TOPIC 6:
HUMAN HEALTH and
PHYSIOLOGY
6.1 DIGESTION
6.1.1: Necessity for digestion
6.1.2: Enzyme action
6.1.3: Various enzymes
6.1.4: Digestive System
6.1.5: Stomach
6.1.5: Small and Large Intestine
6.1.5: Small intestine (x-section)
6.1.7: Villus
6.1.6: Absorption and Assimilation
6.2 THE TRANSPORT SYSTEM
6.2.1: Heart
Pulmonary artery
Aorta
s. vena cava
Pulmonary Vein
Left Atrium
i.vena
cava
Left Atrio-ventricular valve
Right
Atrium
Right Atrioventricular
valve
Right
ventricle
Left ventricle
Semi-lunar valves
Coronary artery
6.2.3: Heartbeat
6.2.4: Heartbeat
6.2.5: Blood Vessels
6.2.5: Blood Vessels
6.2.6: Blood
6.2.7: Transported by Blood
6.3: DEFENCE AGAINST INFECTIOUS DISEASE
Pathogen: an
organism or virus
that causes a
disease.
6.3.1: Antibiotics
Antibiotics block specific
metabolic pathways
found in bacteria.
Viruses reproduce using
the host cell’s metabolic
pathways, which are not
affected by antibiotics.
6.3.1: Skin and Mucus membranes
Mucous membranes line
cavities that are exposed to
the external. They are at
several places continuous
with skin: at the nostrils, the
mouth, the lips, the eyelids,
the ears, the genital area,
and the anus. The sticky,
thick fluid secreted by the
mucous membranes and
glands is termed mucus
Skin
The outer layer of skin is dead and difficult
for pathogens to grow on or penetrate.
The best way to prevent disease is to
prevent pathogens from entering the body.
Skin forms a physical barrier that prevents
most pathogens from entering the body.
Glands in the skin secrete lactic acid and
fatty acid, which make the skin surface
acidic, preventing bacterial growth.
The outer layer of skin flakes off, which
removes bacteria.
Cuts allow pathogens to gain entry to the
body.
6.3.4: Phagocytic leucocytes
6.3.5: Antigen and Antibody
An antigen is a substance or molecule that
when introduced into the body triggers the
production of an antibody by the immune
system which will then kill or neutralize the
antigen that is recognized as a foreign and
potentially harmful invader.
Antibody: A protein produced by Blymphocytes (specialised type of white
blood cell) that binds to a specific antigen
6.3.6: Production of Antibodies
a-f represent only 6 (of the millions) of different
lymphocytes
6.3.7: HIV
HIV reduces the number of active
lymphocytes and therefore a loss of
the ability to produce antibodies
Transmission of HIV
AIDS is a major social problem in all countries, especially in Africa
and Asia. It presently infects an estimated 40 million people
including men, women and children.
Families & friends suffer grief when a loved one is sick with AIDS.
Families become poorer if the victim becomes unable to work,
and individuals with AIDS may be stigmatized by society making it
difficult to find employment, housing, and partners.
In countries with high rates of HIV, people may avoid sex or live in
fear if sexually active.
The AIDS epidemic is so severe in some African countries that
the majority of the workforce has died, thus destroying economies
and eroding cultures.
6.4.1: GAS EXCHANGE
6.4.1:
• Ventilation
• Gas exchange
• Cell respiration
6.4.3: Alveoli
6.4.3: Alveoli
6.4.3: Alveoli
6.4.4: Respiratory System
trachea
Right lung
Right bronchus
Left lung
Left bronchus
bronchioles
diaphragm
alveoli
6.4.5: Mechanism of Breathing
6.4.5: Mechanism of Breathing
6.4.5: Mechanism of Breathing
6.5: NERVES, HORMONES and
HOMEOSTASIS
STATE:
The NERVOUS SYSTEM
consists of the CENTRAL
NERVOUS SYSTEM (CNS) and
PERIPHERAL NERVES, and is
composed of cells called
NEURONS that can carry rapid
ELECTRICAL IMPULSES.
6.5.1: Nervous System
6.5.2: Motor Neuron
6.5.3: Nerve impulse
STATE:
Nerve impulses are conducted from
receptors to the CNS by sensory neurons,
within the CNS by relay neurons, and from
the CNS to effectors by motor neurons.
Na+ channel
K+ channel
K+
Na+
Na+ K+ pump
6.5.4: Resting and Action Potential
6.5.5: Nerve Impulse
6.5.6: Synaptic Transmission
6.5.7: Endocrine System
The endocrine system consists of glands
that release hormones that are
transported in the blood and affect target
organs.
Homeostasis involves maintaining the
internal environment between limits,
including blood pH, carbon dioxide
concentration, blood glucose
concentration, body temperature and
water balance.
6.5.8 and 6.5.9: Homeostasis
STATE: homeostasis involves
maintaining the internal
environment between limits,
including blood pH, carbon dioxide
concentration, blood glucose
concentration, body temperature
and water balance.
6.5.10: Control of Body
Temperature
6.5.10: Arterioles in skin.
6.5.110: Shivering
6.5.10: Sweating
STATE: The endocrine
system consists of glands
that release hormones that
are transported in the
blood.
6.5.11: Control of blood glucose
6.5.10: Islets of Langerhans
6.5.10: Control of Blood Glucose
5.6.11: Type I Diabetes
6.5.11: Type II Diabetes
Type I diabetes (early or juvenile onset):
Auto-immune disease in which the beta-cells
pancreatic are destroyed.
Unable to produce insulin.
Responds well to regular injection of insulin
probably manufactured as the genetically
engineered humulin.
Type II diabetes (Adult onset):
Reduced sensitivity of the liver cells to
insulin.
Reduced number of receptors on the liver
cell membrane
6.6: REPRODUCTION
6.6.1: Male Reproductive System
6.6.1: Female Reproductive
System
6.6.2: Menstrual Cycle
FSH: follicle stimulating hormone
LH: lutenising hormone
6.6.3: Menstrual Cycle
8
Start of cycle
FSH levels rise
8
FSH causes follicles to develop
and estrogen to be secreted by
follicle which causes more
FSH to be released
Lining of uterus (endometrium)
breaks down (due to low levels of
progesterone and estrogen)
Rising estrogen levels cause an
LH surge
8
Estrogen stimulates repair of the endometrium
LH surge causes
ovulation
High LH causes less estrogen to be secreted
(an example of negative feedback)
High LH levels also
allows progesterone
levels to rise
8
After ovulation
follicle develops
into the corpus
luteum which
secretes
progesterone which
maintain the
endometrium
High levels of
progesterone inhibit
FSH and LH secretion
(negative feedback)
8
If no embryo is formed
the corpus luteum
breaks down then
progesterone and
estrogen levels fall and
endometrium will break
down
Low levels of
progesterone and
estrogen allow levels
of FSH to rise
8
6.6.4: Testosterone
Testosterone:
Prenatal development of male genitalia
Development of secondary sexual characteristics
Maintenance of sex drive
6.6.5: IVF
6.6.6: Ethical Issues with IVF
• FOR:
• AGAINST