Brain Ans Nervous System Flashcards
What are the types of nervous system?
Central made of spinal cord and brain, its motor afferent (what we feel goes to cns receives info from internal and external environment.
Peripheral nervous system made of peripheral nerves motor efferent ( impulses from cns to effector organs) two parts somatic (voluntary muscle movement), autonomic (involuntary of smooth muscle or cardiac/glands) two parts parasympathetic (rests and digest) sympathetic(fight or flight).
What are neurones and nerves motor efferent cells and what do they do?
Neural circuits: group of neurones work together to process info
Nerves: bundles of axons surrounded by connective tissue if damaged can form new axon pathways, consists of numerous neurones bound by connective tissue.
Three layers to nerves Endoderium (delicate tissue surround each fibre), Perineurium (surrounds each fibre provides nutrients), Epineurium (fibrous tissue enclosing several bundles of nerves most large nerves covered with this).
Nervous tissue: made of neurones bound together by connective tissue helps control and coordinate body.
What are the meninges ?
Three different types of tissue surrounding brain
Dura mater: two layers of dense fibrous tissue outer periosteal layer (lines inner surface of skull) inner meninges layer (protective covering for brain stops friction) , allows for spaces between layers for passage of blood vessels.
Arachnoid mater: weblike layer doesn’t contain blood vessels or nervous tissue contains CSF (cerebral spinal fluid), continuously bathes CNS and provides nutrients removes impurities.
Pia Mater: thin layer contains tiny blood vessels to supply blood to brain follows contours of brain tissue.
What is cerebral spinal fluid?
Supports and protects brain and spinal cord by maintains pressure around vital structures and acts as a shock absorber. Keeps CNS moist and allows exchange of nutrients and waste, invoked in regulation of breathing by bathing medulla where chemoreceptors (detects pH of blood) are located. Contains water, mineral salts, glucose, few leucocytes.
What does the cerebrum do?
Large part of brain superior to cerebellum and divided by deep cleft (longitudinal cerebral fissure) into right and left hemispheres. Each contains lateral ventricles. Two hemispheres connected by mass of white matter (diff density bc made of nerve cords) called corpus collosum. The superficial part of cerebrum the cerebral cortex is made of nerve cell bodies (grey matter).
Surface of brain has many ridges to increase SA these are called silicon.
Female brain is 1200g male is 1370g, begins to shrink from 55.
What does it mean when the brain has contralateral control?
It means that the left side of the brain controls the right side of the body, eg left motor neurone responsible for right side of body.
What is the Thalamus?
Area of brain deep in cerebellum responsible for arousal and emotional responses, recognition of touch pain temp and acts as a relay sending signal from brain to cerebral cortex and spinal cord.
What is the hypothalamus?
Helps regulate control of hormones for; body temp, water balance, emotional reactions, circadian rhythms, appetite,effectors.
What is the pons?
The pons is responsible for processing the brain, processes info from some cranial nerves. It also contains pneumotaxic area operates with respiratory central in medulla oblongata.
What is medulla oblongata?
2.5cm long and lies within cranium above foramen magnum, contains cardiovascular, respiratory, reflex centres.
The function of the sympathetic nervous system
Body is stimulated with extreme external environment adrenal glands secrete noradrenaline act as neurotransmitter reaching target organs and begin effects; pupil dilate, mucous secretion inhibited, vasodilation, peristalsis reduced urine secretion reduced.
Function of parasympathetic nervous system
Slows down cardio and respiratory activity but stimulates digestion and absorption of food known as the rest and digest.
