SHAP001 Week 5 Coursebook PDF

SHAP001 Human Anatomy and Physiology Week 5 Course Book PRE-TUTORIAL A: THE HEARTBEAT Fill in the blanks: Sinoatrial (SA)...

SHAP001 Human Anatomy and Physiology Week 5 Course Book PRE-TUTORIAL A: THE HEARTBEAT Fill in the blanks: Sinoatrial (SA) node The heart muscle cell (cardiac muscle) is multinucleated in nature which Atrioventricular (AV) bundle means it contains a plasticity that Left ventricle can Atrioventricular (AV) node 1. generate and conduct impulses automatically, and thus 2. coordinates the contraction of auricles and ventricles during a cardiac cycle. Fixing Arrhythmias  The pacemaker called Sinoatrial (SA) node is on the wall of the right atrium. SA node sends out electrical impulses which spread over the two atria → leads to the contraction of two atria. ‚ Then, the electrical impulses arrive at the Atrioventricular ( AV ) node which is on the wall between the right atrium and right ventricle. AV node then sends electrical impulses_ A pacemaker is a small device that's down the bundle of his ; then spread through the _Purkinje placed in the chest or abdomen to fibers Then, both the ventricles contract. help control abnormal heart rhythms. This device uses low-energy electrical pulses to prompt the heart to beat at a normal rate. PRE-TUTORIAL A: WHAT IS ECG? SHAP001 Week 5 Coursebook 1  The electrical activity of the heart can be detected and recorded by placing electrodes on the surface of the skin on certain parts of the body. The recording produced is called an electrocardiogram (ECG), which is essentially a graph of voltage against time. ECG https://www.youtube.com/watch?v= v3b-YhZmQu8 Healthy heartbeat produces a distinctive trace. Certain heart defects produce a modified trace and this makes ECG a useful diagnostic tool. Complete the meanings of the key labels below: SHAP001 Week 5 Coursebook 2  if the intervals between QRS complexes (R-R intervals) are consistent, ventricular rhythm is regular. If intervals between P waves (P-P intervals) are consistent, the atrial rhythm is regular SHAP001 Week 5 Coursebook 3  PRE-TUTORIAL A: ORGANISATION OF THE NERVOUS SYSTEM In human, nervous system consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). Ganglion Nerve Complete the diagram below: SHAP001 Week 5 Coursebook 4  Nucleus Tract CNS Consists of the brain and spinal cord It is responsible for integrating and processing sensory data, issuing motor commands in order to control body functions. It is also the site of higher functions such as intelligence, memory, learning and emotion. PNS Consists of all nervous structures lying outside the brain and spinal cord. It provides sensory information to the CNS. It carries motor commands from the CNS to peripheral tissues and organs. SHAP001 Week 5 Coursebook 5  PRE-TUTORIAL B: CELLULAR COMPONENTS OF THE NERVOUS SYSTEM Both the central and peripheral nervous system structures are composed of (1) groupings of nerve cells enclosed by (2) support cells. Complete the sentences and diagram below. Both cell types share three things in common: They are the ____________ cells in your body. They are ____________. Neurons are _______. They have an extremely _______ metabolic rate (consuming 25% of your daily calories intake). SHAP001 Week 5 Coursebook 6  (1) Nerve cells Typically, a neuron consists of: a nerve  cell body with two types of cellular processes issuing out from it i.e. ‚ dendrites and an ƒ axon Neurons typically convey either sensory signals or motor signals — hence there are sensory neurons and motor neurons. The appearance of each type of neuron is different each still essentially has the same 3 anatomical components above. (2) Support cells Fill in the blanks in the below diagrams. In CNS, SHAP001 Week 5 Coursebook 7  In PNS, Groupings of Nerve Cells in the Nervous System Within both the CNS and the PNS, neurons carrying out the same function are grouped together. Cellular components of neurons are as well. SHAP001 Week 5 Coursebook 8  (a) The nerve  cell bodies with their ‚ dendritic processes are generally grouped together in one place. CNS: nucleus PNS: ganglion (b) ƒ Axons of neurons are also usually bundled together (rather like a bundle of spaghetti) CNS: tract. PNS: nerve. Cardiac Cycle http://www.oupchina.com.hk/vurl/stre aming.aspx?b=animation_E1_3.2_e TUTORIAL A: WHAT HAPPENS IN A CARDIAC CYCLE? The cardiac cycle is the sequence of events that occurs in one complete heartbeat. SHAP001 Week 5 Coursebook 9  1 cardiac cycle lasts for _____ second when the person is at rest; i.e. _____ cycles per minute. 0 to 0.1s 0.2 to 0.4s 0.4 to 0.8s Classwork The diagrams below represent the cardiac cycles of a man at rest and during exercise: SHAP001 Week 5 Coursebook 10 SHAP001 Week 5 Coursebook 11  TUTORIAL A: WHAT IS CARDIAC OUTPUT? Cardiac output = __________________ x ___________________ ( ) ( ) ( ) The average heart rate of a person at rest is 72 beats per minute and the average stroke volume is 70 mL per beat. What would be the cardiac output per minute of this person? = __________ mL (about ____ L) A. Heart rate Concept: Sympathetic nerve: _____ heart beat rate Vagus nerve: _____ heart beat rate SHAP001 Week 5 Coursebook 12  B. Stroke Volume Classwork The following flowchart shows the factors affecting the cardiac output Tutorial B (a) Based on the information provided, state what factor X and Y are in the flowchart. (b) Name one hormone that can increase the strength of contraction of heart muscle during exercise in this man. ________________________________________ SHAP001 Week 5 Coursebook 13  TUTORIAL B: PERIPHERAL NERVE STRUCTURE (PNS) Peripheral nerves which include (1) ________ nerves and (2) ________ nerves are composed of axons of nerve cells whose cell bodies lie either in the CNS or in ganglia within the PNS. SHAP001 Week 5 Coursebook 14  Most peripheral nerves contain mixed populations of axons having sensory, motor, somatic and/or automatic functions. Key labels: Epineurium Perineurium Endoneurium Myelin Sheath Node of Ranvier Axon SHAP001 Week 5 Coursebook 15  Tranverse section of a peripheral nerve Ø Ù Electron micrograph of a peripheral nerve Ù Teased Myelinated Nerve Fibres It contains both myelinated (M) and unmyelinated (U) nerve fibers. The reticular fibers (RF) seen in cross section belong to the endoneurium. Near the center of the figure is a Schwann cell nucleus (S). The perineurial cells (P [over a nucleus], arrows) form a barrier that controls access of materials to nerve tissue. x30,000. Inset: Part of an axon, where numerous neurofilaments and microtubules are seen in cross section. x60,000. SHAP001 Week 5 Coursebook 16  (1) Cranial Nerves The ______ pairs of cranial nerves innervate the sense organs, muscles and glands. Most of the cranial nerves arise from the base of the brain (the pons and the medulla oblongata). The cranial verves are known either by their names or by the appropriate Roman numerical I to XII. Some of the cranial nerves are purely motor, some sensory and others are mixed. As well some are purely somatic, others are autonomic, and some carry both types of information. The cranial nerves can be classified as Special sensory: carrying afferent information from the special senses Somatosensory: carrying afferent information from the general senses Somatomotor: carry efferent information to the skeletal muscles Autonomic motor: carrying efferent information to the autonomic effectors SHAP001 Week 5 Coursebook 17  (2) Spinal Nerves In this section, we will explore several interrelated concepts – (a) the spinal nerves and segments, (b) the components of spinal nerve, and finally (c) the nerve plexuses. (a) Spinal Nerves and Segments Spinal nerves (of which there are ______ pairs, left and right) emerge from the spinal cord between each vertebra. Each spinal nerve is given a name according to where it emerges from the spinal cord e.g. C3 (the spinal nerve that from the 3rd cervical vertebra). There are: _____ pairs of cervical _____ pairs of thoracic _____ pairs of lumbar _____ pairs of sacral _____ pairs of coccygeal spinal nerves. SHAP001 Week 5 Coursebook 18  Spinal Segment Each spinal nerve is composed of nerve fibers that are related to the region of the muscles and skin that develops from one body segment. Each spinal segment has a name, which corresponds to the spinal nerve it gives rise to. So the C3 spinal segment gives rise to the C3 spinal nerve. Thus there are ______ spinal segments. Knowledge of the segmental innervation of the cutaneous area and the muscles is essential to diagnose the site of an injury. SHAP001 Week 5 Coursebook 19  (b) Components of Spinal Nerves (i) Dorsal and Ventral Root Spinal nerves are mixed nerves that contain both sensory and motor nerve fibres. Each spinal nerve is formed by the union of: a dorsal root (containing s_____________or afferent fibres) a ventral root (containing mainly m____________ or efferent fibres). Each spinal nerve is connected to the spinal cord by the dorsal root and the ventral root. Transverse section of the spinal cord Classwork The ventral root of a spinal nerve does not carry a ganglion. Why? _______________________________________________________________________ _______________________________________________________________________ SHAP001 Week 5 Coursebook 20  (ii) Dorsal Ramus and Ventral Ramus On emerging from between the vertebrae the spinal nerves then divide into a large ventral ramus (ramus branch) and a smaller dorsal ramus, each containing both motor and sensory fibres. The dorsal ramus supplies the muscles and skin of the back. The ventral ramus passes anterolaterally and supplies the muscles and skin of the side and front of the body as well as the muscles of the limbs. Dorsal Ramus and Ventral Ramus Dorsal and Ventral Rami SHAP001 Week 5 Coursebook 21  (c) Nerves Plexuses The ventral rami of a number of spinal nerves join at the roots of the limbs (i.e. where the limbs join the trunk) to form a complicated network of nerves, called a nerve plexus. The formation of nerve plexuses allows individual nerve fibres to pass from one spinal nerve to another - as a result, areas of a limb are supplied by nerve fibres that originate from a number of different __________ nerves and hence from a number of different segments, or levels, of the spinal cord. In this way the CNS (spinal cord) is able to exert a __________ degree of control over muscle movement because not one, but several segments of the spinal cord are involved. SHAP001 Week 5 Coursebook 22