What is homeostasis?
ability of the body to maintain a relatively stable metabolism and to function normally despite changes
What is a positive feedback mechanism?
the response to stimuli does not stop but rather keeps the sequence of events going. (requires an external brake)
EX: cervical stretching during childbirth
What is a negative feedback mechanism?
bodys response to stimuli reverses the stimulus in effect turning it off for a while and keeps the body within normal range
What are the two main body cavities and what is contained in them?
1. The dorsal cavity which contains the spinal and cranial cavity
2. The ventral cavity which contains the thoracic, abdominal and pelvic cavities
What is the anatomical position of the body?
Standing with legs shoulder width apart, arms down by side with palms forward
What are the 3 most popular body planes?
1. Sagittal plane which divides left from right (cut down the middle would be mid-sagittal)
2. Frontal plane which divides the body front to back (Coronal)
3. Transverse plane which is a horizontal plane that separates the body into upper and lower portions (cuts you at belly button into upper body and lower body)
What are the different kinds of bonding atoms?
1. Chemical bonds
2. Ionic bonds
3. Covalent bonds
4. Disulfide and Hydrogen bonds
Describe a chemical bond?
Force or attraction between positive and negative charges that keeps atoms closely together
Describe an ionic bond?
Involves loss of electron of one atom and the gaining of an electron on another atom (ex: NaCl or salt)
Describe a disulfide bond?
covalent bond formed between two atoms of sulfur
(ex: strand of hair maintains its shape)
Describe a Hydrogen bond?
does not involve the sharing of electrons but results in hydrogen atoms
(ex: water molecules are attracted to nearby water molecules to form surface tension)
What are the types of chemical reactions in the body?
synthesis reactions: bonds are formed to join two or more atoms to make a new compound
(ex: proteins are sythesized by the bonding of many amino acids)
decomposition reactions: bonds are broken and a large molecule is changed to two or more smaller ones
(ex: digestion of starch into many smaller glucose molecules)
What is cellular respiration?
name for energy production within cells and involves the respiratory gases: oxygen and carbon dioxide
(ex: glucose and oxygen combine to make carbon dioxide, water, ATP and heat)
What is an enzyme and what does it do?
Catalyst: speed up reactions without the use of external energy or heat
What is a buffer and what does it do?
A buffer system is a chemical or pair of chemicals that minimizes changes in pH by reacting with strong acids or strong bases
(ex: buffer bonds to H+ ions when body fluid is becoming too acidic or release H+ ions when fluid becomes too alkaline)
What is a hormone and what does it do?
secretion of an endocrine gland that has effects on target organs
(ex: Insulin - enables cells to take in glucose and lowers glucose levels. Growth hormone - increases protein synthesis and cell division)
What is the cell membrane made up of and what is its function?
outer boundary of a cell made up of phospholipids, cholesterol and proteins.
its main job is to protect the cell and acts as a barrier for communication and assists in transport
What is the cell nucleus and what is its function?
Nucleus is within the cytoplasm and has a nuclear membrane with nucleoli and chromosomes of the cell. Nucleolus is where DNA and all genetic info for human traits lies.
What is cytoplasm?
a watery solution (cytosol) of minerals, gases, organic molecules and cell organelles are found. it gives the cell its shape
What are the cell organelles and what do they do?
ER or endoplasmic reticulum- are tubules that transport materials necessary for cell function within the cell.
Ribosomes- are very small structures made of protein and ribosomal RNA and are found on the surface of rough ER.
Proteasome- is a barrel shaped organelle made of enzymes that cut protein molecules apart.
Golgi apparatus- are flat, membranous sacs where carbohydrates are synthesized and are packed with other materials for cellular secretion.
Mitochondria- are oval organelles bound by a double membrane where cell respiration takes place and site of ATP production.
Lysosomes- are single membrane structures that contain digestive enzymes and eat dead cells and bacteria .
Centrioles- are a pair of rod shaped structures outside the nucleus that spindle fibers during cell division.
Cilia and Flagella- are thread-like projections through the cell membrane that can sweep materials across cell surface and flagellum provide mobility of the cell.
Microvilli- are folds of the cell membrane that increase surface area of membrane when needed. They are good for absorption of nutrients as well.
Cytoskeleton- are the framework and support of the cell. Made of microfiliaments.
What is diffusion and how does it work?
movement of molecules from an area of greater concentration to an area of lesser concentration along the concentration gradient. Very slow process. FOR MOLECULES
(Example: exchange of gases in lungs or body tissues)
What is osmosis and how does it work?
diffusion of water through a selectively permeable membrane. water will move from an area with more present to an area with less water present. takes place in the kidneys which reabsorb large amounts of water. FOR WATER
What is facilitated diffusion and how does it work?
molecules move through a membrane from an area of greater concentration to an area of lesser concentration with the help of a carrier enzyme
(Example: intake of glucose by most cells)
What is active transport and how does it work?
requires ATP to move molecules from an area of lesser to an area of greater concentration.
(Example: sodium pumps to move Na+ out of the cells)
What is filtration and how does it work?
Requires energy of mechanical pressure. Water and dissolved materials are FORCED through a membrane from an area of higher PRESSURE to an area of lower PRESSURE
(Example: formation of tissue fluid and the first step in the formation of urine)
What is hypotonic?
A solution with lower salt concentration than in the cells
(cells burst) MORE WATER THAN IN CELL
What is hypertonic?
A solution with a higher salt concentration than in the cells
(cells shrink) LESS WATER THAN IN CELL
Where is genetic coding found?
In the DNA of our chromosomes or our genome. It is found in the cell nucleus.
What is mitosis?
Cell division involving one cell with the diploid number of chromosomes dividing into two identical cells.
(used for repair of tissues and growth of the organism)
What is meiosis?`
process of cell division that results in the formation of gametes which are egg and sperm cells.
(used for creating human life)
What are the 6 types of epithelial tissue?
1. Simple squamous -one layer of flat cells (alveoli of lungs, permits diffusion of gases)
2. Stratified squamous- many layers of cells (epidermis, lining of esophagus and vagina)
3. Transitional- many layers of cells (lining of bladder, permits expansion)
4. Cuboidal- one layer of cube shaped cells (thyroid gland, salivary gland, kidney tubules) excretory
5. Columnar- One layer of column shaped cells (lining of stomach, lining of small intestine and absorbs products in digestion)
6. Ciliated- one lay of columnar cells with cilia on free surfaces (lining of trachea to sweep mucus and dust pharynx and lining of fallopian tube to sweep ovum toward uterus)
What are the 7 types of connective tissue?
1. Blood- plasma, RBC, WBC and platelets
2. Areolar- Subcutaneous. Connects skin to muscles. Mucous membranes
3. Adipose- Subcutaneous. Sores excess energy in fat. (insulation)
4. Fibrous- Tendons and ligaments and dermis of skin (strong)
5. Elastic- Walls of large arteries and alveoli in lungs (promotes normal exhalation and helps maintain blood pressure)
6. Bone- Support the body, protect internal organs, store calcium and contain and protect red bone marrow
7. Cartilage- Wall of trachea to keep airway open, on joint surfaces to prevent friction, tips of nose and outer ears. Absorbs shock between vertebrae
What are the 2 major types of membranes found in the body?
1. Epithelial membranes
2. Connective Tissue membranes
What are the two types of epithelial membranes?
Serous membranes: line some closed body cavities and cover the organs in those cavities (thoracic and abdominal cavities) CAVITIES THAT AREN'T OPEN TO AIR
Mucous Membranes: line the body tracts that have openings to the environment and have a mucous membrane to keep the lining of the cells wet (vagina, trachea, esophagus and stomach)
What are the serous membranes and where they are located?
Serous membranes are in closed body cavities where the serous fluid prevents friction between the two layers of the serous membrane.
---Thoracic cavity: partial pleura lines chest wall and cisceral pleura covers the lungs.
---Pericardial sac: parietal pericardium lines the fibrous pericardium and the visceral pericardium covers the heart muscle.
---Abdominal cavity: peritoneum lines the abdominal cavity and mesentary covers the abdominal organs
What are the mucous membranes and where are they located?
Line the body tracts open to the environment
---respiratory , digestive, urinary and reproductive
---mucus keeps the living epithelium we and provides lubrication in the digestive tract
---traps dust and bacteria in the respiratory tract