Structure and function of the human nervous system- Part 1 Flashcards
Rostral
anterior- ‘toward the beak’
Caudal
posterior- ‘toward the tail’
Dorsal
superior- ‘toward the back’
Ventral
inferior- ‘toward the belly’
Lateral
toward the side
Medial
toward the midline
Ipsilateral
structures on the same side of the body (in Latin ‘ipse’ means same)
Contralateral
structures on the opposite side of the body (in Latin ‘contra’ means against)
Central Nervous System
includes the brain and spinal cord
Peripheral Nervous System
includes the cranial nerves, spinal nerves and peripheral ganglia
PNS the somatic system
connects the CNS to voluntary muscles
PNS autonomic nervous system
connects the CNS to non-voluntray muscles and glands
Sympathetic system
arousing; prepares the body for activity and therefore expends energy
Parasympathetic system
calming; prepares the body for restoration of energy
The meninges
Three layered sheath surrounding the brain and spinal cord
- Dura mater (‘tough mother’)- the thick outer layer which is very smooth
- Arachnoid mater (‘spider like mother’)- the middle layer, which has a weblike appearance due to the protrusions called arachnoid trabeculae, and is soft and spongy
- Pia mater (‘pious mater’)- delicate inner layer, which follows every fold of brain tissue
subarachnoid space
between the arachnoid mater and the pia mater is the subarachnoid space, which holds the cerebrospinal fluid that bathes the brain and spinal cord, and which contains the main arteries that cover the surface of the brain and spinal cord
cerebrospinal fluid
- protects the brain
- reduces weight and shock
- flows through the ventricles
- the choroid plexus is constantly in production of this fluid
cerebrospinal fluid pathway
- CSF is produced by the choroid plexus located in the lateral ventricles
- From the lateral ventricles CSF flows down to the third ventricle then through the cerebral aqueduct to the fourth ventricle
- exits via a set of openings in the subarachnoid space, before being reabsorbed back into the bloodstream via the arachnoid villae
Development of the CNS
Forebrain- develops into the two lateral ventricles and the third ventricle
Midbrain- narrows to form the cerebral aqueduct
Hindbrain- becomes the fourth ventricle
neural migration
- founder cells in the ventricular zone of the neural tube give rise to cells of the CNS
- radial glia guide neurons during development
- cortical development ceases with apoptosis
Primary somatosensory cortex
a vertical strip of cortex located immediately prosterior to the central sulcus, called the post central gyrus. It receives sensory information from the skin (temperature, touch and pain). Different regions of the skin surface are represented by different areas along the strip of cortex, forming a somatotopic map
Primary visual cortex
an area of cortex that occupies the medial and lateral parts of the occipital cortex at the back of the brain. It receives sensory information from the retina (the photosensitive layer at the back of the eye). Different regions of the retina are represented by different areas within the primary visual cortex, forming a retinotopic map
Primary auditory cortex
an area of cortex that occupies the superior part of the temporal lobe. It receives sensory information from the cochlea. Sounds of different frequencies (e.g. low versus high tones) are represented by different areas within the primary auditory cortex, forming a tonotopic map
Primary motor cortex
a vertical strip fo cortex located immediately anterior to the central sulcus, called the pre central gyrus. Different parts of the primary motor cortex sends signals that control different groups of voluntary muscles (e.g. hands, feet, lips). Like the primary sensory cortices, the primary motor cortex controls muscles on the opposite (contralateral) side of the body
