Cells and tissues/homeostasis Flashcards
name 4 types of tissue
epithelial
connective
muscle
neural
what is a eukaryote, describe it
multi-celled organism
nucleus with DNA
Extensive organelles
large (10-40?)
what is a prokaryote, describe it
single celled organism no nucleus no organelles small (1-5?) hereditary material in cytoplasm
draw/ label a cell
draw it
what does the plasma membrane do
defines boundries
interactions with other cells
controls flow of substances (selectively permeable)
what is cytosol/cytoplasm
viscous fluid in which water, ions, organelles and proteins are suspended
what is the nucleus
control centre
contains chromosomes which carry genetic info - DNA
contains nucleolus - RNA
what is mitosis
cell division necessary for growth, regeneration
what is meiosis
cell division necessary for sexual reproduction
what is endoplasmic reticulum
rough: protein synthesis
smooth: lipid synthesis
what is Golgi complex
carbohydrate modification
packing, modifying and sorting proteins into vesicles
what are mitrochondria responsible for
energy production - ATP synthesis
What are Lysosomes responsible for
contain enzymes to break down small food stuffs and destroy unwanted proteins
what are secretory granules and how do they function
contain products to be released into cells eg insulin, amylase
granules bind to the plasma membrane and their contents are released by exocytosis
what are tissues
aggregation of cells with a specialised structure/function
name 4 types of tissue and what are they specialised to do
epithelium - covering
connective - support
muscle - movement
neural - communication, control
describe epithelia…
what are their 2 functions
where they are found
what are they supported by
layers of closely bound cells which form a protective barrier and control absorption and secretion
covering internal and external surfaces, linings of cavities and tubes
supported by a basement membrane
what are the 3 different shapes of epithelial
squamous
cuboidal
columnar
what are epithelial cells called if there are made up of only one layer
simple
what are epithelial cells called if there are made up of two layers
stratified
what would a simple squamous epithelial look like
what would be its function
give an example of where you’d find one
one layer think, flat surface cells
exchange of nutrients and gases
blood vessels, alveoli
what would a stratified squamous epithelial look like
what would be its function
give an example of where you’d find one
multi-layered, flat surfaced cells
protection, barrier
oral cavity, anus, vagina…
what would a keritinised stratified squamous epithelial look like
what would be its function
give an example of where you’d find one
multi-layered, flat surfaced cells, keratin layer (protein)
protection, waterproof
skin, hair, animal footpad
what would a simple columnar epithelial look like
what would be its function
give an example of where you’d find one
one layer thick, tall cells with basally located nuclei
absorption and secretion
gastrointestinal tract
what would a modified simple columnar epithelial look like
what would be its function
give an example of where you’d find one
one layer thick, tall cells with basally located nuclei, surface modifications e.g microvilli
absorption and secretion
gastrointestinal tract
what would complex columnar epithelial look like
what would be its function
give an example of where you’d find one
appear stratified, all cells touch basement membrane, modifications - cilia and goblet cells
mucociliary escalator
trachea and large respiratory airways
draw cells picture on page 8 of cells slides and label what cells are and where found
draw
draw cells picture on page 8 of cells slides and label
draw
what are the 2 types of connective tissue
connective tissue - supporting tissue (non-living material)
specialised connective tissue - bones and cartilage, ligament, adipocytes, blood
what are the 3 types of muscle tissue
skeletal
cardiac
smooth
what are the 3 types of neural tissue
afferent - CNS (sensory neurons)
efferent - CNS (effector cells - motor neurons)
interneurons - connect neurons
what is homeostasis
stability of the body’s internal environment
what are the 4 processes involved in the homeostasis cycle…sensory receptor cells, ?…,?
1) sensory receptor cells
2) integrating centre (CNS)
3) effector (muscle cells, epithelial cells, nerve cells)
4) change in variable
use temperature as a n example of the 4 stage homeostasis cycle
1) sensory receptor - receptors in skin
2) integrating centre - hypothalamus
3) effector - blood vessels - dilate, sweat glands - secrete fluid
4) change in variable - temp increase or decrease
use blood pressure as an example of the 4 stage homeostasis cycle
1) sensory receptor - baroreceptor
2) integrating centre - medulla oblongata
3) effectors - Heart rate - stroke volume increase, blood vessels - vasoconstriction
4) change in variable - BP increase or decrease
homeostasis can involve positive feedback (self amplifying) - give 2 examples
blood clotting and child birth
define negative feedback
response decreases effect of original stimulus
define positive feedback
response increases effect of original stimulus
what does the integrative centre do
converts synaptic to humoral (hormonal) signal
what does the hypothalamus do
controls hormone secretions from the pituitary gland
how does the body combat stress using homeostatic control mechanisms - 5 steps
1) stress!
2) hypothalamus releases Corticotrophin Releasing hormone
3) actos on the anterior pituitary to produce Adrenocortocotropic Hormone (ATCH)
4) stimulates the adrenal cortex to produce cortisol
5) which activates anti-stress and anti-inflammatory pathways e.g heart, muscle, GI tract, blood vessels
- cortisol inhibits corticotrophin releasing hormone! NEGATIVE FEEDBACK
how is prolactin release regulated by homeostatic control mechanisms - 3 steps
1) Prolactin releasing factor released from hypothalamus
2) stimulates release of prolactin from the pituitary
3) which stimulates mammary gland to produce milk
*Prolactin inhibits prolactin releasing factor and stimulates prolactin inhibiting hormone from ?
how is prolactin release regulated by homeostatic control mechanisms
1) Prolactin releasing factor released from hypothalamus
2) stimulates release of prolactin from the pituitary
3) which stimulates mammary gland to produce milk
*Prolactin inhibits prolactin releasing factor and stimulates prolactin inhibiting hormone from ?
use blood clotting as an example of positive feedback
1) damage to blood vessel
2) Activation of clotting factors
3) activation of thrombin
4) formation of blood clot
thrombin stimulates more clotting factors
