UTS College SHAP001 Human Anatomy & Physiology Week 6 Course Book PDF

**SHAP001** **Human Anatomy and Physiology** **Week 6 Course Book** PRE-TUTORIAL A: Protective mechanisms of the brain **The purpose of the bony skull is to protect the brain from injury.**  A picture containing text Description automatically generated - **Buoyancy: gi...

**SHAP001** **Human Anatomy and Physiology** **Week 6 Course Book** PRE-TUTORIAL A: Protective mechanisms of the brain **The purpose of the bony skull is to protect the brain from injury.**  A picture containing text Description automatically generated - **Buoyancy: gives buoyancy to the CNS organs (1400 grams but the net weight of the brain suspended in the CSF is equivalent to a mass of 25 grams)** - **Mechanical Protection -- serves as a (*[shock / membrane / heat]*) absorber. (*[Circle one correct answer]*)** - **Chemical Protection -- provide optimal environment, e.g. *[(Na^+^ / Ca^2+^ / pH)]* for proper neuronal function. (*[Circle one correct answer]*)** - **Circulation -- allows exchange of (*[glucose / oxygen / potassium / nitrate]*) between blood and brain. (*[Circle 2 correct answers]*)** **[Formation of CSF:]**  http://jonlieffmd.com/wp-content/uploads/2015/09/choroid\_plexus.jpg PRE-TUTORIAL A: the brain  **Lateral and superior views of the brain:\ ** Diagram Description automatically generated  **\ ** Diagram Description automatically generated +-----------------------------------+-----------------------------------+ | **Parts** | **Main functions** | +===================================+===================================+ | **Cerebellum** | **To coordinate balance, posture, | | | and fine motor movements by | | | ensuring smooth, precise, and | | | coordinated muscle activity. It | | | helps maintain equilibrium and | | | refines voluntary movements | | | initiated by the cerebral | | | cortex.** | +-----------------------------------+-----------------------------------+ | **Brainstem (the central trunk)** | **The brain stem is the bridge | | | between the brain and the spinal | | - midbrain | cord. Messages relay from the | | | brain to the motor and sensory | | - pons | nerves of the body and vice versa | | | in a constant \'conversation\'. | | - medulla oblongata | It is the most primitive and | | | vital core of the brain. Its key | | | functions include:** | | | | | | - **Regulation of | | | cardiovascular and | | | respiratory function (ANS)** | | | | | | - **Center of cranial reflex** | | | | | | - **Regulation of the sleep | | | cycle** | | | | | | - **Maintaining consciousness** | +-----------------------------------+-----------------------------------+ | **Diencephalon** | | +-----------------------------------+-----------------------------------+ | - thalamus | It is the \"relay station\" for | | | sensory information, related to | | | sight hearing, taste and touch. | +-----------------------------------+-----------------------------------+ | - hypothalamus and pituitary | Responsible for the production of | | glands | many of the body\'s essential | | | hormones; (for details, refer to | | | **Endocrine System**). | +-----------------------------------+-----------------------------------+ | - epithalamus | contains the pineal gland which | | | secrete melatonin (a | | | sleep-inducing signal) to | | | influence diurnal cycles in | | | conjunction with the | | | hypothalamus. Also has roles in | | | sexual functions. | +-----------------------------------+-----------------------------------+  PRE-TUTORIAL A: Spinal Cord **Spinal cord** (Fill in the blanks) - **is the spinal chord between brain and body** - **extends through vertebral canal from medulla oblongata to lumbar vertebra** - protected by the cerebrospinal fluid.  +-----------------------------------+-----------------------------------+ | **Structures** | **Features / functions** | +===================================+===================================+ | 1. **Spinal Meninges** | - **continuous with the Cranial | | | Meninges - they carry blood | | | vessels which supply the | | | cells of the spinal cord** | +-----------------------------------+-----------------------------------+ | 2. **White matter** | - **appears white because of | | | the myelination of nerve | | | fibres** | +-----------------------------------+-----------------------------------+ | | - **contains many nerves cell | | | bodies of the motor neurons | | | and interneurons** | | | | | | - surrounds the **central | | | canal, which contains CFS and | | | is continuous with the | | | ventricles of the brain** | +-----------------------------------+-----------------------------------+ | 3. **Dorsal roots** | - **carry *[sensory / motor; | | | efferent / | | | afferent]* nerve | | | fibres** | | | | | | - **carry *[sensory / motor; | | | efferent / | | | afferent]* nerve | | | fibres** | +-----------------------------------+-----------------------------------+ TUTORIAL A: Protective mechanisms of the brain A. **Ventricles of the brain and Cerebrospinal fluid (CSF)** https://upload.wikimedia.org/wikipedia/commons/d/d4/Blausen\_0896\_Ventricles\_Brain.png  B. **Reabsorption of CSF**  **In summary,** Diagram Description automatically generated  - **allows the passage of water some gases, and lipid soluble molecules by passive diffusion, as well as the selective transport of molecules such as glucose and amino acids that are crucial to neural function.** - **prevents the entry of lipophilic, potential [neurotoxins](https://en.wikipedia.org/wiki/Neurotoxins). ** http://fblt.cz/wp-content/uploads/2013/12/Kapitola-12-12-ENG-03.jpg  TUTORIAL A: the SPINAL CORD - The right and left dorsal columns are ascending to the brain and - the right and left ventral columns are descending from the brain - The lateral columns contain both ascending and descending nerve fibres. http://www.profelis.org/neu/vorlesungen/jpeg-d/12-32\_SnsryMtrTrct\_1.jpg Sensory nerve impulses pass into the spinal cord through the dorsal roots of the spinal nerves and then ascend to the o\_\_\_\_\_\_\_\_\_\_\_\_\_ side of the brain, e.g. most impulses from the right hand will end up in the left side of the brain. This applies to motor signals too.  http://what-when-how.com/wp-content/uploads/2012/04/tmp14102.jpg PRE-TUTORIAL B: nerve impulse transmission [BETWEEN] NEURONS  https://upload.wikimedia.org/wikipedia/commons/3/33/Blausen\_0843\_SynapseTypes.png **How is an impulse propagated from one neuron to another via a synapse?**  +-----------------------------------+-----------------------------------+ | | | +-----------------------------------+-----------------------------------+ | | | +-----------------------------------+-----------------------------------+ | | **Neurotransmitter diffuses | | | across the synaptic cleft and | | | binds to receptors (ion channels) | | | on the post synaptic membrane** | +-----------------------------------+-----------------------------------+ | | **Binding of neurotransmitter | | | opens Na+ ion channels (the | | | ligand-gated) on the post | | | synaptic membrane** | +-----------------------------------+-----------------------------------+ | | **Na+ ions flow into the cell | | | leading to depolarisation and | | | then action potential. This is | | | known excitatory post-synaptic | | | potential (EPSP).** | +-----------------------------------+-----------------------------------+ | **However, at step , if the K^+^ | | | channels are activated leading to | | | a loss of K^+^ ions, | | | hyperpolarization will be | | | resulted. This is an inhibitory | | | post-synaptic potential (IPSP).** | | | | | | npo000084 | | +-----------------------------------+-----------------------------------+ **PRE-TUTORIAL B: Effects of chemicals at** synapses **Make notes for the following questions while watching the video on Canvas.** - - - Dopamine, serotonin, adrenaline are neurotransmitters targeted. Sends dopamine to the synaptic cleft and blocks the re-uptake of neurotransmitters, which accumulated neurotransmitters in the synaptic cleft. Too many neurotransmitters lead to too many neurotransmitters binding to the ligand gate, too much nerve impulse being transmitted. "overstimulation". Your muscles will keep contracting and it will be harder for them to relax. Increased heart rate is an immediate sign. Euphoric feelings, dilated pupils, surge of energy, flight or fight response, anxiety, blood pumps into muscles. A chronic sign is depression, deviated septum, loss of neuroreceptors (tolerance), addiction. **TUTORIAL B: Effects of chemicals at** synapses +-----------------------------------------------------------------------+ |  **Classwork** | | | | http://t0.gstatic.com/images?q=tbn:ANd9GcQdb4Gja65JgTuEO0O9Gj91RxjySu | | Aw0D3oi0NqbJcH\_DGX0gmVuA | | | | - **Toxin from Blue ringed octopus blocks Na+ channels, causing | | motor paralysis and respiratory arrest within minutes of | | exposure** | | | | - **Toxin from Puffer fish blocks Na+ channels preventing any | | affected nerve from firing action potentials leading to reduced | | muscle contraction and death** | | | | | | | | - **Botulinum toxin blocks the release of a neurotransmitter | | (exocytosis) known as acetylcholine from nerve cells. Without | | acetylcholine, the affected nerve is unable to send a signal to | | the muscle it supplies, resulting in a weakened or no contraction | | of the muscle.** | +-----------------------------------------------------------------------+