Journey Of Sound

Assalamualaikum & hi readers!!

Looks like this week is the last week for our lab project submission....
So, I decide to put video in my last entry. Hope its help in understanding more in science. :)

The Journey Of Sound

Thank you & Assalamualaikum :)

Mammalian Cardiovascular System

Assalamualaikum & hi readers!! Hope all of you having a great day today :)

Okey, today I will write on something that were major important to us, human. Which is cardiovascular system. So, lets proceed !

Coordinated cycles of heart contraction drive double circulation in mammals.

The time delivery of O2 to the body's organs is critical: Some brain cells, for example, die if their O2 supply is interrupted for as little as a few minutes. How does the mammalian cardiovascular system meet the body's continuous demand for O2 ??! To answer this question, we must consider how the parts of the system are arranged and how each part functions. 

Mammalian Circulation.

Lets first examine the overall organization of the mammalian cardiovascular system, beginning with the pulmonary circuit. Contraction of the right ventricle pumps blood to the lungs via the pulmonary arteries. As the blood flows through capillary beds in the left and right lungs, it loads O2 and unloads CO2. Oxygen rich blood returns from the lungs via the pulmonary veins to the left atrium of the heart. Next, the oxygen rich blood flows into the heart's left ventricle, which pumps the oxygen rich blood out to body tissues through the systematic circuit. Blood leaves the left ventricle via the aorta, which conveys blood to arteries throughout the body. The first branches leading from the aorta are the coronary arteries, which supply blood to the heart muscle itself. Then branches lead to capillary beds in the head and arms. The aorta then descends into the abdomen, supplying oxygen rich blood to arteries leading to capillary beds in the abdominal organs and legs. Within the capillaries, there is a net diffusion of O2, from the blood to the tissues and of CO2. into the blood. Capillaries rejoin, forming venules, which conveys blood to veins. Oxygen poor blood from the head neck and forelimb is channeled into a large vein, the superior vena cava. Another large vein, the inferior vena cava, drains blood from the trunk and hind limbs. The two venae cavae empty their blood into the right atrium, from which the oxygen poor blood flows into the right ventricle.

Mammalian Heart.

Lets now take a closer look at how heart works. Located behind the sternum (breastbone) the human heart is about the size of a clenched fist and consist mostly of cardiac muscle. The two atria have relatively thin walls and serve as collection chamber for blood returning to the heart from the lungs or other body tissues. Much of the blood that enters the atria flows into the ventricles while all heart chambers are relaxed. The remainder is transferred by contraction of the atria before the ventricles begin to contract. Compared to the atria, the ventricles have thicker walls and contract much more forcefully especially the left ventricle which pumps blood throughout the body via the systemic circuit. Although the left ventricle contracts with greater force than the right ventricle, it pumps the same volume of blood as the right ventricle during each contraction.

The hearts contracts and relaxes in a rhythmic cycle. When it contracts, it pumps blood, when it relaxes, its chambers fill with the blood. One complete sequence of pumping and filling is referred to as the cardiac cycle. The contraction phase of cycle called systole, and the relaxation phase called diastole. 

Cardiac Cycle

Systole & Diastole phase.

The volume of blood each ventricle pumps per minute is the cardiac output. Two factors determine cardiac output: the rate of contraction or heart rate , and the stroke volume, the amount of blood pumped by a ventricle in a single contraction. The average stroke volume in humans is about 70mL. Multiplying this stroke volume by a resting heart rate of 72 beats per minute yields a cardiac output of 5mL/min about equal to the total volume of blood in the human body. During heavy exercise, the cardiac output increases as much as fivefold. 

Four valves in the heart prevent backflow and keep blood moving in the correct direction. Made of flaps of connective tissues, the valves open when pushed from one side and close when pushed from the other. An atrioventricular (AV) valve lies between each atrium and ventricle. The AV valves are anchored by strong fibers that prevent them from turning inside out. Pressure generated by the powerful contraction of the ventricles closes the AV valves, keeping blood from flowing back into the atria. 

Semilunar valves are located at the two exits of the heart where the aorta leaves the left ventricle and where the pulmonary artery leaves the right ventricle. These valves are pushed open by the pressure generated during contraction of the ventricles. When the ventricles relax, blood pressure built up in the aorta and the pulmonary artery closes the semilunar valves and prevents significant backflow. 

Control Of Heart Rhythm.

Brain and Sense

Assalamualaikum, & hi readers !! Today, I will  write and share with you all about brain and senses.Brain is the center part of body to control all the activity,while sense is our sight,taste,hearing and smell.

Brain

In our body ,brain is most popular as a nervouse system.

There is a brain structure;

MAJOR PARTS OF THE HUMAN BRAIN (FOREBRAIN) Forebrain

 • Telencephalon (cerebrum)  

Diencephalon 

• Cerebrum .

• Derived from the telencephalon .

• Largest part of the human brain (80%). 

• Involves in perception, cognition, higher motor functions.

 • Conscious mind located here. (communication, remember, understand, initiate voluntary movements .

CEREBRUM

29 Divided into 2 halves;

 a) Left hemisphere.

 b) Right hemisphere. Each hemisphere chiefly concerned with the sensory and motor functions of the opposite side of the body.

CEREBRAL CORTEX 

• The outer region composed of gray matter with underlying white matter.

 • Convolutions allow the cortex to have a large surface area and still fit inside the skull. 

• Gyri = elevated ridges.

 • Sulci = depressions.

 • Fissures = big sulci.

DIENCEPHALON

• Central core of the forebrain.

 • Encloses the third ventricle .

• Consists of three paired structures:

 • Thalamus .

• Hypothalamus. 

• Epithalamus.

DIENCEPHALON: THALAMUS 

• Thalamus : “Inner room”.

 • Paired, egg-shaped masses that form the superolateral walls of the third ventricle.

 • Relay center for information coming into cerebral cortex.

 • Information is sorted out and edit.

. • Promotes a state of arousal from sleep and alertn.

HYPOTHALAMIC FUNCTION 

• Regulates blood pressure, rate and force of heartbeat, digestive tract motility, and many other visceral activities.

 • Is involved with perception of pleasure, fear, and rage.

 • Regulation of body temperature.

 • Regulates feelings of hunger and satiety (regulate food intake, water balance and thirst).

 • Regulates sleep and the sleep cycle.

 • Control endocrine function: control release and inhibiting.

BRAINSTEM 

• Positioned between cerebrum and spinal cord.

. • Consist of three parts; medulla oblongata, pons and the midbrain.

 • Function: homeostasis, coordination of movement, and conduction of information to higher brain centers.

THE CEREBELLUM

• Located dorsal to the pons and medulla.

 • Protrudes under the occipital lobes of the cerebrum.

 • Makes up 11% of the brain’s mass.

 • Provides precise timing and appropriate patterns of skeletal muscle contraction (motor function).

There is little bit information about the brain,now i want to show and explain about the sense.

SENSE

CHEMICAL SENSES

  The gustation (taste) and olfaction (smell) and both dependent on chemoreceptors that detects specific chemicals (dissolve in aqueous solution) in the environment.  Taste receptor excited by food chemicals dissolve in saliva . Smell receptor excited by airborne chemicals that dissolve in fluid coating nasal membrane.

OLFACTION 

a) Olfactory receptor cells – neuron that lines the upper portion of nasal cavity and sends impulse directly to olfactory bulb of the brain.

 b) The receptive ends of the cells contain cilia that extend into mucous layer coating the nasal cavity.

GUSTATION  Gustation receptor cells – modified epithelial cells called taste buds. 

 Most taste buds : papillae. 

 Two cells of taste buds: 

i. Taste/gustatory cells 

 Gustatory hairs project from the tips of taste cells and extend through taste pores. 

ii. Basal cells .

 Act as stem cell, dividing & differentiating into new gustatory cells. Taste sensations Substance Transduction Taste map Sweet Organic substance, saccharin, alcohols, amino acids

 Sweetness – sugar bind to protein receptor 

 triggers signal transduction pathway .

 Results in depolarization. Tip of the tongue Sour Acids; dissolve H+ in solution Chemoreceptors detect saltiness (Na+ ions) or sourness (H+ ions) have channels in their plasma membrane through which these ions can diffuse .Influx of H+ and Na+ depolarizes the cell. Side Salty Inorganic salts; eg: table salt Side Bitter Alkaloids and some nonalakaloids substance Substance eg: quinine bind to K+ channel and closes them  resulting in decrease of membrane permeability to K+ . Depolarizes the cell Back of the tongue Umami Amino acids glutamate and aspartate .Binding of glutamate to Na+ channel. When glutamate is bound, Na+ channel open . Na+ diffuses into the cell . cell depolarize to the pharynx 5 taste sen.

Structures of the Eye .

Spherical, fluid-filled structure enclosed by 3 layers : 

1. Outermost : Sclera, cornea.

 2. Middle: Choroid, ciliary body, iris .

3. Innermost : Retina.

Structure of ears

  Three parts of ears: 

The external, the middle & the inner ear.  External  is transmit airborne sound waves to middle ear (amplify sound) and to fluid-filled inner ear.  Inner is houses 2 different sensory system :  the cochlea: receptors for conversion of sound waves into nerve impulses (hearing).  Vestibulars  apparatus is for sense of equilibrium.

so this is the sense that i want to share with you.Sense is most important for us,without sense we cant see,taste,hearing,and smell.

I hope my explanation about the brain and sense will give you all more knowledgble about this,

Thank you for reading :)

Immune System

Assalamualaikum, & hi readers !!!okay,today i would to share a little bit about immune system. Did you ever heard before about this?Yes or no?if no let me explained to you about this information.Immune system is part of our body defens from the virus or bacteria or the other disease.


Homeostatic imbalances of immunity;
a) Immunodeficiency
A medical condition in which your body does not have the normal ability to resist infection.
• Congenital or acquired condition that impairs the function of immune cells or production of certain molecules (phagocytes or complement system).
 • Causes immune cells to behave abnormally.
• Eg: SCID and AIDS.
 
SCID
– Severe combined immunodeficiency syndromes.
 – Genetic defects that produce a marked deficit of B and T cells.
 – Also abnormalities in interleukin receptors.
 – Children afflicted have little or no protection against disease-causing organisms.
 – Fatal if untreated, usually treatment from bone marrow transplants.

• SCID = bubble baby disease.
• Result of an immune system so highly compromised that it is considered almost absent.
• Victims are extremely vulnerable to infectious diseases.
 • David Vetter become famous for living in a sterile environment.

AIDS
-AIDS is caused by the human immunodeficiency virus (HIV) .
- HIV virus transmitted in body secretions : blood, semen, vaginal secretions,
Infected mothers can also transmit to her fetus.
- Commonly enters body via blood transfusions or bloodcontaminated needles and during sexual intercourse.

SYMPHTOMS OF AIDS

Characterized by
 • Severe weight loss.
 • Night sweat.
 •Swollen lymph nodes.
 • Increase frequent opportunistic infections:
  – Pneumonia (Pneumocystis pneumonia).
  – Kaposi’s sarcoma (cancer of blood vessels Symptoms of AIDS may not appear 5 – 10 years after
   being infected with HIV


b)Autoimmune diseases
Produced by failure of the immune system to recognize and tolerate self-antigens.
 – Immune system loses its ability to distinguish friend (self) from foe (foreign antigens).
 – Then arise an overactive immune response of the body against substances and tissues normally      present in the body.
 – In other words, the body attacks its own cells.
 – This may be restricted to certain organs or involve a particular tissue in different places.

   





 c) Hypersensitivities
Abnormal immune responses to antigens.
 – Result when immune system damage tissues as it fights off a threat that is harmless to body (such as pollen and animal dander).
 – People rarely die but just feel uncomfortable.
 – Different types of hypersensitivities reactions distinguished by:
 • Time course.
 • Involvement of antibodies or T cells.


2 major forms :
a) immediate hypersensitivity.
 – caused by abnormal B lymphocyte (antibodies) response to an allergen to produce symptoms within seconds/minutes.
 – What most of us call allergies reaction.
 – Reaction begin within seconds after contact with allergen and last about half an hour.
– Allergen: antigen that causes an allergy reaction.

 b). Delayed/subacute hypersensitivity.
 – caused by T cell response that produces symptoms between 24 and 72 hours.
– T cells take longer to appear (1-3 days).
 – Inflammation and tissue damage result from action of macrophage or cytotoxic T cells.
 – Example: allergic contact dermatitis which follow skin contact with some metals, cosmetics and deodorant chemicals.

Blood System And Blood Transfusion

Assalamualaikum,hai readers .Today i would like to share about Blood System And Blood Transfusion.



ABO blood group system;

Classification of human blood based on the inherited properties of red blood cells (erythrocytes) as determined by the peresence of absence of the antigen A  and antigen B.
Different human blood type are due to he variation in the surface markers on the RBC.
Medically important because the immune system proteins antibodies -recognize and attack the virtually anything.Any molecule that triggers the defensive attack is called antigen which is RBC bear highly specific surface antigen(a glycoprotien).Presence of surface antigen closely associated with blood typing system ABO system.

RED BLOOD CELL ANTIGEN AND BLOOD TYPING

Antigens is found on the surface of cells to help immune system recognize self cells .

 Antibodies - secreted by lymphocytes in response to foreign cells . ABO system is antigens on erythrocyte cell surfaces .Type A is has the A antigen, antibody B . Type B is has the B antigen   antibody A  .Type AB is has both the A and B antigens .Type O is has neither the A nor the B antigen.

BLOOD TRANSFUSION 

Process of transferring blood component (part of a whole blood) from one person into another. The blood used in a transfusion is compatible with one’s blood type. Blood transfusions can be life-saving (massive blood loss, to replace blood lost during surgery) .Used to treat a severe anemia or thrombocytopenia caused by blood disease (hemophilia, sickle-cell disease).

TRANSFUSION REACTIONS: AGGLUTINATION AND HEMOLYSIS

Transfusion reaction (hemolytic) is a serious complication that can occur after a transfusion of blood.  Occurs when mismatched blood type infused . The red blood cells that were given in the transfusion are destroyed by the patient's immune system.  Donor’s RBC will be attacked by the recipient’s plasma antibodies. 

That all for today,thank you for reading :)

Hierarchical Organization of Body Plans

Assalamualaikum & hi readers!!

Okay, today we will discuss on organism's basic unit of structure and function. In life structural hierarchy, cell is the smallest unit of organization that can perform all activities required for life. In fact, the actions of organism are all based on the functioning of cells. 

Cells are organized into tissue, groups of cells with a similar appearance and a common function. Different types of tissues are further organized into functional units called organs. Groups of organs that work together, providing an addition level of organization and coordination, make up an organ system. 

The specialized and complex organ systems of animals are built from limited set of cell and tissues types. There are four main types of animal tissues which is ; epithelial, connective, muscle, and nervous. However, today we will be exploring more on epithelial tissues :)

Occurring as sheets of cells, epithelial tissues or epithelia cover the outside of the body and the line organs and cavities within the body. Because epithelial cells are closely packed, often with tight junction, they function as a barrier against mechanical injury, pathogens, and fluid loss. Epithelia also form active interfaces with the environment. For example, the epithelium that lines the nasal passages is crucial for olfaction, the sense of smell. 

Stratified Squamous Epithelium.

A stratified squamous epithelium is multi layered and regenerates rapidly. New cells formed by division near the basal surface push outward, replacing cells that are sloughed of. This epithelium is commonly found on surface subject to abrasion, such as the outer skin and the linings of the mouth, anus, and vagina.

Pseudostratified Columnar Epithelium.

A pseudostratified epithelium consists of a single layer of cells varying in height and the position of their nuclei. In many vertebrates, a pseudostratified epithelium of a ciliated cells forms a mucous membrane that lines portions of the respiratory tract. The beating cilia sweep the film of mucus along the surface.

Simple Squamous Epithelium.

The single layer of platelike cells that form a simple squamous epithelium functions in the exchange of material by diffusion. This type of epithelium, which is thin and leaky, lines blood vessels and the air sacs of the lungs, where diffusion of nutrients and gases is critical.

Simple Columnar Epithelium.

The large, brick shaped cells of simple columnar epithelium are often found where secretion or absorption is important. For example, a simple columnar epithelium lines the intestines, secreting digestive juices and absorbing nutrients.

Cuboidal Epithelium. 

A cuboidal epithelium, with dice shaped cells specialized for secretion makes up the epithelium of kidneys tubules and many glands, including the thyroid gland and salivary glands.

So, I think that is all for today on epithelial tissues. I will get back to you soon with the new thing to be discuss about, InshaAllah. So, see yaa Assalamualaikum :)

The Genetics Basis Of Life

Assalamualaikum and hi readers! 

For our very first blog entry, I would like to share with you about a very interesting yet tricky topic which is, GENETICS. As we all know, offspring resemble their parents more than they do unrelated individuals. The transmission of traits from one generation to the next is called inheritance, or heredity. However, sons and daughters are not identical copies of either parent or of their siblings. BUT WHY ?!! Naa, this is because along with inherited similarity, there is also variation. :)

Offspring acquire genes from parents by inheriting chromosomes

Family friends may tell you that you have your mother's freckles or your father's eyes. Of course, parents do not, in any literal sense, give their children freckles, eyes, hair, or any other traits. OUH WAIT! then, what is actually inherited ?

Naaa, this is the things that we actually inherited from our parents. A GENES.

The genes we inherited from our mothers and fathers are our genetic link to our parents, and they account for family resemblances such as shared eye colors or freckles. 

So, enough with a little introduction on genetics topic today. Hope all of you have a clearer mind on genetic after reading this entry. InshaAllah. See you soon then, bye, Assalamalaikum :)