Unit 6: Human Anatomy

Anatomy

Field of study focusing on the physical structure of the body

Physiology

examines the normal functions and activities of these biologic components

Pathophysiology

Study of functional changes that accompany a particular disease or syndrome

Topographic anatomy

Help guide EMT to the locations of the locations of internal features that lie beneath

Anatomic Position

Palms and Feet facing towards you.

Planes of the body

1. Coronal (frontal) plane

2. Sagittal (lateral) plane

3. midsagittal (midline) plane

4. Transverse( Axial) plane

Coronal (Frontal) Plane

Runs Vertically through the body and divides it into the front and back sections

Sagittal (lateral) plane

Also runs vertically, but divides the body into left and right. DOES NOT have to be equal halves

Midsagittal (midline) plane

divides the body into left and right, equal halves. Your nose and umbilicus are found around this midline

Transverse (Axial) Plane

Divides the body horizontally into top and bottom sections

Skeletal System

• Provides structural support to bear the body’s weight

• Establishes a framework to attach soft tissues and internal organs

• Protects vital organs (heart and lungs)

• Bone marrow produces red/white blood cells

How many bones are in the human body

206

Axial Skeleton

Forms longitudinal axis of the body, from the skull, to the coccyx.

• Includes the skull, facial bones, thoracic cage, and vertebral column

Appendicular Skeleton

Joint

Where two bones meet

• Names formulated by combining the names of the adjoining bones

Ligaments

Fibrous tissue that connect BONE TO BONE, helping stabilize these joints

Cartilage

Flexible tissue that covers and cushions the ends of articulating bones

Tendons

Tissues that attach bone to muscle, in other joints called symphyses

Joint Capsule

Fibrous sac containing connective tissue that holds together bone ends of a joint

Articular Cartilage

In moving joints, the ends of the bones are covered with a thin layer of cartilage called…

• Allows the ends of bones to glide easily instead

Synovial Membrane

Inner lining of the joint capsule

• responsible for for making thick lubricant called synovial fluid, which allows bones to glide over each other as opposed to rubbing against each other

Ball-and-socket joint

allows rotation and bending etc. shoulder and hip

Hinge Joints

joints with motion restrcited to flexion(bending) and extension (straightening) ex: elbow, fingers, knees

Skull

Consists of 28 bones containing 3 groups: Cranium, Facial bones, Ear bones

Cranium

Contains Frontal, Temporal, Parietal, and Occipital, Ethmoid, and Sphenoid Bones. Fused together to protect the brain

Foramen Magnum

Base of the cranium, large opening, passageway for the spinal cord to connect with the brain and descend into the spinal column

Facial Bones

• Maxilla: upper jawbones

• Mandible: Lower jaw bones (jawline)

• Zygomas: Cheek bones

• Orbit: aka eye socket, cavity formed by joining facial bones

• Upper third of nose made of short nasal bones that form bridge, rest is flexible cartilage

Vertebral(Spinal) Column

Contains 33 Vertebrae, divided into 5 sections

Cervical Spine

First 7 vertebrae (C1 - C7). In the neck. Skull rests on C1, the top being the atlas, and axis, C2

Thoracic Spine

Next 12 Vertebrae. One pair of ribs attached to each of the thoracic vertebrae

Lumbar Spine

Next 5 Vertebrae after Thoracic

Sacrum

Five sacral vertebrae are fused together to form one bone. Joins the iliac bones of the pelvis via strong ligaments at the sacroiliac joints

Coccyx

Last four vertebrae fused together to form coccyx

Intervertebral disks

Vertebrae are connected by ligaments and the gaps between the vertebrae are occupied by cushioning, shock absorbing structures called…

Thorax

aka chest, contains heart, lungs, esophagus, and great vessels (aorta, and venae cavae)

Sternum

Midline of the anterior surface of the chest, Three main parts:

• Manubrium, body, xiphoid process

Manubrium

Upper most part of the sternum. Superior edge of manubrium forms a landmark called the sternal notch

Sternal Body

Middle, largest part of the sternum

Xiphoid Process

Inferior tip of the sternum. Cartilaginous Structure

Upper Extremities

arms, extend to pectoral girdle (shoulder), clavicle, scapula. Also includes Pelvic girdle (hip bones (coxae) sacrum, coccyx). Each coxa is formed by fusion of ilium, ischium, and pubis.

Pubic Symphysis

Cartilage joining left and right pubic bones, limiting movements in these two bones

Acetabulum

where the pelvis articulates with the femur

Lower Extremities

Includes femur, tibia, fibula, femoral head, greater trochanter, lesser trochanter, patella, ankle and foot (calcaneus, talus)

Skeletal system Physiology

• gives body shape

• storage of calcium

• protects organs

• creation of blood cells

Muscle

Form of tissue facilitating movements. Three tyoes: skeletal, smooth, cardiac

Skeletal Muscle

attaches to bones, makes up for bulk of the human mass

Smooth Muscle

Found within blood vessels, and the intestines

• when are tummy growls, it’s the smooth muslces vibrating in the intestine

Cardiac Muscle

In the heart. Unique because it generates its own electrical impulses

Muscoskeletal Physiology

• Production of heat (shivering = muscles generating heat to maintain homeostasis)

• Protects organs

Respiratory System

set of organs responsible for breathing, or respiration, and gas exchange. Includes lungs, trachea, bronchi, bronchioles, alveoli, larynx nose, mouth

Upper Airway

Located anteriorly at the middle: Goes in order:

• Nasopharynx: Upper section of pharynx connecting the nasal cavity

• Oropharynx: back of the throat, form soft palate to the U-Shaped hyoid bone

• Laryngopharynx

• Larynx (voice box)

Lower Airway

Includes:

• Trachea: wind pipe

• Bronchiol Tree(main stem bronchi and bronchioles)

• Alveoli

• Lungs

Gas exchange

Occurs in alveoli (alveolar sacs) exchanged between lungs and bloodstream. Walls of alveoli contain blood vessels carrrying CO2 from the blood and body, and exchanges O2 from the lung.

Mechanics of breathing

The lungs must expand and relax. Several muscles are involved in the making of this. Diaphragm is the primary muscle. It acts both as a voluntary and involuntary muscle. Other muscles involved are the intercostals, neck muscles, abdomen

Inhalation: when you inhale, the diaphragm and intecostals contract, moves slightly down, enlarging the thoracic cage. As the volume of chest cavity increases, air rushes into the lungs (negative pressure)

Exhalation: muscles relax, all dimesnsions of thorax decrease, ribs/muscles return to normal position

Respiratory System physiology

function is the provide body with o2 and eliminate CO2. Also ventilation and respiration

Ventilation

the movement of air between the lungs and the environment, requires chest rise and fall.

Respiration

Process of gas exchange. Exchange allows for body to control pH of blood

Chemical control of breathing

Brain—specifically brain stem— Nerves in area act as sensors for level in CO2 in bloos and spinal fluid. Cells are constantly working to eliminate CO2 to regulate acid-alkaline balance of body. The medulla oblonogata, which stimulates the phrenic nerve, sends a signal to the diaphragm to increase rate of contraction.

Hypoxic Drive

Body’s backup system to control respiration. When oxygen drops, areas in the brain, walls of the aorta, and the carotid arteries act as oxygen sensors

The Pons

Another area in brainstem that controls breathing. Helps augment respirations during emotional or physical stress.

Comparisons of respiratory system in children, infants, and adults

Anatomy:

• Children have a smaller and less rigid system

• Smalled larnyx, trachea and cricoid cartiliage

• This makes it easier for obstruction in children

• Smaller chest in children, meaning they relied more on diaphragm

Respitory Rate:

• children and infants breath faster than adults

Signs that an infant or child not breathing normally

• Muscle retractions, in which muscle is working extra hard

• Nasal flaring

• S=Seesaw retractions, in which sides of chest alternate contractions

• Grunting

Adult lung capacity

Usually 6,000 mL

Normal respiratory Rates

• Adults: 12-20 Breaths per min

• Children: 12-30 BPM

• Infants: 30-60 BPM

Tidal Volume

amount of air moved in or out of lung in a single breath, generally 500 mL in adults

Inspiratory Reserve volume

deepest breath you can take after normal breath

Expiratory reserve volume

maximum air pushed out after normal breath

Residual Volume

Gas remaining in lungs after exhalation

Dead Space

Portion of respiratory system that has no alveoli, little gas exchange. When you ventilate a patient, with any device, you create more dead space, gas must fill the device before it can be moved into the patient

Minute Volume

amount of air moves in and out of lung in 1 minute

Minute Volume = Respiratory rate x Tidal Volume

Scenario where minute volume is essential

Patient presents with normal rate of 20 breaths per min. However, chest is barely moving, little air movement out of mouth.

• Even though respiratory rate is normal, amount of air being moved in inadequate. MV is too low

Characteristics of Normal Breathing

Appear easy

• Normal rate and depth

• Regular rhythm or pattern of inhlation

• Clear, audible breath sound

• Regular rise and fall'\

• Movement of abdomen

Inadequate Breathing in adults

Labored breathing, or significant use of acessory muscles in chest, neck, abs.

• Breathing much slower, or faster

• Muscle retractions above clavicles, between ribs, below rib cage, especially in children

• Pale of blue skin

• Cool, damp (clammy) skin

• Tripod position (hands on knees)

Agonal Gasps

Patient in cardiac arrest may appear to be breathing, gasping breaths. Respiratory signal in brain still send signals to breathing muscles.

• These patients need artifical ventilation, and most likely chest compressions

Circulatory System

Contains capillaries, veins, arteries. System that delivers blood to the body

Systemic Circulation

circuit in the body. Carries oxygen-rich blood from left ventricle through the body, back to the right atrium. Blood passes through tissue and organs giving up oxygen and nutrients and retaining CO2 and waste

Pulmonary circulation

In the lungs. Gives up O2 and retains CO2

Circulation

Right side of the heart receives blood from the veins of the body, blood enters the superior and inferior vena cava into atrium and to ventricle through tricuspid valve. When the right ventricle contracts, blood goes through the pulmonary arteries from the pulmonary vein, and goes to the lungs.

Left side of the heart receives oxygenated blood from the lungs from the pulmonary veins. Goes to atrium through mitral valve, into the ventricle. The ventricle contracts, the blood goes through the aortic valve to the aorta and throughout the body.

Chordae tendineae

thin bands of fiborous tissue that attach to the valves in the heart and prevent them from inverting

Normal Heartbeat i adults

Adults: 60/100 BPM resting

Athletes: 45/60 BPM resting

Stroke Volume

Amount of blood moved in 1 beat

Cardiac Output

Amount of blood moved in one minute

CO= HR x SV

Electrical Conduction System in the heart

• Depolorization: electrical changes on the surface of the cell goes from positive to negative

• Repolarization: Resting state to postive charge

• Electrical impulse starts high in the atria, in the sinoatrial Node, then travels to the atrioventricular node, producing smooth flow of electricity

Arteries

Carry all blood from the heart to all tissues of the body.

• Branch into smaller arterioles, and then into capillaries

• Contract to accommodate loss of blood and increase in blood pressure

• Middle layer called tunica media

• Main one in body is aorta

Capillaries

Fragile divisions of the arterial system that allow contact between the blood and the cells of the tissues

Veins

Once oxygen depleted blood passes through the network of capillaries, moves into venules.

Blood returns to the heart via larger network of veins (superior and inferior vena cavae)

Systemic Vascular Resistance (SVR)

Resistance to blood flow within all blood vessels except the pulmonary vessels.

Effects of Blood vessel diameter on the blood

• Constricted blood vessel: Decreased size of container, increase in pressure within container

• Normal: equal

• Dilated Blood Vessel: Increased size of container, decrease pressure within container

Spleen

Located under rib, in upper left quadrant of abdomen. As blood cells degrade, this filters it out by digesting it. Hemoglobin is recycled

Blood Pressure

Force circulating blood against wall of arteries.

• systolic: when the left ventricle contracts, pumping blood into aorta, pressure during this time

  • Indicates heart pumping effectiveness ad indicates blood available in the heart

• Diastolic: pressure in arteries when ventricle is relaxed

  • Indicates adequate cardiac relaxation and pressure in the arteries between heartbeats. Also indicates amount of blood within blood vessels.

Measured in mmHg

Perfusion

circulation of blood in an organ or tissue

Hypoperfusion

Organs, tissues, and cells no longer adequately supplied with oxygen or right amount of blood

• Can effect the whole body leading to shock

Mean Arterial Pressure

The average arterial pressure during systole and diastole

Hydrostatic Pressure

occurs as fluid pushes against the vessel walls to force fluid out of the capillary

Oncotic Pressure

opposing force and occurs because proteins in the blood plasma cause water to be pulled into the capillaries due to diffusion

Functions of Blood

• Fights Infection: White Blood Cells

• Transports Oxygen: Red Blood Cells

• Transports Carbon Dioxide: Plasma

• Controls pH (Buffer): Within Plasma

• Transports wastes and nutrients: Plasma (water)

• Clotting (Coagulation): platelets and clotting factors in the plasma

Alpha-Adrenergic Receptors

found in the blood vessels. When stimulated, blood vessels constrict, increasing blood pressure

Beta-Adrenergic Receptors

Beta-1: Located in the Heart: cause heart to increase its rate and squeeze harder with each contraction, increasing cardiac output

Beta-2: Located in Lungs. Causes the bronchi to dilate, allowing more air to be inhaled and exhaled, allowing more oxygen to enter cells of the body.

Central Nervous System

Control center of the body, containing brain and spinal cord

Peripheral Nervous System

Nerves outside of the brain and spinal cord that link CNS to various organs throughout the body

• Can be split into somatic and autonomic nervous systems