Nervous Tissue Flashcards
What is the role of the cell body?
- contains mitochondria, lysosomes, golgi body and ER.
- Site of protein synthesis
What is the role of dendrites?
- receive impulses from other neurones
- many which are short and highly branched
What are the key neurotransmitters?
- Noradrenaline - mobilises the body, alert
- Adrenaline - fight or flight
- Dopamine - makes you feel good
- Serotonin - contricts muscle, balances mood
- Histamine - inflammatory response
- Acetylecholine - between motor neurones to activate movement
Where are multipolar neurones found?
- Multiple dendrites, one axon
- brain, spinal cord and adjacent to muscle
Where are bipolar neurones found?
- One main dendrite, one axon
- found in the retina, inner ear and olfactory area of the brain
What are the cells within the nervous tissue?
CNS
- Astrocytes
- Oligodendrocytes
- Microglial cells
- Ependymal cells
PNS
- Schwann cells
- Satellite cells
What do astrocytes do?
- Form the main supporting tissues of the CNS
- Star shaped
- footplates form a sheath around blood vessels and form part of the blood brain barrier
-Selective filter
What does an oligodendrocyte do?
- Smaller than astrocytes
-adjacent to cell body and along myelinated nerve fibres to form and maintain myelin - similar role to schwann cells in PNS
- insulate and support axons in CNS
What is a microglial cell?
- small with few processes
- monocytes which migrate to CNS during ebryonic development
- Close to blood vessels and phagoctose microbes and damages tissues where here is inflammation
What do ependymal cells do?
- epithelial cells arranged in a single layer, which vary in shape
- found in ventricles of the brain and central canal of spinal cord
What do satellite cells do?
- they are a major group of cells found in PNS near to sensory, symp and parasymp ganglia
- control microenvironment
- Protect and cussion
- express receptors to interact with neuroactive chemicals
What is a schwann cell?
- found in PNS
- produce myelin
- can help repair and replace nerve fibres if cell body is in tact
What does myelination do?
- myelin sheath on neurons, covering axons
- insulated the axon
- accelerated the speed of impulses
- Schwann cells have neurolemma which can regenerate axon after injury
- No way to regenerate in CNS
What are the parts of the brain?
- Cerebrum
- Midbrain
- Pons Varolii
- Medulla Oblongata
- Cerebellum
What lobes is the cerebrum made up of?
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
- Named after bones of the skull
What is the function of the cerebral cortex?
- Most highly developed part of the brain
- Mental
- Sensory perception
- Initiation and control
What makes up the interior of the cerebellum?
- nerve fibres - white matter, arranged in tracts or pathways
- commissural fibes, links between gyri of each hemisphere, form corpus callosum
- Projection fibres, connect cerebral cortex to other parts of the CNS.
What are the basal ganglia associated with?
- skeletal muscle tone
- subconscious contractions
- attention
- memory
- planning
What does the pituitary gland produce?
-Adrenocorticotrophic Hormone (ACTH)
-Thyroid Stimulating Hormone (TSH)
-Growth Hormone (GH)
-Luteinizing Hormone (LH)
-Follicle Stimulating Hormone (FSH)
-Prolactin
-Antidiuretic Hormone (ADH)
-Oxytocin
