Option H - Further Human Physiology

Front 1

Hormones

Back 1

chemical messengers, secreted by endocrine glands directly into the blood which carries them to target cells

Front 2

types of hormones

Back 2

1. Steroids e.g. estrogen, progesterone, testosterone
2. Peptides e.g. Insulin, ADH, FSH, LH
3. Tyrosine derivatives e.g. thyroxin

Front 3

Mode of action of peptide hormones

Back 3

- do not enter cells
- bind to receptors on the plasma membrane of the target cells
- release of a secondary messenger inside cells
- change to the activities of the cell, usually by activating and inhibiting enzymes

Front 4

Mode of action of steroid hormones

Back 4

- pass through the plasma membrane of the target cell
- form a Hormone-receptor-complex (regulator of gene transcription by binding to specific genes)
- transcription of some genes is promoted and other genes are inhibited

Front 5

Draw the structure of the hypothalamus and pituitary gland

Back 5

Front 6

Hypothalamus

Back 6

small part of the brain that links the nervous and endocrine systems

Front 7

anterior pituitary

Back 7

- neurosecretory cells secrete hormonones into capillaries in the Hypothalamus which are then carried by the portal vein to the anterior pituitary gland
--> releasing hormones stimulate the anterior pituitary to secrete hormones e.g. GnRH stimulates the release of FSH and LH

Front 8

posterior pituitary

Back 8

- neurosecretory cells synthesize hormones
- passed via axons to nerve endings in the pituitary gland
e.g. secretion of ADH is controlled in this way

Front 9

Control of ADH secretion

Back 9

1. neurosecretory cells in the hypothalamus synthesize ADH, transport it down their axons and store it in nerve endings in the posterior pituitary gland
2. osmoreceptors in the Hypothalamus monitor the concentration of the blood Plasma
3. ADH causes a reduction in the concentration of the blood plasma by stimulating the kidney to produce hypertonic urine
4. low blood concentration: release of ADH is not stimulated
high blood concentration: release of ADH stimulated

Front 10

examples of exocrine glands

Back 10

salivary glands, pancreas

Front 11

digestion

Back 11

chemical breakdown of large molecules into their components and Absorption

Front 12

exocrine glands

Back 12

- secretory cells in a layer that is one cell tick
- digestive juices released by exocytosis
- travels along ducts

Front 13

acinus

Back 13

one group os secretory cells clustered around the end of a duct

Front 14

feature of exocrine gland cells

Back 14

1. one or two prominent nucleoli inside the Nucleus for production of ribosome subunits
2. extensive area for the RER
3. Golgi apparatus for processing Proteins
4. many large vesicles (secretory granules)
5. mitochondria

Front 15

control of gastric juice secretion

Back 15

- nervous and hormonal control
- sight and smell of food stimulates the brain to send nerve impulses to exocrine glands in the cell wall of the stomach, starts to secrete gastric juices
- food detected by touch receptors in the stomach, by chemoreceptors and by stretch receptors, impulses send to brain which send more impulses to exocrine gland cells
- secretion of a hormone called gastrin: stimulates the increase of the secretion of hydrochloric acid

Front 16

membrane-bound digestive enzymes

Back 16

- produced by the cell wall of the small intestine, but are not secreted
- remain on the surface of the villi

Front 17

Digestive Juices/source and content

Back 17

saliva/salivary glands/ salivary amylase, mucks
gastric Juice/glands in stomach wall/pepsinogen, hydrochloric acid, mucus
pancreatic Juice/pancreas/pancreatic amylase, lipase, phospholipase, trypsinogen, carboxypeptidase

Front 18

Pepsin

Back 18

pepsinogen + hydrochloric acid

Front 19

trypsin

Back 19

Trypsinogen + enterokinase

Front 20

draw the structure of the stomach wall!

Back 20

Front 21

bile salts

Back 21

- natural detergents
- hydrophobic end and hydrophilic end

Front 22

emulsification

Back 22

process in which bile salts coat lipid droplets, causing them to break into smaller droplets

Front 23

bile

Back 23

- contains bile salts
- secreted by the liver
- stored in the gall bladder
- emulsifies lipids which speeds up their digestion

Front 24

Helicobacter pylori

Back 24

acid-tolerant bacterium that infects the lining of the stomach, causes several diseases

Front 25

stomach ulcers

Back 25

- areas of damage to the lining of the stomach
- caused by H.pylori
- proteases abd other enzymes that are released by H.pylori damage the stomach lining

Front 26

stomach cancer

Back 26

- growth of tumours in the walls of the stomach
- caused by H.pylori
- reduced vitamin C concentration in gastric juice - increase the chance of a tumour forming