Metabolism

The total chemical changes that occur in cells.

Two sub-categories: Anabolism & Catabolism

(These processes are often called cellular respiration or cellular metabolism).

Anabolism

The energy requiring process that builds larger molecules by combining smaller molecules.

Catabolism

How Adenosine Triphosphate (ATP) is made:

ATP Production

1. Glycolysis produces a total net gain of 8 ATP.

2. The Krebs citric acid cycle produces for each of the 2 pyruvic acid molecules 14 ATP via electron transport and 1 ATP or GTP. The total production in the cycle is 28 ATP and 2 GTP or 30 ATP.

3. The 8 ATP from glycolysis and the 30 ATP from the citric acid cycle yield a total of 38 ATP from each glucose molecule.

Production of ATP from General Food Compounds

1. The cellular furnace that "burns" food to produce ATP consists of glycolysis, the Kreb's citric acid cycle, and electron transport.

2. Carbohydrates feed into the furnace at the level of glucoes in glycolysis.

3. Fats are digested into glycerol, which feeds into the furnace at the phosphoglyceric acid stage of glycolysis, and fatty acids, which feed into the citric acid cycle.

Production of ATP from General Food Compounds

Continued

4. Proteins are digested into amino acids. They feed into the furnace at different stages of glycolysis and the citric acid cycle based on their chemical structure.

5. Carbohydrates, fats, and proteins are all potential sources of cellular energy because they can all be broken down and their chemical energy can be converted into another form of chemical energy, ATP, which runs the cell's machine.

Cellular Reproduction

The process by which a single cell duplicates itself.

The process by which our genetic material is passed on to our offspring from one generation to the next.

Mitosis

Duplication of genetic material in the nucleus.

When we cut our finger or bruise our tissues, the cells are repaired and replaced by mitosis.

Cytokinesis

Meiosis

A reduction division of the nuclear material; it occurs only in the gonads. It reduces the genetic material from 46 (diploid or 2N) to 23 (haploid or N) chromosomes.

Meiosis consists of 2 divisions, resulting in 4 cells. The first meiotic division reduces the number of chromosomes in half. The second meiotic division corrects their duplicated nature.

The Cell Cycle

The process by which a cell divides into two and duplicates its genetic material.

A cell cycle is divided into three stages: interphase, mitosis, and cytokinesis.

Comparison of Mitosis and Meiosis

Mitosis produces two daughter cells with the exact same genetic material as the parent cell.

Meiosis produces four daughter cells, each with half the genetic material of the parent cell.

Meiosis occurs only in the gonads. Unlike the cells produced by mitosis, meiotic cells cannot live on their own. They must unite in fertilization in the female reproductive tract.

Comparison of Mitosis and Meiosis
continued

Mitosis is a process of cellular division by which we grow, maintain, and repair ourselves.  Most cells of our body undergo mitosis. Nerve and muscle cells rarely divide, and liver cells divide only when damaged. They usually have cells lasting a full year.

In Meiosis, homologous pairs of chromosomes line up in prophase I and exchange genetic material in a process called crossing-over.

Mitosis consists of 1 division, whereas meiosis consists of 2 divisions.

Cancer

Cellular Reproduction Explained

In this process of cellular reproduction, special cells called sex cells, the egg and the sperm, are produced. In this type of cellular reproduction, the genetic material must not only be duplicated, but it must also be reduced in half so that the female egg carries half of the genetic material or 23 chromosomes and the male sperm carries the other one half of the genetic material or 23 chromosomes.

When the sperm and egg unite in fertilization, the genetic material is returned to its full complement of 46 chromosomes.

Interphase

A cell spends most of its time this stage. This phase, the longest and most dynamic part of a cells life, is not part of cell division.

______ means between phases.

During this time, the cell is growing, metabolizing, and maintaining itself. The nucleus is seen as a distinct structure surrounded by its nuclear membrane.

Adenosine Triphosphate (ATP)

Anaerobic Glucose decomposition

1. One type of anaerobic decomposition occurs in yeast cells (a type of fungus) and is called fermentation.

2. The other type occurs in our muscle cells when we exercise and experience muscle fatigue and cannot get enough oxygen to our muscle cells.

Deoxyribonucleic Acid (DNA)

Hereditary material of the cell.

It not only determines the traits an organism exhibits, but it is exactly duplicated during reproduction so that offspring exhibit their parents' basic characteristics.

DNA governs chemical reactions by the chemical mechanism of controlling what proteins are made.

Cells in a developing embryo

Histology

The Four Basic types of Tissues

Epithelial

Connective

Muscle

Nervous

These tissues combine to form organs. The various organs make up the systems of the body that allow us to function and survive in our complex world.

Epithelial Tissue

1. Functions in 4 ways: it protects underlying tissues; it absorbs nutrients, it secretes hormones, mucus, and enzymes; and it excretes waste like urea in sweat.

2. The basement membrane acts as an anchor and adhesive for ____ cells.

3. ____ Tissue can be named according to shape, arrangement, or function.

4. ____ Tissue is made of cells closely packed together with very little intercellular material.

Epithelial Tissue

based on shape

1. Squamous cells are flat and serve a protective function like lining our mouths or skin.

2. Cuboidal cells are shaped like cubes and function in protection and secretion. In kidney tubules, they function in absorption.

3. Columnar cells are tall and rectangular. They are found ilining the ducts of certain glands (i.e mammory glands) and the bile duct of the liver. They function in secretion and absorption.

Epithelial Tissue

based on arrangement

1. Simple arrangement is one cell layer thick. It is found in the lining of blood capilaries, the alveoli of the lungs, and in the loop of Henle in the kidney tubules.

2. Stratified  arrangement is several layers thick. Stratified squamous lines our mouth and throat and the outer layer of skin. Stratified cuboidal lines our sweat gland ducts and salivary gland ducts. Stratified columnar lines the ducts of mamory glands and in parts og the male uretha.

3. Pseudostratified arrangement looks like it is several layers thick, but, in reality, all cells extend from the basement membrane to the outer surface.

4. Transitional epithelium consists of several layers of closely packed easily stretched cells. When stretched, they appear flat; when relaxed they look ragged or saw-toothed.

Epithelial Tissue

based on function

Mucous membrane produces mucous. It protects, absorbs nutrients, and secretes enzymes and bile salts in addition to mucous. *It lines all body cavity that open to the outside.

Glandular epithelium form glands.

Exocrine glands have excretory ducts that lead the secreted material from the gland to the surface of a lumen (passageway) on the skin. There are two types of exocrine glands.

 *Simple exocrine glands such as sweet and sebaceous glands have single unbranching ducts.

*Compound exocrine glands are made of several branching lobules with branching ducts. Examples are the mamory glands and the large salivary glands.

Epithelial Tissue

based on function  Continued

*Endocrine glands are ductless and secrete hormones directly into the
  bloodstream. Endothelium lines the blood and lymphatic vessels.  The
  endothelium of the heart is called the endocardium.

*Mesothelium or serous tissue lines the great cavities of the body. The pleura is the serous membrane that lines the Thoracic cavity. The peritoneum lines the abdominal cavity. The pericardium is the serous membrane that covers the heart. The peritoneum is the serous membrane that lines the abdominal cavity.

Connective Tissue

This type of tissue allows movement and provides support for other types of tissues. In this tissue, unlike epithelial, there is an abundance of material called matrix.

Fibers of tough collagen or fibers of flexible elastin can be can be embedded into this matrix.

Three subgroups: loose connectove tissue, dense connective tissue, and specialized connective tissue.

Loose Connective Tissue

As the name implies, the fibers of ___ ___ tissue are not tightly woven amoung themselves.

There are three types of __ __ tissue are: areolar, adipose, and recticular.

 __ __ tissue fills space between and penetrates into organs.

Areolar Loose Connective Tissue

The most widely distributed type of the ___ ___ tissue.

It contains 3 types of cells:

•  fibroblasts: make fibrils for repair
• histiocytes/macrophage: large stationary phagocytic cells that eat up debris and micro organisms outside the blood circulatory system  (phagocytosis).
• mast cells: are found close to small blood vessels. Mast cells produce the anticoagulant heparin and histamine, and inflammatory substance

Adipose Loose Connective Tissue

Tissue is loaded with fat cells. Fat is stored in its cells. It protects and insulates.

___ acts as a firm, protective packing around and between organs, bundles of muscle fibers, and nervesm and it supports blood vessels. The kidneys have a surrounding layer of adipose tissue to protect them from blows or jolts.

Additionally, because fat is a poor conductor of heat, ___ tissue acts as insulation for the body, protecting us from excessive heat losses orexcessive heat increases in temperature.

Recticular Loose Connective Tissue

Consists of a fine network of fibers that form the framework of the liver, spleen, lymph nodes, and bone marrow.

Dense Connective Tissue

As the name implies, __ __ tissue is composed of tightly packed protein fibers.

Examples of ___ ___ tissue having a regular arrangement of embedded fibers are tendons (attach muscle to bone), ligaments (attach bone to bone), and aponeuroses (wide and flat tendons).

__ __ __ having an irregular arrangement of embedded are muscle sheaths (the dermis layer of the skin), joint capsules, and fasia (a connective tissue covering a whole muscle).

Specialized Connective Tissue

A number of types of connectie tissue have specialized functions. Cartliage is one of these special kinds of tissues.

Cells of cartiliage are called chondrocytes.

The three types of cartilage tissue are hyaline, fibrocartilage, and elastic.

Hyaline Cartilage

(Specialized Connective Tissue)

When viewed under a microscope, ___ cartilage has a matrix with no visable fibers in it, hence the name ___, which means clear.

As the fetus forms in the womb, the skeletal system is made entirly of __ cartilage and is visable after the first three months of pregnancy.

Found in the costal cartilages that attach the ribs to the sternum, in the septum of our nose, and in the rings that keep our trachea and bronchi open.

Fibrocartilage Cartilage

(Specialized Connective Tissue)

Has a majority of tough collagenous fibers embedded in the matrix. These fibers make ths type of cartilage dense and very resistant to stretching.

The intervertebral disks that surround our spinal cord and act as shock absorbers between our vertebrae are made of this strong cartilage.

Elastic Cartilage

(Specialized Connective Tissue)

This type of cartilage has a predominance of elastin fibers embedded in the matrix. These fibers permit this type of cartilage to be easily stretched and flexible while being capable of returning to its original shape.

It is found in the ears, epiglottis, and auditory tubes.

Two types of Bone Tissue

Bone is a very firm specialized connective tissue. The two types of bone tissue are compact or dense & cancellous or spongy

Bone cells are called osteocytes. They are embedded in a matrix of calcium and phosphorous, the mineral salts resonsible for the hardness of bone.

Dentin

Another specialized connective tissue. The material that forms our teeth. Closey related to bone in structure but is harder and dnser.

Dentin is light brown, the dentin tooth is covered with white enamel.

Blood Tissue

Another example of a specialized connective tissue. ___ is unique connective tissue that is composed of a fluid portion (called plasm) and the formed elements of blood.

The erythrocytes (red blood cells) and leukocytes (white blood cells). 

Blood cells are formed in red bone marrow, and some white blood cells are also formed in lymphoid organs.

Blood transports oxygen, nutrients, hormones, enzymes, and waste products such as carbon dioxide gas and urea. It also protects the body through its white blood cells and helps to regulate the temperature of the body.

Lymphoid Tissue

Another specialized connective tissue.

Makes up our lympth glands, thymus, spleen, tonsils, and adenoids.  This tissue produces the plasma cells or B lymphocytes that produce antibodies.

The tissues main role is antibody production and protects us from disease and foreign microorganisms.

The Reticuloendothelil (RE) System

Involved in phagocytosis in connective tissue. Kupffer's cells line the liver; RE cells also line the spleen and bone marrow.

These cells are also refferred to as histiocytes or "resting Wandering" cells because they are fixed in tissue until they must wander to an invader and devour it. Any phagocytic cell of the RE system can be called a macrophage,

Neuroglia cells do support and microglia cell is a phagocytic cell found in the central nervous sstem.

Synovial Membrane

Line joints and bursae.

They produce synovil fluid, which lubricates joints and nourishes cartilage.

Connective Tissue Functions

It supports other tissues.

It provides nourishment: blood carries nutrients.

It transports, blood transports enzymes and hormones.

It connects various tissues to one another.

It provides movement via bones.

It protects vital organs (bones of skull and thorax) and immunity (lymphoid tissue and white blood cells).

It insulates and maintains temperature (adipose).

It provides storage areas: bone stores calcium and phospherous, adipose tissue stores fat.

It attaches and seperates other tissues of the body.

Muscle Tissue

The basic charistic of __ tissue is its ability to shorten and thicken or contract.

Three types of muscle tissue: smooth, skeletal,and cardiac

Due to interaction of two proteins; actin and myosin, muscle cells can shorten their length or contract.  Some pull on bones through tendons and bring about movement.

Smooth Muscle Tissue

Smooth muscle cells are long, unicellular, and nonstriated.

They are involuntary  (we do not control its contraction/ it is controled by the autonomic nervous system) and are arranged in two layers around hollow organs; an outer longitudunal layer nd an inner circular one.  They are found in the digestive tract (called peristalsis), arteries and veins, and the ureters of the kidney.

Striated or Skeletal Muscle Tissue

The normal muscle we think about when we mention muscle.

Striated or skeletal muscle cells are long, multinucleated, and striated.  They are voluntary, and pull on bone, causing movement.

Muscle makes up about 40% of our total weight and mass.

When we eat "meat" of animals and fish, it is usually muscle that we are consuming.

Cardiac Muscle

Cardiac muscle cells are found only in the heart.

Like skeletal muscle it is striated and like smooth muscle it is unnucleated and under control of the autonomic nervous system (involuntary).

They are striated, uninucleated, an cylindrical in shape with branches that connect to branches of other cardiac cells via intercalated disks.  These cells are responsible for pumping blood through the heart.

Nervous Tissue

Nervous Tissue is composed of two types of nerve cells:

neurons are conducting cells and neurolglia are supporting and protecting cells.

Nervous tissue makes up the brain, spinal cord, and various nerves of the body. It controls an coordinates the activities of the body. It allows us to percieve our environment and to adapt to changing conditions. It coordinates our skeletal muscles. Its special senses include sight, taste, smell, and hearing.  It controls our emotions and our reasoning capabilities. It allows us to learn through the memory process.

Neurons

Parietal

Histology

Tissue

What are the two types of multicellular glands?

Visceral

Matrix

Intercellular material.

Matrix is variable in both type and amount. It is one of the main sources of differences between the different type of connective tissue.

There are also fibers of collagen and elastin embedded in the matrix.

Compact  Bone

Cancellous Bone

Osteocytes

Bone cells that are also found in cavities or lucunae much like cartilage.

However, the matrix of a bone isimpregnated with mineral salts, particularly calcium nd phosphorous, which gives bone its firm, hard appearance.