- Cephalic or neurogenic phase: This phase is initiated by the sight, smell, taste, or thought of food that causes stimulation of vagal nuclei in the brain. Vagus nerve directly stimulates parietal cells to secrete acid; in addition, it also stimulates antral G cells to secrete gastrin in blood (which is also a potent stimulus for gastric acid secretion) (Figure 859.2). Cephalic phase is abolished by vagotomy.
- Gastric phase: Entry of swallowed food into the stomach causes gastric distension and induces gastric phase. Distension of antrum and increase in pH due to neutralization of acid by food stimulate antral G cells to secrete gastrin into the circulation. Gastrin, in turn, causes release of hydrochloric acid from parietal cells.
- Intestinal phase: Entry of digested proteins into the duodenum causes an increase in acid output from the stomach. It is thought that certain hormones and absorbed amino acids stimulate parietal cells to secrete acid.
- Hydrochloric acid (HCl): This is secreted by the parietal cells of the fundus and the body of the stomach. HCl provides the high acidic pH necessary for activation of pepsinogen to pepsin. Gastric acid secretion is stimulated by histamine, acetylcholine, and gastrin (Figure 859.2). HCl kills most microorganisms entering the stomach and also denatures proteins (breaks hydrogen bonds making polypeptide chains to unfold). Its secretion is inhibited by somatostatin (secreted by D cells in pancreas and by mucosa of intestine), gastric inhibitory peptide (secreted by K cells in duodenum and jejunum), prostaglandin, and secretin (secreted by S cells in duodenum).
- Pepsin: Pepsin is secreted by chief cells in stomach. Pepsin causes partial digestion of proteins leading to the formation of large polypeptide molecules (optimal function at pH 1.0 to 3.0). Its secretion is enhanced by vagal stimulation.
- Intrinsic factor (IF): IF is necessary for absorption of vitamin B12 in the terminal ileum. It is secreted by parietal cells of stomach.
Location: Rectum of Mammals
Function: It extends from the pelvic floor downward and posteriorly to the anus.
Location: Frog’s kidney sperms.
Function: It connects testis to kidney and conducts
Function: It runs from gall bladder to duodenum through which bile flows.
Location: Mammalian eye
Function: It lies near the junction ofcornea and sclera, this canal passes circularly around the cornea, and drains the aqueous humour.
Location: Spinal cord
Function: It is situated in the centre of gray matter and extends entire length of the cord. Cerbrospinal fluid flows in it.
Function: Canal of cervix of uterus
Location: Internal ear of mammals
Function: It is middle canal in the cochlear duct filled with peri lymph
Location: Kidney of mammals
Function: These are many and collect urine.
Location: part of bile duct in vertebrates,
Function: which leads from gall bladder receives branches from various part of the liver and it eventually forms the common bile duct.
Location: Salivary glands of mammals
Function: Ducts of sublingual glands (Sublingual ducts) lie just beneath the floor of the mouth and open into the floor qf the mouth.
Location: Internal ear of mammals
Function: It is a small short duct connected with saccule and end blindly in the endo lymphatic sac.
Location: Middle ear of all land vertebrates
Function: It connects middle ear with pharynx.
Function: These are longitudinal canals found characteristically in long bones.
Location: Liver of vertebrates
Function: It originates from liver cells and unites with the cystic duct from the gall bladder to form the common bile duct.
Location: Eye of mammals
Function: It extends between optic disc and the lens.
Location: Reproductive organs of male mammal.
Function: It connects abdominal cavity to scrotal cavity.
Location: Eyes of man
Function: These are two (superior and inferior) connect lacrimal gland with lacrimal sac.
Location: Mammary glands of placentals
Function: These carry milk from mammary glands to the tip of
Location: Reproductive organs of liver fluke
Function: It is temporary copulatory canal which opens on the dorsal body surface.
Location: Thorax of vertebrates
Function: It is a short duct receives lymph from the right side of the head, the right upper extremity and the right side of the thorax.
Location: Lower jaw of mammals
Function: It originates from mandibular foramen for in- ferior alveolar vessels and nerve and lies on the inner surface of each ramus.
Function: It connects lacrimal sac with inferior nasal meatus.
Location: Vertebrate embryo
Function: It is a canal joining the primitive gut with the cavity of neural tube.
Function: The duct which conducts enzymes from the pancreas into the duodenum.
Location: Kidney of mammals (part of renal tubule)
Function: These open on the tip of renal papilla and pour their contents into a minor calyx of the renal pelvis.
Location: Salivary gland of mammals
Function: It passes anteriorly to pour into the yes- tibule of the mouth, opposite the upper second molar tooth.
Location: Internal ear of vertebrates
Function: These are filled with endolymph and concerned with equilibrium.
Location: Salivary gland of mammals
Function: It extends from the anterior end of each submaxillary gland and opens into the floor of the mouth on each side of the frenulum.
Location: Thorax and Abdomen of mammals
Function: The chief collecting duct of lymphatic system receive lymph from lacteals. It lead towards left subclavian
Location: On the floor of pharynx in mammals
Function: An embryonic duct between thyroid and pharynx. it disappears in adults.
Location: Cervical vertebrae of mammals, birds and reptiles
Function: These canals are found at the base of transverse processes of cervical vertebrae for the passage of cervical blood vessels and nerves.
Location: Long bones of mammals
Function: These are transverse canals, connecting Haversian canals. These carry blood.
- The cytoplasm contains one or many nuclei.
- Contractile vacuole is absent.
- Mouth is absent.
- Cytoplasm contains food vacuoles. They take up the process of digestion.
- Megalospheric form: Its proloculum is big in size. A single large nucleus is present in one of the chambers. It takes up sexual reproduction.
- Microspheric form: Its proloculum is small in size. Many nuclei are present in the cytoplasm. This form reproduces by asexual reproduction.
- The cristae detect turning movements of the head.
- The maculae in the utriculus and sacculus detect changes in the position of the body at rest and in the forward movement. With a change in the position of the body, the otoliths change their position due to gravity and bring pressure on the underlying sensory hairs and this stimulates the neurosensory cells. The body position is corrected. Thus equilibrium is brought forward.
- The maculae & lagena will detect under water sound vibrations to some extent.
The new edition features over 800 exam-type questions & answers, discussions of each answer, a 100-question practice test, improved illustrations, and more high-yield facts.
More than 800 USMLE Step 1-type questions
100-question practice test, Detailed explanation for each answer, Rationales for right and wrong answers.
The most comprehensive, useful, and up-to-date USMLE Step 1 preparation for anatomy questions, Learn more in less time, Evaluate your areas of strength and weakness, Reinforce knowledge, confidence, and skills.
Ideal for medical, dental, allied health, and nursing programs, this book guides students through the fundamentals of human anatomy, explaining the how and why behind each structure, and offering readers the hands-on guidance they need to make sound clinical choices.
Organized by body region from surface to deep structures, this new edition features:
- Updated design and layout allowing for a shorter, more focused text
- Enhanced color illustrations and art program to facilitate visual learning
- Basic Clinical Anatomy sections with essential information on gross anatomic structures of clinical significance
- Chapter Objectives that focus students on material most important to their preparedness for the patient encounter
- Clinical Notes highlighting the clinical importance of anatomical information
- Embryologic Notes with insight on developmental anatomy
- Numerous examples of clinical images to support the text
- Surface Anatomy sections explaining surface landmarks of important structures
- Online E-Book and Interactive Question Bank
Description: Clinical Anatomy Made Ridiculously Simple pdf Edition 3 by Stephen Goldberg