Human Anatomy and Physiology

by hamdi_234 (student)

Done by Fowsia Cabdulrahman
MBC101106446
unit 5
Andrew Oldnall

Cell Membrane

The cell membrane is a thin semi-permeable membrane that surrounds the cytoplasm of a cell its function is to protect the honesty of cell by allowing certain substances into cells, while keeping other substances out. It also serves as a base of attachment for the cytoskeleton in some organisms and the cell wall in others. This the cell membrane also serves to help support the cell and help maintain its shape. ‘Animal cells, plant cells, prokaryotic cells, and fungal cells have cell membranes’. (Education biology book)

Cell membrane surrounds the cell, it is made up of lipid chains and phosphate heads, there are some protein which contain within the cell membrane, they are called, peripheral protein, glycol protein and integral protein, they often form channels for substances to pass in and out of the cell. Protein molecules is also known as ‘identity markers or ‘reception site’, they are called this because substances, e.g. hormones cannot pass them without their permission. The function of the cell membrane is that it supports, protects and controls movement in and out of the cell, it is also a barrier between the cell and its environment, for example, it protects the ribosomes and lysosomes from coming near each other and it also maintains homeostasis.

Cell Membrane Structure

The cell membrane is mainly calm of a mix of and . Depending on the membrane’s location and role in the body, lipids can make up anywhere from 20 to 80 percent of the membrane, with the remainder being proteins. While lipids help to give membranes their flexibility, proteins monitor and maintain the cell's chemical climate and help to transfer of molecules across the membrane.

Cell membrane lipids

Phospholipids are major component of cell membranes. They form a lipid bilayer in which their attracted to water head areas suddenly arrange to face the aqueous cytosol and the extracellular fluid, their hydrophobic (repelled by water) tail areas face away from the cytosol and extracellular fluid. The lipid bilayer is semi-permeable, allowing only certain molecules to strew across the membrane. is another lipid component of cell membranes. It helps to thicken cell membranes and is not found in the membranes of . Glycolipids are located on cell membrane surfaces and have a sugar chain attached to them. They help the cell to recognize other cells of the body.

Cytoplasm

Cytoplasm is also known as ‘cell material’, it refers to anything between the nucleus and the cell membrane, a chemical reaction called ‘metabolism’ take place in the cytoplasm. Something called glycogen is stored in the cytoplasm, the glycogen is mainly stored in cells where we need energy the most and they are the muscle cells and the liver cells. For example, when we eat food the food breaks down into glucose, the glycogen then takes in some of the glucose and stores it until we need them. This is important because, if we ate food and used all the energy that it provides we would be tired immediately. Melanin is what makes up our skin colour and it is found in the cytoplasm, it protects from diseases, such as skin cancer. Cytoplasm supports and protects all the cell organelles; the cytoplasm is also storage for the glycogen and melanin. If there was not a cytoplasm, the substances would crush to each other and the cell its self would crush.

Nucleus

The nucleus usually is the largest structure inside the cell and is the one that gives the substances permission to come in and out of the cell. Some cells have more than one nucleus and this is called Multinucleate, the cells with no nucleus are called a nucleate. The nuclear is the heart of the cells and controls all the activities in the cell. Red blood cells have no nucleus, however they only live for a short period of time and eventually die; they usually live for 120 days. The function of the nucleus are many, for example, nothing can happen without the permission of the nucleus, for example, if a hormone wants to enter the cell, it also controls what is inside the nucleus, because if the cell did not have a heat which controls something, everyone would die because the viruses and the infections would come in without permission, the nucleus contains all heditary material of the cell.

The nucleus is bounded by a double membrane called the nuclear envelope. This membrane separates the contents of the nucleus from the . The envelope helps to maintain the shape of the nucleus and assists in variable the flow of molecules into and out of the nucleus through nuclear pores. are also located in the nucleus for example when a cell is "resting" not , the chromosomes are organized into long tangled structures called and not into individual chromosomes as we naturally think of them.

Nuclear Membrane

Nuclear membrane is similar to the cell membrane, however the nuclear membrane has gaps which pores through which protein can pass, and the function of the nuclear is that it controls movement in and out of the nucleus. If there was not a nuclear membrane the nucleus would just move around the cell and crush other cell substance, which is why it is important to create a wall for the nucleus.

Mitochondria

Mitochondria is a substance which locates in the cells, however it cannot be spotted because they very tiny, it has process in ...

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Nuclear Membrane

Mitochondria

Mitochondria is a substance which locates in the cells, however it cannot be spotted because they very tiny, it has process in itself. Every cell has at least 1000 mitochondria, however active cells for example, muscles and liver has more than 1000 mitochondria, because the active cells need to use more mitochondria than the other cells, to release more energy. Energy is released and stored in the mitochondria and mitochondria also stored glucose until we need them. There is a process inside the substance which is called, adenosine triphosphate (ATP) and adenosine diphosphate (ADP).

Mitochondria, ADP and ATP Diagram

This diagram shows how ADT and ATP work. Energy supplied from glucose breakdown and energy released to do work or produce new materials.

Golgi apparatus
Golgi was a famous scientist who specialised in cells and tissues in 19th and 20th century, however Golgi apparatus is a series of flattened, fluid filled sacs, stacked like pancake, it packages protein and wraps it up for delivery to their organelles or outside the cell. For example, if someone wants to give present to someone, the person has to buy the item first and wrap it up to give it to the person. The Golgi apparatus produces’ lysosomes’ and breaks down larger food molecules into smaller molecules; it digests old cell parts and is in charge of breaking down bacteria, viruses and infection. The Golgi apparatus modifies proteins made by cells. White blood is also loaded with lysosomes to destroy bacteria , lysosomes is more freely in the cell and breaks down anything that should not be there, for example foreign bodies such as parasites. They use enzymes to do so.

Smooth and Rough Endoplasmic Reticulum (ER)

Both smooth and rough ER are shaped like a wobbly clay and they look alike they are located in the cell, the difference between the smooth and the rough ER is that there are ribosomes attached to the rough ER rough ER produces cell proteins and acts as a temporary storage area. For example hormone is a type of proteins. The rough ER makes proteins which is hormones. The ribosome makes sure that the protein goes to the Golgi apparatus and releases it. The function of the smooth endoplasmic reticulum is that it metabolises lipids and breaks it down to fatty acids

P2
Body Tissues
Epithelial tissue

Epithelial is made up from epithelia; epithelia’s are the linings of internal and external; surfaces and body cavities, for example, tubes. In our skin we have chunks of epithelial cells. The epithelial is like a cover for our main organs. For example, our kidney’s have a layer of epithelia covering it. The epithelia may be made up of one layer or more. One single layer of epithelia is called single epithelia, many layers of epithelia is called compound epithelia.

There are nerve supplies to epithelia; epithelia also receive blood supply from the body to form up quickly. Epithelia’s are exposed to ‘friction’ as they are on the surface. For example, if a person tries to rub their skin the consequence would be that the upper layer of the epithelial will get damaged. However the capacity for growth and repair is greater than the other tissues, growth and repair occurs during the sleep.

Simple and compound epithelial

Simple epithelial

Simple epithelial is made up of three things, squamous cells, cuboidal cells and columnar cells. The squamous cells look flat, that is why they are called squamous. They allow amosis, because they have small gaps, they are located on lung alveoli and blood capillaries. The cuboidal cells look like cuboids if we look in 3 dimensional ways. They allow amosis although they are stronger; they are located in kidneys, sweat duts, thyroid gland and breast tissues. Columnar cells is also known as ciliated cells, they look like columns and are tall in length. They locate in the nose and the wind pipe. Function

Compound Epithelial

The function of compound epithelial is to protect deeper tissue. The compound epithelial is found in the mouth, tongue, vagina and oesophagus, they are all lined with stratiphied epithelia, they consist of squamous cells, cuboidal cells and columnar cells, they are usually in pink colour and they are called mucous membrane . The deeper you go down the skin, the more melanin you will find and it is called pigment cells. The more you go up the skin, you will find keratin, keratin makes our skin waterproof, and if keratin did not exist the water would flow down our skin. The skin has an outer layer of epithelium similar in structure to the stratified epithelium but with the important addition of a layer of crushed dead cells on the outside. This is known as the epidermis. As the cells move on from the basement membrane, they gradually become fillet with a protein called keratin and are said to be keratinised or cornfield. This layer is very important to prevent micro-organisms invade deeper structure, and it has a waterproofing effect on the skin.

Muscular tissues

Muscular tissue contains of three different sections, striated muscle tissue, non-striated muscle tissue and cardiac muscle tissue.

Striated muscle tissue

Striated muscle tissue is also known as, voluntary and skeletal muscle tissue. The striated muscle is attached to the bones of the skeleton; however some of the striated muscle are attached to the skin in the face. They are called voluntary because they are attached to the flexible parts of the body. For example, we can move our arms, legs and we can pull up our faces. This kind of muscle gets permission, it will contact on receipt of nerve impulsive controlled by conscious thought from the central nerve system which is located in the brain and the spinal cord. For example, if someone asks someone to move their arm, the message will transfer to the brain.

Non-striated muscle

Non striated muscle still contains filaments, buts not in orderly pattern, muscle fibres are cigar shaped with a single central nucleus. This kind of muscle is non skeletal, which means it is not attached to the bones, it is totally involuntary, which means they cannot be moved and it tend to be smooth. This muscle is located in the stomach, bladder, uterus (womb) and in the eyes.

Cardiac muscle

Cardiac muscle is also known as myogenic, this means that it rhythmically contracts without receiving any nervous stimuli, the entire heart is made up of cardiac muscle, and there isn’t anywhere else in the body which is made up of cardiac.

Connective tissues.

Connective tissue contains several sections, blood. Bone, adipose, areoler tissue and cartilage. The blood tube consists of different substances, for example, hormones, white blood cells, plasma, red blood cells, glucose, bacteria and data.

Adipose Adipose tissue is a form of loose connective tissue that stores fat.
Cartilage
Cartilage is a form of fibrous connective tissue that is composed of closely packed collagenous fibres in a chewy gummy substance called chondrin. The skeletons of sharks and human embryos are composed of cartilage. Cartilage also provides flexible support for certain structures in adult humans including the nose, trachea and ears.
Bone
Bone is a type of mineralized connective tissue that contains collagen and calcium phosphate, a mineral crystal. Calcium phosphate gives bone its resolve.
Blood
amusingly enough, blood is measured to be a type of connective tissue. Even though it has a different function in contrast to other connective tissues it does have an extracellular medium. The matrix is the plasma and , and platelets are pending in the plasma.

Plasma

Plasma makes up over 50% of blood, so basically it makes up half of the blood, the composition of the plasma is 90% and the 10% is dissolve substances, the colour of plasma is yellow, there are thousand s of substances in the blood including vitamins, minerals, fibres and protein, plasma is what keeps blood flowing. For example, of we pour blood on a blood sample and we leave it for a while, we would see the yellow fluid which is the plasma. If there was not any plasma in the blood tubes, the substances would not flow and we would eventually die.

Red Blood Cells

Red blood cells do not have nucleus and they are also known as erythrocyte, they are very flexible, they can twist and bend, they are so tiny that they can flow in the smallest and thinnest blood capillaries. There are about 25 trillion of red blood cells in veins, they live for 120 days maximum, and however 3 million red blood cells are made per second. Red blood cells are made in bone barrow. In infant’s bodies, every bone will make red blood cells, this is because they are still growing and need more red blood cells to live and grow. In adults bodies, only limited parts of the body makes red blood cells, these are: femur and humerous, cranial bones, thoracic bones and vertebral. The function of red blood cells is to carry oxygen from the lungs to all tissues of the body.

White Blood Cells

White blood cells are also known as leukocytes, their job is to defend the body against bacteria and viruses, WBC has different functions, and some of the functions are to digest bacteria and detoxify foreign substances and produce anti bodies. For example if cold spreads to people and you don’t catch the cold, it means that your body can fight against the virus. WBC is formed in different places, for example, red bone marrow, spleen, lymph noles and thymus. WBC lifespan various depends on the role that they have. For example, WBC that detoxifies foreign substances die first, this is because the WBC is fighting against dangerous and powerful substances. WBC travel trough circulating systems to where they are needed which is mostly where the infection is, for example, if you cut your finger the WBC will gather to the infection area to fight them off.

Platelets

They are also known as thrombocytes, platelets are very small black seeds that heel a scar and when they gather together they form like a stone. They live for 5 to 9 days, this is because for example, if you trip over and have a big scar on your knee, the scar will heal by the platelets and will come off after 5 to 9 days. They are formed in the bone marrow, there are about 250,000 to 350,000 of platelets in our blood and they look like plates that are why they are called platelets.

Areolar tissue is a type of connective tissue, this is the most common tissue in the body, it binds al the muscles, bones and nervous together. If we hadn’t have areolar tissue in our body we would not be able to move and feel anything, this is because our brain controls our body so if we were meant to move and we did not have areolar tissues the message would not reach the bones and muscles. Areolar tissue offers a degree of support to the tissues that is surrounds, it also provides flexibility. It is made up of collagen fibres and elastic fibres.

Adipose tissue is known as fatty tissue this is because it is made up of fat. It commonly locates under the skin and around the major organs, for example, kidneys, breasts and digestive tracts; it is also a very useful storage place for high energy. The function of this tissue is that it insulates the body keeps it warm. Our body will use fat if there is no carbohydrate left.

Cartilage is a smooth and firm substance that protects bones during friction; it is a protection shield but looks like a thin layer of the bone. It has no blood supply but is nourished by the bone beneath. It is located in the ears, nose and joints.

Bones tissue

This tissue is a much harder substance than the cartilage but can still be worn away by friction. The hips, shoulders, knees and elbows are exposed to friction. Matrix means back ground, the back ground of the bone is calcium salts which forms around collagen fibres, collagen fibres gives the bone the hard texture. For example, if we do not eat cheese and drink milk to make calcium, our bones will become brittle and break easily. Collagen fibres offer the bones the ability to bend under strain and it protects the bones from being too brittle. Bones has nerves and there is blood supply that runs through the bones, it is not guaranteed that our bones and 100% concrete. Scientific discovered that children bones are flexible than adult bones.

Nervous tissue

This tissue is only found in central nervous system which is located in the brain, spinal cord and nerves. Nervous tissue receives stimuli from external and internal sources. For example, external stimuli might be that we might touch hot water and cannot bare the pain or someone might get pinched by someone and cannot brae the pain. Internal stimuli might be that our bladder might be full and we have to use the toilet or we might have stomach pain. Nervous tissues serve to create consistent, co ordination and communication between parts of the body. The nervous system interprets stimuli form the sense of the organs so that vision, hearing, smell and touch can be noticeable. Neuron means highly spenialed cells transmit nerve impulses.

The body organs

Hearts - The is the organ that helps supply blood and oxygen to all parts of the body. It is divided by a partition or septum into two halves, and the halves are in turn divided into four chambers. The heart is located within the chest cavity and surrounded by a fluid filled sac called the . This amazing muscle produces electrical impulses that cause the heart to contract, pumping blood throughout the body. The heart and the together form the .

Lungs - The lungs are organs of the respiratory system that allow us to take in and expel air. In the breathing process, the lungs take in oxygen from the air through inhalation. Carbon dioxide produced by is in turn released through exhalation. The lungs are also closely associated with the as they are the sites for gas exchange between the air and the blood.

Brain- The brain is one of the largest and most important organs of the human body. Weighing in at about three pounds, this organ has a wide range of responsibilities. From coordinating our movement to managing our emotions, the brain does it all. The brain is made up of three main parts: the forebrain, the brainstem, and the hindbrain.
Forebrain- The  is the most complex of the three parts. It gives us the ability to "feel," learn, and remember. It consists of two parts: the contains the cerebral cortex and corpus callosum and contains the thalamus and hypothalamus.
Brainstem- The brainstem consists of the  and the hindbrain. Just as the name suggests, the brainstem resemble the stem of a branch. The midbrain is the upper part of the branch that is connected to the forebrain. This region of the brain sends and receives information. Data from our senses, such as the eyes and ears, are sent to this area and then directed to the forebrain.
Hindbrain- The brainstem consists of the  makes up the lower part of the brainstem and consists of three units. The medulla oblongata controls reflex functions such as digestion and breathing. The second unit of the hindbrain, the pons, also assists in controlling these functions. The third unit, the cerebellum, is responsible for the skill of movement.

Stomach- The stomach is a muscular organ located on the left side of the upper abdomen. The stomach receives food from the esophagus. As food reaches the end of the esophagus, it enters the stomach through a muscular valve called the lower esophageal sphincter.

The stomach secretes acid and enzymes that digest food. Ridges of muscle tissue called rugae line the stomach. The stomach muscles contract periodically, churning food to enhance digestion. The pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.

Pancreas- the pancreas is located deep in the abdomen, sandwiched between the stomach and the spine. It lies partially behind the stomach. The other part is nestled in the curve of the duodenum (small intestine). To imagine the position of the pancreas. Your hand will be at the rough level of your pancreas. Because of the pancreas’ deep location, tumors are hardly ever plain able to felt by pressing on the abdomen. It also explain why many symptoms of pancreatic cancer often do not appear until the tumor grows large enough to interfere with the function of nearby structures such as the stomach, duodenum, liver or gallbladder.

Duodenum- the duodenum is a short portion of the small intestine connecting it to the stomach. It is about 10 inches (25cm) long, while the entire small intestine measures about 20 feet.

Kidney- The kidneys are a pair of organs located in the back of the abdomen. Each kidney is about 4 or 5 inches long -- about the size of a fist.

The kidneys' functions are to strain the blood. All the blood in our bodies passes through the kidneys several times a day. The kidneys remove wastes, control the body's fluid balance, and control the balance of electrolytes. As the kidneys filter blood, they create urine, which collects in the kidneys' pelvis funnel-shaped structures that drain down tubes called ureters to the bladder.

References

Neil, M (2010). Health and social care level 3 books 1. London: Edexcel. P178-187.

Ross and Wilson (2010).Anatomy and Physiology London: p-25-45