Cell membrane- holds all the
cell pieces and fluids inside the cell and keeps other things out.
Nucleus- contains the
Cytoplasm- the material
within the cell, this is excluding the nucleus.
Mitochondria- It is like a
digestive system that takes nutrients, breaks them down and creates molecules
which are rich in energy for the cell. It is also popularly known as the
powerhouse of the cell.
Endoplasmic reticulum- works
as the manufacturing and packaging system.
Smooth ER- acts as a storage organelle.
Rough ER- synthesizes
proteins. Called the rough ER because it has ribosomes attached to the surface.
Golgi apparatus- It is
another packaging organelle like the ER. It gathers simple molecules and
combines them to make more complex molecules. It then takes them, stores them
for later or sends them out of the cell or packs them in vesicles.
Lysosome- A single membrane
organelle that holds a variety of enzymes. The enzyme proteins are first made
in the ER and packaged in a vesicle and sent to the Golgi apparatus where the
final work is done and then it is a lysosome and is kept in the cytoplasm until
it is needed.
Outline the structure of the
main tissues of the body.
Epithelial tissue- it
protects and covers and it is a reproductive tissue. Protects the body from
dirt, dust and bacteria etc. It can come in a variety of shapes but the cell is
usually thin, flat and elongated. Colour of epithelial tissue is pink. The
epithelial cells are very closely packed together and dense.
Different types of
Epithelial tissue can be either simple or compound. The
difference between the two is. Simple epithelium consists of a single layer of
living cells whereas compound epithelium consists of a few layers of living and
non-living cells. Simple does mainly secretory and absorptive functions and
compound performs the protective function. Lastly, for the simple epithelium
all the cells are set on basement membrane but with the compound epithelium the
cells are set on the deepest layer of the basement
The different types of
Simple squamous epithelium
This type of epithelium tissue is found in the lining of
the heart, air sacs of the lungs, lymphatic vessels and blood vessels. The
function of the squamous epithelium is to allow different types of materials to
pass through by diffusion and filtration.
Simple cuboidal epithelium
This type of epithelium is found in hidden portions of
small glands, kidney tubules and the ducts. It is found in organs that
specialise in secretion like the ones I have named. The tissue consists of a
single layer of cuboidal cells on the basement membrane.
Simple columnar epithelium
It is found in the ciliated tissues including the
bronchi, uterine tubes, uterus; smooth non-ciliated tissues are in the
digestive tract bladder. The function of this tissue is to absorb and secrete
the enzymes and mucous.
This occurs in
many places, including the brain, digestive system and reproductive tract. This
is a body tissue that is lined with cells that are like small hairs which can
either help the cells move along tissue or can help move waste along the
surface of the cells.
types of compound epithelium:
This is made up
of multiple layers of cells and has a limited role in secretion and absorption.
The main function of the compound epithelium is to protect against chemical and
The cells on the
surface of the keratinized epithelium are very flat. The cells are also no
longer alive and are cemented together to create thick skin. They have no
nucleus or organelles. They are filled with a protein called keratin which
makes our skin water proof and protects it from damage or stress.
The connective tissue is
tissue that connects, supports, binds or separates other tissue or organs.
Unlike the epithelial tissue which has cells that are closely packed together,
connective tissue normally has cells scattered throughout an extracellular
matrix of fibrous proteins and glycoproteins attached to a basement membrane.
Different types of
Although there is a separate
function for blood, It is also a connective tissue as it has an extracellular
matrix. The matrix contains the plasma. Whilst the red blood cells, white blood
cells and the platelets are suspended in the plasma.
This is a firm tissue that
is much more soft and flexible than the bone. It is found in the joints between
the bones such as elbows and knees.
This is a firm, solid
connective tissue that has a large amount of 2 matrix material which is
collagen and elastic fibres.
This is a form of loose connective tissue that stores fat. It lines
organs and body cavities to protect organs and protects the body against heat
loss and produces endocrine hormones which is a system that is made up of a
network of glands which secretes hormones to regulate many bodily functions
like growth and metabolism.
This is found in surrounding blood vessels, nerve bundles, muscles and
organs. It attaches epithelium to underlying tissues and allows diffusion of
nutrients to epithelial cells.
Muscle tissue is a collection of cells that bond in order to produce
movement of the body parts. This tissue is well supplied with blood vessels. The
muscles are dense tissues which primary function is to allow the body to move
by repeated contraction. Besides movement, the muscle is also responsible for
maintaining posture, stabilizing the joints and producing body heat through
This muscle tissue is mainly attached to the bones and skin and is
responsible for the mobility of the body and limbs. Striated means striped, so
the muscle is striped.
This muscle is also known as the smooth muscle. This muscle forms organs
like the stomach and bladder and it changes shape to facilitate bodily
This is a tissue that has evolved to pump blood throughout the body. The
cardiac muscle is only found in the heart and makes up the bulk of the hearts
Nervous tissue is found in the brain, spinal cord and nerves. It is
responsible for controlling many body activities. It stimulates muscle
contraction, makes you aware of your surroundings and plays a major role in
your memory, your emotions and your reasoning. Nervous tissue is the tissue that
makes the central nervous system and the peripheral nervous system.
Nervous neuron tissue
Neurones are responsible for sensing stimuli and transmitting signals to
and from different parts of an organism. The structure of a neuron is uniquely
suited to its function within nervous tissue.
A neuron consists of two major parts:
Cell body: this contains the neurons nucleus which is
associated with cytoplasm and other organelles.Nerve processes: these are able to conduct and transmit signals
from the cell body. There are wo types of these. Axons- carries signals away
from the cell. Dendrites- carries signals towards the cell body.
Nervous Neuroglia tissue
These cells that form myelin,
protect, support and maintain equilibrium in your nervous system. They are
called glial cells. They compose a big support system that is essential to the
proper operation of nervous tissue and the nervous system.
An outline of the gross
structure of the main body systems listed below:
The cardiovascular system is also known as the
circulatory system which contains the heart, the blood vessels and the blood
itself as its 3 components. The circulatory system consists of two circuits
that blood travels through; pulmonary circuit and systemic circuit.
The pulmonary circuit
carries blood to the lungs to be oxygenated and
then back to the heart. In the lungs, carbon dioxide is removed from the blood,
and oxygen taken up by the haemoglobin in the red blood cells.
The systemic circuit
carries blood around the body to deliver the oxygen and returns de-oxygenated blood to the heart.
Blood also carries nutrients and waste.
Exercise affects these systems, causing the heart to pump
blood faster around the body, which in turn allows you to exercise for longer.
It is a double circulatory system. It comprises two
separate circuits and blood passes through the heart twice.
Consisting of specific respiratory organs, blood vessels and muscles,
the respiratory system is responsible for inhaling oxygen and carrying out the
exchange of oxygen and carbon dioxide in the human body.
Main functions of the respiratory system:
Inhaling and exhalingExchange of oxygen and carbon dioxide between the lungs and bloodstreamExchange of oxygen and carbon dioxide between the bloodstream and
tissuesCreating vibration of the vocal cords to produce soundHelping with the sense of smell The human respiratory system has several main parts. The
table summarises these and lists their functions.
The windpipe – it leads from the nose and mouth to the
Tube leading from the trachea to a lung
Contain the gas exchange surfaces
Smaller tubes inside the lungs leading from the
bronchus to the alveoli
Tiny air sacs at the end of bronchioles, where gas
Allow the lungs to move easily during ventilation
Provide a moveable cage to enclose and protect the
Allow the ribcage to change in volume for ventilation
Works with the intercostal muscles to allow ventilation
Digestion is the breakdown of large molecules into
smaller, soluble molecules that can be absorbed into the body. Digestion
happens inside the gut, and relies on enzymes. It is a group of organs working
together to convert food into energy and the basic nutrients to feed the entire
This system consists of the kidneys, ureters, urinary
bladder and urethra. The kidneys are a pair of bean-shaped organs found along
the wall of the abdominal cavity. The kidneys are surrounded by a layer of
adipose that holds them in place and protects them from damage. The kidneys
filter metabolic wastes, excess ions, and chemicals from the blood to form
urine. The ureters, urinary bladder and urethra together from the urinary
tracts all act as a plumbing system and drain the urine from the kidneys to
store it and then release it during urination. As well as filtering and
eliminating wastes from the body, the renal system also maintains the
homeostasis of water, ions, Ph, blood pressure etc.
The nervous system consists of the brain, spinal cord,
sensory organs, and all the nerves that connect these organs with the rest of
the body. Together, these organs are responsible for the way the body is
controlled and the communication amongst its parts. The spinal cord and brain
form the control centre which is known as the central nervous system (CNS).
This is where information is evaluated and decisions are made. The sensory
nerves and sense organs of the peripheral nervous system (PNS) monitor conditions
In and outside of the body and send this info to the CNS. Efferent nerves in
the PNS carry signals from the control centre to the muscles, glands, and
organs to regulate their functions.
The endocrine system is the collection of glands that
produce hormones that regulate metabolism, growth and development tissue
function, sexual function, reproduction, sleep, and mood. This system is made
up of the pituitary gland, thyroid gland, parathyroid glands, adrenal glands,
pancreas, ovaries (in females) and testicles (in males), the mayo clinic notes.
The reproductive system is a collection of internal and
external organs, which are in both males and females. They work together for
the purpose of procreating.
The male reproductive system consists of 2major parts. The
testes, which is where the sperm are produced. The testes are carried in an
external pouch known as the scrotum which is where they remain slightly cooler
than body temperature to enable sperm production.
The female reproductive system includes the clitoris,
labia, minora, labia majora and the Bartholin’s glands. The major internal of
the female reproductive system include the vagina and uterus which acts as the
receptacle for semen- and the ovaries, which produce the female’s ova. The
vagina is attached to the uterus through the cervix, while the fallopian tubes
connect the uterus to the ovaries. In response to hormonal changed, one egg-or
more in the case of multiple births- is released and sent down the fallopian
tube during ovulation. If not fertilized, this egg is eliminated because of
This system is a network of tissues and organs that help
the body to get rid of toxins, waste and other unwanted materials. The function
of the lymphatic system is to transport lymph- which is a fluid containing
infection-fighting white blood cells, throughout the body. The lymphatic system
consists of lymphatic vessels. The vessels are connected to lymph nodes- which
is where the lymph is filtered. The tonsils, adenoids, spleen and thymus are
all part of the lymphatic system.
This system provides stability and movement to the human
body. It consists of the body’s bones, muscles, tendons, ligaments, joins,
cartilage and other connective tissue. In addition to movement, muscle
contraction also helps with other important function’s in the body such as
posture, joint stability and heat production- nearly 85% of the heat produced
in the body is the result of muscle contraction.
This system is a network of cells, tissues and organs
that work together to defend the body against attacks. These are primarily
microbes- tiny organisms such as bacteria, parasites, and fungi that can cause
infections. The human body provides an ideal environment for many microbes. It
is the immune systems job to keep them out or to destroy them. When the immune
system hits the wrong target, however, it can unleash a torrent of disorders,
including allergic diseases, arthritis, and a form of diabetes. If the immune
system is crippled, other kinds of diseases result. The immune system is made up
of all the body’s organs.