Arthritis – inflammation of the joint



Arthritis – inflammation of the joint

Bursae – small fluid-filled sac that provides cushion between bones and tendons and/or muscles around a joint

Bursitis – inflammation of the bursae

Dislocation – displacement of the bone in a joint

Fracture – a cracking or breaking of a bone

Kyphosis – exaggerated forward curvature; humpback

Lordosis – exaggerated lumbar or cervical curvature of the spine

Scoliosis – excessive lateral deviation of the vertebral column

Spina bifida – failure in vertebral fusion that may lead to spinal cord protrusion through the opening

Ligament – fibrous tissue that connects bones to each other

Tendon – fibrous tissue that connects muscles to bones

Sprain – tear or damage of the ligament

Strain – tear or damage of the tendon

For the first three weeks we are going to study the basic anatomy and physiology of the human body.

□ Anatomy – structure of the human body/organ

□ Physiology – function of the human body/organ

In anatomy we usually divide the body into three imaginary planes, each of which is a cut through the body in a different direction.

1. Midsagital plane – divides the body into equal left and right halves

2. Frontal (coronal) plane – divides the body into front and back portions

3. Transverse plane – divides body into upper and lower halves

□ Superior – above; in a higher position

□ Inferior – below; in a lower position

□ Anterior and ventral – toward the front of the body

□ Posterior and dorsal – toward the back of the body

□ Cranial – closer to the head\

□ Caudal – closer to the end of the spinal cord

□ Medial – closer to the midline

□ Lateral – farther away from the midline

□ Proximal – closer to the main part of the body

□ Distal – farther away from the main part of the body

□ Superficial – closer to the surface

□ Profundus – farther away from the surface

These are terms that are used in the medicine extremely often and it would be preferable for you to be familiar with them. However, these are relative terms and not absolute.

For example, the nose is superior to the chin, but inferior to the forehead.

OSTEOLOGY – branch of anatomy studying bones.

The adult human body on average has 206 bones, but newborns have approximately 270. This is because as the newborns grows certain bones fuse with each other making one large bone.

Main functions of the bones:

1. Framework for the entire body

2. Protection for delicate structures

3. Movement production when working with attached muscles.

4. Storage for calcium (that can be reabsorbed into the blood when there is not enough calcium in the diet)

5. Blood cells production (red bone marrow)

Bones are composed mainly of bone tissue, called osseous (Os-e-us) tissue. Between these tissues there are calcium deposits. The calcium is what makes our bones so strong.

There are different type of bones:

1. Flat (ribs, skull)

2. Cube shaped (wrist, ankle)

3. Irregular (vertebrae)

4. Long bones

Long bones consist of two parts:

□ Diaphysis – long shaft; the middle portion of the bone

□ Epiphysis – the two irregular ends of the bone

The complete bony framework of the body is called skeleton.

Skeleton – complete bony framework of the body

We divide the skeletal system into two parts:

□ Axial skeleton – includes framework of the head and the trunk

□ Appendicular skeleton – includes framework of the extremities (limbs) and framework for the shoulders and hips.

Framework of the head:

CRANIAL BONES

□ Frontal bone – forms the forehead, the front of the skull’s roof, and part of the roof over the eyes and the nasal cavities

□ Parietal bones – form most of the top and the side walls of the cranium

□ Temporal bones – form part of the sides and some of the base of the skull

□ Ethmoid bone – located between the eyes; forms the small portion of the medial wall of the eye

□ Sphenoid bone – lies in front of the temporal bones

□ Occipital bone – forms back and a part of the base of the skull

FACIAL BONES

□ Mandible – is the lower jaw

□ Maxillae – upper jaw bone and front part of the hard palate

□ Zygomatic bones – form the prominences of the cheeks

□ Nasal bones – form the bridge of the nose

□ Lacrimal bones – lie in the inside corner of the eye; form part of the eye socket wall

□ Vomer – forms the lower part of the nasal septum

□ Palatine bone – form the back part of the hard palate

□ Inferior nasal conchae – extend horizontally along the lateral wall (sides) of the nasal cavities.

MIDDLE EAR BONES

□ Malleus

□ Incus

□ Stapes

VERTEBRAL COLUMN

□ Cervical spine – consists of 7 cervical vertebrae. The first cervical vertebra is called atlas and it supports the head; the second one is called axis

□ Thoracic spine – consists of 12 thoracic vertebrae; posterior ends of the ribs are attached to these vertebrae

□ Lumbar spine – consists of 5 lumbar vertebrae

□ Sacrum – are five separate bones in the child that eventually fuse to form a single bone, called the sacrum.

□ Coccyx – consists of four to five tiny bones in the child. These fuse to form a single bone in adults.

Ribs – are bony structures that form ribcage.

Sternum – is a flat bone located in the middle of the chest to which individual bones attach.

SHOULDER GIRDLE

□ Clavicle (collarbone) – curved bone attached medially to the sternum and laterally to the scapula

□ Scapula – shoulder blade

UPPER EXTREMITY

□ Humerus – arm bone; forms joint with scapula and forearm bones

□ Ulna – one of the two forearm bones; lies on the medial (little finger) side

□ Radius – one of the two forearm bones; lies on the lateral (thumb) side

□ Carpal bones – bones of the proximal part of the palm

□ Metacarpal bones – bones of the palm; their rounded distal ends form the knuckles

□ Phalanges – finger bones

LOWER EXTREMITY

□ Femur – thigh bone; longest and strongest bone in our body

□ Patella – kneecap

□ Tibia – shin bone

□ Fibula – located laterally to the tibia

□ Tarsal bones – bones of the ankle and foot

□ Metatarsal bones – framework of the instep; heads of these bones form the ball of the foot

□ Phalanges – bones of the toes

PELVIC BONES

Os coxa – formed by ilium, ischium, and pubis

□ Ilium – forms the upper part of the pelvic girdle; can be felt just bellow the waist

□ Ischium – lowest and strongest part of the pelvic girdle

□ Pubis – forms the anterior part of the pelvic girdle

ARTHROLOGY – branch of medicine studying joints.

A joint is the location at which two or more bones make contact

Joints are classified into three main types:

1. Fibrous joints – immovable; bones are held together by fibrous connective tissue (bones in the skull)

2. Cartilaginous joints – slightly movable; bones are connected by cartilage (vertebral joints, pubic bones)

3. Synovial joints – make up the majority of the joints; freely movable; bones are held together by ligaments.

In synovial joints the bones are held together by ligaments. Additional ligaments attached at different points help to stabilize the joint.

The bone surfaces in freely movable joints are protected by a smooth layer of cartilage.

SHOULDER JOINT

The major bones of the shoulder joint are:

1. Humerus

2. Acromion

3. Clavicle

ELBOW AND WRIST

The major bones of the elbow

1. Humerus

2. Ulna (pinky side)

3. Radius (thumb side)

The major bones of the wrist

1. Humerus

2. Ulna

3. Carpal bones (most commonly injured – pisiform that can be felt as a bump on the anterior medial side; lunate that is commonly dislocated; trapezium which is often times broken)

SACROILIAC JOINT

The major bones of the sacroiliac joint

1. Sacrum

2. Ilium

During birth all the joints of the pelvic girdle become more flexible which allows them to stretch and facilitate the passage of the fetus.

HIP JOINT

The major bones of the hip joint

1. Pelvic girdle

2. Femur

KNEE and ANKLE

The major bones of the knee

1. Femur

2. Tibia

The bones of the ankle

1. Tarsal bones

Circumduction – circular motion

Flexion – bringing two body parts closer together

Lateral flexion – sideway bending of the neck or low back from side to side

Extension – moving two body parts away from each other

Rotation – movement around own axis

Internal rotation – rotation towards the midline

External rotation – rotation away from the midline

Abduction – movement away from the midline

Adduction – movement towards the midline

Supination – turning the palm face up

Pronation – turning the palm face down

Deviation – movement of the hand from side to side

Inversion – movement of the ankle inward

Eversion – movement of the ankle outward

Dorsiflexion – movement of dorsum of foot superiorly

Plantar flexion – movement of foot inferiorly

MYOLOGY – specialized study of muscles and muscular tissue

Atrophy – decrease in the mass of the muscle

Cramp – spasmodic contraction of the muscle

Hernia – protrusion of the body structures through the body’s natural openings

Muscular Dystrophy – group of genetic muscle diseases (Emmery-Dreifuss, Duchene, Beker) causing progressive muscle weakness

Torticolis – acquired or congenital abnormality of the sternocleidomastoideus muscle in which the head is tilted to one side.

There are three types of muscles in the human body:

1. Striated or skeletal muscle - involuntary

2. Smooth muscle - involuntary

3. Cardiac muscle or myocardium – involuntary

The two main purposes of the skeletal muscles are motion and generation of heat.

The skeletal muscles are responsible for:

1. Movement

2. Generation of heat

All skeletal muscles are attached to bones and, if you look at them, they have two distinguished parts.

1. Body of the muscle (belly) – middle portion of the muscle

2. Tendon – outer portion of the muscle

At one end the tendon is inserted into the muscle and at other – into the bone, fixing the muscle to that bone.

Between muscles/tendons and bones are bursae – a small fluid-filled sacs that minimize the friction between those structures.

A muscle has two (or more) attachments. One of these attachments is connected to a more freely movable part than the other.

Origin – less movable (more fixed) attachment

Insertion – more movable attachment

All muscles work in coordination. All our movements are coordinated. Many skeletal muscles in our bodies function in pairs. A movement is produced by muscles called the prime mover (or synergist); muscle that produces an opposite movement is called antagonist. There are numerous other muscles that assist prime movers or serve to steady body parts.

There are more than 650 individual muscles in our bodies that comprise the 40% of the body mass.

Facial muscles – responsible for facial expressions and chewing

Sternocleidomastoideus – flexes head; rotates head toward opposite side

Shoulder muscles – do not worry about it

Biceps brachii – flexes forearms and supinates hand

Triceps brachii – extends forearm

Trapezius – raises shoulder and pulls it back; extends head

Latissimus dorsi – extends and adducts arm behind back

Deltoid – abducts arm

Abdominal muscles

External and internal oblique; transversus and rectus abdominis – compress abdominal cavity and expel substances from body; flex spinal column

Sacrospinalis – extend vertebral column to produce erect posture

Intercostal muscles – elevated ribs and enlarge chest cavity

Diaphragm – dome descends to enlarge chest cavity from top to bottom

Quadriceps – (a group of four muscles) extends leg

Hamstrings – (a group of three muscles) – flexes leg

Gluteus maximus – extends thigh

Gluteus medius – abducts thigh

Groin pull – adduct thigh

Calves (gastrocnemius, soleus) – extends foot

DAY 1

Acne vulgaris (commonly called acne) - skin disease characterized by inflammation of the sebaceous glands and associated hair follicles.

Tinea pedis (athlete’s foot) – fungal infection of the skin of the foot.

Blister – fluid collection between the epidermis and dermis (may be caused by friction or burn)

Callus – thickened outer layer of the skin as a result of repeated contact and friction.

Corn – small painful callus on the foot.

Dermatitis – inflammation of the skin.

Eczema – group of allergic skin disorders (most commonly dermatitis) marked by red, itching crust or scale.

Gangrene – tissue death as a result of obstructed blood flow.

Melanoma – type of cancer of the skin characterized by uncontrolled reproduction of melanocytes.

Nevus – birthmark or mole.

Wart – small, rough tumor of the skin caused commonly by a virus.

Anorexia nervosa – psychiatric illness causing eating disorder characterized by loss of appetite and progressive severe weight loss.

Bulimia – eating disorder characterized by episodes of binge eating followed by purging.

Constipation – infrequent or absent defecation.

Diarrhea – frequent defecation or defecation of semi-solid or solid feces.

Gastric ulcer – open sore in the stomach wall.

Hemorrhoids – varicose veins of the lower rectum.

Nausea – sensation of unease or discomfort in the stomach with an urge to vomit.

CELLS, TISSUES, ORGANS, AND SYSTEMS

The building block of every living system is a cell.

□ Cell – basic unit of all life.

It shows all characteristics of life:

1. growth

2. metabolism

3. responsiveness

4. reproduction

5. homeostasis

Most of the cells are microscopic, meaning that it is impossible to visualize them with bare eye.

Every individual looks differently, but all individuals share common features. The same way cells share some common features but there are thousands and thousands of different types of cells.

When similar cells group together they form tissue.

□ Tissue – group of cells similar in structure, arranged in a characteristic pattern, and specialized for the performance of specific tasks.

Different tissues combined together form organs. And organs make up systems.

There are two major types of cells:

□ Eukaryotic cells – cells that have a nucleus that is enclosed in membrane

□ Prokaryotic cells – cells that do not have well defined nucleus.

All eukaryotic cells share similar features.

□ Cells membrane (plasma membrane) – outer layer of the cell composed mainly of lipids and proteins.

Cell membrane regulates what can enter the cell and what can leave the cell.

The cell is filled with a substance that contains nutrients, minerals, enzymes, and other specialized material in water. It is called cytoplasm.

□ Cytoplasm – colloidal suspension that fills inside of the cell and holds cell content.

Just as our bodies have different organs that carry out different vital functions, the same way the cells have organelles that carry out the need of the cells.

1. Nucleus – large, dark-staining body near the center of the cell composed of DNA and proteins which regulate all activities in the cell including reproduction.

2. Nucleolus – means “little nucleus; composed of DNA, RNA, and protein and responsible for protein production.

3. Ribosomes – responsible for protein production within the cell; attached to the endoplasmic reticulum.

4. Endoplasmic reticulum – means “network within the cytoplasm”; responsible for transport of protein, storage of calcium, production and storage of different macromolecules.

5. Mitochondria – round or bean-shaped organelles with folded membranes inside; responsible for energy production in a form of ATP.

6. Golgi apparatus – layers of membrane responsible for putting together special substances within the cell.

7. Lysosomes – small sacs containing digestive enzymes used to digest substances within the cell.

8. Centrioles – rod-shaped bodies (usually 2) near the nucleus helping to separate the chromosomes in cell division.

9. Cilia – short, hair-like projections from the cell that create movement around the cell.

10. Flagelum – ling, whip-like extension from the cell that moves the cell.

So, as we know, when similar cells group together they form tissues. In our bodies, there are four types of tissues which are:

□ Epithelial tissue – covers surfaces, lines cavities, and forms glands.

a. Squamous (SKWA-mus) – flat and irregular

b. Cuboidal – square

c. Columnar – long and narrow

□ Connective tissue – supports and forms the framework of all parts of the body.

a. Soft connective tissue (adipose/fat tissue)

b. Fibrous connective tissue (ligaments, tendons, fascia)

c. Hard connective tissue (cartilage, bones)

d. Liquid connective tissue (blood)

□ Nervous tissue – conducts nerve impulses.

a. Neurons – nerve cells

□ Muscle tissue – contracts and produces movement.

a. Skeletal muscle

b. Smooth muscle

c. Cardiac muscle

DAY 2

The skin is often considered a membrane that just covers the body. However, the skin has more complex functions and responsibilities. It is the largest organ in our body.

Very often it is referred to as integumentary system because it includes glands, vessels, nerves that work together as a body system.

Integument – covering

Cutaneous – related to skin

The skin has three layers:

□ Epidermis – outermost layer which divided into other layers, made of epithelial cells with no blood vessels.

□ Dermis (corium) – true skin located under the epidermis; a framework of connective tissue and contains blood vessels, nerve endings, and glands.

□ Hypodermis – located between the dermis and underlying tissues.

The skin has several functions which are:

□ Protection of deeper tissues against drying and invasion by pathogenic organisms or their toxins.

□ Regulation of body temperature by dissipation of heat to the surrounding air.

□ Receipt of information about the environment by means of nerve endings distributed throughout the skin.

□ Aiding in vitamin D synthesis.

□ Protection from the sunlight through the means of melanocytes producing melanin.

Between the skin layers lies another tissue which is call subcutaneous layer which is also referred to as superficial fascia.

□ Subcutaneous layer (superficial fascia) connects the skin to the surface muscles; consists of:

a. Elastic connective tissue

b. Fibrous connective tissue

c. Adipose (fat) tissue

The fat in this layer serves as an insulation and as a reserve store for energy. The major vessels that supply the skin with blood run through the subcutaneous layer.

The skin has several appendages.

□ Sweat glands

□ Sebaceous glands

□ Hairs

□ Nails

SWEAT GLANDS – coiled, tube-like structures located in the dermis and the subcutaneous tissue.

They regulate body temperature through the evaporation of sweat from the body surface.

The sweat glands located in the armpits and the groin are of another type. They release secretions through the hair follicles in response to emotional or sexual stimulation. The secretions contain cellular material that is broken down by bacteria, producing body odor.

SEBACEOUS GLANDS – are sac-like in structure and secrete sebum (oily secretion) that lubricates the skin, hair and prevents drying; ducts open into the hair follicles.

Blackheads consist of a mixture of dried sebum and keratin that may collect at the openings of sebaceous glands.

Inflammation of these glands produces acnes.

HAIR ANDE NAILS

Almost all of our bodies is covered by hair. Hair are made of keratin and are nor living. A hear develops within a sheath called a follicle. New hair form from the cells at the bottom of the follicles.

There are thin involuntary muscles attach to most of our hair. The contraction of these muscles result in erection or the hair producing “goose bumps”. Also, when the muscle contracts it presses on the sebaceous gland forcing it to release sebum.

Nails are protective structures made of hard keratin produced by cells that originate in the outer layer of the epidermis. New cells form continuously at the proximal end of the nail in area called nail root. Nails of both the toes and the fingers are affected by general health.

ENDOCRINE SYSTEM

Endocrine system is one of the two main controlling and coordinating systems of the body. The effect of the endocrine system occur slowly and over a long period of time.

Endocrine system controls and coordinates the body through the chemical substances it produces.

□ Hormones – are chemical messengers that have specific regulatory effects on certain other cells or organs in the body.

Hormones are secreted into the bloodstream and carried to distant organs where they exert their effect. Some hormones affect only one specific type of tissue. Another ones affect a large number of tissues.

The main hormone secreting organs are:

1. Pineal gland – located in the brain

2. Pituitary gland – located in the brain

3. Thyroid gland – located in the neck

4. Parathyroid glands – located on the back side of the thyroid hormone

5. Thymus – located in the chest

6. Adrenal glands – located in the abdominal cavity

7. Islets of Langerhans – located in the pancreas

8. Ovaries – located in the pelvic cavity

9. Testes – located in the scrotum

Target tissue – specific tissue affected by each hormone.

These are several hormones:

1. Growth hormone – promotes growth of all tissues

2. Follicle-stimulating hormone – stimulates ovaries, growth of testes; promotes development of sperm cells

3. Thyroid hormone – increases metabolic rate, influences mental and physical activity; required for normal growth

4. Epinephrine/norepinephrine – prepares the body for “fight or flight” response

5. Insulin – decreases blood sugar level

6. Glucagon – increases blood sugar level

7. Estrogens – stimulates growth of primary sexual organs and development of secondary sexual organs.

8. Testosterone – stimulates growth and development or sexual organs and secondary sexual characteristics

DAY 3

DIGESTIVE SYSTEM

Every body needs a constant supply of nutrients to provide energy and building blocks for the cells. To meet those needs we need to intake food. The food that we take in goes through several stages.

1. Ingestion – the food enters the mouth.

2. Mastication – after entering the mouth the food gets broken down into smaller pieces through a mechanical process of chewing. Also the food mixes with saliva.

3. Deglutition – the chewed food gets swallowed.

4. Digestion – the food gets broken down by enzymes in the digestive tract.

5. Absorption – the broken down food is enters the circulation to be delivered to tissues and organs.

6. Defecation – the remaining of the food that has not been absorbed passes through as a waste and exits the body.

The digestive system, for our convenience is divided into two parts;

1. Digestive tract – a continuous passageway beginning at the mouth and terminating at the anus.

2. Accessory organs – organs necessary for the digestive process but are not a direct part of the digestive system.

PERITONEUM

The abdominal cavity is covered with a thin, shiny serous membrane which is called peritoneum that also covers most of the abdominal organs. It has two portions.

□ Parietal peritoneum – covers the abdomen

□ Visceral peritoneum – covers the organs

The inflammation of the peritoneum is called peritonitis and most of the time it is a medical emergency that has to be dealt with immediately.

The digestive tract is a muscular tube extending through the body. It is composed of several parts:

MOUTH

Also called oral cavity. Has three digestive functions:

A. To receive a food – ingestion

B. Prepare food for digestion

C. To begin the digestion of starch

After the food was masticated and mixed with saliva it gets swallowed into the pharynx (throat) and esophagus.

The masticated food is called a bolus.

Bolus – masticated food

STOMACH

The stomach is an expanded J-shaped organ in the upper left region of the abdominal cavity. The stomach serves as:

A. Storage

B. Digestive organ

The digestion in the stomach is possible because of the gastric juice that is composed of:

1. Hydrochloric acid (HCl) – softens connective tissue and destroys foreign organisms

2. Pepsin – digests proteins

Stomach has muscular layers that aid in gastric movements that grind the food and mix it with digestive enzymes.

The semi-liquid mixture of gastric juice and food that leaves the stomach is called chime.

Chime – semi-liquid mixture leaving the stomach.

SMALL INTESTINES

This is the longest part of the digestive tract. It consists of several parts:

1. Duodenum

2. Jejunum

3. Ileum

Cells of the duodenum secrete digestive enzymes that digest proteins and carbohydrates. In addition, digestive juices from the liver and pancreas enter the small intestine through a small opening in the duodenum.

Most of the digestive process and absorption take place in the small intestine. The small intestine is covered with numerous folds that greatly increase the absorptive surface.

LARGE INTESTINES

The large intestine begins in the lower right region of the abdomen. It consists of several parts:

1. Cecum

2. Appendix

3. Ascending colon

4. Transverse colon

5. Descending colon

6. Sigmoid colon

7. Rectum

8. Anal canal

Large intestine receives the chime from the small intestine and absorb the excess of water and form the feces. Some of the nutrients are also absorbed here.

ACCESSORY ORGANS

LIVER

The liver is the largest glandular organ of the body. It is located in the right upper corner of the abdominal cavity.

It has many function and some of them include:

1. The storage of glucose in the form of glycogen

2. The formation of blood plasma proteins

3. The synthesis of urea, a waste product of protein metabolism.

4. The modification of fats

5. The manufacture of bile.

6. The destruction of old red blood cells.

7. The detoxification (removal of poisonous properties) of harmful substances such as alcohol and certain drugs.

8. The storage of some vitamins and iron.

The main digestive function of the liver is the production of bile. The salt in the bile act as detergent and break the fat up into small droplets. The bile produces by the liver is stored in the gallbladder – a small sac located underneath the liver. From there the bile can be released into the duodenum to assist in digestive process.

PANCREAS

This is a long gland that extends from the duodenum to the spleen. The pancreas produces enzymes that digest fats, proteins, carbohydrates, and nucleic acids.

The two main functions of the pancreas are:

1. Secrete digestive enzyme to assist in the process of digestion

2. Secrete insulin and glucagons to control the blood glucose (sugar) level

APPENDIX

The purpose of the appendix is not fully understood yet. However, there are some theories that it can have a role in immune responses of our bodies. Appendix is prone to an infection. The inflammation of the appendix is called appendicitis and it is one of the most common reasons for surgery.

Thrombus – blood clot attached to the artery wall or the heart

Embolus – dislodged circulating blood clot, tissue, or gas bubble

Ischemia – poor blood flow to the tissue

Cyanosis – bluish discoloration due to ischemia

Angina pectoris – chest pain related to myocardial ischemia

Myocardial infarction – death of a portion of the heart muscle due to obstructed blood flow

Innervation – supply with nerves/nervous stimulation

Anoxia – absence of oxygen; shortage of oxygen in tissues and organs

Hypoxia – low than normal levels of oxygen

Asphyxia – suffocation

Dyspnea – difficulty breathing

Asthma – chronic respiratory disease characterized by recurrent attacks of dyspnea

Bronchitis – inflammation of bronchi (can be acute or chronic)

Epistaxis – nosebleed

Hyperventilation – abnormally fats or deep respiration causing carbon dioxide, fal in blood pressure, and fainting.

Oxygenated – rich in oxygen.

Deoxygenated – containing low levels or no oxygen.

Our body consists of billions and billions of cells that need nutrients and oxygen every second in order to survive and function.

Oxygen and nutrients are delivered to the tissues and organs through the blood.

Oxygen carried in the blood in erythrocytes. Erythrocytes contain hemoglobin to which the oxygen attaches.

*** Erythrocyte – red blood cell containing hemoglobin

*** Hemoglobin – molecular structure in erythrocytes that carries the oxygen

Blood travels through our body within blood vessels. We classify the blood vessels into:

*** Artery – blood vessels that carry the blood away from the heart.

*** Arterioles – small diameter arteries.

*** Veins – blood vessels that bring the blood to the heart.

*** Venules – small diameter veins.

*** Capillaries – smallest of the body’s blood vessels that connect arterioles to venules.

All blood vessels together make circulatory system:

*** Circulatory system – network of blood vessels of the body that directs the blood flow.

For our convenience, we divide the circulatory system into two parts:

*** Systemic circulation – blood circulating between the heart and the rest of the body except for lungs.

*** Pulmonary circulation – blood circulating between the heart and lungs.

The arteries are rich in oxygen (with the exception of pulmonary artery) and the veins are rich in carbon monoxide that is considered to be a waste product and should be removed the body.

Lungs enrich blood with oxygen ( Heart ( Aorta ( Arteries rich in oxygen ( arterioles rich in oxygen ( capillaries ( gas exchange ( venules rich in carbon monoxide ( veins rich in carbon monoxide ( Superior and Inferior Vena Cava ( Heart.

THE HEART

Our blood circulates throughout the body delivering the necessary nutrients and oxygen to the organs and tissues. This is possible because of the pumping action of the heart.

*** Heart – hollow muscular organ that pumps the blood into pulmonary and systemic circulations.

The heart is located in the middle of the chest and is slightly tilted to the left. In the chest cavity it is located between the right and left lungs. This area is called mediastinum.

*** Mediastinum – area in the middle of the chest limited by right and left lungs.

The heart is turned upside down, so the top of the heart is pointing downwards and the bottom of the heart is pointing upwards.

*** Top of the heart – apex.

*** Bottom of the heart – base.

The heart is covered by a fibrous membrane that surrounds and completely encloses the heart and is called pericardium.

*** Pericardium (pericardial sac) – fibrous membrane surrounding and completely enclosing the heart; contains small amount of fluid that reduces the friction between the heart and surrounding tissues.

The functions of the pericardium is to isolate the heart from the surrounding tissues making it harder for the infection to spread to the heart, and it also reduces the friction between the heart and surrounding tissues.

Inflammation of the pericardium is called pericarditis.

*** Pericarditis – inflammation of the pericardium (pericardial sac).

The heart is a hollow muscular organs and it has four chambers. The two superior small chambers are called atria, and the inferior two large chambers are called ventricles.

*** Atrium – one of the two superior chambers of the heart.

*** Ventricle - one of the two inferior chambers of the heart.

The heart is divided into two parts – right and left, by a thick muscular wall that is called interventricular septum (or just septum).

*** Iterventricular septum – thick muscular wall dividing the heart into right and left sides.

The right part of the heart deals with deoxygenated blood and the left part of the heart deals with oxygenated blood.

There is a system of large blood vessels that deliver blood to the heart and take the blood away from the heart.

HEART CHAMBERS

Right atrium receives two large blood vessels that bring deoxygenated blood to the heart – superior and inferior vena cava.

*** Superior vena cava – large vein that drains blood into the right atrium from the upper parts of the body (head, neck, arms)

*** Inferior vena cava – large vein that drains blood into the right atrium from the lower parts of the body (rest of the body).

The blood drained into the right atrium gets pumped into the right ventricle. Right ventricle then pumps the blood into a large artery that takes it to the lungs to get oxygenated. That artery is called pulmonary artery.

*** Pulmonary artery – large artery leaving the right ventricle that takes deoxygenated blood to the lungs.

In the lungs, the blood gets oxygenated and then returns to the left atrium through pulmonary veins. There are four pulmonary veins that enter the left ventricle.

*** Pulmonary veins – 4 blood vessels that bring oxygenated blood to the left atrium.

From the left atrium the blood gets pumped into the left ventricle and from there the ventricle pumps it into the bodies largest artery – aorta, that takes the blood into the systemic circulation to supply the body.

*** Aorta – largest artery of human body that exits the left ventricle and supplies all the tissues in human body.

HEART VALVES

It is important for the blood to flow in one direction only. The structures in the heart that ensure unidirectional, forward movement of the blood are called valves. There are four valves in the human heart.

*** Tricuspid valve – located between the right atrium and right ventricle

*** Pulmonary (or pulmonic) valve – located between the right ventricle and pulmonary artery.

*** Bicuspid (mitral) valve – located between the left atrium and left ventricle.

*** Aortic valve – is located between the left ventricle and aorta.

Superior and inferior vena cava ( right atrium ( right ventricle ( pulmonary artery ( lungs ( pulmonary veins (4) ( left atrium ( left ventricle ( aorta ( systemic circulation.

There are few appendages of bicuspid and tricuspid valves – chordae tendinae and papillary muscles.

*** Papillary muscles – finger-like protrusions from the ventricular wall to which chordae tendinae are attached.

*** Chordae tendinae – fibrous structures at one end attached to the papillary muscles and at another end to the valves.

HEART CONDUCTIVE SYSTEM

The heart muscle has two unique features. These are:

*** Automaticity – ability of each individual myocardial cell to beat independently.

*** Interconnectedness – the cells of the myocardium are interconnected in order for the electrical impulse to travels faster and more efficiently.

If the myocardial cells beat independently without any coordination with each other the heart contraction as a whole would be impossible. So, the heart has a control conductive system that coordinates and controls the heartbeat.

*** Sinoatrial node (SA node; natural pacemaker) – specialized conductive tissue located in the right ventricle that generates electrical impulses at a rate of 6- to 100 beats per minute.

The SA node generates electrical impulses that travel through the atria and make them contract. Then the impulse travels down the heart and reaches another accumulation of the specialized conductive tissue that is called atrioventricular node.

*** Atrioventricvular node (AV node) – specialized conductive tissue located in the right ventricle that delays the impulse generated in the SA node allowing ventricles enough time to fill with blood; also serves as a back up system for SA node and can generate electrical impulses at a rate of 60 beats per minute and lower.

From the atrioventricular node the electrical impulse travels down through a specialized group of fibers that is called Bundle of His.

*** Bundle of His – a group of specialized conductive fibers that conduct the electrical impulse from the atria into the ventricles.

Almost at the apex, the Bundle of His separates into two branches – left and right bundle branches that deliver electrical impulse to the left and right ventricles respectively.

*** Bundle branches – a group of specialized conductive fivers originating from the Bundle of His and delivering the electrical impulse to the right and left ventricles.

Bundle branches give origin to highly specialized fibers that are called Purkinje fibers.

*** Purkinje fibers – highly specialized fibers that originate from bundle branches and deliver electrical impulse to the ventricular tissue and make them contract.

Ventricular tissue can serve as a back up system if the SA and Av nodes fail. It can generate electrical impulses at a rate of 40 beats per minute and lower.

THE HEART AND THE NERVOUS SYSTEM

Although the heart has its own conductive system it is also connected to the brain that may affect the work of the heart.

The SA node can generate electrical impulses at a rate of 60 to 100 beats per minute. However, the brain can influence the SA node and make it generate electrical impulses at a much higher rate.

The nervous system is divides into two major anatomical categories – central nervous system and peripheral nervous system.

*** CNS – includes brain and spinal cord.

*** PNS – includes nerves that branch out of the spinal cord and brain (the 12 cranial nerves)

All of the cranial nerves innervate the head and throat except for vagus nerve that enters the thoracic cavity and innervates the heart.

Functionally the nervous system is divided into two parts – somatic nervous system and autonomic nervous system.

*** SNS – controls voluntary function (for example, moving)

*** ANS – controls involuntary functions (digestion or the rate of the heart)

Autonomic nervous system in turn is divided into two parts – sympathetic and parasympathetic nervous systems.

*** Sympathetic NS – prepares the body for “fight or flight” reaction/response

*** Parasympathetic NS – “relaxes” the body (decreasing heart rate, increasing digestion)

So, when the sympathetic nervous system is activated the heart rate increases. When the parasympathetic nervous system is activated, the heart rate decreases.

FETAL CIRCULATION

The fetal circulation differs from the circulation of an adult person. Because the fetus cannot breath through the lungs in the mother womb, the fetus receives the oxygen from the mother’s blood.

Umbilical cord attached the fetus to the placenta that is connected to the mother’s circulation through its own vascular system.

*** Umbilical cord – connects the fetus to the placenta in the womb.

*** Placenta – structure connecting fetal circulation to the mother’s circulation.

Umbilical arteries carry deoxygenated blood and umbilical veins carry oxygenated blood.

The main difference in the fetal heart from the adult heart is the presence of a shunt between the right atrium and left atrium which is called foramen ovale.

*** Foramen ovale – an opening in the interventricular septum in fetal heart that connects the right atrium to the left atrium.

The foramen ovale closes before the birth. However, in some cases, the child is born with a congenital defect – unclosed forament ovale. This leads to insufficient oxygenation of the blood which, in turn, leads to cyanosis.

*** Blue baby syndrome – bluish discoloration of the baby due to congenital heart defect (unclosed foramen ovale) that leads to ischemia.

INTERCOSTAL SPACES

Intercostal spaces are the spaces between the ribs. These are very important anatomical landmarks.

***Intercostal spaces – spaces between the ribs.

*** Each intercostals space shares the number of the rib above it.

ELECTROCARDIOGRAPH AND ELECTROCARDIOGRAM

*** Electrocardiograph – device that records heart’s electrical activity.

*** Electrocardiogram – recording of the patient’s heart’s electrical activity.

EKG provides extremely important information about the heart’s condition. Based on EKG the physician can see whether there is any disease present in the heart.

The EKG picture has waves each of which signifies a part of the heart’s activity.

*** P wave – represents atrial contraction

*** QRS complex – represents ventricular contraction

*** T wave – represents ventricular relaxation

*** U wave – unknown

*** PR interval – time needed for the electrical impulse to travel from the SA node to the ventricles

*** ST segment – provides information about heart’s blood supply; ST segment elevation – heart attack; ST segment depression – ischemia.

*** Coronary arteries – a system of arteries that provide blood supply of myocardium.

RESPIRATORY SYSTEM

Respiratory system includes:

1. Nose

2. Nasal cavity

3. Pharynx

4. Larynx

5. Trachea

6. Bronchi and bronchioles

7. Lungs

Functions of respiratory system include:

1. Gas exchange

2. Production of sounds

3. Aiding in defecation and urination processes, and facilitating expulsion of the fetus during labor.

*** Nose – external part of the respiratory system that protrudes from the face with the two nostrils and communicating with the sinuses.

*** Nasal cavities – located just behind the nose and divided by nasal septum onto left and right nasal cavities. Have several functions:

1. Trapping foreign material

2. Warming the air

3. Moistening the air

*** Pharynx – muscular organ divided into three parts:

1. Nasopharynx – located behind the nasal cavity

2. oropharynx – located behind the oral cavity

3. Laryngopharynx – lowest portion of the pharynx

*** Larynx (voice box) – located between the pharynx and trachea; epiglottis covers the larynx when the person swallows food preventing it from going into the trachea.

*** Trachea – cartilaginous tube extending from the lower part of the larynx to the upper part of the chest above the heart.

*** Bronchi – air passageways that give numerous branches and get progressively smaller in diameter as they do so

Left and Right Bronchi ( Bronchioles ( Terminal Bronchioles ( Alveoli

*** Alveoli – small highly vascularized sacs that represent smallest subdivisions of the terminal bronchioles; the gas exchange takes place in alveoli.

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