Module: Foundation Principles of Life Science for Midwifery Practice. WHH1008-N

Welcome to the Anatomy Workbook. This directed learning has been developed to prepare you for lectures designed to study aspects of life science in the module WHH1008-N. The workbook is for you to complete either before or after you commence the BSc (Hons) Midwifery programme in September 2017. An expectation is that you will have completed and reviewed elements of this workbook prior to taught teaching. It is hoped that by completing the workbook you will gain a good knowledge of the anatomical structures that make up systems of the human body.

Please work through each stage of the workbook in preparation for the related life science lecture.

The Nervous System

The human nervous system consists of two main parts known as the Central Nervous System (Brain and Spinal Cord) and the Peripheral Nervous System.

Central Nervous System

The Brain

List functions of the brain and categorise them into broad activities.

 The human brain weighs 1500g and is situated in the skull, bathed in fluid. Name the fluid which bathes the brain and outline its function.

The brain is divided into the following areas:

 The forebrain that consists of the cerebrum

 The midbrain that lies before the fore and hindbrain

 The hind brain that is known as the pons, medulla oblongata, cerebellum

 Draw and label the above areas of the brain.

Describe the function of each following area of the brain.

 The Cortex

 The Brain Stem

 The Medulla Oblongata

2017 Page 1 The Spinal Cord

The spinal cord commences at the foremen magnum and extends to the first lumber vertebra. It gives rise to the spinal nerves which relay information to and from the brain. Like the cerebrum the spinal cord is deeply clefted at the back and front so that it is almost divided into right and left sides.

 Where is the Foremen Magnum?

 Draw and label a cross section of the Spinal Cord.

The spinal cord is protected by the vertebral column which has four curves when viewed from the side.

 Locate the sacrum and the sacral promontory on the spinal column?

Peripheral Nervous System

Nerve Cells

Nerve cells (or neurones) vary in their shape and size however they can be classified according to their function.

Describe the following neural functions?

 Sensory

 Motor

 Intermediate

2017 Page 2 Neurones are made up of nerve fibres; bundles that vary in thickness and which repeatedly branch to penetrate different parts of the body. Draw and label a sensory nerve and a motor nerve.

 What makes matter grey or white?

 What is a Nerve Ganglion?

43 pairs of nerve fibres leave the central nervous system, 12 pairs of Cranial Nerves and 31 pairs of Spinal Nerves.

Can you name them?

2017 Page 3 The Respiratory System

The Respiratory System provides a route by which the supply of oxygen (O2), present in atmospheric air gains entry into the human body. It also provides the route of excretion for carbon dioxide (Wilson, 1981).

Listed below are various parts and organs that make up the respiratory system.

Draw a diagram and label the following parts:

Structure

Nasal and oral passage

Pharynx

Right and left bronchi

Right and left bronchioles

Alveoli

Right and left lobes of the lung

Pleura

Diaphragm

Intercostal muscles

The Lungs

2017 Page 4 Humans have two lungs. One positioned each side of the midline and situated within the thoracic cavity.

 Describe the Thoracic Cavity?

 Describe the lobes that make up the right and left lung?

Lungs are cone shaped organs that have the following features: an Apex, a Base and a Hilius. Define these structures.

The Bronchi and Alveoli

Two bronchi commence when the trachea divides. Outline changes in their structure as they progress towards the alveoli?

The Alveoli

Draw and label an alveoli cross section.

The Pleura

The pleura is a closed sac of serous membrane which contains small amounts of serous fluid. Two layers of membrane exist; one is associated with the lung and the other with the thoracic cavity.

 What is the pleura’s main function?

 What does serous mean?

 What is the role of serous fluid?

2017 Page 5  Outline boundaries that make up the pleural cavity

Nerve supply to the respiratory system

Name the nerves associated with breathing.

Blood vessels of the respiratory system

Name the blood vessels that bring blood to and from the lungs.

The Cardio-Vascular System

Blood Vessels

Name five types of blood vessel that can be found in the human body.

2017 Page 6 Draw and label the structure of an artery and vein.

List the similarities and differences that can be found between an artery and a vein?

Artery Vein

Decide which are ‘True’ or ‘False’?

True False

Arterioles divide into minute vessels called capillaries.

2017 Page 7 An arteriole has more elastic fibres than an artery and an artery has more smooth muscle fibres than an arteriole.

Capillaries are composed of a single layer of endothelial cells.

The diameter of a capillary is greater than a red blood cell.

Capillaries link the smallest arteriole to the smallest venule.

Where the answers are false write the correct response.

The Heart

Draw and label a cross section of the human adult heart.

2017 Page 8 What do you notice about the heart’s shape?

What is the length and diameter of an adult heart? How much does it weigh?

The heart is positioned in the thoracic cavity in the middle of the mediastinum, between the lungs. What is the mediastinum?

Its angle is oblique, and it lies slightly to the left. On your diagram identify the base and apex.

Place the following anatomical structures in the correct position relating to the heart.

Anatomical structures Position in relation to the heart

Aorta Inferior to the heart

Superior Vena Cava

2017 Page 9 Pulmonary Artery Superior to the heart

Pulmonary Vein

Inferior Vena Cava Posterior to the heart Thoracic Vertebrae

Trachea

Left and Right Lung Anterior to the heart

Oesophagus

Sternum Laterally to the heart Ribs

Intercostal Muscles

The interior structure of the human heart is divided into a left and right side by muscular tissue and the endocardium (called the Septum). Each side is further divided into upper and lower chambers.

Name four chambers of the heart using your diagram

Valves in the heart help to divide the upper and lower chambers. Valves open and close as a result of pressure changes caused by the heart contracting. Describe the position, structure and function of the following heart valves.

Tricuspid Valve Bicuspid Valve (Why can it also be called a Mitral valve?)

2017 Page 10 Outline the characteristics and function of the following three layers:

1. Pericardium

2. Myocardium

3. Endocardium

Blood Supply to the Heart

As a rule, arteries take blood away from the heart whereas veins bring blood to the heart. Draw and label the pulmonary circulation. Name the artery that takes deoxygenated blood away from the heart?

Name the blood vessels that supply the myometrium.

The Digestive System

The digestive system is a collective term to describe a group of structures involved in the digestion and absorption of food substances.

List the structures that make up the digestive system from the mouth to the rectum in order of action.

Structure Function

2017 Page 11 Rectum

Diagrams of the digestive system in text books show a system that includes a number of organs and glands that are anatomically linked. You will notice from your list of structures is that each stage of digestion and absorption depends on the effective action of the previous stage.

The Alimentary Tract

What is the Alimentary Tract?

Excluding the mouth and pharynx, list four layers of tissue that make up the alimentary tract walls.

2017 Page 12 4

Note differences between each layer?

Parts of the Alimentary Tract

Draw and label a cross section of the mouth?

2017 Page 13 Where is the soft and hard palate?

Draw and label a cross section of the stomach

2017 Page 14 Where is the pyloric sphincter?

What nerves supply the stomach?

The Renal System

List structures that make up the Renal System.

2017 Page 15 The Kidney

Macro structure of the kidney

The kidney is a paired organ. Each kidney is situated on either side of the vertebral column behind the peritoneum. They lie between the 12th Thoracic and 3rd Lumber Vertebrae. Adipose tissue attaches the kidneys to the posterior abdominal wall. (Stables and Rankin, 2010, p254)

What is the Peritoneum?

Draw and label a cross section of a kidney

Using an anatomy textbook answer the following questions about the kidney.

Anatomical characteristics Answer

What shape is an adult kidney

What size is the kidney?

What is the average weight of a kidney?

In which cavity is the kidney positioned?

Name structures that relate to the kidney, using the following anatomical directions:

2017 Page 16 Anterior

Posterior

Superior

Inferior

Name the blood vessels that take blood to and from the kidney?

Name the nerves that supply the kidney

Beneath the outer capsule of a kidney there are three regions. Name them:

What is the anatomical difference between the left and right kidney?

Micro structure of the kidney

One kidney contains approximately 1 million nephrons. A Nephron is the functional unit of a kidney. (Stable and Rankin, 2010, p254)

Draw and label a Nephron including the afferent and efferent blood vessels.

2017 Page 17 The ureters

A Ureter is a hollow muscular tube that lies behind the peritoneum. There are two ureters which extend from the renal pelvis to the posterior wall of the urinary bladder.

What type of muscle is found in the ureters?

The Urinary Bladder

The bladder is muscular organ that is hollow and able to distend. It acts as a reservoir for urine storage.

Draw and label a cross section of the urinary bladder.

Anatomical characteristics Answer

Describe the bladder’s shape.

What is the Trigone?

What is the bladder’s capacity for holding urine?

In which cavity is the bladder positioned?

What structures will you find in relation to the bladder? Use the following directional

2017 Page 18 terms:

Superior

Inferior

Name the blood vessels that take blood to and from the bladder?

Name the nerves that supply the bladder.

The Urethra

The Urethra is a narrow tube that leaves the bladder. It is ………… cm long

What muscular structure lies at the entrance to the urethra?

The Liver

Introduction

The Liver is the largest organ within the human body. It is described as an accessory organ, having a close association with the small intestine. Its main function is the regulation of the composition of the blood.

Anatomy

The Liver has four primary lobes: the right and left lobes (anterior), the caudate lobe and the quadrate lobe (Posterior). The liver is suspended from the diaphragm by the falciform ligament. On the posterior side of the liver is the common hepatic duct, bile ducts, hepatic portal vein, hepatic artery proper and the gallbladder. The larger hepatic vein leads from the liver to the central vein, from here blood flows to the inferior vena cava and through the body.

2017 Page 19 Making up the lobes are a network of hepatocytes (liver cells) which for form lobules. These lobules are hexagonal in shape (six sided). At each side of the lobule is a portal triad of 3 basic structures, including: the hepatic artery proper, hepatic portal vein and a bile duct.

Position

Occupies the right upper hypochondriac region of the abdominal cavity and epigastric plane. Located under the diaphragm, almost entirely protected by the rib cage. (Appendix one)

Question 1

Please complete the labels of the structure of the liver

Marieb E et al (2016,10th ed) pages 902-903

Function

Among the many functions of the liver are the following:

Carbohydrate metabolism

Soluble sugars mainly excess glucose are transported from the gut to the liver in the hepatic portal vein. Once in the liver glucose is converted to glycogen and stored. Conversion of glycogen is controlled by the hormone insulin from the Islets of Langerhans in the pancreas.

Protein metabolism

The uptake of amino acids from the gut and transportation within the liver assists in protein synthesis, thus stabilising the protein pool within the blood. The process is finely balanced by an equal breakdown of plasma proteins which have a limited lifetime in the circulation. Plasma proteins at the end of their lifetime, together with excess amino acids absorbed within the gut are deaminated by the liver cells and converted to ammonia. Ammonia is very toxic and enters a

2017 Page 20 sequence of reactions in the liver which converts ammonia to the less toxic urea. Urea is then released by the liver and excreted by the kidneys.

Lipid metabolism

Fats and oils from the gut can be converted into glycogen and stored in the liver. The liver can also make cholesterol even in the absence of cholesterol in the gut. Cholesterol in the blood is used in the synthesis of proteins. Excess levels of cholesterol in the blood can be absorbed by the liver and eliminated in bile. However, excess levels of cholesterol can precipitate gallstones when deposited in the gallbladder prior to excretion.

Iron metabolism

The iron-globin complex is metabolised in the liver. Globin is broken down into amnio acids which are used in the synthesis of proteins. Iron is retained for the production of fresh haemoglobin. Excess iron is stored in the liver as ferritin and hemosiderin.

Bile & Bilirubin

Bile is an alkaline solution, containing among many products salts, cholesterol, phospholipids, electrolytes and pigments (mainly bilirubin). Bilirubin is a waste product, formed during the process of breaking down haemoglobin. It is absorbed by the hepatocytes of the liver and excreted in the bile to the small intestine.

Detoxification

The liver acts as a filter removing toxic substances from the blood, making them less harmful and preparing them for excretion.

Adaptations to the liver during pregnancy.

During pregnancy the hepatic system undergoes several adaptations which is important in supporting maternal and fetal nutrition. Changes to the presentation and position of the liver occur as pregnancy progresses (appendix 1). Altered production of liver enzymes, plasma proteins, and bilirubin and serum lipids takes place.

Question 2

Please answer true or false

The size of the liver increases during pregnancy

Oestrogen does not affect the production of bilirubin during pregnancy

2017 Page 21 Fibrinogen increases in pregnancy by up to 50% to protect against excessive blood loss

Cholesterol increases during pregnancy to support the production of hormones from the placenta.

Most liver enzymes return to the pre-pregnant state by 7 days post delivery

Tucker Blackburn S (2013, 4th Ed)

Question 3

What waste product is excreted by the liver?

Question 4 What is the correct name given to the cells of the liver?

Question 5

During new-born adaptation to extra uterine life the liver plays a vital role in what biochemical processes?

Appendix One

2017 Page 22 Appendix 2

2017 Page 23 2017 Page 24