Transport Systems and Processes in Plants

Plants have two systems for the transportation of substances - using two different types of transport tissue.
Xylem transports water and solutes from the roots to the leaves, while phloem transports food from the leaves to the rest of the
plant. Transpiration is the process by which water evaporates from the
stomata or the pores on the surface of leaves, which results in more
water being drawn up from the roots. Plants have adaptations to reduce
excessive water loss.

Xylem and phloem

Plants have two transport systems to move food, water and minerals
through their roots, stems and leaves. These systems use continuous
tubes called xylem and phloem, and together they are known as vascular
bundles.
The movement of food materials from leaves to other parts of the plant
is called translocation.

Human circulatory systems

The human circulatory system involves the pulmonary and systemic circulatory systems. The pulmonary circulatory system consists
of blood vessels that transport deoxygenated blood from the heart to the lungs and return oxygenated blood from the lungs to the
heart. In the systemic circulatory system, blood vessels transport oxygenated blood from the heart to various organs in the body
and return deoxygenated blood to the heart.

Pulmonary circulation system

In the pulmonary circulation system, deoxygenated blood leaves the heart through the right ventricle and is transported to the lungs
via the pulmonary artery. The pulmonary artery is the only artery that carries deoxygenated blood. It carries blood to the capillaries
where carbon dioxide diffuses out of the blood into the alveoli (lung cells) and then into the lungs, where it is exhaled. At the same
time, oxygen diffuses into the alveoli, and then enters the blood and is returned to the left atrium of the heart via the pulmonary
vein.

Flow diagram depicting movement of blood from the heart through the circulatory system. The blue boxes represent deoxygenated blood, the
purple boxes represent capillary networks where gaseous exchange occurs and the red boxes represent stages at which the blood is oxygenated.

The human respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide. The primary organs
of the respiratory system are:

 Lungs - carry out this exchange of gases as we breathe.

 Red blood cells - collect the oxygen from the lungs and carry it to the parts of the body where it is needed, During the
process, the red blood cells collect the carbon dioxide and transport it back to the lungs, where it leaves the body when we
exhale.

The human body needs oxygen to sustain itself. A decrease in oxygen is known as hypoxia and a complete lack of oxygen is known as
anoxia.
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HUMAN BRAIN

The brain is an amazing three-pound organ that controls all functions of the body, interprets
information from the outside world, and embodies the essence of the mind and soul.

Intelligence, creativity, emotion, and memory are a few of the many things governed by the
brain.

The brain receives information through our five senses: sight, smell, touch, taste, and hearing -
often many at one time. It assembles the messages in a way that has meaning for us, and can
store that information in our memory. The brain controls our thoughts, memory and speech,
movement of the arms and legs, and the function of many organs within our body.

The central nervous system (CNS) is composed of the brain and spinal cord.
The peripheral nervous system (PNS) is composed of spinal nerves that branch from the spinal
cord and cranial nerves that branch from the brain.

Protected within the skull, the brain is composed of the cerebrum, cerebellum, and brainstem.

 Cerebrum: is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions
like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of
movement.
 Cerebellum: is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and
balance.
 Brainstem: acts as a relay center connecting the cerebrum and cerebellum to the spinal cord. It performs many
automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing,
coughing, vomiting, and swallowing.

RIGHT BRAIN – LEFT BRAIN

The human brain weighs about 3 pounds (1.4 kilograms).

The human brain is the command center for the human nervous system. It
receives input from the sensory organs and sends output to the muscles. The
human brain has the same basic structure as other mammal brains, but is
larger in relation to body size than any other brains.

Facts about the human brain

 The human brain is the largest brain of all vertebrates relative to body size
 It weighs about 3.3 lbs. (1.5 kilograms)
 The brain makes up about 2 percent of a human's body weight
 The cerebrum makes up 85 percent of the brain's weight
 It contains about 86 billion nerve cells (neurons) — the "gray matter"
 It contains billions of nerve fibers (axons and dendrites) — the "white
In the figure, the cerebrum is divided into left and
matter"
right hemispheres. The two sides are connected by the
 These neurons are connected by trillions of connections, or synapses nerve fibers corpus callosum.

The cerebrum is divided into two halves: the right and left hemispheres. They are joined
by a bundle of fibers called the corpus callosum that transmits messages from one side to
the other.

Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side
of the brain, your left arm or leg may be weak or paralyzed.

Theleft hemisphere controls speech, comprehension, arithmetic, and writing.

The right hemisphere controls creativity, spatial ability, artistic, and musical skills.

Skull
The purpose of the bony skull is to protect the brain from injury. The skull is formed from 8
bones that fuse together along suture lines. These bones include the frontal, parietal (2),
temporal (2), sphenoid, occipital and ethmoid. The face is formed from 14 paired bones
including the maxilla, zygoma, nasal, palatine, lacrimal, inferior nasal conchae, mandible,
and vomer.

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LOBES OF THE BRAIN

The cerebrum is divided into four lobes: frontal, parietal, occipital and temporal.
Frontal lobe

 Personality, behavior, emotions Occipital lobe

 Judgment, planning, problem solving
 Speech: speaking and writing (Broca’s area)  Interprets vision (color,
 Body movement (motor strip) light, movement)
 Intelligence, concentration, self awareness
Temporal lobe
Parietal lobe
 Understanding language
 Interprets language, words (Wernicke’s area)
 Sense of touch, pain, temperature (sensory  Memory
strip)  Hearing
 Interprets signals from vision, hearing, motor,  Sequencing and
sensory and memory organization
 Spatial and visual perception

Cortex
The surface of the cerebrum is called the cortex.
It has a folded appearance with hills and valleys.
The nerve cell bodies color the cortex grey-brown giving it its name – gray
matterbeneath the cortex are long nerve fibers (axons) that connect brain
areas to each other — called white matter.

Hypothalamus:
It is located in the floor of the third ventricle and is the master control of the autonomic system. It plays a role in controlling
behaviors such as hunger, thirst, sleep, and sexual response. It also regulates body temperature, blood pressure, emotions, and
secretion of hormones.

Pituitary gland:
The pituitary gland is connected to the hypothalamus of the brain. It controls other endocrine glands in the body. It secretes
hormones that control sexual development, promote bone and muscle growth, and respond to stress.

Pineal gland:
It helps regulate the body’s internal clock and circadian rhythms by secreting melatonin. It has some role in sexual development.

Thalamus:
It serves as a relay station for almost all information that comes and goes to the cortex. It plays a role in pain sensation, attention,
alertness and memory.

Basal ganglia: includes the caudate, putamen and globus pallidus. These nuclei work with the cerebellum to coordinate fine
motions, such as fingertip movements.

Limbic system: is the center of our emotions, learning, and memory. Included in this system are the cingulate gyri, hypothalamus,
amygdala (emotional reactions) and hippocampus (memory).

MEMORY
Memory is a complex process that includes three phases: encoding (deciding what information is important), storing, and recalling.
Different areas of the brain are involved in different types of memory (Fig. 6). Your brain has to pay attention and rehearse in order
for an event to move from short-term to long-term memory – called encoding.

 Short-term memory, also called working memory, occurs in the prefrontal cortex. It stores information for about one
minute and its capacity is limited to about 7 items. For example, it enables you to dial a phone number someone just told
you. It also intervenes during reading, to memorize the sentence you have just read, so that the next one makes sense.

 Long-term memory is processed in the hippocampus of the temporal lobe and is activated when you want to memorize
something for a longer time. This memory has unlimited content and duration capacity. It contains personal memories as
well as facts and figures.

 Skill memory is processed in the cerebellum, which relays information to the basal ganglia. It stores automatic learned
memories like tying a shoe, playing an instrument, or riding a bike.
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RESPIRATORY SYSTEM

The human respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide. The primary organs
of the respiratory system are lungs, which carry out this exchange of gases as we breathe.

Red blood cells collect the oxygen from the lungs and carry it to the parts of the body where it is needed. During the process, the
red blood cells collect the carbon dioxide and transport it back to the lungs, where it leaves the body when we exhale.

The human body needs oxygen to sustain itself. A decrease in oxygen is known as hypoxia and a complete lack of oxygen is known as
anoxia

Parts of the Respiratory System

As we breathe, oxygen enters the nose or mouth and passes the sinuses, which are hollow spaces in the skull. Sinuses help regulate
the temperature and humidity of the air we breathe.

The trachea, also called the windpipe, filters the air that is inhaled. It branches into the bronchi, which are two tubes that carry air
into each lung. (Each one is called a bronchus.)

The bronchial tubes are lined with tiny hairs called cilia.

Cilia move back and forth, carrying mucus up and out.

Mucus, a sticky fluid, collects dust, germs and other matter that has invaded the lungs. We expel mucus when we sneeze, cough, spit
or swallow.

The bronchial tubes lead to the lobes of the lungs. The right lung has three lobes; the left lung has two.
The left lung is smaller to allow room for the heart. Lobes are filled with small, spongy sacs called alveoli, and this is where the
exchange of oxygen and carbon dioxide occurs.

The alveolar walls are extremely thin (about 0.2 micrometers). These walls are composed of a single layer of tissues called epithelial
cells and tiny blood vessels called pulmonary capillaries.

Blood passes through the capillaries. The pulmonary artery carries blood containing carbon dioxide to the air sacs, where the gas
moves from the blood to the air. Oxygenated blood goes to the heart through the pulmonary vein, and the heart pumps it
throughout the body.

The diaphragm, a dome-shaped muscle at the bottom of the lungs, controls breathing and separates the chest cavity from the
abdominal cavity. When a breath it taken, it flattens out and pulls forward, making more space for the lungs. During exhalation, the
diaphragm expands and forces air out.

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ENDOCRINE SYSTEM

 Antidiuretic hormone (vasopressin): Controls

water loss by the kidneys
 Oxytocin: Contracts the uterus during childbirth
and stimulates milk production

The hormones secreted by the posterior pituitary are

actually produced in the brain and carried to the pituitary
gland through nerves. They are stored in the pituitary
gland.

URINARY SYSTEM

Every living organism generates waste in its body and has a

mechanism to expel it. In humans, waste generation and
disposal are taken care of by the human excretory system.

The human excretory system comprises of the following

structures:

2 Kidneys
The endocrine system is made up of glands that produce and
2 Ureters
secrete hormones. These hormones regulate the body's
1 Urinary bladder
growth, metabolism (the physical and chemical processes of
1 Urethra
the body), and sexual development and function.

The major glands of the endocrine system are the

hypothalamus, pituitary, thyroid, parathyroids, adrenals,
pineal body, and the reproductive organs (ovaries and testes).

Pituitary Gland

The pituitary gland is located at the base of the brain beneath

the hypothalamus. It is often considered the most important
part of the endocrine system because it produces hormones
that control many functions of other endocrine glands. When
the pituitary gland does not produce one or more of its
hormones or not enough of them, it is called hypopituitarism.

The pituitary gland is divided into two parts: the anterior lobe
Kidneys
and the posterior lobe. The anterior lobe produces the
Kidneys are the main organ of the human excretory system.
following hormones, which are regulated by the
The kidneys are paired organs in each individual. They are the
hypothalamus:
primary excretory organ in humans and are located one on
 Growth hormone: Stimulates growth of bone and each side of the spine at the level of the liver The functional
tissue (Growth hormone deficiency results in growth unit of a kidney is called the nephron.
failure. Growth hormone deficiency in adults results
in problems in maintaining proper amounts of body Ureters
fat and muscle and bone mass. There is one ureter that comes out of each kidney as an
 Thyroid-stimulating hormone (TSH): Stimulates the extension of the renal pelvis. The ureter is a thin muscular
thyroid gland to produce thyroid hormones (A lack of tube that carries urine from the kidneys to the bladder.
thyroid hormones either because of a defect in the
pituitary or the thyroid itself is Urinary Bladder
called hypothyroidism.) It is a sac-like structure that is lined with smooth muscle layer
 Adrenocorticotropin hormone (ACTH): Stimulates the and is responsible for storage of urine till it is expelled from
adrenal gland to produce several related steroid the body by micturition. Micturition is the act of expelling
hormones urine from the body. The bladder receives urine from the
 Luteinizing hormone (LH) and follicle-stimulating ureters, one from each kidney. The level of the urinary bladder
hormone (FSH):Hormones that control sexual placement in the body differs in men and women.
function and production of the sex steroids, estrogen
and progesterone in females or testosterone in males Urethra
 Prolactin: Hormone that stimulates milk production in This is a tube that arises from the urinary bladder and
females functions to expel urine to the outside by micturition. The
urethra is shorter in females and longer in the males. In males,
the urethra functions as a common path for sperms and urine.
The posterior lobe produces the following hormones, which The opening of the urethra is guarded by a sphincter that is
are not regulated by the hypothalamus: autonomically controlled.

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