Download Physiology is the study of function of the body.

1
Anatomy & PhysiologyI
Chapter 1 (Major Themes of A & P and Orientation to Human Anatomy)
Human body is more complex than a super computer.
HCPs must learn about human body in order to fix it (like a mechanic learns car)
Anatomy is study of structure (morphology) of the body & their relationship to each other
It includes Gross anatomy (seen with naked eye) and Microscopic anatomy (seen with microscope).
Physiology is the study of function of the body.
Cellular physiology deals with cells & their function.
Anatomy & Physiology are inter-related: function depends on the structure & vice versa
LEVELS OF ORGANIZATION:
There are 6 levels of organizationChemicals (C, H, O, N, P, S)  Cells (skin, muscle)
 Tissues (muscle, nerve, epithelial &
connective)  Organs (heart, brain)  Body Systems (CVS, RS, GIT)  Organism (human)
Cells are basic living units of organisms.
Body systems have many organs performing same function (stomach, intestines, liver etc. form GIT)
BODY SYSTEMS:
There are 11 major body systems that work in coordination to sustain life.
1. Integumentary System – Skin & accessory organs like hair, nails, sweat glands, oil glands
- Protects tissues from injury & water loss, regulates temperature, feels sensations and produces
chemicals (Vitamin D).
2. Skeletal System – Bones, joints, ligaments & cartilage.
- Protects underlying organs, attaches muscles, moves body, stores Ca, PO4 & produces blood cells.
3. Muscular System –Maintains posture, moves body, stores energy as glycogen, produces heat.
4. Nervous System – Brain, Spinal Cord, Nerve cells (neurons) and Nerves.
-Controls body, feels stimuli and helps communication between organs.
5. Endocrine System – Pituitary, Pineal gland, Thyroid, Adrenals, Testes and Ovaries.
-Secretes hormones that regulate cellular activity and control reproduction.
2
6. Cardiovascular System – Heart, Blood & Blood vessels.
-Maintains blood circulation. Blood defends the body, supplies O2 & nutrients and takes away
toxins & Co2.
7. Lymphatic System – Spleen, Thymus, Tonsils & Lymph nodes.
-Defends the body by filtering & producing leukocytes (T-cells).
8. Digestive System – Mouth, Pharynx, Esophagus, Intestines & accessory organs (liver, pancreas)
-Digests and absorbs nutrients from food & discards wastes.
9. Respiratory System – Nasal cavities, pharynx, larynx, trachea, bronchi & lungs.
-Absorbs O2 and discards Co2. Regulates acidity of body fluids. Helps produce sounds.
10. Urinary System – Kidneys, Ureters, Urinary bladder & Urethra.
-Removes wastes from the blood and produces hormones & chemicals (erythropoetin, renin)
11. Reproductive System – Testes, Ovaries, Penis, Uterus, Vagina, Fallopian tubes etc.
It helps procreation.
LIFE PROCESSES:
Basic life processes differentiate living from the non-living.
Disruption of these processes causes disease & death.
Basic life processes include:
1. Metabolism – It includes all chemical reactions in the body.
-Catabolism is breakdown of complex substances to simple substances releasing energy.
-Anabolism is synthesis of complex substances from simple substances requiring energy.
2. Responsiveness – It is the detection of & reaction by the body to internal or external changes
3. Movement – Cells, Blood, muscles, bones move from place to place.
4. Reproduction – Cellular reproduction helps growth & repair of tissue.
Sexual reproduction produces offspring.
5. Growth – It is in the increase in size or number of cells, or size of extracellular matter.
-For growth to occur, anabolism must exceed catabolism.
6. Differentiation – It changes unspecialized cells to specialized cells to perform a specific function.
(eg. Stem cells to blood cells or muscle cells or neurons)
3
HOMEOSTASIS:
Homeostasis is the maintenance of equilibrium (“same environment always”) in the body.
A healthy body maintains homeostasis.
Severe changes in homeostasis may cause death (↓ glucose level or ↓ BP).
Homeostasis is primarily controlled by the Nervous system (rapidly) & Endocrine system (slowly).
Negative & Positive Feedback:
A Stressor is a stimulus that disrupts internal conditions causing homeostatic imbalance.
Body systems (Nervous, endocrine etc.) try to bring back conditions within normal range by:
1. Negative feedback – Maintains homeostasis by creating a response opposite to the imbalance.
eg. Increased BP Decreased heart rate + Vasodilatation Decreased BP.
Decreased BP  Increased heart rate + Vasoconstriction  Increased BP.
2. Positive feedback – Maintains homeostasis by creating a response that stimulates the imbalance.
It speeds up the imbalance to cause quick conclusion (eg. Child birth)
eg. Labor – Uterine Contraction Oxytocin release Increased contraction  child birth
Clotting – Platelet aggregation Release of clotting factors  faster clotting
The 3 basic components of a feedback loop are: Receptor, Control center & Effector.
Anatomical Terms - the language used in anatomy.
Anatomical position –A person standing with arms to the side, toes & palms directed forward.
Regions of the Body:
Body is divided into axial (head, neck & trunk) and appendicular (limbs) portions.
Trunk (torso) includes thorax, abdomen & pelvis.
Directions in the Body: Describes the position of a part in relation to another part (p.12, 13)


Superior(cephalic/cranial)– Part is above another or closer to the head (head superior to feet)
Inferior (caudal) – Part is below another or closer to the feet (feet inferior to head)


Anterior (Ventral) – In front of (stomach is anterior to pancreas)
Posterior (Dorsal) – Behind (pancreas is dorsal to stomach)



Medial – Near the midline of body (eyes are medial to ears)
Lateral – Away from the midline (ears are lateral to eyes)
Intermediate – Between two structures
4


Proximal – Closer to trunk or point of attachment (knee is proximal to ankle)
Distal – Away from trunk or point of attachment (ankle is distal to knee)


Superficial – Near the surface (muscles are superficial to the bones)
Deep – Away from the surface (bones are deeper than muscles)


Visceral – Organ or its’ covering (visceral pleura lines lungs)
Parietal – Wall of a body cavity (parietal pleura lines chest wall)


Ipsilateral – On the same side
Contralateral – On the opposite side
Planes & Sections of the Body:
3 imaginary planes (drawn perpendicular to each other) are used to understand body relationships:
1. Sagittal Plane (longitudinal plane)–Divides body into right & left part.
Mid-sagittal plane passes through midline & divides body into equal left & right halves.
Parasagittal plane divides body into unequal left and right sides.
2. Transverse Plane (horizontal plane) – Divides body into superior & inferior parts.
Sections cut are called cross sections.
3. Frontal Plane (Coronal Plane)- Divides body into anterior & posterior parts.
4. Oblique Plane – Divides body at an angle between the planes.
Body Cavities:
Cavities are spaces in the body containing internal organs (viscera).
2 main cavities are –
1. Dorsal Cavity – Includes Cranial cavity (contains brain) & Spinal cavity (contains spinal cord).
2. Ventral Cavity – Includes Thoracic cavity (contains heart, lungs, esophagus, trachea & vessels)
(larger)
& Abdomino-pelvic cavity (stomach, intestines, liver, spleen, bladder & uterus)
Diaphragm separates the thoracic from the abdominopelvic cavities.
Pericardial cavity surrounds the heart
Pleural cavity surrounds each lung, separately.
Mediastinum is the central part of thoracic cavity between lungs, sternum and vertebrae.
-It contains heart, thymus, trachea, esophagus and large blood vessels.
5
Abdominopelvic cavity is anatomically divided into:
i) Abdominal cavity containing stomach, liver, spleen, kidneys, small & most of large intestine
ii) Pelvic cavity containing urinary bladder, some reproductive organs & part of large intestine
To better describe the location of organs, abdominopelvic cavity may be virtually divided into:
4 Quadrants
An imaginary mid-sagittal & a transverse plane passing at umbilicus divides abdomino-pelvic cavity
into 4 quadrants (RUQ, LUQ, RLQ, LLQ)
9 regions
Imaginary two parasagittal & two transverse planes divide abdomino-pelvic cavity into 9 regions
{Epigastric, Umbilical, Hypogastric, R&L Hypochondriac, R & L Lumbar, R & L inguinal(or iliac)}
--X--