2. There are three mechanisms of human behavior that help the
individual to respond and interact to the environment. These are the
receiving mechanisms or receptors, the connecting mechanisms
or the connectors and the reacting mechanisms or reactors.
Mechanism of Human Behavior
3. THE RECEIVING MECHANISM
Mechanism of receptors:
This is the different sense ( eyes, ears,
nose, mouth and skin) of the body receive
the stimuli from the environment.
4. •Interoceptors: are found in the linings of the respiratory, digestive and
genital -urinary tracts. These nerves when stimulated produce
orgasmic sensation associated hunger, thirst, sex and
excretion.
3 Kinds of receptors of the human body
that receive the outside stimuli:
•Exteroceptors: a person becomes aware of the color, shape, smell, taste,
sound, heat, softness or roughness and cold of his envi’nt.
through the receptors w/c are located in the eyes, nose,
mouth and skin.
•Proprioceptors: are situated in the lining of the tendons, muscles and
joints. The nerve linings w/c are connected with the nerve
pathways to the brain make the muscles feel the
sensations.
5. The Eyes and Visual Sensation
• The Eyes:
- The human eye is an organ which reacts to light from several
purpose.
- The eyes give sense of vision which allows one to see the world
- One has to consider the
stimulus that produces
vision which is light.
- The eyes react to light which
causes Visual Sensation.
6. •THE THREE COATS OF EYEBALL
- The eyes are ball-shaped so that they moved
in different directions.
- It is found within a bony cavity called Eye Socket.
- The bony cavity which contains the eyeball and its
associated muscles, vessels, and nerves.
Sclerotic coat is the tough white sheath that
forms the outer-layer of the ball. The white
sclerotic continues around the eye; most of
which is not visible while the eyeball is
located in its socket within the face/skull.
The main area of the eye that is not covered
by the area is the front part of the eye that is
protected by the transparent cornea instead.
7. - Cornea is the transparent front part of the
eye that covers the iris, pupil, and anterior
chamber.
- The cornea, with the anterior chamber and
lens, refracts light, with the cornea accounting
for approximately two-thirds of the eye's total
optical power.
- Choroid coat , also known as the
choroidea or choroid coat, is the
vascular layer of the eye, containing
connective tissue, and lying between
the retina and the sclera .
- The front part of Choroid is Iris.
8. - Iris is a thin, circular structure in the eye,
responsible for controlling the diameter and
size of the pupils and thus the amount of light
reaching the retina. "Eye color" is the color of
the iris, which in humans can be green, blue,
brown, and in rarer cases, hazel , grey or
even violet.
- Pupil is a hole located in the center of
the iris of the eye that allows light to enter
the retina. It appears black because light
rays entering the pupil are either absorbed
by the tissues inside the eye directly, or
absorbed after diffuse reflections within
the eye that mostly miss exiting the
narrow pupil.
9. - Once light passes through the pupil, it enters the Lens
which is located behind the pupil.
- The lens act to bend rays of light to focus them on the
retina.
10. •Retina:
- Is the most innermost coat which
contains the true receptor cells.
•Rods:
-Are long and cylindrical.
-Are responsible for twilight vision or light
of low intensity.
•Cones:
-Are short, thick and tapered.
- Are responsible for daylight vision and
colors.
11. •Fovea centralis:
-Is the center of the retina which is the point
of the clearest vision in the daylight.
- Is a very sensitive region of the retina.
•Optic nerve:
-Is a bundle of ganglion axons at the back
of the eyeball.
- It carries visual information to the brain.
•Blind spot:
-As the optic nerve leaves the retina,
there are neither rods nor cones.
12. •Optic nerve:
- The optic nerves coming from each eye splits
at
the optic chasm.
- Optic chasm is a point between and behind
the
eye wherein the more impulses from the optic
nerve are reversed in the brain.•Color Vision and Night
blindness:- There are people who have limited
perception of light and colors. People who
find difficulty in seeing light or object at night
are called night-blind because they have
defective rods. Night blindness can be
corrected by taking large doses of vitamin A.
Vitamin A is richly found in green, leafy and
yellow fruits and vegetables.
13. •Color blindness:
There are people who cannot distinguish certain colors either
totally or partially. This condition is called color blindness. There are
certain kinds of color- blindness, like the following:
- Dichromats- can match the entire colors or spectrum into
two colors. There are two of this type deuteranopes
that see red as poor yellow and green as gray and
protanopes that cannot see red but black and green
as
whitish gray.
- Trichomats- can see three colors from the spectrum.
14. •Common Eye Deviations from Normal Vision:
-Myopia or Nearsightedness:
This is cause by abnormal long eyeball so that the
image is focused in front of retina. A myopic or nearsighted
person cannot see objects at a far distance. They have to
use eyeglasses with concave lenses.
-Hyperopia or farsightedness:
This happens when the eyeball is so short that the
image is so short that the image is focused in the front of
the retina. A person with this defect cannot see effectively
near objects. A hyperopic person has to use eyeglass with
convex lenses to correct the condition.
15. -Presbyopia:
This is farsightedness of old age which is caused by the
slow hardening of the lens. Since the eyes cannot see near
object one has to put the object little away from him in order
to visualize it. A presbyopic person has to use corrective eye
glasses.
-Astigmatism:
This is caused by the uneven curvature of the cornea.
This generally is congenital (from birth) but it may be caused
by injury of inflammation. Too much eyestrain may contribute
to astigmatism
-Cross-eye:
Generally cross-eye is congenital farsightedness.
Crossed-eyed person have unequal two visions in two eyes.
Crossed-eyed persons have one eyed either turned outward
or inward. The treatment could be done through operation.
16. THE EARS AND THE AUDITORY SENSATION
The Ears are the sense organs for hearing
and the stimulus; it is made sensitive by the
sound waves which is caused by the
vibration of objects.
The ears consist of 3 parts:
Outer Ear
Middle Ear
Inner Ear
17. PARTS OF THE EAR
OUTER EAR
Pinna – is the visible part of the ear that
catches the sound and bring this sound to
the auditory canal down to the middle Ear.
Auditory Canal – is a tube-like passage in
the ear through which sound moves to the
ear drum.
Eardrum – is a miniature (small) drum that
vibrates when sound waves hit it.
18. PARTS OF THE EAR
MIDDLE EAR – is the small chamber which
has tiny bones called malleus (hammer),
incus (anvil) and stapes (stirrup)
How does it works?
The malleus transfers vibration to the anvil. The
anvil transfers the vibration to the stirrup, and the
stirrup brings the vibration to the oval windo.
The oval window is thin membrane between the
middle ear and the inner ear.
19.
20. PARTS OF THE EAR
INNER EAR – is the component of the ear
that actually change the sound vibration into
the form a form that can be transmitted to
the brain.
21. HEARING DEFECTS
Conductive Deafness – is a result of
disturbance in the conduction of air waves
from the outer to the inner ear. Defects in
oval window and basilar membrane which
amplify sounds prevents the flow of
vibration.
Nerve Deafness – is cause by loss of
sensitivity of the receptors.
22. THE SENSE OF SMELL AND OLFACTORY
RECEPTORS
The sense of smell or olfactory receptor is
located in the upper part of the nasal
cavities in a small space called olfactory
region.
There are large membrane of sensitive
nerve ending know as olfactory bulb. These
receptors are very sensitive to gaseous
elements.
24. TASTE RECEPTORS AND GUSTATORY
SENSATION
The receptor cell for taste are located in the TASTE
BUDS which are distributed across the tongue.
There are tiny hair cell within the taste buds. These
hair cells are connected to a nerve that reacts when
taste stimuli cut in the taste pores. The taste is
sensitive to taste. This means that solid food may
be tasted only when it has become dissolved whole
or partly by saliva.
26. Hypogeuia – loss of taste which is accompanied by
the loss of smell or anosmia.
Hypogeuia and Anosmia – caused by respiratory
infections within the nasal passages which has
been extremely congested and obstructed.
27. SKIN RECEPTORS AND CUTANEOUS
SENSATION
The sense organ involved in the sense of touch is
the SKIN
The skin sensation respond to: touch, pressure,
warmth, cold and pain.
Pain and Pressure are referred as Tactual or
tactile experiences
Warmth and cold are called thermal experiences.
28. Sensitivity of the skin to the various
stimulation is not equally distributed.
Lips and fingertips are very sensitive
to touch and pressure. Skin tissue is
sensitive to pain when pinched or
pricked. The legs is sensitive to cold.
31. CENTRAL NERVOUS SYSTEM (CNS)
The CNS is made up of brain and spinal cord.
Brain – encased in the skull. It is responsible for
the interpretation of sensory impulses, coordination
and control of body activities and expression of
emotions and thoughts. It is divided into 3 main
parts:
Forebrain
Midbrain
Hindbrain
32. Forebrain – located at the front part of the brain. This
consists of the cerebrum, cerebral cortex, thalamus
and hypothalamus.
The cerebrum is the largest of the brain mass. Its
principal part is the cerebral cortex which is seated of
higher mental process, abstract reasoning, planning and
higher mental process.
The thalamus is the receiver of information from the
senses and relay this information to the cerebral cortex
for processing. It is also responsible for the wakefulness
and sleep.
Hypothalamus serves as the integrating center of many
kind of physiological activities such as eating, sex, etc. it
is also involves emotional responses and homeostasis.
33. Midbrain – this part serves as the connecting link
between the hindbrain and the forebrain. It connects
the sensory motor pathways between the lower and the
upper portion of the nervous system.
Hindbrain – composed of medulla oblongata, pons and
the cerebellum. The medulla oblongata is the
connecting link between the spinal cord and the brain
proper. It plays important functions in the essential
physiological processes like respiration, heartbeat,
breathing etc. The pons serves as a connection center
and is involved in the motor coordination and
equilibrium too. The Cerebellum function is to maintain
posture and smooth out complex muscular coordination
like walking, writing and even dancing.
34. THE SPINAL CORD
It is a large rope-like segments of nerve tissues
running along the spine carrying message between
the brain and the peripheral nervous systems.
In the spinal cord are spinal nerves which divide
into 2 roots: dorsal and ventral.
Dorsal roots – carries sensory nerve fibers
Ventral roots – carries motor nerve fiber
35.
36. PERIPHERAL NERVOUS SYSTEM (PNS)
The PNS branches out from the spinal cord and the
brain, and extended to the extremities of the body. It
carries information in and from the CNS.
2 divisions:
Somatic – control of voluntary movements of the
skeletal muscles and communication of information to
and from the sense organ.
Autonomic – concerned with the parts of the body that
makes it alive – heart, blood vessels, glands, lungs, etc.
It has two subdivision.
37. AUTONOMIC SUB-DIVISIONS
Sympathetic subdivision – is the part that prepares
the body to respond to stressful emergency
situation. It increases heartbeat, raises BP and
sends the blood to peripheral muscles.
Parasympathetic subdivision – acts to calm and
relax body after the emergency situation is
resolved.
38. Neurons – specialized cells that are the basic
structural unit of the nervous system that transmit
messages. Principal Parts:
Cell body – found in protoplasm which is the living part
of the neuron.
Dendrites – are clusters of nerve fibers which carry
messages toward the cell body.
Axon – is a long, slim, tube like extension which carries
messages away from the cell body.
Synapses – are point of connections between the
dendrites of some neurons and axons of others.
39. CLASSIFICATION OF NEURONS
Sensory Neuron – carry message from the
receptors to the spinal cord and brain.
Motor Neuron- carry messages from the brain and
spinal cord and send them to the motor organs like
the muscles and glands.
Connector Neurons – provide connection between
the sensory and motor neurons. These are found in
the brain and spinal cord.
41. 3 KINDS OF MUSCLES
Voluntary – muscles that can be moved at the person’s
will. Also known as striped muscles, skeletal muscles.
Involuntary – muscles that cannot be moved at will. It
has its own movement which are rhythmical. Also known
as visceral muscle, smooth muscle. Involuntary muscles
are generally found in the internal organs of the body.
Cardiac – muscles that are found in the heart.
42. CHARACTERISTICS OF MUSCLES
1. Contractility – ability to change from a long
narrow shape while at rest and a shorter
and thicker form while in action.
2. Extensibility – the capacity to be stretched
or made longer.
3. Elasticity – the power of the muscle to go
back to its original size and shape after
contracting or stretching.
4. Tonicity – the ability to be in condition of
healthy tension or partial contraction at
rest.
43. FUNCTION OF MUSCLES
Shapes our body
Secure internal organs of the body
Muscles are made for motion
Muscles are utilized for locomotion
Muscles are used to produced heat in the
body
44. GLANDS
Glands are special secreting organs which
pour the secretion either directly into the
blood streams or pass it through the ducts
or canals.
Endocrine Glands
These secrete hormones, affect body growth and
functioning. Hormones are chemicals that
circulate throughout the blood and affect the
functioning and the growth of the parts of the
body.(e.g. reproduction, metabolism)
45. Pituitary Glands
The most influential gland which is found at the
base of the brain. It is called as “master gland”
because of its influence on the endocrine glands.
It has 2 parts:
Anterior lobe – secrete growth hormone
Posterior Lobe – secrete2 important types of
hormones, the vasopresin which controls the
secretion of water through the kidney, and
oxytocins which stimulate the breast to produce
milk.
46. Thyroid Gland
Located at the base of the throat. It secrets two
known hormones: thyroxine and idothyroxine.
Parathyroid Gland
Found behind the thyroid glands. They produce
substance called parathormone which controls
the different minerals in the blood stream
specially calcium. Lack supply of this hormone
will result to tetany which is the stiffening of the
hand and fingers, muscles cramps and irritability.
47. Adrenal Gland
Located on the top of each kidney. It is made up of 2 parts:
adrenal cortex which secrets cortin, and adrenal medulla
which secrets adrenaline hormone which serves to give
extra energy needed during emergency.
Island of Langerhans
IoL are small bodies floating in the pancreas. It secretes
hormone called insulin which are directly responsible in
controlling sugar amount in the blood.
Gonads
Gonads are sex glands. Male – Testosterone promotes male
sex secondary characteristics that make the male look kike
masculine. Female – Estrogen and Progesterone
