Anatomy and Physiology

1. Define the terms element, atom, molecule, electrolyte and compound and give examples of each

Elements are composed of identical particles atoms. Atoms are the smallest particles that retain the physical and chemical properties of the element. Compounds consist of atoms more than one type that are joined together by chemical bonds.There are 92 naturally occurring elements and others created as a part of a nuclear reaction. They are chemical substances that cannot be divided into similar substances and are made up of atoms.

Atom - the smallest particle of a chemical element that can exist : a single oxygen atom

Elements– A chemical whose atoms are all the same type : oxygen and hydrogen

Molecule - A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction : Water, Carbon Dioxide

Electrolyte – An inorganic ion in body fluids, which conducts electricity : Sodium Ion (Na+) , potassium (K+)

Compound – A molecule containing more than one elements – Water, Carbon Dioxide

2. Identify the chemical symbols and formulae for biologically important elements and compounds.

O for oxygen, H for hydrogen, Cl for chlorine, I for Iodine, Fe for iron, K for potassioum, C for carbon, N for nitrogen, Ca for calcium and Na for Sodium.

H20 for water, C02 for carbon dioxide, HCl for hydrogen chloride, NaCl for soduim chloride, H2CO3 for carbonic acid.

3. Outline the principles of the pH scale

Is an algorithmic scale - every change of one unit in pH represents a tenfold change in hydrogen ion concentration. It a negative scale, a falling pH represents a rise in hydrogen ion concentration and a rising pH represents a falling ion concentration. Six and below are acids and Eight and above untill fourteen is Alkaline while seven is neutral.

1. Describe the role of the cell in the human body

A cell is the smallest functional unit of life. A tiny living structure, it swaps information, makes proteins and when it produces new cells it passes on our genetic structure in form of DNA. A well organised cluster of specialised cells forms an organ such as a muscle of the liver. They are grouped together to form tissues which are specialised. Different tissues are grouped together to form organs, organs are then grouped to create systems.

2. Outline the structure and function of the plasma membrane and internal organelles, including the nucleus.

Fluid mosaic model - The arrangement of molecules in the membrane. The phospholipid head is electrically charged and is hydrophilic and the tail without charge is hydrophobic. The molecules automatically arrange themselves into a bilayer - the head face out towards the water on either side of the membrane. The centre of the bilayer is hydrophobic so that the membrane does not allow water- soluble substances through it - it act as a barrier to these dissolved substances.

The plasma membrane consists of two layers, bilayer of phospholipids with proteins and sugars embedded in them which is "fluid" and constantly moving. In addition to phospholipids the lipid cholesterol is also present, cholesterol is a type of fat and fit between and bind between the hydophobic tails causing them to pack closer together making the membrane less fluid and more rigid. Some proteins form channels in the membrane that allow small or charged particles through the membrane. Carrier proteins transport molecules and ions across the membrane by active transport and facilitated diffusion. Proteins also act as receptor for molecules like hormones in cell signalling.

Glycolipids and glycoproteins stabilise the membrane by forming hydrogen bonds with surrounding water molecules. They are the sites where drugs, hormones and antibodies bind as well as act as receptors for cell signalling. Branched carbohydrate molecules give the cell its immunological identity. They also have antigens on the cell surface molecules involved in the immune response.

2. Outline the structure and function of the plasma membrane and internal organelles, including the nucleus.

Nucleus - The command centre of the cell. A large organelle surrounded by a nuclear envelope which contains many pores that regulates the passage in and out of the nucleus. The nucleus contains chromatin which is made from proteins and DNA and a nucleolus which is a site where ribosomes are produced.

Lysosome - A round organelle surrounded by a membrane pinched off from the Golgi apparatus containing digestive enzymes and are used to digest invading cells or to break down worn out components of the cell.

Ribosome- A very small organelle composed of RNA and protein that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum. It is the site where proteins are synthesised from amino acids using RNA as a template.

Rough Endoplasmic Reticulum - A system of membrane enclosing a fluid - filled space. The surface is covered with ribosomes and it folds and processes proteins that have been made at the ribosomes.

Smooth Endoplasmic Reticulum - Synthesises and processes lipids and steriod hormones, it is also associated with the detoxification of some drugs. Some of the lipids are used to replace and repair the plasma membrane and membranes of organelles.

2. Outline the structure and function of the plasma membrane and internal organelles, including the nucleus.

Vesicles - A small fluid-filled sac in the cytoplasm that transports substances in and out of the cell and between organelles. Some are formed by the Golgi apparatus or the endoplasmic reticulum while others are formed at the cell surface.

Golgi Apparatus - A group of fluid-filled flattened sacs where vesicles can be seen around the edge. It processes and packages new lipids and proteins as well as making lysosomes.

Mitochondria - Oval-shaped with a double membrane with folds called cristae. Inside is the matrix which contains enzymes involved in respiration as it is the site of aerobic respiration where ATP is produced. They are found in cells that ae very active and require a lot of energy.

Cytoskeleton - Consists of an extensive network of tiny proteins fibres : Microfilaments - Provide structual support, maintain the characteristics shape of the cell and permit contraction. Microtubules - Involved in the movement of organelles in the cell, chromosomes during cell divison and cell extensions. Cell Extensions - Allows movement with cilia and microvilli for high surface area. Centrosome : Centriole - Small hollow cylinders containing a ring of microtubules and is involved with the separation of chromosomes during cell division.

3. List four mechanisms for cell membrane transports with examples.

• Diffusion is the net movement of particles from an area of higher concentration to a lower one down the concentration gradient. Molecules can diffuse both ways untill particles are evenly distributed and requires no energy eg. Oxygen and Carbon Dioxide. Rate of Diffusion - A higher concentration gradient, a thinner exchange surface and a larger surface area will all increase the rate of diffusion.

• Osmosis is the diffusion of water molecules across a partially permeable membrane from a higher water potential to a lower one. Water potential is the likelihood of water molecules to diffuse out or in a solution. Pure water has the highest water potential. A cell in a higher water potential ( hypotonic solution ) net movement in cell causing it to lyse. A cell in a same water potential ( isotonic solution ) net movement in cell is equal. A cell in a lower water potential ( hypertonic solution ) net movement in cell causing it to crenate.

3. List four mechanisms for cell membrane transports with examples.

• Facilitated Diffusion uses carrier proteins and proteins channels as some larger molecules eg. amino acids and glucose and charged atoms eg. chloride ions cannot diffuse directly. Its a passive process and does not use energy and goes from a high to a lower concentration. Carrier proteins move large molecules and attach to the protien in the membrane while the protein changes shape then releases the molecule on the opposite side of the membrane. Channel proteins however form pores in the membrane for charged molecules to diffuse through down the concentration gradient.

• Active Transport move substances against a concentration gradient and uses engery to move molecules and ions eg. calcium across the plasma membrane. A molecule attaches to the carrier protein where it changes shape moving the molecule to the other side.

4. Identify four basic types of body tissue and describe their structure and fuctions.

Epithelial tissue covers the body and lines cavities hollow organs and tubes and found in the glands. The functions include protection of underlying structure from dehydration, mechanical and chemical damage as well as secretion and absorption. Can be simple (single layered) or stratified (several layers).

Squamous epithelium – single layered of flattened cells: diffusion eg. Blood and lymph vessels, alveoli and the heart.

Cuboidal epithelium – cube-shaped on a basement membrane: secretion, absorption and excretion eg. Kidney tubules and the thyroid.

Columnar epithelium –single layered of rectangular in shape: secretion of mucus through goblet cells and microvilli eg. Small intestine and respiratory tract.

Stratified squamous epithelium – several layers growing to the surface where they are shed eg. Skin, hair and nails.

Transitional epithelium – several layers of pear-shaped : stretching eg. Bladder

4. Identify four basic types of body tissue and describe their structure and fuctions.

Connective tissue is widely spread with a good blood supply with functions such as: binding and structural support, protection, transport and insulation. Found in all organs supporting the specialised tissue. Loose or areolar connective tissue provide elasticity and tensile strength connecting and supporting other tissues in the: skin, between muscles, supporting blood vessels and nerves.

Fibroblasts – Large cells manufacturing collagen and elastic and are active in tissue repair. Bind together in wounds to form granulation tissue.

Macrophages – Large irregular-shaped cells with granules in the cytoplasm, actively phagocytic engulfing and digesting cells, bacteria and other foreign bodies.

Leukocytes – White blood cells are found in health connective tissue, they synthesise and secrete defensive antibodies into the blood tissues.

Reticular tissue – Reticular tissue is found in lymph nodes and all organs of the lymphatics system.

Fibrous tissues – Packed bundles of collagen fibres forming ligaments which bind bones together and protecting covering for bone and organs.

4. Identify four basic types of body tissue and describe their structure and fuctions.

Cartilage is a form of firm connective tissue and lie embedded in matrix reinforced by collagen and elastics fibres.

Hyaline cartilage – smooth tissue arranged in small groups providing flexibility, support and smooth surfaces for movements at joints. Found on the ends of long bones that form joints, costal cartilages attaching the ribs to sternum as well as forming part of larynx, trachea and bronchi.

Fibrocartilage – Dense masses of white collagen fibres, it’s a tough, slightly flexibles, supporting tissue. Acts as pads between the bodies of the vertebrae, between the bones of the knee joint and bone sockets.

Elastic Fibrocartilage – Flexible tissue with yellow elastic fibres providing support and maintains shape of pinna or lobe of the ear.

Bone cells , osteocytes surrounded by collagen fibres strengthened by salts, calcium and phosphate providing strength and rigidity: good growth in the first two decades and regeneration throughout life. Compact bone : solid and dense , Cancellous bone : spongy, fine honeycomb appearance.

4. Identify four basic types of body tissue and describe their structure and fuctions.

Muscle Tissue is able to contact and relax providing movement within the body. Muscle contraction requires a blood supply that will provide oxygen, calcium, nutrients as well as removing waste products such as carbon dioxide.

Skeletal muscle -   forms the muscles that move the bones with voluntary and involuntary movements

Smooth muscle – does not have striations and is not under conscious control. Intrinsic ability to create its own contractions. In innervated by the automatic nervous system. Contraction is slower and more sustained than skeletal muscle and is found in the walls of hollow organs: diameter of blood vessels and respiratory tract and expelling contents of urinary bladder and uterus. Spindle shaped with one central nucleus.

Cardiac muscle – Only found in the heart wall, not under conscious control

Nervous Tissue  is Excitable cells – neurons that initiate , receive , conduct and transmit information and non- excitable cells – also known as glial cells that support the neurones.

1. List the functions of the skeleton and describe the structure and physiology of bone growth and healing after fractures.

The functions of the bones include : providing a body framework , giving attachment to muscles and tendons and allowing movement of the body as a whole and of parts of the body by forming joints that are moved by muscles. Forming the boundaries of the cranial , thoracic and pelvic  cavities and protecting organs they contain. Haemopoiesis , the production of red blood cells in the bone marrow. Finally a mineral storage for calcium phosphate essential for maintenance of blood calcium levels.

Hard – specialised form of connective tissue consists of a collagenous matrix which becomes calcified through the deposition of crystals of minerals ( calcium and phosphate ). Osteoid consists of collagen fibres , glycoproteins and confers strength and flexibility on the tissue.

1. List the functions of the skeleton and describe the structure and physiology of bone growth and healing after fractures

•Osteoblasts-bone forming cells,found mainly close to the periosteal and endosteal membranes and are responsible for secreting the osteiod that forms the non cellular matrix of the bone

•Once they have become surrounded by the osteoid that they have secreted, osteoblasts stop secreting and become mature bone cells. These are the osteocytes

•Osteoclast-remodel and replace the skeleton which takes place all the time in response to growth wear and tear and the changing mechanical requirements of the body they promote the destruction and resorption of old bone –replaced by new tissue

2. Demonstrate an understanding of the difference between synovial, cartilaginous and fibrous joints and their movements.

Immoveable, fibrous joints are between plates of the adult skull and at the peg and socket joints between the teeth and jaw. – Bones of the skull: no movement

Slightly moveable, cartilaginous between the vertebrae and at the symphysis pubis. Joints are formed by a pad of tough fibrocartilage that acts as a shock absorber – Bone ends connected by cartilage

Free moveable, synovial articulating bones are separated by a cavity filled held together by a sleeve of fibrous tissue with synovial fluid. – Ball and socket joint –hip and shoulder which

1. Differentiate between the axial and appendicular parts of the skeleton and identify the bones that form each.

The skeleton consist of axil and appendicular components. The axil skeleton consist of the skull, vertebral column, ribs, sternum and bones of the thorax. ( inner bones ) While the appendicular skeleton consist of the pectoral girdle, pelvic girdle and bones of upper and lower limbs. ( outer limbs )

2. Indentify examples of long, short, flat and irregular bones.

4. Locate and name the principal muscles of the arm and the leg.

1. Describe the layers of the skin

Epidermis – composed of keratinised stratified squamous epithelium: keratinocytes, melanocytes, Langerhans cells and merkel cells . Outer stratum corneum : layers of dead keratinocytes that continuously shed. Stratum lucidum : 3-5 layers of flattened clear dead keratinocytes that contain keratin. Stratum granulosum : contains flattened and irregular. Stratum Spinosum