called metabolism. Metabolism is the sum of all anabolic and catabolic reactions
that take place in the body (Figure 1.6). Both anabolism and catabolism occur simultaneously and continuously to keep you
alive.
Anabolic reactions are building reactions, and they consume energy. Catabolic reactions
break materials down and release energy. Metabolism includes both anabolic and catabolic reactions.
Every cell in your body makes use of a chemical compound, adenosine triphosphate (ATP), to store and release energy.
The cell stores energy in the synthesis (anabolism) of ATP, then moves the ATP molecules to the location where energy is
needed to fuel cellular activities. Then the ATP is broken down (catabolism) and a controlled amount of energy is released,
which is used by the cell to perform a particular job.

Responsiveness
Responsiveness is the ability of an organism to adjust to changes in its internal and external environments. An example
of responsiveness to external stimuli could include moving toward sources of food and water and away from perceived
dangers. Changes in an organism’s internal environment, such as increased body temperature, can cause the responses of
sweating and the dilation of blood vessels in the skin in order to decrease body temperature, as shown by the runners in
Movement
Human movement includes not only actions at the joints of the body, but also the motion of individual organs and even
individual cells. As you read these words, red and white blood cells are moving throughout your body, muscle cells are
contracting and relaxing to maintain your posture and to focus your vision, and glands are secreting chemicals to regulate
body functions. Your body is coordinating the action of entire muscle groups to enable you to move air into and out of your
lungs, to push blood throughout your body, and to propel the food you have eaten through your digestive tract. Consciously,
of course, you contract your skeletal muscles to move the bones of your skeleton to get from one place to another (as the
runners are doing in), and to carry out all of the activities of your daily life.

Development, growth and reproduction
Development is all of the changes the body goes through in life. Development includes the processes of differentiation,
growth, and renewal.
Growth is the increase in body size. Humans, like all multicellular organisms, grow by increasing the number of existing
cells, increasing the amount of non-cellular material around cells (such as mineral deposits in bone), and, within very narrow
limits, increasing the size of existing cells.
Reproduction is the formation of a new organism from parent organisms. In humans, reproduction is carried out by the
male and female reproductive systems. Because death will come to all complex organisms, without reproduction, the line
of organisms would end.