Informations and Guidelines for Bio and Life Science Students: July 2020

Lab protocols

Ø Drinking, eating or smoking is not allowed in lab. Tie back long hair, restrain loose clothing and jewelry.

Ø Locate exits, fire extinguishers, first aid kit, sharps containers and eyewash station in your laboratory.

Ø There are NO open lab hours. All labs can be done within the allotted amount of time, providing you prepare for the lab.

Ø When handling dangerous substances, wear gloves, laboratory coats, and Safety shield or glasses.

Ø Do not use your mouth to ingest chemicals or pipette any substance.

Ø Clean up your work area before leaving.

Ø Wash hands before leaving the lab and before heating.

Ø Do not store food in laboratories.

Ø Do not leave an ongoing experiment unattended.

Ø Never taste anything.

Ø Never use open flames in laboratory unless instructed by Teacher.

Ø Never do unauthorized experiment.

Ø Never allow a solvent to come in contact with your skin.

Ø Never smell a solvent.

Ø Read label on solvent bottle to identify contents.

Ø Never return Chemicals to reagent bottles.

Ø Always Wear Safety glasses or goggles when working with dangerous chemical.

Ø Some Times you will be told to use a certain concentration of solution.

Ø If you Spill a chemical wipe it up immediately.

Ø Consult with the instructor for instruction when disposing of sharp, or contaminated supplies, or for the disposal of chemicals.

Date Day

RESULT:

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EXPERIMENT 1

The study of Human Skeleton

Human skeleton :

The human skeleton is the internal framework of the body. It is composed of around 270 bones at birth – this total decreases to around 206 bones by adulthood after some bones get fused together.The human skeleton can be divided into the Axial Skeleton and the Appendicular Skeleton.

Axial skeleton:

The axial skeleton (80 bones) is formed by the vertebral column (32–34 bones; the number of the vertebrae differs from human to human as the lower 2 parts, sacral and coccygeal bone may vary in length), a part of the rib cage (12 pairs of ribs and the sternum), and the skull (22 bones and 7 associated bones).

The upright posture of humans is maintained by the axial skeleton, which transmits the weight from the head, the trunk, and the upper extremities down to the lower extremities at the hip joints. The bones of the spine are supported by many ligaments. The erector spine muscles are also supporting and are useful for balance.

Appendicular skeleton:

The appendicular skeleton (126 bones) is formed by the pectoral girdles, the upper limbs, the pelvic girdle or pelvis, and the lower limbs. Their functions are to make locomotion possible and to protect the major organs of digestion, excretion and reproduction.

Function:

The functions of the skeleton are to provide support, give our bodies shape, provide protection to other systems and organs of the body, to provide attachments for muscles, to produce movement and to produce red blood cells.

The main bones of the human skeleton are:

· The Skull - Cranium, Mandible and Maxilla

· Shoulder girdle - clavicle and scapula

· Arm - humerus, radius and ulna

· Hand - Carpals, Metacarpals and Phalanges

· Chest - Sternum and Ribs

· Spine - Cervical area (top 7 vertebrae), Thoracic (next 12), Lumbar (bottom 5 vertebrae), Sacrum (5 fused or stuck together bones) and Coccyx (the tiny bit at the bottom of the spine).

· Pelvic girdle - Ilium, Pubis and Ischium.

· Leg - Femur, Tibia and Fibula

· Ankle - Talus and calcaneus bone (not shown above)

· Foot - Tarsals, Metatarsals and Phalanges.

Date Day

Result :

_________________________________________________________

__________________________________________________________

Experiment #2

THE STUDY OF TYPES OF BONES IN HUMAN SKELETON

Bone:

A bone is a rigid organ that constitutes part of the vertebrate skeleton. Bones support and protect the various organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have a complex internal and external structure. They are lightweight yet strong and hard, and serve multiple functions.Bone tissue is a hard tissue, a type of dense connective tissue. It has a honeycomb-like matrix internally, which helps to give the bone rigidity.

Types Of Bones:

There are 5 types of bones in the human body. These are long bones, short bones, flat bones, irregular bones and sesmoid bones.

Long Bones

Long bones are some of the longest bones in the body, such as the Femur, Humerus and Tibia and fibula.

Short Bones:

Short bones are defined as being approximately as wide as they are long and have a primary function of providing support and stability with little movement. Examples of short bones are the Carpals and Tarsals - the wrist and foot bones. They consist of only a thin layer of compact, hard bone with cancellous bone on the inside along with relatively large amounts of bone marrow.

Flat Bones

Flat bones are as they sound, strong, flat plates of bone with the main function of providing protection to the vital organs and being a base for muscular attachment. The classic example of a flat bone is the Scapula (shoulder blade). The Sternum (breast bone), Cranium (skull), os coxae (hip bone) Pelvis and Ribs are also classified as flat bones. Anterior and posterior surfaces are formed of compact bone to provide strength for protection with the center consisting of cancellous (spongy) bone and varying amounts of bone marrow. In adults, the highest number of red blood cells are formed in flat bones.

Irregular Bones

These are bones in the body which do not fall into any other category, due to their non-uniform shape. Good examples of these are the Vertebrae, Sacrum and Mandible (lower jaw). They primarily consist of cancellous bone, with a thin outer layer of compact bone.

Sesamoid Bones

Sesamoid bones are usually short or irregular bones, embedded in a tendon. The most obvious example of this is the Patella (knee cap) which sits within the Patella or Quadriceps tendon. Other sesamoid bones are the Pisiform (smallest of the Carpals) and the two small bones at the base of the 1st Metatarsal. Sesamoid bones are usually present in a tendon where it passes over a joint which serves to protect the tendon.

Date Day

Result:

_________________________________________________________

Experiment#3

MICROSCOPIC STUDY OF WRIGHT’S STAINed blood smear

Wright’s stain:

Wright's stain is a histologic stain that facilitates the differentiation of blood cell types. It is classically a mixture of eosin (red) and methylene blue dyes. It is used primarily to stain peripheral blood smears, urine samples, and bone marrow aspirates which are examined under a light microscope.

Requirements:

Prepared slide of Wright’s stained blood smear ad microscope .

Procedure:

Find a good viewing area low power (10x)

A properly made blood smear is divided into

– region where the drop of blood was applied to the slide is central region,

feather edge is away from the center region.

Appropriate viewing region is in from the feather edge where RBCs are just touching each other.

1-View area where cells are well spread but still touching each other.

2-This area is too far in from the feather edge.

The blood is too thick.

Cells overlap and are distorted RBCs appear small.

3-This too near the feather edge

– the RBCs are not touching– the cells appear large

The normal range for men is 5 million to 6 million cells/mcL,

for women it’s 4 million to 5 million cells/mcL.

4-Get an idea of the total white

blood cell count.

4,500 to 10,000 cells per microliter (cells/mcL)

The normal ratio of WBCs to RBCs is about 5,000 to 5,000,000 (1:1000)

5-Get an idea of the total platelet count by examining several fields using the high power (oil) lens. The normal range is 140,000 to 450,000 cells/mcL.

The normal ratio of platelets to RBCs is about 250,000 to 5,000,000 (1:20).

Date Day

Result:

__________________________________________________________

Experiment #4

Microscopic study of blood smear

Blood smear:

A blood smear is a blood test used to look for abnormalities in blood cells. The three main blood cells that the test focuses on are:

red cells, which carry oxygen throughout your body

white cells, which help your body fight infections and other inflammatory diseases

platelets, which are important for blood clotting.

Clinical significance to study the blood smear:

The blood smear test is often done to diagnose conditions that are causing:

Unexplained jaundice.

Unexplained anemia (low levels of normal red blood cells).

Abnormal bruising.

Persistent flu-like symptoms.

sudden weight loss.

Unexpected or severe infection.

Skin rashes or cuts.

Reagents, equipment and supplies:

Glass slides, Strerile cotton swabs, Sterile lancet

Procedure:

1. Using the sterile lancet, place a drop of blood, about 2 mm in diameter approximately on the middle of the slide.

2. Hold the slide in your left hand.

3. With your right hand, place the smooth clean edge of a second (spreader) slide on the specimen slide, just in front of the blood drop.

4. Hold the spreader slide at a 45 angle, and draw it back against the drop of blood.

5. Allow the blood to spread almost to the edges of the slide.

6. Label the slide with patient name, and date.

7. Allow the blood film to air-dry completely before staining. (Do not blow to dry. The moisture from your breath will cause RBC artifact.)

Precautions:

1. Cold agglutinin - RBCs will clump togethjer. Warm the blood at 37 C for 5 minutes, then remake the smear.

2. Lipemia - holes will appear in the smear. There is nothing you can do to correct this.

3. Rouleaux - RBC’s will form into stacks resembling coins. There is nothing you can do to correct this.

Results:

A blood smear is considered normal when your blood contains a sufficient number of cells and the cells have a normal appearance. A blood smear is considered abnormal when there’s an abnormality in the size, shape, color, or number of cells in your blood. Abnormal results may vary depending on the type of blood cell affected.

Date Day

Result: ___________________________________________________

_________________________________________________________

Experiment# 5

Microscopic study of cross section of kidney

Requirements :

Prepared slide of cross section of kidney and microscope.

Microscopic view of cross section:

Simple cuboidal epithelium (cross section of the kidney)

Explanation:

The red and blue arrows point to simple cuboidal epithelial tissue.This is a slide of a thin section taken from the mammalian kidney showing the many tubular ducts that make up much of this organ. The walls of these ducts (pointed by the red arrows) are comprised of simple cuboidal epithelial cells, which are usually six-sided in shape but may appear square from a side view.

Generally, the cuboidal epithelial cell we are examining are specialized for the transport of water, ions, and certain organic substances, thus modifying the composition of the urine as the urine is being formed.

While examining the simple cuboidal epithelium, note the following characteritics:

This epithelium consists of a single layer of cuboidal cells.
The height of each epithelial cell is nearly equal to the width of the cell.
The cells are tightly packed, forming a continuous sheet of cells that effectively forms the wall of a kidney tubule.
The nucleus is spherical and sits at the near-center of the cell.
The nuclei of adjacent cells are relatively close together, certainly closer than in a simple squamous epithelium, and are aligned in a single row.

Precautions:

Always view the slide in the area with appropriate light for accurate examination.

Date Day

Result:____________________________________________________

__________________________________________________________

Experiment # 6

MACROSCOPIC STUDY OF CROSS SECTION OF KIDNEY

Requirements:

Anatomical model of dissected kidney.

Functioning :

The function unit of the vertebrate kidney is the nephron, which is a microscopic structure. Each human kidney contains approximately one million nephrons. When stretched out, each nephron is 35 mm in length, but is less than 1 mm in diameter.

Explanation:

Renal Cortex

Renal cortex is superficial portion of the kidney in contact with the fibrous capsule. its reddish brown and granular

Renal Medulla

Renal medulla consists of 6-18 distinct triangular structures called Renal Pyramids. The base of each pyramid touches the cortex. The tip of each pyramid known as the Renal Papilla projects into the Renal sinus

Renal Sinus

Renal sinus is a cavity within the kidney which is occupied by the renal pelvis, renal calyxes, blood vessels, nerves and fat.

Renal Capsule

Renal capsule is a tough fibrous layer surrounding the kidney and covered in a thick layer of perinephric adipose tissue. It provides some protection from trauma and damage

Hilum of Kidney

Hilum of kidney or renal pedicle is the part of the kidney, that is, its recessed central fissure where its vessels, nerves and ureter pass.

CROSS SECTION OF KIDNEY

Renal Lobe

Renal lobe consists of a renal pyramid, the overlying area of renal cortex and adjacent tissues of renal columns

Renal pyramid

Renal pyramid is one of the 6-18 structures shaped like a triangle... consist mainly of tubules that transport urine from the cortical, or outer, part of the kidney, where urine is produced, to the calyces, or cup-shaped cavities in which urine collects before it passes through the ureter to the bladder. The point of each pyramid, called the papilla, projects into a calyx

Renal papilla

Renal papilla is the location where the renal pyramids in the medulla empty urine into the minor calyx in the kidney. Histologically it is marked by medullary collecting ducts converging to form a papillary duct to channel the fluid.

Renal column

The renal column is a medullary extension of the renal cortex in between the renal pyramids. It allows the cortex to be better anchored. Each column consists of lines of blood vessels and urinary tubes and a fibrous material.

Minor calyx

Minor calyx are ducts within each renal papilla discharge urine into "Cup Shaped drains" there are four or five of these in each kidney

Major calyx

Urine formed in the kidney passes through a renal papilla at the apex into the minor calyx; two or three minor calyxes converge to form a major calyx. two minor become one major and so on.

Renal pelvis

Renal pelvis is the point of convergence of two or three major calyxes.

Ureters

The duct by which urine passes from the kidney to the bladder .

Date Day

Result :____________________________________________________

__________________________________________________________

Experiment # 7

STUDY OF ANATOMY OF HUMAN BRAIN

THEORY:

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. Protected within the skull, the brain is composed of the cerebrum, cerebellum, and brainstem. The brainstem acts as a relay center connecting the cerebrum and cerebellum to the spinal cord.

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. It also determines how we respond to stressful situations (such as taking a test, losing a job, or suffering an illness) by regulating our heart and breathing rate.

Rquirement:

Human brain model.

Procedure of understanding and studying:

Brain

The brain is composed of the cerebrum, cerebellum, and brainstem.

The 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.

The cerebellum is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance.

The brainstem includes the midbrain, pons, and medulla. It 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. Ten of the twelve cranial nerves originate in the brainstem.

Right brain – left brain

The right and left hemispheres of the brain are joined by a bundle of fibers called the corpus callosum that delivers messages from one side to the other. Each hemisphere controls the opposite side of the body. If a brain tumor is located on the right side of the brain, your left arm or leg may be weak or paralyzed.

Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people.

Lobes of the brain

The cerebral hemispheres have distinct fissures, which divide the brain into lobes. Each hemisphere has 4 lobes: frontal, temporal, parietal, and occipital. It’s important to understand that each lobe of the brain does not function alone. There are very complex relationships between the lobes of the brain and between the right and left hemispheres.

1-Frontal lobe

Personality, behavior, emotions

Judgment, planning, problem solving

Speech: speaking and writing (Broca’s area)

Body movement (motor strip)

Intelligence, concentration, self awareness

2-Parietal lobe

Interprets language, words

Sense of touch, pain, temperature (sensory strip)

Interprets signals from vision, hearing, motor, sensory and memory

Spatial and visual perception

3-Occipital lobe

Interprets vision (color, light, movement)

4-Temporal lobe

Understanding language (Wernicke’s area)

Memory

Hearing

Sequencing and organization

Messages within the brain are carried along pathways. Messages can travel from one gyrus to another, from one lobe to another, from one side of the brain to the other, and to structures found deep in the brain (e.g. thalamus, hypothalamus).

Date Day

Result :____________________________________________________

_________________________________________________________

Experiment #8

MICROSCOPIC Study of cross section of small intestine

Requirements:

Prepared slide of cross section of small intestine, and microscope.

Simple columnar epithelium (cross section of the small intestine)

Explanation:

1. Smooth muscle (long. layer)

2. Smooth muscle (circ. layer)

3. Simple columnar epithelium

4. Goblet cell

5. Lumen of the intestine

This slide is a cross section from the small intestine. Projecting into the intestinal lumen (space) are numerous finger-like projections called villi, which function to slow the passage of food and increase the surface area for the absorption of nutrients.

The lining of these villi is a tissue layer called the mucosa, which is made up of simple columnar epithelial cells, among these columnar cells are goblet cells that secrete mucus into the lumen of the intestine. During routine histological preparation, the mucus is lost, leaving a clear or lightly stained cytoplasm. Beneath a thin, outer covering of the intestine called the serosa is a thick layer of smooth muscle cells called the muscularis externa. The muscularis externa is divided into an outer longitudinal muscle layer with cells that run along the axis of the intestine and an inner, circular muscle layer whose fibers encircle the organ. Peristaltic contraction of these two muscle layers keeps food moving through the digestive tract.

Date Day

Result :____________________________________________________

_________________________________________________________

Experiment # 9

Microscopic study of vein

Theory:

The blood and heart are not sufficient by themselves to form a circulatory system. A network of tube-like structures functions to carry blood away from the heart, to body tissues and back to the heart. Therefore, the blood vessels contribute to the circular pattern of blood flow throughout the body. They accept blood, subject to the pumping pressure of the heart, and distribute it to various body regions. Five different kinds of blood vessels compose the vascular network of the circulatory system: arteries, arterioles, capillaries, venules, and veins.

Requirements:

Prepared slide of vein, Microscope.

The main properties of veins are:

They carried blood from the body towards the heart.They have a comparatively thin middle layer and thus smaller capacity for contraction (from muscle) and stretching (from elastic fibers). Pressures have dropped off in systemic veins because the blood has travelled a greater distance from the powerful left ventricle, compared with the trip through arteries.

Explanation:

In transverse section of vein, we can see that each vein has an inner space, or lumen, through which the blood flows and a multilayered vessel wall.

The inner coat is the tunica intima. Its simple squamous epithelium is the tissue that provides a relatively smooth trip for blood as it flows along this inside, free surface.

This surface reduces friction as blood flows through the vessel.It is usually termed endothelium because it lines the inside surface of the blood vessel. The midlayer, the tunica media, is the thickest layer in either vessel. However, it is proportionately thicker in the artery.Smooth muscle cells, mostly arranged circularly, and reinforcing collagen and elastic fibers

constitute its makeup.The outermost layer, the tunica externa/ tunica adventetia, is mainly a wrapping of dense connective tissue and loose connective tissue. This layer prevents the vessel from collapsing.

Date Day

Result :____________________________________________________

__________________________________________________________

Experiment#10

Microscopic Study of cardiac muscle

Requirements:

Prepared stained slide of cardiac muscle and microscope.

Microscopic study of Cardiac Muscle Cells:

This is a high power view of cardiac muscle cells. Like smooth muscle, each cardiac muscle cell has a single (sometimes two) centrally located nucleus. Like skeletal muscle, cardiac muscle cells are striated due to a similar arrangement of contractile proteins. Unique to the cardiac muscle are a branching morphology and the presence of intercalated discs found between muscle fibers. The intercalated discs stain darkly and are oriented at right angles to the muscle fibers. They are often seen as zigzagging bands cutting across the muscle fibers. In the intercellular spaces, note the supporting tissue with an extensive network of capillaries. The abundance of capillaries ensures adequate delivery of oxygen and nutrients to meet the high metabolic demands of cardiac cells.

Date Day

Result:____________________________________________________

__________________________________________________________

Experiment #11

Microscopic study of artery

Theory:

Requirements:

Prepared slide of cross section of artery and microscope.

Properties of Arteries:

Arteries transport pumped blood away from the heart. A major artery supplying a body region eventually subdivides into smaller arteries, which subdivide into smaller and more numerous arterioles.

The main properties of arteries can be listed as follows:

1)they are elastic.

2)they are contractile.

3) they contain blood flowing under high pressure and they allow for fluctuating blood pressure.

The first two descriptions result from the substantial thickness of the middle layer of smooth and elastic fibers.

Nerves supplying the smooth muscle here can stimulate contraction of the circularly arrayed muscle fibers.Contraction of these muscles can produce a reduction of the vessel lumen, or vasoconstriction. Relaxation of thismuscle leads to vasodilation.

The last two descriptions originate not only from structure but from the vessel location as well.

Arteries are relatively close to the source of pressure, the heart. The pressure fluctuates up and down, reflecting the systole (contraction) and diastole (relaxation) of the heart’s left ventricle. Thus, this is a changing pressure.

In transverse section of arterty we can see that each artery has an inner space, or lumen, through which the blood flows and a multilayered vessel wall.The inner coat is the tunica intima. Its simple squamous epithelium is the tissue that provides a relatively smooth trip for blood as it flows along this inside, free surface. This surface reduces friction as blood flows through the vessel. It is usually termed endothelium because it lines the inside surface of the blood vessel. The midlayer, the tunica media, is the thickest layer in either vessel.However, it is proportionately thicker in the artery.Smooth muscle cells, mostly arranged circularly, and reinforcing collagen and elastic fibers constitute its makeup.The outermost layer, the tunica externa/tunica adventitia, is mainly a wrapping of dense connective tissue and loose connective tissue. This layer prevents the vessel from collapsing.

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The main bones of the human skeleton are:

Long Bones

Short Bones:

Flat Bones

Irregular Bones

Sesamoid Bones

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