Cytology Flashcards
cell structure, cell function
define “cell”.
the basic unit of all living things, responsible for carrying out all life processes
cell membrane:
limits and encloses the cytoplasm and acts as a selective barrier to the movement of substances into and out of the cell. (semi-permeable)
cytoplasm:
granular fluid that acts as a support for all structures within the cell.
endoplasmic reticulum:
network of clear, tubular structures that allow substances & other organelles to move around
- rough ER: ribosomes
- smooth ER: no ribosomes
ribosomes:
small granules in the inner surface of the endoplasmic reticulum. actual sites of protein synthesis in the cells.
mitochondria:
site of food breakdown to release energy in the form of heat and adenosine triphosphate (ATP). “powerhouse of the cell”
lysosomes:
cell demolition sites concerned with inner-cellular digestion.
golgi apparatus:
structure located near the nucleus that collects proteins from the endoplasmic reticulum and prepares them for secretion into the cell membrane
centrioles:
paired, tubular structures near the nucleus that direct the formation of the mitotic spindle during mitosis.
nucleus:
organelle that controls and regulates metabolic processes. it contains all the cell’s hereditary/genetic material (chromosomes, genes and DNA). directs all cell activity, essential for reproduction
what is DNA?
deoxyribonucleic acid. “blueprint” that contains instructions for building proteins.
what are chromosomes?
thread-shaped bodies located in the nucleus that contain DNA. humans have 23 pair of chromosomes that house 100s of genes
what are genes?
a DNA segment that carries the info for building one protein. it is responsible for physical trait like hair and eye colour, height, etc.
define tissue:
a collection of cells performing a particular function .
what are the 4 tissues of the body?
- Connective tissue: support (bone, tendons, fascia, ligaments, blood, lymphatic fluid)
- Epithelial: coverings (skin, mucous membranes)
- Muscular: movement through contraction and relaxation
- Nervous: control (brain, spinal cord, nerves)
define organ
groups of tissue designed to perform specific functions
define organ systems
groups of organs that cooperate to perform a common function
how many organ systems in the human body? name them.
- integumentary (skin)
- respiratory
- digestive
- urinary
- reproductive
- skeletal
- muscular
- nervous
- cardiovascular
- lymphatic
- endocrine
define mitosis
asexual cellular reproduction where one parent cell splits in 2 genetically identical daughter cells (diploid cell)
what are the phases of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
what are the functions of mitosis?
- growth of tissues and organs after birth
- replacement of dead cells
- repair of damaged tissue
describe interphase
majority of a cell’s lifespan is spent in this phase. it is a phase of rest, growth and maturation. chromosomes are scattered throughout the nucleus.
define homeostasis
the body’s ability to respond to changes in its in its environment in order to maintain stable internal conditions and function normally. a dynamic state if balance
what is metabolism?
a complex chemical action whereby the body’s cells are supplied with the energy needed to function. the proper functioning of the cell.
describe the two phases of metabolism.
- anabolism: constructive metabolism, simpler substances, formed into more complex ones
- catabolism: destructive metabolism, complex substances broken down into similar ones
