Midterm I Flashcards
Endocrine signaling
Long distances through the bloodstream
eg adrenaline, estrogen
Paracrine signaling
short distances through diffusion
eg growth factors
Autocrine signaling
signaling and responding within the same cell
eg developmental decisions, cell division
Endoderm
(as part of the Blastocyst –> Gastrula)
cells lining inside of digestive tract and lungs
liver and pancreas cells
Ectoderm
(as part of the Blastocyst –> Gastrula)
cells in outer layer of skin
pigment cells
nerve cells in the brain
Mesoderm
(as part of the Blastocyst –> Gastrula)
cells in inner layer of skin
muscle, bone and red blood cells
Totipotent
can give rise to a complete organism
eg the fertilised egg
Pluripotent
can give rise to any of the 3 germ layers and therefore any cell of the body –> can’t on their own give rise to an entire organism
eg inner cell mass
Multipotent
can form a limited number of types of specialised cells
eg cells of germ layers
Epidermis
outer layer of skin, serves as water-resistant protective barrier
Dermis
supports the epidermis, also has cushioning effect
Epithelial cells
cells arranged in one or more layers
Basal Lamina
a specialised form of extracellular matrix found beneath all epithelial tissues
eg connects dermis to epidermis
Microtubule
helps maintain cell shape and internal structure
radiates out from centrosome
functions as tracks –> kinesin transports cargo toward + end ; dynein transports load to - end
Microfilaments
reinforces plasma membrane
associate with myosin to transport cargo
eg vesicles
Intermediate filaments
attached to cell junctions at cytoplasmic side –> anchoring results in structural continuity
Cadherins
calcium-dependent adherance proteins
only bind to others of the same type
Integrins
cell adhesion molecules that enable cells to adhere to extracellular matrix
also acts as receptors
Tight Junction
prevents the movement of substances through the space between cells
made up of: tight junction proteins
Adherens Junctions
cell - cell adhesion/anchoring
made up of: microfilaments, cadherin proteins
Desmosome
cell - cell adhesion/anchoring
made up of: intermediate filaments, cadherin proteins
Hemidesmosome
cell - extracellular matrix adhesion/anchoring
made up of: intermediate filaments, integrin
connects to basal lamina
Gap Junction
allows materials to pass directly from one cytoplasm to the next
made up of: channels (connexins)
Sensory Neurons
receiv and transmit info about the environment/internal physiological state
Interneurons
process the info from sensory neurons and transmit it to different body regions, communicates with motor neurons
Motor Neurons
produces suitable responses to the info from interneurons
Ganglia
grous of nerve cell bodies that process sensor info received from a nearby region, resulting in a signal to motor neurons
Depolorisation
increase in membrane potential
(like before an action potential is fired)
Hyperpolarisation
further decrease in membrane potential
EPSP
(Excitatoy Postynaptic Potential)
positive change in membrane potential
IPSP
(Inhibitory Postsynaptic Potential)
negative change in membrane potential
Temporal Summation
(of EPSPs and IPSPs)
the frequency of synaptic stimuli determines whether the postsynaptic cell fires an action potential
Spacial Summation
(of EPSPs and IPSPs)
the number of synaptic stimuli received from different regions of the dendrites
Peripheral Nervous System
( + type of neuron)
sensory and motor nerves
afferent neurons
Central Nervous System
brain and main nerve cord
efferent neurons
Somatic system
Voluntary/ conscious reactions
eg sensing and responding to external stimuli
Autonomic System
Involuntary/ unconscious reactions
eg homeostasis
Sympathetic division
part of the autonomic system
results in arousal and increased activity
“fight or flight”
Parasympathetic division
part of the autonomic system
“rest and digest”
Cerebellum
coordinates complex motor tasks (uses motor and sensory info)
Brainstem
initiates and regulates motor functions, breathng, swallowing
low levels of activity enable sleep
Thalamus
central relay station for sensory info sent to higher brain centers of the crebrum
Hypothalamus
h o m e o s t a s i s
interacts closely with autonomic and endocrine systems to regulate the general physiological stat of the body
Cerebral cortex
sensory perception, memory, learning
Limbic system
controls physiological drives, instincts, emotions, motivation and sense of reward
Hippocampus
long-term memory formation
Frontal lobe
decision making, planning
Temporal lobe
processes sound
includes auditory cortex
Parietal lobe
body awareness and the ability to perform complex tasks
includes primary somatosensory cortex
Occipital lobe
processes visual info
includes visual cortex
Neurosecretory cells
neurons that release hormones which act on endocrine glands or other targets
Peptide and amide hormones
hydrophilic –> bind to membrane receptors on cell surface
more abundant than steroids
Steroid hormones
Hydrophobic –> diffuse freely across cell membrane to bind with receptors
derived from cholesterol
Anterior pituitary gland
forms from epithelial cells
hypothalamus secretes releasing factors into the bloodstream that cause these cells to release hormones
Posterior pituitary gland
develops from neural tissue
neurosecretory cells extend their axons all the way here, where they releae their hormones into the bloodstream
Parathyroid gland
secretes parathyroid hormone (PTH)
works with calcitonin to regulate levels of calcium in the blood
Pineal gland
responds to darkness, secretes melatonin
Cone cells
contains ospins, sensitive to different wavelengths of light
enables color and sharp vision
Rod cells
contains rhodopsin, most sensitive to blue-green light
enables vision in low light
Photoreceptors in the dark
continuously releases glutamate (neurotransmitter)
Photoreceptors in the light
when retinal changes from cis –> trans
Na+ channels close
cell membranes become hyperpolarised
releases less glutamate
