Basic Anatomy

Gary Davis MD

Anatomical and Physiological Systems

• Cardiovascular• Skeletal• Nervous• Lymphatic• Respiratory

• Digestive• Urinary• Endocrine• Reproductive• Integumentary

system

Cardiovascular System

• Transport

Skeletal System

• Protection

• Movement

Lymphatic system

• Protection

Integumentary System

• Skin

• Protection

• Body Temp Control

• Sensory

• Excretion

Muscular System

• Movement

Nervous System

• Sensory

• Integration

• Control

Central Nervous System

• Brain and Spinal Cord

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Spinal Cord

• Passes inferiorly through foramen

magnum into vertebral canal

• 31 pairs of spinal nerves branch off

spinal cord through intervertebral

foramen

• Spinal cord made of a core of gray

matter surrounded by white matter

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Organization of Nervous System• Central Nervous System (CNS) = brain and spinal cord• Peripheral Nervous System (PNS) = nerves

CNS PNS

Spinal Nerves (31 pairs)

• Each pair of nerves located in particular segment (cervical, thoracic, lumbar, etc.)

• Each nerve pair is numbered for the vertebra sitting above it (i.e. nerves exit below vertebrae)– 8 pairs of cervical spinal nerves; *C1-C8

– 12 pairs of thoracic spinal nerves; T1-T12

– 5 pairs of lumbar spinal nerves; L1-L5

– 5 pairs of sacral spinal nerves; S1-S5

– 1 pair of coccygeal spinal nerves; C0

Spinal Cord Segments

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Respiratory System

• Gas Exchange

The Respiratory System

Copyright Pearson Prentice Hall

Epiglottis

Trachea

Nose Pharynx Larynx

Lungs

Bronchus

Mouth

Diaphragm

Bronchioles

Digestive System

• Process food• Nutrient absorption

General Structure and Functionsof the Digestive System

• The GI tract organs:

– Oral cavity

– Pharynx

– Esophagus

– Stomach

– Small intestine

– Large intestine

General Structure and Functionsof the Digestive System

• Form a continuous tube that extends about 30 feet (9–

10 meters) from the mouth to the anus

• Smooth muscle in the GI tract wall pushes materials

from one end to the other

• Accessory digestive organs: do not form the long GI tube,

but often develop as outgrowths from and are

connected to the GI tract

• Assist the GI tract in the digestion of food

Supporting Elements for the Digestive System

• Sphincter-a circular muscle that constricts a passage or closes a natural orifice (opening)

• Cardiac sphincter• Pyloric sphincter• Food sits in stomach for 1-

4 hours• Gastric juices contain

hydrochloric acid- activates pepsin, kills bacteria

Small Intestine

• Finishes the chemical digestion process and is responsible for absorbing most of the nutrients

• Ingested nutrients spend at least 12 hours in the small intestine as chemical digestion and absorption are completed

• Coiled, thin-walled tube about 6 meters (20 feet) in length• Extends from the pylorus of the stomach to the cecum of

the large intestine, and thus occupies a significant portion of the abdominal cavity

Digestive Organ’s Functions cont.

Small Intestine It has three parts, duodenum, jejunum and ileum

Duodenum Is responsible cor continuing to break down of food

Jejunum Absorbing nutrients into the blood stream

Iluem Absorbing nutrients into the blood stream

Small Intestine

• The duodenum forms the first segment of the small intestine

• Approximately 25 centimeters (10 inches) long and originates at the pyloric sphincter

• The jejunum is the middle region of the small intestine

• Extending approximately 2.5 meters (7.5 feet), it makes up approximately two-fifths of the small intestine’s total length

Small Intestine

• Primary region for chemical digestion and nutrient absorption

• The ileum is the last region of the small intestine• At about 3.6 meters (10.8 feet) in length, the ileum

forms approximately three-fifths of the small intestine

• Its distal end terminates at the ileocecal valve, a sphincter that controls the entry of materials into the large intestine

Digestive Organ’s Functions cont.

Large Intestine Also known as the colon

It has three major parts, ascending colon, transverse colon and descending colon

Rectum Part of the colon, used to store waste for disposal

Gall Bladder Stores bile from the liver and releases bile into the duodenum

Large Intestine

• Approximate length of 1.5 meters (5 feet) and a

diameter of 6.5 centimeters (2.5 inches)

• Absorbs most of the water and electrolytes from the

remaining digested material

• Watery material that first enters the large intestine

soon solidifies and becomes feces

Large Intestine

• Stores this fecal material until the body is ready to

defecate

• Absorbs a very small percentage of nutrients still

remaining in the digested material

• Composed of four segments:

– The cecum, colon, rectum, anal canal

Large intestine

• Separated from small intestine by ileocecal valve

• Final absorption of water, storage of indigestible

material, absorption of vitamins B and K by bacteria

• Colon connects to rectum-anal canal opens to the

anus (final opening)

– Fecal material is expelled

The Liver is where it all happens!!!!

• Liver- largest gland in your body

• Secretes bile-emulsifies fat, makes them water soluble.

• Stores glucose in the form of glycogen

• Makes clotting proteins• Detoxifies blood

The Liver

• Produce bile: a greenish fluid that breaks down fats

into small droplets to assist in their chemical

digestion

• Detoxify drugs, metabolites, and poisons

• Store excess nutrients and vitamins and release them

when they are needed

The Liver

• Synthesize blood plasma proteins such as albumins,

globulins, and proteins required for blood clotting

• Phagocytize debris in the blood

• Help break down and recycle components of aged

erythrocytes and damaged or worn-out formed

elements

Digestive Organ’s Functions cont.Accessory Organs: Gall Bladder and Pancreas

Pancreas The body’s sugar control board. Produces insulin and glucagon

Liver Food doesn’t pass through this organ, instead the liver secretes bile

Gall Bladder Stores bile from the liver and releases bile into the duodenum

Appendix We do not need our appendix, sometimes a piece of food gets stuck in here and causes an infection.

Pancreas

• Mixed gland because it exhibits both endocrine and exocrine

functions

• Endocrine functions are performed by the pancreatic islets

• Exocrine activity results in the secretion of digestive enzymes,

collectively called pancreatic juice, into the duodenum

• Secretes insulin, a hormone that transports glucose into cells

• Secretes glucagon- increases glucose in bloodstream

Gallbladder

• Concentrates bile produced by the liver and stores

this concentrate until it is needed for digestion

• Cystic duct connects the gallbladder to the common

bile duct

• Can hold approximately 40 to 60 milliliters of

concentrated

Endocrine System

• Hormones-chemical messengers carried by blood

• May stimulate other glands– Regulate growth,

development, metabolism, sex processes

Major Glands of the Endocrine System

• Pituitary• Thyroid• Parathyroid• Adrenal• Pancreas• Ovaries• Testes

Pituitary gland

• Master gland of body• Located in the depression of sphenoid bone• Produces many hormones that affect other glands

– Thyroid stimulating hormone– Somatotropin -- growth hormone– Lutenizing (LH) -- causes ovulation– ICSH -- causes testes to secrete testosterone– Melanocyte stimulating -- distribution of melanin in skin– ADH -- antidiuretic hormone

Pituitary Gland Abnormalities

• Gigantism: oversecretion of somatotropin before puberty

• Dwarfism: under secretion of somatotropin– Cause: tumor, injury, infection,

genetics• Diabetes insipidus- decreased

ADH

Thyroid

• Produces hormones that control metabolism

• Thyroid gland must have source of iodine

• Goiter: not enough iodine

• Hyperthyroidism• hypothyroidism

Adrenal Glands

• Located just above the kidney

• Secretes many hormones– Epinephrine – Norepinephrine

• Many steroid hormones– Estrogen– Androgen

Reproductive System

• Necessary for offspring and continuation of the

species

• Endocrine and some exocrine function

• Supported by fascial attachments to the bony pelvis

Male Reproductive System

Female Reproductive System

Female Pelvic Organs

• Pelvic organs are protected by the bony pelvis and

are supported by the levator ani muscles and their

parietal fascia

Urinary System

• Maintains water and electrolyte balance

Bladder and Urethra

• A bladder is a pouch or other

flexible enclosure with

waterproof or gas-proof walls

• In the human female, the

urethra is about 1-1.5 inches

(2.5-4 cm) long and opens in

the vulva between the clitoris

and the vaginal opening

Summary

• All physiologic and anatomical systems are

interrelated

• Function determines structure

• Surgical procedures are often designed to restore

function and hopefully function