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26/11/2013
PROF.SSA C. MEOLA
OUTLINE (1)
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Definition of Biology;
The study of Anatomy;
Gross Anatomy;
Microscopic Anatomy;
Human anatomy;
The major systems of human anatomy;
Our body parts;
The human brain.
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Biology is the study of life and living organisms,
from the smallest bacteria to giant
sequoias. Biologists use observation and
experimentation to gain an understanding
about the natural world. Branches of biology
include anatomy, biotechnology, botany, cell
biology, ecology, genetics, medicine,
microbiology, molecular biology, and
zoology. Many people entering the field of
biology become specialized in a particular area.
Anatomy is the scientific study of the structure of
living things including their systems, organs, and
tissues. It includes the appearance and position of
the various parts, the materials from which they are
composed, their locations and their relationships with
other parts.
From Greek, “anatomy” means “cut up, cut open”.
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Human anatomy, including gross human
anatomy and histology, is primarily the scientific
study of the morphology of the adult human
body.
For example, an anatomist is concerned with
the shape, size, position, structure, blood
supply and enervation of an organ such as the
liver.
Anatomy differs from physiology because anatomy is
about the morphology of biological structures, while
physiology is the way those structures actually work.
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The discipline of anatomy can be subdivided into
several branches including gross or macroscopic
anatomy and microscopic anatomy.
Gross Anatomy is the study of structures that
are large enough to be seen with the naked
eye. It can be studied using both invasive and
non-invasive methods with the goal of obtaining
information about the structure and organization
of organs and systems. Methods used include
dissection, in which the body is surgically
opened and its organs studied, and endoscopy,
in which a video camera-equipped instrument is
inserted through a small incision in the body
wall and used to explore the internal organs and
other structures.
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Microscopic Anatomy is the study of structures
on a microscopic scale, including histology (the
study of tissues), and embryology (the study of
the human organism in its immature condition.
The term "anatomy" is commonly taken to refer
to human anatomy. However, substantially the
same structures and tissues are found
throughout the animal kingdom and the term
also includes the anatomy of other animals.
The structure and tissues of plants are of a
dissimilar nature and they are studied in plant
anatomy
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The history of anatomy is characterized by a
continual development in understanding of the
functions of the organs and structures of the
human body.
Methods have also improved dramatically,
advancing from examination of animals, through
dissection of dead human bodies, to 20th century
techniques including:
X-ray,
ultrasound,
magnetic resonance imaging.
The major systems of the human body
are summarized as follows:
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System
Function
Structures
Pumping and channelling blood to and
heart, blood, and blood vessels
Circulatory system from the body and lungs.
mouth, salivary glands, esophagus, stomach, liver,
gallbladder, pancreas, intestines, rectum, and anus
endocrine glands such as hypothalamus, pituitary,
Communication within the body using pineal body, thyroid, parathyroids, adrenals, and
gonads
Endocrine system hormones.
Digestive system
Digesting and processing food.
Immune system
Integumentary
system
Fights off infections and infestations
Covers body, reduces water loss,
prevents entry of pathogens.
Lymphatic system
Musculo-skeletal
system
Nervous system
Reproductive
system
skin, hair and nails
Transfers lymph between tissues and
the blood stream.
lymph, lymph nodes and lymph vessels
Muscles provide movement and a
skeleton provides structural support muscles, bones, cartilage, ligaments, and
and protection.
tendons.
Collecting information from senses,
processing it, commanding muscles, eyes, ears, semicircular canals, other sensory
glands.
organs, brain, spinal cord and nerves
Reproduction.
Respiratory system Breathing and gas exchange.
Urinary system
leukocytes, tonsils, adenoids, thymus, spleen and
bone marrow
Fluid balance, electrolyte balance,
and excretion of urine.
female: ovaries, fallopian tubes, uterus, vagina,
clitoris, breasts; male: testicles, vas deferens,
seminal vesicles, prostate, and penis
pharynx, larynx, trachea, bronchi, lungs, and
diaphragm
kidneys, ureters, bladder and urethra
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OUR BODY PARTS
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ANKLE
ARM
CHEEK
CHEST
CHIN
EAR
ELBOW
EYE
FINGER
FOOT
FOREHEAD
HAND
HIP
KNEE
KNUCKLES
MOUTH
NECK
NOSE
SHOULDER
THIGH
THUMB
TOE
TORSO
WAIST
WRIST
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The human brain
The human brain has the same general structure as
the brains of other mammals, but it is larger than any
other in relation to body size. Large animals such as
whales and elephants have larger brains in absolute
terms, but when measured using the encephalization
quotient which compensates for body size, the human
brain is bigger. Much of the expansion comes from the
part of the brain called the cerebral cortex, especially
the frontal lobes, which are associated with executive
functions such as self-control, planning, reasoning,
and abstract thought. The portion of the cerebral
cortex devoted to vision is also greatly enlarged in
humans.
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The human cerebral cortex is a thick layer of neural
tissue that covers most of the brain. This layer is
folded in a way that increases the amount of surface
that can fit into the volume available. The pattern of
folds is similar in individuals, although there are many
small variations.
The cortex is divided into four "lobes", called the
frontal lobe, parietal lobe, temporal lobe, and
occipital lobe.
Within each lobe there are numerous cortical areas,
each associated with a particular function such as
vision, motor control, language, etc.
The left and right sides of the cortex are broadly similar in
shape, and most cortical areas are replicated on both sides.
Some areas, though, show strong lateralization, particularly
areas that are involved in language. In most people, the left
hemisphere is "dominant" for language, with the right
hemisphere playing only a minor role. There are other
functions, such as spatiotemporal reasoning, for which the
right hemisphere is usually dominant.
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Despite being protected by the thick bones of the skull,
suspended in cerebrospinal fluid, and isolated from the
bloodstream by the blood–brain barrier, the human
brain is susceptible to damage and disease. The most
common forms of physical damage are closed head
injuries such as a blow to the head, a stroke, or
poisoning by a variety of chemicals that can act as
neurotoxins. Infection of the brain, though serious, is
rare due to the biological barriers which protect it.
The human brain is also susceptible to degenerative
disorders, such as:
Parkinson's disease;
multiple sclerosis;
Alzheimer's disease.
A number of psychiatric conditions, such as schizophrenia
and depression, are thought to be associated with brain
disfunctions, although the nature of such brain anomalies
is not well understood.
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Huma n brain a nd s kull
Celebral lobes: frontal lobe (pink), parietal lobe (green)
and occipital lobe (blue).
“Brain” comes from the Latin “Cerebrum”
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The adult human brain weighs on average about 1.4 kg
with a volume of around 1130 cubic centimetres (cm 3) in
women, and, 1260 cm 3 in men, although there is
substantial individual variation.
Men with the same body height and body surface area
as women have on average 100 grams heavier brains,
although these differences do not correlate in any
simple way with IQ (intelligence quotient) or other
measures of cognitive performance
The human brain is composed of neurons, glial
cells, and blood vessels.
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The cerebral hemispheres (the cerebrum) form the
largest part of the human brain and are situated
above other brain structures. They are covered with a
cortical layer (the cerebral cortex) which has a
convoluted topography. Underneath the cerebrum
lies the brainstem, resembling a stalk on which the
cerebrum is attached. At the rear of the brain,
beneath the cerebrum and behind the brainstem, is
the cerebellum, a structure with a horizontally
furrowed surface, the cerebellar cortex, that makes it
look different from any other brain area.
The dominant feature of the human brain is
corticalization. The cerebral cortex in humans is
so large that it overshadows every other part of
the brain. The cerebellum, for example, has a
medial zone connected mainly to subcortical
motor areas, and a lateral zone connected
primarily to the cortex. In humans the lateral zone
takes up a much larger fraction of the cerebellum
than in most other mammalian species
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The cerebral cortex is nearly symmetrical, with left and
right hemispheres that are approximate mirror images of
each other. Each hemisphere is conventionally divided
into four "lobes", the frontal lobe, parietal lobe,
occipital lobe, and temporal lobe. With one exception,
this division into lobes does not derive from the structure
of the cortex itself, though: the lobes are named after the
bones of the skull that overlie them, the frontal bone,
parietal bone, temporal bone, and occipital bone.
Bisection of the head of an
adult female, showing the
cerebral cortex, with its
extensive folding, and the
underlying white matter
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The four parts of the cerebral cortex
The parietal lobe contains areas involved in somatosensation, hearing, language, attention, and spatial
cognition. The division into lobes is convenient for
reference. The main functions of the frontal lobe are to
control attention, abstract thinking, behavior, problem
solving tasks, and physical reactions and personality.
The occipital lobe is the smallest lobe; its main functions
are visual reception, visual-spatial processing,
movement, and color recognition.
The temporal lobe controls auditory and visual
memories, language, and some hearing and speech.
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Outline (2) : The skeletal system and
muscular system
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What it is;
How it can be divided;
The function;
What it is made of;
How to keep the bones healthy;
The muscular system.
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Skeletal System
The Skeletal system is all of the bones in the
body and the tissues such as tendons, ligaments
and cartilage that connect them.
Teeth are also considered part of the skeletal
system but they are not counted as bones. Teeth
are made of enamel and dentin. Enamel is the
strongest substance in the body.
How can the skeleton be divided?
• The human skeleton can be divided into
the axial skeleton and the appendicular
skeleton. The axial skeleton is formed by
the vertebral column, the rib cage and
the skull.
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• The appendicular skeleton, which is attached
to the axial skeleton, and is formed by
the pectoral girdles, the pelvic girdle and the
bones of the upper and lower limbs.
• The human skeleton serves six major
functions; support, movement,
protection, production of blood cells,
storage of ions and endocrine
regulation.
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How does the Skeletal System help us?
• Support
The main job of the skeleton is to provide
support for our body. Without your skeleton
your body would collapse. The skeleton is
strong but light, and without bones there
would be no posture.
• Protection
The skeleton also helps protect the
internal organs and fragile body tissues.
The brain, eyes, heart, lungs and spinal
cord are all protected by your skeleton.
Your cranium (skull) protects the brain and
eyes, the ribs protect the heart and lungs,
and the vertebrae(spine, backbones)
protect the spinal cord.
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• Movement
Bones provide the structure for muscles
to attach so that our bodies are able to
move. Tendons are tough inelastic bands
that hold attach muscle to bone.
• Who has more bones a baby or an adult?
Babies have more than adults. At birth,
you have about 300 bones. As you grow
older, small bones join together to make
big ones, so adults end up with about 206
bones. The bone mass in the skeleton
reaches maximum density around the
age of 30.
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• Are bones alive?
Absolutely. Old bones are dead, dry and
brittle. But in the body, bones are very
much alive. They have their own nerves
and blood vessels, and they do various
jobs, such as storing body minerals like
calcium. Bones are made of a mix of hard
material that gives them strength and
millions of living cells which help them
grow and repair themselves.
• What is a bone made of?
A typical bone has an outer layer of hard
or compact bone, which is very strong,
dense and tough. Inside this is a layer of
spongy bone, which is like honeycomb,
lighter and slightly flexible. In the middle
of some bones there is the jelly-like bone
marrow, where new cells are constantly
being produced for the blood. Calcium is
an important mineral that bone cells need
to stay strong.
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• How do bones break and heal?
Bones are tough and usually don't break
even when we have quite bad falls. Bones
will bend a little in a falling situation, but if
you fall the wrong way from some sort of
equipment, the bone can break. A broken
bone is called a fracture.
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Luckily, bones are made of living cells.
When a bone is broken your bone will
produce lots of new cells to rebuild the
bone. These cells cover both ends of the
broken part of the bone and close up the
break.
• How to keep bones healthy
Bones need regular exercise to stay as
strong as possible. Walking, jogging,
running and other physical activities are
important in keeping your bones strong
and healthy.
• Milk and other dairy products, all contain
calcium, which help bones harden and
become strong.
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Which is the biggest bone, and, which is the
smallest bone?
• The biggest bone is the femur.
• The smallest bone is the stirrup or stapes in
the middle ear.
Skeletal System
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Some questions to help you
revise the human skeletal
system:
What is the skeletal system?
A All the bones in the body
B All the muscles and tendons
C All the body's organs, both soft and hard tissue
D All the bones in the body and the tissues that
connect them
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Which of the following statement is
INCORRECT?
A Bone is where most blood cells are made.
B Bone serves as a storehouse for various minerals.
C Bone is a dry and non-living supporting structure.
D Bone protects and supports the body and its
organs.
How many bones are there in the average
person's body?
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B
C
D
150
206
36O
It varies by the individual.
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Which bone protects the brain?
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B
C
D
Calcium
The cranium
The cerebrum
The cerebellum
Besides the brain, the skull also protects ...
A
B
C
D
the lungs
the diaphragm
the body's cells
the sense organs
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The purpose of the rib cage is to...
A
B
C
D
protect the stomach
protect the spinal cord
protect the heart and lungs
provide an object to which the lungs can
attach
What makes bones so strong?
A
B
C
D
Silica
Cartilage
Blood and marrow
Calcium and phosphorous
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What is the difference between cartilage and
bone?
A Bone is rubbery, and cartilage is firm.
B Cartilage is rubbery, and bone is firm.
C Bone is a more primitive tissue than cartilage.
D Bone is inside the body, and cartilage is
outside
The hollow space in the middle of bones is filled
with ...
A
B
C
D
air
blood
bone cells
bone marrow
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What is a joint?
A
B
C
D
A hinge
A ball and socket
The place where two bones are joined
The place where tendons are fastened
together
Front View (Anterior)
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The muscular system
• There are about 640 skeletal muscles in a
human body. On average, the body weight is
40% muscle. Out of the 640 muscles, 30 of
them are facial muscles which allow all the
different expressions.
• The muscles surrounding the eye are the
busiest muscles in our body.
Research indicates that we probably blink
more than 100,000 times a day.
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• Each muscle belongs to one of three
categories: skeletal muscles, which move
bones ; smooth muscles, which control
involuntary movements such as breathing
and digestion; and cardiac muscle, which
is found in the heart. The job of a muscle
is to move your body. Without muscles
you couldn't move your skeleton.
• Muscles are a type of tissue that is
composed of contractile cells or fibers.
The cells or fibers actually contract, and
when they contract, they create
movement on the bone that they are
attached to.
• Muscle tissue also has the property of
irritability, conductivity and elasticity.
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• There are three different types of muscle
tissue:
• Smooth muscle: This muscle tissue is called
involuntary because it is NOT under
conscious control. Involuntary muscle tissue
is found in the internal organs; namely the
digestive tract, respiratory passages, urinary
and genital ducts, urinary bladder,
gallbladder, walls of the blood vessels. The
blood vessel walls are also muscle tissue.
• Striated muscle: This muscle tissue is found in
all skeletal muscles, and movement is under
conscious control. It also occurs in the tongue,
pharynx, and upper portion of the esophagus.
Voluntary muscles are under conscious
control because we consciously tell them what
to do.
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• Cardiac muscle: This muscle tissue is only
found in the heart. The fibers branch and
form a continuous network. At certain
intervals, there are prominent bands or
intercalated disks that cross the fibers.
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• Muscles work by contracting and
relaxing. For example, bringing up your
arm.
Muscles do not push, they pull. The tiny
muscle fibers work like a sliding glass door
on a track.
In order for a muscle to work, it has to cross
a joint. So in order to bend your knee, the
muscles in your thigh have to cross over to
the other side of the knee joint and attach.
Then when you tighten the muscle, the knee
bends.
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• It is possible to hurt a muscle because
they can become pulled, hence "pulled
muscle." You can actually tear a muscle the
same way that a ligament or tendon gets
torn or a bone gets broken. They can heal
by resting and with time.
• Some questions to help you revise the
muscular system:
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Muscles are made of ...
A
B
C
D
silica
polyester threads
calcium and phosphorous
groups of cells called fibres
How do muscles attached to the bones move
the body?
A
B
C
D
automatically
pull movement only
push movement only
push and pull movement
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What is the function of a tendon?
A
B
C
D
To link bones to bones
To link muscles to bones
To link muscles to ligaments
To bind the cells in compact bone closer
together
How many muscles are there in a human body?
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A
B
C
D
356
580
640
600
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What kind of muscle is the heart?
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A
B
C
D
Skeletal muscle
Voluntary muscle
Involuntary muscle
Smooth muscle
Outline (3)
The human heart and digestive system
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What the heart is;
The four chambers;
Contraction and relaxation;
Blood delivery;
Digestion process;
Organs involved.
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The heart is a muscular organ about the size of a fist, and
sits in the middle of the chest, behind the breastbone
and between the lungs, in a moistened chamber that is
protected all round by the rib cage. It is made up of a
special kind of muscle (cardiac muscle) that works
involuntarily, so we don't have to think about it. The
heart speeds up or slows downs automatically in
response to nerve signals from the brain that tells it how
much the body is being exerted. The heart pumps blood
through the network of arteries and veins called the
cardiovascular system.
The heart has four chambers:
The right atrium receives blood from the veins and
pumps it to the right ventricle.
The right ventricle receives blood from the right atrium
and pumps it to the lungs, where it is loaded with
oxygen.
The left atrium receives oxygenated blood from the
lungs and pumps it to the left ventricle.
The left ventricle (the strongest chamber) pumps
oxygen-rich blood to the rest of the body. This ventricle
pumps most forcefully, which is why a person's
heartbeat is felt more on the left side of the chest. The
left ventricle’s vigorous contractions also create our
blood pressure.
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Normally the heart contracts and
relaxes between 70 and 80 times per
minute, each heartbeat filling the four
chambers inside with a fresh round of
blood.
Surrounding the heart is a sac called
the pericardium.
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When the heart contracts, the chambers become
smaller, forcing blood first out of the atria into the
ventricles, then from each ventricle into a large
blood vessel connected to the top of the heart.
These vessels are the two main arteries. One of
them, the pulmonary artery, takes blood to the
lungs to receive oxygen. The other, the aorta,
transports freshly oxygenated blood to the rest of
the body. The vessels that bring blood to the heart
are the veins. The two main veins that connect to
the heart are called the vena cava.
Blood Delivery
Since the heart lies at the centre of the blood
delivery system, it is also central to life. Blood both
supplies oxygen from the lungs to the other organs
and tissues and removes carbon dioxide from the
lungs, where the gas is breathed out. Blood also
distributes nourishment from the digestive system
and hormones from glands. Likewise our immune
system cells travel in the bloodstream, seeking out
infection, and blood takes the body's waste
products to the kidneys and liver to be sorted out
and trashed.
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The digestive system
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What is digestion?
Digestion is the process of turning large pieces of
food into its component chemicals. Mechanical
digestion is the physical breakdown of large pieces
of food into smaller pieces.
The human digestive system is a complex series
of organs and glands that processes food. In
order to use the food we eat, our body has to
break the food down into smaller molecules that
it can process; it also has to excrete waste.
Most of the digestive organs (like the stomach
and intestines) are tube-like and contain the
food as it makes its way through the body. The
digestive system is essentially a long, twisting
tube that runs from the mouth to the anus, plus
a few other organs (like the liver and pancreas)
that produce or store digestive chemicals.
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Where does digestion start?
The start of the process - the mouth:
The digestive process begins in the
mouth. Food is partly broken down by
the process of chewing and by the
chemical action of salivary enzymes
(these enzymes are produced by the
salivary glands and break down
starches into smaller molecules).
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The esophagus - After being chewed and
swallowed, the food enters the esophagus.
The esophagus is a long tube that runs from
the mouth to the stomach. It uses rhythmic,
wave-like muscle movements (called
peristalsis) to force food from the throat into
the stomach. This muscle movement gives us
the ability to eat or drink even when we're
upside-down.
In the stomach - The stomach is a large,
sack-like organ that churns the food and
bathes it in a very strong acid (gastric
acid). Food in the stomach that is partly
digested and mixed with stomach acids is
called chyme.
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In the small intestine - After being in the
stomach, food enters the duodenum, the first
part of the small intestine. It then enters the
jejunum and then the ileum (the final part of
the small intestine). In the small intestine, bile
(produced in the liver and stored in the gall
bladder), pancreatic enzymes, and other
digestive enzymes produced by the inner wall
of the small intestine help in the breakdown
of food.
In the large intestine - After passing through
the small intestine, food passes into the large
intestine. In the large intestine, some of the
water and electrolytes (chemicals like sodium)
are removed from the food. Many microbes
(bacteria like Bacteroides, Lactobacillus
acidophilus, and Klebsiella) in the large
intestine help in the digestion process. The first
part of the large intestine is called the cecum
(the appendix is connected to the cecum).
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Food then travels upward in the
ascending colon. The food travels across
the abdomen in the transverse colon,
goes back down the other side of the
body in the descending colon, and then
through the sigmoid colon.
The end of the process - Solid waste is
then stored in the rectum until it is
excreted via the anus.
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Other organs that help digestion
• The liver:
• The liver is the body’s largest gland: an adult
human liver weighs between 3.2 and 3.7
pounds. It sits to the right of the stomach
where it not only detoxifies the blood, but
also helps in digestion by creating bile, a
substance needed to digest fats. Bile’s salts
break up fat into smaller pieces so that it can
be absorbed more easily in the small intestine.
• Other functions of the liver:
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• Detoxifies the blood to rid it of harmful
substances such as alcohol and drugs
• Stores some vitamins and iron
• Stores the simple sugar glucose
• Converts stored sugar to usable sugar when the
body’s sugar (glucose) levels fall below normal.
• Breaks down hemoglobin as well as insulin and
other hormones
• Converts ammonia to urea, which is vital in
metabolism
• Destroys old red blood cells
• The pancreas:
The pancreas is a gland located deep in the
abdomen. It produces enzymes (chemicals) made
by cells in the pancreas which pass into the gut to
help digest food. The hormones insulin and
glucagon are also made in the pancreas and help
to regulate the blood sugar level.
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Some questions to help revise the human heart:
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1. What is the heart?
2. How many chambers divide the heart?
3. What are the functions of the chambers?
4. How many times a minute does the heart
contract and relax in a normal situation?
• 5. What do the pulmonary artery, the aorta
and vena cava do?
• 6.What occurs during blood delivery?
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The digestive system:
• 1. What is digestion?
• 2. Where does digestion start?
• 3. Which are the next steps in the process and
where does it end?
• 4. Which other organs are involved in
digestion?
• 5. What is/are the function(s) of the liver?
• 6. What is/are the function(s) of the pancreas?
Outline (4)
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•
•
•
The human eye;
The human ear;
The teeth;
The skin.
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The human eye
• Eyes detect brightness and colour, and,
allow us to see the world in 3D (a depth
perception).
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How the Human Eye Works
• In a number of ways, the human eye works
much like a digital camera:
1. Light is focused primarily by the cornea —
the clear front surface of the eye, which acts
like a camera lens.
Cones detect colour.
2. The iris of the eye functions like the
diaphragm of a camera, controlling the
amount of light reaching the back of the
eye by automatically adjusting the size of
the pupil (aperture).
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3. The eye's crystalline lens is located directly
behind the pupil and further focuses light.
Through a process called accommodation,
this lens helps the eye automatically focus
on near and approaching objects, like an
autofocus camera lens.
4. Light focused by the cornea and crystalline
lens then reaches the retina where there
are cells called rods. The retina acts like an
electronic image sensor of a digital camera,
converting optical images into electronic
signals. The optic nerve then transmits
these signals to the visual cortex — the part
of the brain that controls our sense of sight.
Rods detect light.
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Other parts of the eye
Other parts of the human eye play a supporting
role in the main activity of sight:
• Some carry fluids (such as tears and blood) to
lubricate or nourish the eye.
• Others are muscles that allow the eye to
move.
• Some parts protect the eye from injury (such
as the lids and the epithelium of the cornea).
• And some are messengers, sending sensory
information to the brain (such as the painsensing nerves in the cornea and the optic
nerve behind the retina)
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The human ear
The human ear serves as an astounding transducer,
converting sound energy to mechanical energy to a
nerve impulse that is transmitted to the brain. The
ear's ability to do this allows us to perceive the pitch
of sounds by detection of the wave's frequencies, the
loudness of sound by detection of the wave's
amplitude and the timbre of the sound by the
detection of the various frequencies that make up a
complex sound wave.
The basic parts of the ear
• The ear consists of three basic parts - the
outer ear, the middle ear, and the inner ear.
Each part of the ear serves a specific purpose
in the task of detecting and interpreting
sound.
• The sound is collected by the pinna which is
the visible part of the ear, and then, it is
directed to the outer ear canal.
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• The outer ear serves to collect and channel
sound to the middle ear. The middle ear
serves to transform the energy of a sound
wave into the internal vibrations of the bone
structure of the middle ear and ultimately
transform these vibrations into a
compressional wave in the inner ear.
• The inner ear serves to transform the
energy of a compressional wave within the
inner ear fluid into nerve impulses that can
be transmitted to the brain.
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• The outer ear consists of an earflap and an
approximately 2-cm long ear canal. The earflap
provides protection for the middle ear in order to
prevent damage to the eardrum. The outer ear
also channels sound waves that reach the ear
through the ear canal to the eardrum of the
middle ear. It is not until the sound reaches the
eardrum at the interface of the outer and the
middle ear that the energy of the mechanical
wave becomes converted into vibrations of the
inner bone structure of the ear.
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• The middle ear is an air-filled cavity that
consists of an eardrum and three tiny,
interconnected bones - the hammer, anvil,
and stirrup/stapes. The eardrum is a very
durable and tightly stretched membrane
that vibrates as the incoming pressure
waves reach it. A compression forces the
eardrum inward and a rarefaction forces
the eardrum outward, thus vibrating the
eardrum at the same frequency of the
sound wave.
• The inner ear consists of a cochlea, the
semicircular canals, and the auditory nerve.
The cochlea and the semicircular canals are
filled with a water-like fluid. The fluid and
nerve cells of the semicircular canals provide
no role in the task of hearing; they merely
serve as accelerometers for detecting
accelerated movements and assisting in the
task of maintaining balance.
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The human teeth
• Teeth are hard, bony structures that grow
from the jawbone.
• Humans and other animals use their teeth
to bite and chew food.
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• Humans grow two sets of teeth during
their lives. The first set (primary) has 20
baby teeth. When a child is about 6 years
old, these teeth become loose and fall
out. Over the next few years
28 permanent teeth replace the baby
teeth. When a person is around 20, four
more back teeth, called wisdom
teeth grow in. Many people have
their wisdom teeth removed, so that the
others have more space to grow straight.
• We have different types of teeth in our
mouth. Each one has a different
function. The four front teeth are
called incisors. They are very sharp and
are used for cutting and chopping food.
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• The pointy teeth beside the incisors
are canine teeth or cuspids. There are four
of them, two on top and two on bottom.
They help tear and grind food.
• Teeth with two points are called bicuspids;
there are eight of them in all, four on the
top and four on the bottom.
• We have eight back teeth, called molars. They are
even wider and stronger than bicuspids.
• Wisdom teeth (also called third molars) are the last
teeth in the corner of the mouth. They erupt from
the ages of 17 to 21/22.
• They aren’t used for anything and are
often removed because they can cause problems in a
person’s mouth. They are called wisdom
teeth because they come later on in life when a
young person is older and “wiser”.
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The human skin
• The skin is the largest organ of the body,
with a total area of about 20 square feet.
The skin protects us from microbes and
the elements outside, it helps regulate
body temperature, and allows the
sensations of touch, heat, and cold.
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• Skin has three layers:
• The epidermis, the outermost layer of skin,
which provides a waterproof barrier and
creates our skin tone.
• The dermis, beneath the epidermis, which
contains tough connective tissue, hair
follicles, and sweat glands.
• The deeper subcutaneous tissue
(hypodermis) which is made of fat and
connective tissue.
• The skin’s color is created by special cells
called melanocytes, which produce the
pigment melanin. Melanocytes are
located in the epidermis.
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• Human skin is enormously well supplied
with blood vessels; it is pervaded with a
tangled, mass of arteries, veins, and
capillaries. Such a supply of blood, far in
excess of the maximum biologic needs of
the skin itself, is evidence that the skin is
at the service of the blood vascular
system, functioning as a cooling device. To
aid in this function, sweat glands pour
water upon its surface, the evaporation of
which absorbs heat from the skin.
• If the environment is cold and body heat
must be conserved, cutaneous blood
vessels contract in quick, successive
rhythms, allowing only a small amount of
blood to flow through them. When the
environment is warm, they contract at long
intervals, providing a free flow of blood.
During muscular exertion, when great
quantities of generated heat must be
dissipated, blood flow through the skin is
maximal.
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Bodyzone Video
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The Human Machine:
The lungs;
The eyes/sight;
The ears/sound;
The bones;
The muscles;
Parts of the body containing keratin;
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Blood and the heart;
Nutrition;
Digestion;
The liver;
The kidneys;
Cells;
Nerves/the nervous system;
The brain.
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Exam sessions 2014:
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January/February;
June;
July;
September.
• Written and oral, 3CFU.
• Prof. s s a C. Meola
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