Lab practical overview

Anatomy and Physiology II Spring 2026 Lab Practical 1 Overview

The Lab Practical 1 will cover several critical areas significant to the study of Anatomy and Physiology II. The following topics will be the focal points during the practical:

I. Histology
A. Endocrine System
B. Digestive System

II. Models
A. Endocrine System
B. Digestive System

III. Cat Dissection
A. Selected Glands
B. Digestive System
C. Selected Muscles

IV. Enzyme Lab

Objectives of the Lab Practical

The lab practical will integrate various methodologies including histology, human models, and cat dissection. An important reminder from Anatomy & Physiology 1: a binocular microscope will be utilized in the lab for the examination of histological images presented in the following slides. The study of histology encompasses the examination of tissues which can be identified through slides from specific systems such as the endocrine and digestive systems.

Tissues and Organs to be examined include:

  • Endocrine System Terminology:

    • Pituitary Gland

    • Thyroid Gland

    • Adrenal Gland

    • Thymus

    • Pancreas

  • Digestive System Terminology:

    • Liver

    • Tooth

    • Tongue

    • Esophagus

    • Stomach

    • Small Intestine:

      • Duodenum

      • Jejunum

      • Ileum

    • Colon

GI Tract Organization:
The gastrointestinal tract is organized into distinct layers known as tunics, which include from the innermost to the outermost:

  1. Mucosa

  2. Submucosa

  3. Muscularis

  4. Serosa

Histology of the Endocrine System

The histological examination includes the following glands:

1. Pituitary Gland and Hypothalamus

  • Hypothalamus

  • Infundibulum (stalk)

  • Anterior Pituitary (adenohypophysis)

  • Posterior Pituitary (neurohypophysis)

2. Thyroid Gland

  • Follicles

  • Follicular Cells (principle cells)

  • Colloid: A substance found within the follicles, composed of thyroglobulin.

  • Parafollicular Cells (C-cells): Responsible for the secretion of calcitonin.

3. Parathyroid Gland

  • Chief Cells: Secrete parathyroid hormone (PTH), which regulates serum calcium levels.

4. Adrenal Gland

  • Adrenal Cortex (composed of three zones):

    • Zona Glomerulosa

    • Zona Fasciculata

    • Zona Reticularis

  • Adrenal Medulla: The inner region responsible for the secretion of catecholamines (epinephrine and norepinephrine).

5. Thymus

  • Capsule: Connective tissue enclosing the gland.

  • Cortex and Medulla: Distinct regions facilitating immune function.

  • Adipose Tissue: Present in and around the thymus.

  • Trabeculae (septa): Extensions of the capsule that divide the thymic tissue into lobes.

6. Pancreas

  • Islets of Langerhans: The endocrine portion functioning in glucose regulation through insulin and glucagon secretion.

  • Acini Cells: The exocrine portion producing digestive enzymes.

Detailed Histology Observations

Anterior Pituitary

The slide for the Anterior Pituitary demonstrates:

  • Infundibulum (stalk)

  • Posterior Pituitary Structure

Histology of the Thyroid Gland and Parathyroid
Thyroid Gland Observations:

  • Follicles

  • Follicular Cells

  • Colloid

  • Parafollicular Cells

Parathyroid Gland Observations:

  • Chief Cells responsible for the secretion of PTH

Adrenal Gland

Detailed examination shows:

  • Adrenal Cortex: The outer part subdivided into zones:

    • Zona Glomerulosa (mineralocorticoids)

    • Zona Fasciculata (glucocorticoids)

    • Zona Reticularis (androgens)

  • Adrenal Medulla: Functions in fight or flight response.

Histology of the Gastrointestinal Tract and Accessory Organs

The histological observations will include:

  • Accessory Organs:

    • Tooth

    • Tongue

    • Liver

    • Pancreas (part covered under the endocrine system)

  • Gastrointestinal Tract consists of:

    • Esophagus

    • Stomach

    • Duodenum

    • Jejunum

    • Ileum

    • Colon

Tongue and its Papillae

Examined under magnification:

  • Filiform Papillae (non-taste bud bearing)

  • Foliate Papillae (taste bud-bearing)

    • Observed at various magnifications (40x and 400x).

Tooth Structure

Components of a tooth include:

  • Dentin

  • Cementum

  • Enamel

  • Pulp Cavity

  • Gingiva

  • Alveolar Bone

  • Periodontal Ligament

  • Anatomy Note: The crown is above the gum (gingiva), and the root is below the gum, noting that the slide may not show the "true crown".

Esophagus Structure

The esophagus histology includes:

  • Lumen

  • Mucosa (Stratified squamous epithelium)

  • Submucosa

  • Muscularis (arrangement with circular and longitudinal muscles)

  • Adventitia

Stomach Structure

Key features observed:

  • Lumen

  • Tunica Mucosa: Contains gastric glands with parietal and chief cells.

  • Rugae: Folds present in the gastric lining.

Small Intestine Structure and Comparison

The histological examination will cover:

  • Tunica Mucosa, highly folded into villi.

  • Tunica Submucosa and Tunica Muscularis.

Comparison Among Small Intestine Regions
1. Duodenum:

Identifying characteristic: Brunner’s Glands present in the submucosa.

2. Jejunum:

Identifying characteristic: Absence of Brunner’s Glands and Peyer’s patches in the submucosa.

3. Ileum:

Identifying characteristic: Peyer’s Patches prominent in the submucosa.

Endocrine and Digestive System Models

The human models utilized will be focusing on:

  1. Endocrine Glands

    • Including Thyroid, Adrenal glands, Testis, Hypothalamus and Pituitary, Pancreas, Parathyroid, and Ovary

  2. Digestive System Models:

    • Covering major components in the thoracic and abdominal contexts, highlighting the liver (with lobules), stomach, small intestine, colon, and accessory structures such as the gallbladder.

  3. Key Organs in Human Model:

    • Liver, Gall bladder, Stomach, Small intestine, Colon

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Cat Dissection Overview

This section provides insights into selected anatomical structures of the cat through dissection:

Head and Neck

Key components:

  • Masseter

  • Sternomastoid

  • Cleidomastoid

  • Digastric

  • Mylohyoid (reflected)

  • Thyrohyoid

  • Sternothyroid

  • Sternohyoid

  • Parotid salivary gland

  • Submandibular salivary gland

Chest Muscles

Examination includes:

  • Pectoantebrachialis (contextual reference)

  • Pectoralis Major

  • Pectoralis Minor

  • Xiphihumeralis (contextual reference)

Abdominal Muscles

Dissection includes:

  • External Oblique

  • Internal Oblique

  • Transverse Abdominis

  • Rectus Abdominis (showing variations with and without rectus sheath)

Enzyme Lab

Purpose & Background

  • Digestion initiates in the mouth with the enzyme amylase found in saliva that breaks down starch into sugars.

  • The objective of this lab is to observe the activity of amylase on starch via colorimetric changes.

Hypothesis

The hypothesis posits that adding amylase to starch will reduce the starch content and yield sugars as evidenced by specific tests.

Experimental Design & Observations
Tests Used

  • Iodine Test: A procedure used to identify the presence of starch.

  • Benedict’s Test: A test employed to detect the presence of reducing sugars.

Test Tube Setup

  • Iodine / Starch:

    • Test Tube A: Water + Iodine (Control)

    • Test Tube B: Water + Starch + Iodine

    • Test Tube C: Starch + Amylase + Iodine

  • Benedict’s / Sugar Test:

    • Test Tube D: Water + Benedict’s (Control)

    • Test Tube E: Water + Starch + Benedict’s

    • Test Tube F: Starch + Amylase + Benedict’s

Data Recording: Observations, results, and conclusions should be documented in the lab reference sheet, followed by discussion with the lab team.