Central Nervous System

1. Central Nervous System

2. ___________________– membranes that protect the brain and spinal cord. It is located between _______ and _______tissue. There are 3 layers: • ___________________:outer most covering. _________, white, dense connective tissue. • ____________– attached to the inner surface of the skull. • _________________– it is called the spinal __________ sheath, not attached to the vertebrae, instead there is an epidural space between the dura mater (spinal dural sheath) and the vertebrae.

3. ___________________: between the dura mater and pia mater. • The _____________ space is between the ____________ and pia layer. • This space contains CSF (cerebrospinal fluid) • ___________________: inner most layer which __________ the brain and spinal cord cells. It is attached to the surface of the brain and spinal cord and follows their contours.

5. The Spinal Cord Starts at the ___________ ______________ and ends at the 1st or 2nd lumbar vertebrae

6. Structure of the Spinal Cord The spinal cord consists of ___ segments, each of which gives rise to a pair of spinal nerves. A ___________________ ___________________ gives rise to nerves leading to the upper limbs, and a ___________________ ___________________ gives rise to those innervating the lower limbs.

7. Functions of the Spinal Cord • The spinal cord has two major functions: ______________________________________________________________________________________________________________ • Tracts carrying sensory information to the brain are called _________________________; (Ex. Spinothalamic tract: from spinal cord  thalamus) • ___________________ carry motor information from the brain to muscles and/or glands. (Ex. Corticospinal tract: from cortex of brain  spinal nerve

8. Special Parts of the spinal Cord: • ___________________ : Sensory neurons to CNS • ___________________ : Motor neurons to CNS • ___________________ : cluster of cell bodies of sensory neurons.

9. Spinal cord labeling

10. The Brain The brain can be divided into 4 major parts: • The ___________________(largest portion and associated with higher mental functions, memory, and reasoning) • The ___________________(processes sensory input) • The ___________________(coordinates voluntary muscular activity) • The ___________________(coordinates and regulates visceral activities).

11. Cerebrum Structure of the Cerebrum 1. Consists of two ____________ _____________. 2. A deep ridge of nerve fibers called the _______________________________ connects the hemispheres. (200 million axons from one hemisphere to the other to exchange information.) 3. The surface of the brain has ridges called ___________________(______). ________– shallow groove________– deep groove

12. Cerebrum 4 lobes of the cerebrum • ___________: controls motor function and conscious use of muscles. • ___________: receives information from skin receptors (touch or pain) • ___________: visual • ___________: hearing, speech, and smelling

15. The ventricles are continuous with the central canal of the spinal cord, and are filled with cerebrospinal fluid. Choroid plexuses, specialized capillaries from the pia mater, secrete cerebrospinal fluid.

16. Cerebrum Functions of Cerebrum

17. Diencephalon • Located between the cerebral hemispheres and above the midbrain. • _______________________: “gateway to the cortex” relay center for sensory information coming in and from the cerebral cortex. • _______________________: formed when optic nerves cross each other. • _______________________: maintains homeostasis for the body (heart rate, body temperature, water regulation, blood pressure, etc.) _______________________: parts of the diencephalon and cerebral cortex work together to control emotional experience and expression – fear, anger, pleasure, and sorrow. Involved in learning and memory (emotionally charged events make the most vivid memories) also smell/taste

18. Brain Stem Connects the brain to the spinal cord. There are 3 main parts: • _______________________: auditory and visual reflexes (controls head movements) • __________: relay center for impulses going to and from the medulla and cerebellum to the cerebrum, helps medulla regulate breathing. • __________________________________: controls vital visceral activities such as impulses to smooth muscles breathing rate and depth and rate of heart contractions. Also, swallowing, sneezing, and coughing. _______________________decides what needs to be done and instructions are sent to medulla. (regulate hunger, sleep, thirst, water balance)

19. Cerebellum The cerebellum functions to integrate _________ information about the position of body parts and coordinates skeletal muscle activity and maintains posture. Helps maintain _________and _________ Ex.

20. Hemisphere Dominance Both cerebral _______________ function in receiving and analyzing _________ input and sending motor impulses to the opposite side of the body. Most people exhibit hemisphere _____________ for the __________________________________________________________________________________________________ The ______ hemisphere is dominant in ______ of the population, although some individuals have the ______ hemisphere as dominant, and others show _______ dominance in _______ hemispheres.

21. ____________________ ____________________ Throughout the brain stem, hypothalamus, cerebrum, and cerebellum is a complex network of _________ fibers connecting tiny islands of _________ matter; this network is the ______________ ______________. • Decreased activity in the ______________ _____________ results in ____________; increased activity results in wakefulness. • The ______________ _____________ filters incoming sensory impulses.

22. _________ _________ • _________ pairs of cranial nerves arise from the underside of the _________, most of which are _________ nerves.

23. 12 Cranial Nerves