Physiology Exam 5 (NEED TO KNOW)

What are the two types of control systems associated with Cannon’s Postulates?

Tonic and antagonistic control

What is tonic control?

Regulates physiological parameters in an up-down fashion (putting your foot on the gas, no break)

What is antagonistic control?

Controls heart rate, some speed it up while others slow it down (using the break)

What are the steps in reflex control?

Stimulus, sensor/receptor, afferent pathway, integrating center, efferent pathway, target/effector and response

What is the first law of thermodynamics?

Energy cannot be created nor destroyed

What is the second law of thermodynamics?

Final entropy must be larger than initial entropy for an irreversible process

What is the third law of thermodynamics?

The entropy of a system approaches a constant value as the temperature approaches absolute zero

What is secretion?

The release of water, acids, enzymes, buffers and salts

What are the three layers to the enteric nervous system?

Myentric plexus, submucosal plexus and mucosal epithelium

What does the myenteric plexus do?

Controls smooth muscle and regulates gastrointestinal tract motility

What does the submucosal plexus do?

Controls glands and endocrine cells

What does the mucosal epithelium do?

It has a sensory neuron that sends signals to autonomic and central nervous systems

What is peristalsis?

Promotes forward movement, circular and longitudinal muscles

What is segmentation?

No net forward movement, promotes mixing

What displays the two patterns of motility and what does it cause?

Autorhythmicity and it causes depolarizations that don't necessarily make it to threshold (slow wave potentials)

What is gastric mucosa?

Its arranged in pits and glands and it consists of folds called rugae

What is muscularis externa?

It contains an extra layer of smooth muscle and is oblique

What secretes mucus?

surface mucous cell and mucous neck cell

What secretes pepsinogen and gastric lipase?

Chief cells

What does the exocrine pancreas do?

Secretes pancreatic juices containing many digestive enzymes

What does the endocrine pancreas do?

Secretes hormones insulin and glucagon to control the amount of sugar in blood

What does amylase do?

breaks down carbohydrates

What does trypsin do?

breaks down proteins

What does chymotrypsin do?

breaks down proteins

What does elastase do?

breaks down proteins

What does lipase do?

breaks down fats

What are the three different regions of the small intestine?

Duodenum, jejunum and lleum

What does maltase do?

breaks down disaccharides

What does secondary active transport with Na+?

Glucose and galactose

What does facilitated diffusion diffuse?

Fructose

What does secondary active transport with Na+ or facilitated diffusion diffuse?

Amino acids, dipeptides and tripeptides

What does simple diffusion diffuse?

Short/long-chain fatty acids and monoglycerides

What are the enzymes for protein digestion?

Endo and exopeptidase

What is endopeptidase?

Digests internal peptide bonds

What is exopeptidase?

Digests terminal peptide bonds to release amino acids

What do triglycerides digest into?

Monoglycerides and free fatty acids

What is happening in the process of digestion and absorption of fats?

Bile salts coat fat droplets to make them more soluble which are then broken down by lipase and colipase into monoglycerides and fatty acids and are then absorbed with cholesterol and proteins to form chylomicrons

What are the three phases of digestion?

Cephalic, gastric and intestinal

What does the cephalic phase do?

Prepares the mouth and stomach for food that's about to be eaten

What does the gastric phase do?

Promotes gastric juice secretion and gastric motility

What does the intestinal phase do?

Promotes digestion in the small intestine and slows the digestion in the stomach

What are the steps in the gastric phase of digestion?

Food enters stomach, pH of gastric juices increase and stretching of stomach walls begin, chemoreceptors and stretch receptors detect pH change, submucosal plexus, parietal cells secrete HCI and increase in acidity of the stomach chyme along with mixing of the stomach contents and emptying of the stomach

What are the steps of the GI reflexes?

Cephalic phase, secretory cells of the stomach/small intestine, GI peptides, Gi smooth muscle and exo/endocrine cells of stomach pancreas and intestine, and changes in GI motility release of bile and pancreatic secretions

What are absorptive state reactions?

catabolism of glucose/amino acids/dietary lipids, protein synthesis, glyco/lipogenesis and transport of triglycerides

What are the steps in a fasted-state metabolism?

Liver glycogen becomes glucose, adipose tissue becomes free fatty acids and glycerol that enters blood, muscle glycogen can be used for energy and the brain can only use glucose and ketones for energy

What does insulin do?

helps sugar enter the body so it can be used for energy

What does glucagon do?

helps blood glucose levels increase

In a fed state what dominates?

Insulin

In a fasted state what dominates?

glucagon

What do anabolic pathways do and what state is it?

Builds large molecules and is absorptive (fed) stated

What do catabolic pathways do and what state is it?

Breaks down large molecules and is postabsorptive (fasted) stated

What nutrient pools are available for immediate use?

Free fatty acids, plasma glucose and amino acid pool

What six factors affect metabolic rate?

Age and sex, amount of lean muscle mass, activity level, energy intake (diet), hormones and genetics

What effectors increase in body temperature?

Vasoconstriction decreases heat loss through skin, adrenal medulla released hormones to increase cellular metabolism, skeletal muscles contract (shivering) and thyroid gland releases hormones that increase metabolic rate

What is the response to increased temperature?

Sympathetic cholinergic neurons

What is the response to decreased temperature?

Sympathetic adrenergic neurons and somatic motor neurons

What do sertoli cells secrete?

anti-mullerian hormone

What does testosterone control?

Development of Wolffian duct and male external genitalia

What does anti-mullerian hormone control?

regression of mullerian duct

How many chromosomes are there per cell?

46

What does mitosis do?

Germ cell proliferation

What does meiosis do?

DNA replicates but no cell division (46 chromosomes duplicated)

What does first meiotic division do?

Primary gamete divide into two secondary gametes (23 chromosomes duplicated)

What does second meiotic division do?

secondary gamete divides (23 chromosomes haploid)

What are the six steps of cell division?

Mitosis, meiosis, first meiotic division, secondary meiotic division, unfertilized egg passes out of body and second polar body disintegrates

Where is GnRH released from?

Hypothalamus

Where is FSH and LH released from?

Anterior pituitary

What causes a long feedback loop?

The release of GnRH and FSH/lH

What causes a short feedback loop?

The release of GnRH ONLY

What do the seminiferous tubules of testes contain?

Spermatogenic, sertoli and leydig cells

What supports developing sperm?

Sertoli cells

Where does estrogen and LH peak?

Right before ovulation

When does progesterone peak?

During the formation of the corpus luteum

What day is ovulation?

Day 14

What is menses and when does it occur?

Bleeding from uterus as endometrium is shed (occurs if pregnancy is not achieved) during 0-7 days

What is the proliferative phase and when does it occur?

Endometrium grows in preparation for pregnancy during 7-14 days

What is the secretory phase?

Endometrial secretions promote implantation during 14-28 days

What happens in the late follicular phase?

LH surges, Estrogen changes from + to - and the secretion of inhibin and progesterone begin

When does the corpus luteum develop?

During early to mid luteal phase around day 18

What happens during the late luteal phase?

Endometrium dies and corpus luteum undergoes apoptosis after 12 days

What allows an erection to occur?

Vasodilation in arterioles and this is parasympathetic activation

What does oxytocin stimulate?

prostaglandin release and uterine contractions

Where is oxytocin released from?

Posterior pituitary

What are the steps to parturition?

Fetus drops in lower uterus, cervical stretch, oxytocin is released and uterine contractions occur and prostaglandins from uterine wall

What type of control are saliva secretions under?

Autonomic

What do enteroendocrine cells do?

epithelial cells that secretes hormones into the bloodstream

What are the two types of cells of the gastrointestinal tract?

Autorhythmic and contractile fibers

What does the proton pump transport into the parietal cells?

Potassium (K+)

What enzyme yields glucose as its end product?

Maltase

What does the oblique layer do?

Enhances gastric motility in the stomach